Results and submissions : REF 2021

Accelerating Pharmaceutical Manufacturing Development Using Automated Self-optimisation ...

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Technological
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Optimising pharmaceutical manufacturing processes is expensive, time-consuming, and negatively impacts patients waiting for new or improved treatments. University of Leeds research has developed automated platforms for the self-optimisation of chemical transformations, which have been deployed within pharmaceutical development by global pharmaceutical companies. These platforms act as autonomous units, combining continuous flow reactors with in-line analytics, reactor control and evolutionary algorithms to optimise pharmaceutical processes rapidly. This has significantly reduced development time, resulting in substantial productivity gains and faster translation of materials to clinical trials. Applications have included development of the AstraZeneca anti-cancer agent TAGRISSO^TM in an accelerated timeframe, which has current annual sales of ~£3Bn.

2. Underpinning research

The Institute of Process Research and Development (iPRD) was established in 2008 as a joint venture between the School of Chemical & Process Engineering and the School of Chemistry at the University of Leeds to exploit expertise in process chemistry and develop new technologies for, and in partnership with, the fine chemical and pharmaceutical manufacturing industries. Alongside the construction of a new 650 m² process development laboratory, the Institute was bolstered by four joint appointments between the two Schools, three relevant to this study: Dr Richard Bourne (continuous processing, process optimisation), Professor John Blacker (process chemistry, continuous processing), and Professor Frans Muller (reaction engineering, kinetic modelling). Bourne and Muller are returned in UoA12, Blacker in UoA8.

Bourne was recruited in 2012 to lead the development of automated continuous flow reactor systems and he has directly supervised eleven industrially-funded/sponsored PDRAs and PhD students in collaboration with four global pharmaceutical companies (AstraZeneca, GlaxoSmithKline, Pfizer, Dr. Reddy’s Laboratories), developing Self-Optimising Flow Reactors (SOFR).

Initially, AstraZeneca sponsored the development of a platform for self-optimising the synthesis of pharmaceutical compounds using closed-loop feedback at meso-scale. Prior work worldwide had focused on self-optimisation in micro reactors, or in niche media such as supercritical fluids. The shift to meso-scale pharmaceutical synthesis critically required development of suitable analytical methods, meso-volume reactor platforms with material saving modifications, accurate pumping solutions, and development of machine learning optimisation algorithms. In 2015, Bourne received a Royal Academy of Engineering Industrial Fellowship (ISS1516\8\32) to spend 50% of his time establishing a replica of the University’s SOFR system within the AstraZeneca (Macclesfield) Process Research and Development group, and apply it to ‘live’ manufacturing projects such as the kinase inhibitor AZD9291 proposed for lung cancer therapy. The SOFR combined online analysis with evolutionary feedback algorithms to rapidly achieve optimum conditions for the final bond-forming steps in synthesising AZD9291. Optimisations were initially carried out on a model compound, with the data used to track the formation of various impurities and propose a mechanism for their formation. This was then applied to the optimisation of a two-step telescoped reaction to synthesise AZD9291 in 89% yield [1].

Subsequently, AstraZeneca continued to sponsor research projects at Leeds to improve automated optimisation platforms. These included developing direct mass spectrometry for reaction analysis, which greatly expanded the scope of chemistries to include compounds without chromophores [2]. This has proved critical to the development of viable flow processes including a large scale production for clinical trials. The research also developed techniques for multi-objective optimisation (visualising the trade-off between objectives such as purity and productivity) and optimising multiple unit operations (i.e. reactor and separation) [3]. This approach was applied to the synthesis of BACE1 inhibitor AZD3293 proposed for Alzheimer’s disease therapy [4].

AstraZeneca (Macclesfield) began applying these automated platforms to assess reaction kinetics [5, 6] (co-funded through the University of Leeds EPSRC Impact Acceleration Account). This work explores the use of mixed integer linear programming for model discrimination and automated parameterisation of models. In addition, development of networked systems for parallelised optimisations across different sites was initiated through the £2M EPSRC grant ‘Cognitive Chemical Manufacturing’ (EP/R032807/1) with AstraZeneca, Swagelok and IBM, who are developing novel algorithms to reduce experimental burden and provide more robust multi-objective optimisations.

In 2019, Bourne was appointed as an AstraZeneca / Royal Academy of Engineering Senior Research Fellow in Digital Manufacturing and Discovery of Pharmaceuticals (RCSRF1920\9\38), in recognition of the impact of his research upon manufacturing and development practices in the pharmaceutical industry.

3. References to the research

[1] Holmes N, Akien GR, Blacker AJ, Woodward RL, Meadows RE, and Bourne RA. Self-optimisation of the final stage in the synthesis of EGFR kinase inhibitor AZD9291 using an automated flow reactor. Reaction Chemistry & Engineering 1, 366–371 (2016). https://doi.org/10.1039/C6RE00059B

Novel application of implementing a self-optimising automated flow reactor for a two-step telescoped process in the synthesis of active pharmaceutical ingredient AZD9291.

[2] Holmes N, Akien GR, Savage RJD, Stanetty C, Baxendale IR, Blacker AJ, Taylor BA, Woodward RL, Meadows RE, and Bourne RA. Online quantitative mass spectrometry for the rapid adaptive optimisation of automated flow reactors. Reaction Chemistry & Engineering 1, 96–100 (2016). https://doi.org/10.1039/C5RE00083A

Online quantitative mass spectrometry was developed as a tool for rapid analysis during self-optimisation, greatly reducing process development time.

[3] Schweidtmann AM, Clayton AD, Holmes N, Bradford E, Bourne RA, and Lapkin AA. Machine learning meets continuous flow chemistry: Automated optimization towards the Pareto front of multiple objectives. Chemical Engineering Journal 352, 277–282 (2018). https://doi.org/10.1016/j.cej.2018.07.031

Application of machine learning global multi-objective optimisation algorithm for the self-optimisation of reaction conditions and visualisation of the trade-off between competing economic and environmental objectives.

[4] Clayton AD, Schweidtmann AM, Clemens G, Manson JA, Taylor CJ, Niñ CG, Chamberlain TW, Kapur N, Blacker AJ, Lapkin AA, and Bourne RA. Automated self-optimisation of multi-step reaction and separation processes using machine learning. Chemical Engineering Journal 384, 123340 (2020). https://doi.org/10.1016/j.cej.2019.123340

Multi-objective optimisation and self-optimising platforms were combined for the rapid development of multi-step processes, including steps towards the synthesis of AZD3293.

[5] Hone CA, Holmes N, Akien GR, Bourne RA, and Muller FL. Rapid multistep kinetic model generation from transient flow data. Reaction Chemistry & Engineering 2, 103–108 (2017). https://doi.org/10.1039/c6re00109b

A method for kinetic model generation from transient flow data was developed resulting in a significant reduction in the time and material required compared to conventional approaches.

[6] Taylor CJ, Booth M, Manson JA, Willis MJ, Clemens G, Taylor BA, Chamberlain TW, and Bourne RA. Rapid, automated determination of reaction models and kinetic parameters. Chemical Engineering Journal, in press, 127017 (2020).https://doi.org/10.1016/j.cej.2020.127017

A kinetic modelling methodology was developed to determine reaction models and kinetic parameters using an autonomous framework involving transient flow measurements.

All of the above journals are internationally recognised with rigorous review processes and international editorial boards. The quality of the underpinning research being at least 2* is demonstrated by all six references.

4. Details of the impact

The development of the SOFR platform at the University of Leeds has changed business practice and outcomes.

AstraZeneca established their own SOFR platform at their Macclesfield site, facilitated through Bourne’s RAEng Industrial Fellowship secondment, which included his training of AstraZeneca staff [A]. This transformative approach has enabled AstraZeneca to rapidly develop viable continuous flow process(es) to meet the demands of rapid drug development timelines, and contributes to the company’s on-going improvement [text removed for publication] [A].

To date, AstraZeneca have applied this technology to [text removed for publication] projects across different therapy areas and it is now part of their standard workflow [A], leading to significant financial impact and impact on patient health. AZD9291 is an example of such a product in the public domain:

AZD9291, a kinase inhibitor for the treatment of lung cancer, was fast-tracked for approval by the Federal Drugs Administration (FDA) due to an unmet patient need [B]. By applying the SOFR technology developed at the University of Leeds, AstraZeneca was able to develop a manufacturing process in an unprecedentedly short 2.5 years from a normal medicine development cycle of approximately 8 years [A]. The SOFR technology played a key role [text removed for publication] in the final stage of the synthesis. AZD9291 was launched in 2018 as TAGRISSO^TM, which is now an approved first line treatment in over 75 countries [C], so the speed at which AZD9291 became available has significantly impacted patient health worldwide. This is now AstraZeneca’s biggest selling medicine with current annual sales of ~£3Bn, and has had significant societal impact by extending cancer patients’ lives [text removed for publication] compared to previous standard-of-care treatments [A].

Such success created a route to international innovation, with AstraZeneca transferring SOFR technologies to their Gothenburg site in the Sample Development team. Bourne and AstraZeneca (Gothenburg) colleagues developed a new proof-of-concept system in 2017 (based on the original SOFR) [D], [text removed for publication]. In addition, a scientific role was created by AstraZeneca within the Bourne group at the University of Leeds for a three-year period from January 2019 to advance the technology of the system [D]. AstraZeneca is planning a significant internal investment [text removed for publication] to evolve and deploy these systems to AstraZeneca research sites [text removed for publication] [D].

[text removed for publication].

Acellular Biological Scaffolds for Tissue Repair and Regeneration

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Technological
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Since 2014, University of Leeds spinout Tissue Regenix has established new manufacturing facilities in Leeds (UK), in Texas (USA), and a Joint Venture Agreement with GTM-V tissue bank Rostock (Germany). Company revenues have grown from zero in 2013 to £11.6M in 2018, together with an increase in the number of people employed from 35 in 2013 to over 100 in 2017. Over this period Tissue Regenix has increased commercial sales of wound care product DermaPure^TM in USA and Europe, completed clinical trials of OrthoPureXT^TM ligaments, and progressed the development of CardioPure^TM dCELL^® heart valves. Furthermore, NHS Blood and Transplant have developed, manufactured and successfully translated the dCELL^® acellular dermis for chronic wound repair as clinical products supplied within the NHS in the UK.

2. Underpinning research

Original multidisciplinary research on acellular biological scaffolds, led jointly by Professor John Fisher in the School of Mechanical Engineering and Professor Eileen Ingham (UoA 5) at the University of Leeds, investigated the creation of tissue specific acellular biological scaffolds that could regenerate with the patient’s own autologous cells. Williams, and prior to leaving the University, Korossis, Katta, Abdelgaied, Russell, and Stanley, contributed to the original research as part of Fisher’s research group.

The initial discovery, original publications and patent in 2001–2002 [1, 2, 7] defined unique bioprocesses that could remove cells and DNA from animal and human tissue, including cardiovascular tissues, heart valves and dermis, while leaving the collagen and elastin structures (the scaffold) intact. This allowed the form, structure and specific properties of the individual native tissue types to be retained, whilst creating an immunocompatible biological scaffold that could be repopulated with the patient’s own host cells. The engineering researchers worked collaboratively with biologists to develop the decellularisation process and to evaluate and modify the process to optimise the physical properties and biomechanical function of the acellular biological scaffolds to closely match the properties and biomechanical function of the native host tissue that the scaffold was replacing.

This research programme has progressed as a platform technology over the last 18 years to create novel, tissue specific biological scaffolds for regeneration of heart valves, dermis, vascular patches and blood vessels, meniscus, ligaments and tendons, bone and cartilage [1–6]. The distinctiveness of our tissue specific acellular biological scaffolds, which are derived from either animal or human tissue, is that they create a tissue (or site) specific scaffold with the appropriate multiscale architecture, physical properties, structure and function—mimicking that of the target host site tissue. This provides the correct multiscale environment for repopulation by host cells, to deliver the appropriate biological and mechanical stimuli and cues to support site/tissue specific cell differentiation, constructive tissue remodelling, regeneration and repair by natural processes. This site specificity cannot be achieved with synthetic scaffolds or with alternative generic biological scaffolds applied to multiple different sites.

Following successful research and development of thin membrane-like scaffolds, our research progressed to focus on thicker structural soft tissue applications for musculoskeletal repair. New bioprocesses were patented and published to produce acellular biological scaffolds derived from ligament and tendon tissue in 2004 [3], and then subsequently meniscus tissue in 2008 [4, 5].

Many musculoskeletal tissue structures comprise combinations of bone and soft tissue (cartilage, ligaments, tendons). Since 2010 we have further advanced the work to develop, evaluate, patent and publish novel bioprocesses for creating composite hard/soft tissue acellular scaffolds for applications such as bone ligament constructs or osteochondral grafts [6].

The University has continued to support new product development through collaborative research on acellular scaffolds led by Fisher and Ingham, with continuous funding from EPSRC from 2003 to the present day (see EPSRC ‘Grants on Web’), with additional support from the ERC (Advanced Grant), the Wellcome Trust, and the NIHR.

Recognition to Professor John Fisher:

CBE for Services to Medical Engineering 2012
UK Biomaterials Society President’s Prize 2013
European Inventor of the Year Nominee 2018
IoM³ Chapman Medal 2019

Recognition to Professor John Fisher’s Institute of Medical and Biological Engineering:

Queen’s Anniversary Prize for Higher Education 2011

3. References to the research

[1] Booth C, Korossis SA, Wilcox HE, Watterson KG, Kearney JN, Fisher J, and Ingham E. Tissue engineering of cardiac valve prostheses I: Development and histological characterisation of an acellular porcine scaffold. Journal of Heart Valve Disease 11, 457–462 (2002). https://pubmed.ncbi.nlm.nih.gov/12150290

[2] Korossis S, Booth C, Wilcox HE, Ingham E, Kearney JN, Watterson KG, and Fisher J. Tissue engineering a cardiac valve prosthesis II: Biomechanical characterisation of decellularised porcine heart valves. Journal of Heart Valve Disease 11, 463–471 (2002). https://pubmed.ncbi.nlm.nih.gov/12150291

[3] Ingram JH, Korossis S, Howling G, Fisher J, and Ingham E. The use of ultrasonication to aid recellularization of acellular natural tissue scaffolds for use in anterior cruciate ligament reconstruction. Tissue Engineering 13, 1561–1572 (2007). https://doi.org/10.1089/ten.2006.0362

[4] Stapleton TW, Ingram J, Katta J, Knight R, Korossis S, Fisher J, and Ingham E. Development and characterization of an acellular porcine medial meniscus for use in tissue engineering. Tissue Engineering Part A 14, 505–518 (2008). https://doi.org/10.1089/tea.2007.0233

[5] Abdelgaied A, Stanley M, Galfe M, Berry H, Ingham E, and Fisher J. Comparison of the biomechanical tensile and compressive properties of decellularised and natural porcine meniscus. Journal of Biomechanics 48, 1389–1396 (2015). https://doi.org/10.1016/j.jbiomech.2015.02.044

[6] Fermor HL, Russell SL, Williams S, Fisher J, and Ingham E. Development and characterisation of a decellularised bovine osteochondral biomaterial for cartilage repair. Journal of Materials Science: Materials in Medicine 26(5), 186 (2015). https://doi.org/10.1007/s10856-015-5517-0

All of the above journals are internationally recognised with rigorous review processes and international editorial boards. The quality of the underpinning research being at least 2* is demonstrated by all six references.

Underpinning patents licensed by the University and subsequently assigned to Tissue Regenix to enable development of the dCell technology and new products:

[7] Fisher J, Ingham E, and Booth C. Decellularisation of tissue implant material. UK Patent GB2375771A (2001). https://patentscope.wipo.int/search/en/detail.jsf?docId=GB134969187

[8] Ingham E, Fisher J, Stapleton T, and Ingram J. Preparation of Tissue for Meniscal Implantation. International Application Number PCT/GB2007/004349 (2008). Publication number WO 2008/059244 A3.

4. Details of the impact

The underpinning research described in Section 2 has been translated through: 1. strategic collaboration with NHS Blood and Transplant (Tissue and Eye Services) (NHSBT); and, 2. through formation of University spin out company Tissue Regenix PLC.

Patents were filed by the University, with university academic and research staff named as inventors [7, 8]. NHSBT were granted a licence in 2006 to use the patented processes to generate acellular scaffolds (as human tissue products) for supply into the NHS in the UK. We have collaborated closely with NHSBT to further develop and manufacture acellular human tissue scaffolds for supply into the NHS (2006 to 2020) including acellular dermis for wound care, heart valve grafts and bone tendon bone grafts for ligament regeneration.
To commercialise the creation of acellular biological scaffolds derived from animal tissues as class three medical devices, and to develop and commercialise the processing of acellular biological scaffolds derived from human tissue outside of the UK, the University of Leeds spin out company Tissue Regenix was incorporated in 2006. Fisher was founding chairman and Ingham was founding director. The original patent families for the dCELL^® technology [7,8] were licensed into the company and first-round investment was secured from IP Group in 2007. Second-round investment was secured in 2008 to support development of the first commercial product. The company was floated on the Alternative Investment Market (AIM) as Tissue Regenix Group (TRG) in 2010 and, in 2012, raised further funds (£25M) to support development and manufacture of a wider range of commercial products for cardiovascular and musculoskeletal applications.

Tissue Regenix has grown significantly during the REF2021 period, supported by further fund raising and investments to develop and grow the business reported since 2013 [A, B, C, D]. At the end of 2013, revenues from sales had not yet been established [A] but by 2017, Tissue Regenix had achieved sales revenues of £5.2M [B, D] and by 2018, Tissue Regenix had achieved sales revenues of £11.6M with a (proforma) growth of 47% during 2018 [D]. The dCELL^® technology product portfolio based on University of Leeds research IP and patents includes the wound care product DermaPure^TM, launched in the USA in 2014 [A], which achieved £3.4M sales in 2018, together with products SurgiPure™, CardioPure^TM, and OrthoPure^TM. Successful clinical trials of the OrthoPure^TM ligament repair system have now been completed in Europe. Heart valves (CardioPure^TM) have been developed and manufactured in Europe. The number of people employed by Tissue Regenix has grown from 35 in 2013 to over 100 in 2017 [B].

Tissue Regenix established new manufacturing facilities in Leeds in 2015 [C]. Responsible for all porcine tissue manufacturing, this facility produces SurgiPure™ (surgical patch for internal soft tissue repair) for export to the US, and also OrthoPure™ (for ligament repair). This facility also acts as the corporate headquarters and research and development hub for future dCELL^® applications. In January 2016, Tissue Regenix entered into a Joint Venture Agreement, forming a partnership with the GBM-V tissue bank in Rostock, Germany, granting for the first time a dCELL^® human tissue licence (2016) [C]. GBM-V revenues reached £1.8M in 2018 [D]. In August 2017, Tissue Regenix acquired CellRight Technologies^® (a US Food & Drug Administration accredited facility in University City, San Antonio) [B], which enabled expansion of DermaPure^TM manufacture and sales in the USA [B]. Following this acquisition, it is difficult to attribute commercial growth and impact exclusively to original University of Leeds research and IP, and so reference is not made to the 2019 Annual Report.

NHS Blood and Transplant (Tissue and Eye Services) (NHSBT) have developed, manufactured and successfully translated dCELL^® acellular dermis for chronic wound repair (2014 to 2020) and, following completion of our collaborative research, are developing manufacturing processes for acellular bone patellar on grafts for ligament repair (2017 to 2020), based on the underpinning patents licensed from the University of Leeds. Following a successful clinical study ( Wound Repair and Regeneration 21, 813–822 (2013), https://doi.org/10.1111/wrr.12113\), NHSBT now routinely supply dCell^® Human Dermis for treatment of chronic wounds. Details of the dCell^® Human Dermis product range, case studies and clinical trial results are available on the NHSBT website [E]. The dCell^® Human Dermis graft fully integrates into the wound bed replacing the lost dermis.

Overall wider patient and societal benefits: the dCELL^® technology portfolio removes DNA and other cellular material from tissue leaving intact an acellular matrix (biological scaffold) that can be colonised by a patient’s own cells, creating a positive environment for tissue regeneration. The potential applications of dCELL^® are diverse and address critical clinical needs in wound care, heart valve replacement, and knee repair. Patients receiving acellular scaffolds benefit from improved tissue repair and regeneration and outcomes [F].

Advanced Pre-clinical Simulation Methods Enabling the Development of Longer Lasting ...

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Technological
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Since 2014, new pre-clinical simulation methods and equipment for replacement hip joints have been developed and commercialised in collaboration with industry partner Simulation Solutions. A new international standard for pre-clinical assessment of hip prostheses (ISO14242-4) has been developed, approved and adopted. This provides, for the first time, a recognised approach to evaluating hip implant designs and materials that simulate variation in surgical translational and rotational positioning, which leads to edge-loading on the joint replacement. New products developed using our advanced simulation methods by our industry partners DePuy Synthes, Invibio, and Mathys and demonstrating lower wear under real world conditions have benefited over 300,000 patients every year (approximately 10 percent of the global market).

2. Underpinning research

The starting point for this research programme in 2001 was the global clinical need for longer lasting and lower wearing total replacement hip and knee joints. These improved prostheses can result in lower revision rates in the longer term (10 to 30 years) for an active ageing population with expectations of ‘fifty active years after fifty’^®.

State-of-the-art pre-clinical joint simulation technology prior to 2001 represented a single activity standard for a normal walking cycle, described in the first international standard published in 2001 that was based upon our previous research. These standard simulations were able to generate predictions for the average wear rates found in the general population. They did not replicate the variation in conditions that can lead to deterioration and the variation in function and higher wear rates that result in the need for revision in individual patients.

Since 2001, our research programme has developed more advanced systems and methods to simulate different clinical conditions. These include the effect of variations in surgical positioning (including combinations of translational and rotational positioning), resulting in edge loading in the hip joint bearing and the effect of variations of different activities, alignment and soft tissue reconstruction in the knee joint. These methods have been subsequently adopted by industry.

In the hip: In 2001 we described that in alumina ceramic-on-ceramic bearings, simulation of dynamic microseparation of the centres of the bearing and replicating edge loading conditions led to stripe wear and higher levels of wear found clinically in some patients [1]. We went on to investigate the effect of edge loading in ceramic matrix composite, metal-on-metal, and polyethylene bearings. We progressed this to investigate the causes of edge loading and the independent effects of the inclination of the cup and the medial lateral offset [2]. More recently, in 2017, we published on the combined effects of both inclination and offset on the bearing mechanics and function, the level and severity of separation, and edge loading. This work demonstrated a synergistic effect with increased levels of inclination combined with increased offsets producing higher levels of separation (>2 mm), producing more severe edge loading and bearing damage, and further increases in wear [3].

In the knee: In 2005 we created new experimental simulation systems and methods for the tibial femoral joint and reported on the effect of different kinematics on the wear of conventional polyethylene [4]^. This showed that increased internal external rotation resulted in increased wear. We progressed this work in 2007 to develop simulations that showed abnormal abduction and lift off also increased wear [5]. More recently, our experimental simulations have been combined with advanced computational simulations to predict wear in cross-linked polyethylene in knee prostheses [6]. The computational methods have been used to simulate contact mechanics and wear for different prostheses designs and for different femoral bearing materials.

The research was undertaken with collaborators in the University of Leeds Faculty of Biological Sciences (Ingham and Tipper (UoA 5) [1, 2]), and in the University of Denver (Komistek [5]). Publications 1, 3, 4, and 6 also have industry collaborators as co-authors. Prior to leaving the University, Al-Hajjar, Abdelgaied, Bell and Haythornthwaite contributed to the original research [2–6] as part of Fisher’s research group in the School of Mechanical Engineering.

The underpinning collaborative research work has been supported continuously by EPSRC since 2001, and has included Platform grants, Portfolio Partnership funding, and funding for the Medical Technologies IKC and Centre for Innovative Manufacturing in Medical Devices (see EPSRC ‘Grants on Web’).

External recognition to Professor John Fisher:

CBE for Services to Medical Engineering 2012
UK Biomaterials Society President’s Prize 2013

External recognition to the Institute of Medical and Biological Engineering:

Queen’s Anniversary Prize for Higher Education 2011

3. References to the research

[1] Stewart T, Tipper JL, Streicher R, Ingham E, and Fisher J. Long-term wear of HIPed alumina on alumina bearings for THR under microseparation conditions. Journal of Materials Science: Materials in Medicine 12, 1053–1056 (2001). https://doi.org/ 10.1023/a:1012802308636

[2] Al-Hajjar M, Fisher J, Williams S, Tipper JL, and Jennings LM. Effect of femoral head size on the wear of metal on metal bearings in total hip replacements under adverse edge loading conditions. Journal of Biomedical Materials Research, Part B: Applied Biomaterials 101B, 213–222 (2013). https://doi.org/10.1002/jbm.b.32824

[3] O’Dwyer Lancaster-Jones O, Williams S, Jennings LM, Thompson J, Isaac GH, Al Hajjar M, and Fisher J. An in vitro simulation model to assess the severity of edge loading and wear, due to variations in component positioning in hip joint replacements. Journal of Biomedical Materials Research, Part B: Applied Biomaterials 106, 1897–1906 (2018). https://doi.org/10.1002/jbm.b.33991

[4] McEwen HMJ, Barnett PI, Bell CJ, Farrar R, Auger DD, Stone MH, and Fisher J. The influence of design, materials and kinematics on the in vitro wear of total knee replacements. Journal of Biomechanics 38, 357–365 (2005). https://doi.org/10.1016/j.jbiomech.2004.02.015

[5] Jennings LM, Bell CJ, Ingham E, Komistek RD, Stone MH, and Fisher J. The influence of femoral condylar lift-off on the wear of artificial knee joints. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 221, 305–314 (2007). https://doi.org/10.1243/09544119JEIM215

[6] Brockett C, Abdelgaied A, Haythornthwaite T, Hardaker C, Fisher J, and Jennings LM. The influence of simulator input conditions on the wear of total knee replacements: An experimental and computational study. Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 230, 429–439 (2016). https://doi.org/10.1177/0954411916645134

All of the above journals are internationally recognised with rigorous review processes and international editorial boards. The quality of the underpinning research being at least 2* is demonstrated by all six references.

4. Details of the impact

Simulation equipment, methods and standards

Fisher and Jennings have a long-standing collaboration with the company Simulation Solutions. Letter [A] corroborates that since 2013 the company has worked with Fisher and Jennings on “the advancement of novel simulation methods and systems and the development of simulation equipment”. Since 2013, the company has “invested in the design and new product development of advanced equipment including new six-axis electromechanical hip joint simulators EM13, 14, 16 and 17 and six axis electromechanical knee joint simulators”, and Simulation Solutions have “sold this novel simulation equipment and provided services and supported the use of these simulators in UK, Europe and Asia to global industry and research institutions”. Since 2013, Simulation Solutions has “sold approximately 300 stations of simulator capacity with a value of around £15M, representing over 50% of the global market”, with the bulk of these sales being in Asia where “Simulation Solutions Ltd and the University of Leeds have worked together to raise levels of awareness and understanding of the need for more rigorous testing standards”.

In this period, Fisher and Jennings furthermore applied their research to initiate and author the new international standard [B] for pre-clinical assessment of total hip prostheses (ISO 14242-4), enabling wider use of the novel simulation methods to evaluate and demonstrate reduced wear under real world conditions and to improve the longevity of joint replacements under development. Published in May 2018, the new standard has been approved and adopted globally to evaluate newly developed hip prostheses prior to CE mark approval. Letter [A] confirms that Simulation Solutions supported the work of Fisher and Jennings in developing this standard, and in pursuing it to final approval and adoption. Jennings also chaired the ISO standard sub-committee for Bone and Joint Replacements (ISO/TC 150/SC 4) from 2012 to 2020 [B].

Improved products and new product development

Since 2013, the University has applied its distinctive experimental simulation methods and systems, which subsequently formed the new standard, in collaborative research to support new product developments with implant manufacturers DePuy Synthes, Mathys, and Invibio to reduce wear (under adverse real-world conditions) and improve the longevity of new joint replacements. We provide direct evidence through our cited industrial collaborations of our research impacting on over 300,000 joint replacement implants per year, more than 10% of the global market.

DePuy Synthes: Letter [C] corroborates the benefit of the collaborative research with the University since 2013, and gives two examples:

The continued sales of ceramic-on-ceramic bearings and the increased sales of ceramic femoral heads for hip prostheses. In REF2014 we reported sales by DePuy of approximately 50,000/annum ceramic composite femoral heads. Letter [C] estimates sales now at over 100,000 per year, a two-fold growth in sales of ceramic femoral heads since 2013. This addresses the increased clinical use of ceramic femoral heads by the orthopaedic community in the UK as reported by UK National Joint Registry [D].
The development and launch to the market of the ATTUNE knee system in 2013, supported by University of Leeds research. As of March 2020, more than 950,000 ATTUNE knee implants have now been provided for patients around the world [C, E].

In June 2015, DePuy Synthes opened their new global R&D facility in Leeds, providing over 500 skilled jobs [C, F]. Letter [C] states that “together with the University of Leeds, [this facility] maintains the Leeds City Region as a global centre of excellence for technology innovation in orthopaedic implants”. This collaboration and centre of excellence forms part of the Leeds City Region Med Tech Hub described in the UK Industrial Strategy, Life Sciences Sector Deal 2, 2018 [G]. Letter [C] confirms “Over 40 Leeds graduates and PhDs work for DePuy Synthes worldwide.”

Mathys: University of Leeds collaborative research with Mathys has directly supported the development and manufacture of their new ceramic matrix composite hips Ceramys and Symarec. Letter [H] corroborates the importance of Fisher and Jennings research in “determining the strategic direction of our new product developments”, and “generating essential evidence for dossiers to gain product approval”, and notes that “Mathys currently sell or supply approximately 50,000 ceramic hip joints every year”.

Invibio: Since 2013 the University of Leeds has worked closely with Invibio to support the development of their novel all-polymer knee system, undertaking all pre-clinical tribological simulations. Letter [I] confirms that “The University of Leeds has been the research and simulation partner of choice”, and that the research “has been critical in determining the strategic direction of the new product development”.

Estimating Official UK Valuations of Travel Time Savings – with Implications for ...

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Economic
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Arguably the most important concept in transport appraisal is the ‘value of travel time savings’ (VTTS)—the monetary value of reducing travel time by one minute, all else being equal—since time savings are typically the single largest component of the benefits of transport infrastructure schemes. In 2014/15, University of Leeds researchers re-estimated the Department for Transport’s (DfT’s) official national VTTS, and following extensive industry consultation, these re-estimates were committed to DfT’s Transport Analysis Guidance (TAG) in 2017. Since the appraisal of publicly-funded transport schemes must adhere to TAG, the University’s estimates of VTTS have had a substantive impact on the Value for Money (VfM) of all schemes submitted to DfT— and thus influenced which schemes were funded. For example, re-analysing the official economic case for HS2 with the new values, the forecasted net benefits increased by £5.1bn and the benefit-cost ratio increased from 1.8 to 2.0.

2. Underpinning research

The underpinning research is largely associated with a government-funded programme starting in 2010 to review the theoretical, methodological and evidential basis of TAG guidance on VTTS, and culminating in 2014 with the commissioning of a £1.4M study to update TAG with re-surveyed national estimates of VTTS. Given the significant influence of VTTS on the funding of transport schemes, the research programme was authorised at ministerial level.

As of 2010, DfT’s official valuations were based on time vs. money trade-offs from a survey of travellers conducted in 1994. Over the subsequent 20 years, these values were regularly updated by DfT for GDP growth, but were not resurveyed. This was despite the fact that there had not only been changes in GDP since 1994, but also in many features of the journey experience, such as wi-fi, hands-free communication technology, and in-vehicle entertainment, as well as advancements in research methods for estimating VTTS.

The underpinning research studies include the following contracts, which were awarded to the Institute for Transport Studies, University of Leeds (ITS Leeds) as key members of various consortia, via competitively tendered procurement processes.

[i] In 2010, ITS Leeds, John Bates Services (independent transport economics consultant) and the Danish Technical University were commissioned by DfT to conduct a scoping study of the research activities that would be required to update VTTS for non-work travellers (£75k contract value to ITS Leeds).

[ii] In 2013, ITS Leeds, John Bates Services and the Swedish Royal Institute of Technology were commissioned by DfT to review methods and evidence concerning the VTTS for business travellers (£56k). Output [1], which arose from this study, entails a systematic review of alternative approaches for valuing business travel time savings. A key recommendation of this study was that DfT should replace the established Cost Saving Approach (CSA) with the Willingness-To-Pay (WTP) approach for estimating business VTTS to take account of the increased productivity of travel time due to laptops and mobile devices. DfT subsequently accepted this recommendation, specifying that WTP should be used to estimate VTTS for business in their Invitation-To-Tender for the 2014/15 study [v].

[iii] In 2013, ITS Leeds and John Bates Services were commissioned to analyse the degree of statistical uncertainty around DfT’s existing non-work VTTS (£5k). Output [2], which arose from this study, developed and implemented a novel methodology for deriving confidence intervals around VTTS estimates from the previous (2003) UK study of VTTS.

[iv] In 2013, ITS Leeds was commissioned by the European Investment Bank to develop a meta-model of the relationship between VTTS and socio-economic and technological factors (€30k). A key output from this study was re-estimation of the ‘elasticity of VTTS with respect to GDP’—a metric which is used to update VTTS for GDP growth over time.

[v] In 2014, building upon the preparatory studies [i–iv], Arup, ITS Leeds and Accent (market research agency) were commissioned to undertake a major study to re-estimate official UK values of travel time savings (£500k to ITS Leeds from total contract value of £1.4M). This study delivered recommendations for revised national average values of in-vehicle travel time savings, derived from a WTP survey of some 11,500 travellers across the UK, covering all surface transport modes, and both business and non-work travel purposes. With regards to non-work travel, the study reported commute values that were ca.50% higher, and other non-work values ca.25% lower, than previous TAG guidance. With regards to business, the study reported marked variation in values by trip distance, with values ca.75% lower than previous TAG for trips of less than 20 miles, achieving parity with TAG at trips of ca.100 miles, and exceeding TAG for still longer trips.

Output [3] details the technical specification of the behavioural model that was developed and implemented in the course of the 2014/15 study. This includes treatment of the phenomenon of ‘reference dependence’, whereby travellers may perceive changes in travel time with respect to some cognitive reference point, which was previously explored in output [4]. Outputs [5] and [6] informed further aspects of the methodology for the 2014/15 study, with [5] developing the approach used to model uncertainties around VTTS estimates, and [6] developing the approach, grounded in Bayesian statistics, used to design the time vs. money trade-off experiments.

3. References to the research

[1] Wardman M, Batley R, Laird J, Mackie P, and Bates J. How should business travel time savings be valued? Economics of Transportation 4(4), 200–214 (2015). https://doi.org/10.1016/j.ecotra.2015.08.003

[2] Wheat P and Batley R. Quantifying and decomposing the uncertainty in appraisal values of travel time savings. Transport Policy 44, 134–142 (2015). https://doi.org/10.1016/j.tranpol.2015.06.010

[3] Hess S, Daly A, Dekker T, Ojeda Cabral M, and Batley R. A framework for capturing heterogeneity, heteroskedasticity, non-linearity, reference dependence and design artefacts in value of time research. Transportation Research Part B 96, 126–149 (2017). https://doi.org/10.1016/j.trb.2016.11.002

[4] Stathopoulos A and Hess S. Revisiting reference point formation, gains-losses asymmetry and non-linear sensitivities with an emphasis on attribute specific treatment. Transportation Research Part A 46(10), 1673–1689 (2012). https://doi.org/10.1016/j.tra.2012.08.005

[5] Daly AJ, Hess S, and de Jong G. Calculating errors for measures derived from choice modelling estimates. Transportation Research Part B 46(2), 333–341 (2012). https://doi.org/10.1016/j.trb.2011.10.008

[6] Bliemer MCJ, Rose JM, and Hess S. Approximation of Bayesian efficiency in experimental choice designs. Journal of Choice Modelling 1(1), 98–127 (2008). https://doi.org/10.1016/S1755-5345(13)70024-1

All of the above journals are internationally recognised with rigorous review processes and international editorial boards. The quality of the underpinning research being at least 2* is demonstrated by all six references. Furthermore, these outputs arose from, or fed into, the underpinning research studies. The final reports from studies [i–iii] and [v] were subject to DfT, independent expert and industry stakeholder review, before publication on the DfT website. The final report from [iv] was expert reviewed by the European Investment Bank, but remains commercial-in-confidence.

Prior to leaving the University, Wardman contributed to the original research underpinning this case study through, e.g. Reference [1].

4. Details of the impact

Impact 1: Underpinning research by ITS Leeds directly informs DfT’s policy decision to commission a major £1.4M research study to update UK national values of travel time savings (2014).

The underpinning research studies [i-iv] were the primary resource used by DfT to formulate a policy position on the robustness of TAG guidance on the valuation of travel time savings. DfT’s position is documented in report [A] from 2013, which references ITS Leeds (p22 & p25) and concludes that a major new research study to re-estimate national values of VTTS should be commissioned (p25). Having secured ministerial approval, the £1.4M contract for the major study to re-estimate national values of travel time savings was tendered through the T-TEAR Lot 2 Framework and, following a commercial bidding competition, was awarded to the Arup/ITS Leeds/Accent consortium in June 2014.

Impact 2: ITS Leeds successfully delivers the study to update UK national values of travel time savings (2015), and the values recommended by ITS are adopted in DfT’s official TAG guidance (2017).

Although commissioned across a challenging timeframe of 11 months, study [v] was completed on time and to specification [B]. Following a period of assimilation, DfT released the final report [C] from study [v], along with their own interpretation of the findings and proposals for updating national values of VTTS in TAG [D]. On p11 of [D] it is stated: ‘This document relates to a research project recently undertaken on behalf of the Department by Arup, Accent and the Institute for Transport Studies (ITS), University of Leeds’. DfT then consulted industry stakeholders [E] (see references to ITS Leeds on p12, p18 & p39) before finalising their proposals on VTTS, securing ministerial approval for these changes, and issuing new TAG guidance in 2017 [F] (see references to ITS Leeds on p4 & p5).

Impact 3: DfT and other policy stakeholders apply the updated TAG guidance on VTTS—based on research by ITS Leeds—to re-run the economic cases for major investment schemes (2017 onwards).

As noted in DfT’s letter of corroboration [G]: ‘ In practical terms, this means that from 2017 onwards, all business cases submitted to DfT for transport infrastructure schemes which generate time savings have been based upon the analysis conducted by ITS Leeds in the course of the 2014/15 study. This includes at least 35 schemes to date, ranging in size and scale from local schemes to regional and national transformational schemes including HS2, RIS1 and Crossrail2’.

Furthermore, the implementation of the updated values in live appraisal work has had a material impact on the VfM of major investment projects in DfT’s portfolio [H]. Overall, given the distribution of journey purposes and the different changes to VTTS for business and other non-work purposes, the updated guidance led to a ca.10% reduction in transport scheme benefits, but this masks significant variation across scheme types. More marked reduction in benefits (ca.40%) occurred where schemes were focussed mainly on leisure and/or shorter-distance business travel. On the other hand, the updated values had a small-to-moderate positive impact on benefits where schemes were focussed mainly on commuting and/or longer-distance business travel.

To illustrate, Table 6 (p26) of [H] summarises official HS2 Ltd. analysis of the impact of the new VTTS estimates on the net benefits and benefit/cost ratio (BCR) of the High Speed 2 rail scheme, whilst holding all other drivers of the BCR constant (e.g. implying that there is no change in travel behaviour as a result of the change in VTTS). The forecasted net benefits increase from £73bn to £78.1bn (2015/16 price and discounting base year), and the BCR increases from 1.8 to 2.0.

Similarly, Table 7 (p27) of [H] summarises official DfT/Highways England analysis of the ‘Roads Investment Strategy’ (RIS1), a cornerstone of which is a multi-year investment plan to improve the strategic road network. As a result of updating VTTS (and again holding all other drivers of the BCR constant), the forecasted net benefits decrease from £40.3M to £35.3M (2010 price and discounting base year), and the BCR reduces from 4.6 to 4.0.

Impact 4: The reach of the impacts extends to other countries, via engagement of ITS Leeds researchers as expert reviewers/advisers/researchers at international policy forums and on other national VTTS studies (2018 onwards).

The UK is one of a relatively small number of countries which commits significant public investment to comprehensive national VTTS studies. As such, many countries seek insight from ITS Leeds expertise to inform the design of their own studies, or to translate UK valuations to their own domestic conditions; see letter of corroboration from the NZ Ministry of Transport [I].

For example, in 2018, the International Transport Forum of the OECD convened a Roundtable at which Batley and Dekker (together with Iven Stead of the UK DfT) presented an invited discussion paper on the 2014/15 UK study [H]. During 2019–20, four further engagements followed which demonstrate various aspects of international impact:

In the context of a new Dutch national study of VTTS, Batley was engaged by the successful bidder, the Significance consultancy, as one of three international experts providing critical review and advice.
In the context of a new NZ national study of VTTS, an ITS Leeds team led by Batley was engaged by the NZ Ministry of Transport on an 18-month contract to provide client-side advice on VTTS and related interests.
In the context of a new Irish national study of VTTS, a consortium of ITS Leeds ( Batley & Dekker) and the SYSTRA consultancy were commissioned to translate (with permission of the UK DfT) the behavioural model from the 2014/15 UK study to Irish travel and socio-economic conditions. As a result, the Irish Government were able to generate updated estimates of VTTS through a research investment of less than €100k—a fraction of the £1.4M invested by the UK DfT in the 2014/15 study.
In the context of a new Australian national study of VTTS, an ITS Leeds team led by Batley was engaged by Austroads, the apex organisation of road and traffic agencies in Australia and New Zealand, to provide client-side advice.

Flow Modelling Research Leads to Innovative and Profitable Products and Systems

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Technological
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Flow modelling research has created impact through improved product designs, increased product development capabilities, and better-trained technical staff. These enabled: (i) Parker Hannifin to develop filtration systems [text removed for publication]; (ii) Sandvik Coromant to develop new cutting tools with step-change improvements in reliability and lifetimes; (iii) GSK to optimise the performance of manufacturing systems for semi-solid and colloidal products; (iv) the NHS to benefit from: improved ambulance designs with lower fuel consumption, and modified ventilators and air-driven Venturi valves to improve the treatment of COVID-19 patients; and, (v) Asynt to bring flow chemistry to a wider group of chemists.

2. Underpinning research

Since 2009, research in the School of Mechanical Engineering ( de Boer, Gilkeson, Kapur, Summers, Thompson, Toropov) has created new computer-based flow modelling and optimisation methodologies for a range of flow systems and products in the commercial and public sectors.

In Diesel Filtration Systems

Kapur and Thompson’s research on gas-liquid flow systems with droplets created an accurate flow optimisation methodology for droplet flows in the jet pumps of filtration systems used in diesel engines [1]. The research challenge was to develop, and validate, an accurate flow model with a computationally-inexpensive geometry parameterisation that could predict when shock waves form in the jet pump. Kapur and Thompson developed an accurate computer-based flow modelling methodology whose predictions agreed well with experiment and used it to investigate how the shape and geometry of the pump affected local pressure changes and shock formation [1]. Toropov’s research on meta-model building using the concept of the Moving Least Squares Method (MLSM) [2] was very effective in representing the results of their flow simulations in a computer-based design optimisation tool. This has been widely exploited within the company Parker Hannifin to bring about process and product optimisation.

In Twist-Drills

During a Knowledge Transfer Partnership project (KTP009868), Thompson and Summers developed flow models of the coolant flow and heat transfer when coolant flows out of coolant channels, over the cutting edge, and then interacts with chips created by the twist-drill cutting action [3]. The flow models correlated very well with experimental wear scar maps and the measured tool lifetimes. Flow modelling results were encapsulated in MLSM meta-models that enabled cutting tool geometry to be optimised accurately and efficiently for specified performance and sustainability objectives.

In Pharmaceutical Manufacturing

During his RAEng/GSK Chair in Pharmaceutical Engineering (2014–2019), Kapur worked with de Boer, developing new flow modelling methods for understanding and optimising the performance of industrial rotor-stator mixers, mixer wear mechanisms and cleaning systems [4].

In the NHS

Emergency Response Vehicles (ERVs):

During a Knowledge Transfer Secondment, Toropov and Thompson combined MLSM-based optimisation techniques developed in [2] with high fidelity Computational Fluid Dynamics (CFD) to optimise the aerodynamic design of emergency response vehicles (ERVs). They worked with de Boer and Gilkeson using flow modelling and optimisation techniques [2], validated by wind tunnel experiments, to optimise the aerodynamic design of ERVs, leading to >12% improvements in ERV fuel economy [5].

COVID-19:

Kapur applied flow modelling and optimisation expertise initially developed in [1] to modify Continuous Positive Airway Pressure ventilators and develop an innovative air-driven Venturi valve to improve treatments for COVID-19 patients.

In Chemical Flow Reactors

Kapur developed flow modelling and optimisation techniques to create laboratory-scale, chemical flow reactors [6], which have brought the benefits of flow chemistry to a wider group of chemists.

Contributions from researchers outside the UoA

D. Copley and A. Mincher (Design Engineers, Parker Hannifin, 2009–present) provided experimental validation of the jet pump model. P.H. Gaskell and R.W. Hewson were former members of the Unit and contributed to the work reported in Ref. 5, but left the University of Leeds prior to this REF period. A.J. Blacker and B.N. Nguyen contributed to the work reported in Ref. 6, but are returned to UoA 8.

4. Details of the impact

Impact of Flow Modelling of Diesel Filtration Systems on Parker Hannifin (confirmed by Statement [A])

This UoA’s flow modelling and optimisation research provided Parker Hannifin with a new product optimisation software design tool, which the company used successfully to design jet pump components of their droplet filters which were 20% more energy-efficient. The new Super Impactor crankcase ventilator—the engineering solution developed as a result of the Leeds modelling— reduces engine emissions in line with Euro 6 requirements, and boosts fuel efficiency.

The exploitation of the Leeds research by using the software design optimisation tool during the design of their Super Impactor product range has led to Parker Hannifin securing new business [text removed for publication]. The company is now employing [text removed for publication] additional people working in this product area. By January 2020, the annual sales revenue from the Super Impactor product range had grown [text removed for publication], with this figure rising steadily as the company continued to win new customers.

Impact of Coolant Flow Modelling on Sandvik Coromant (confirmed by Statement [B])

Coolant is used to improve drill life by transporting heat away from the cutting zone and evacuating waste material (chips) to prevent clogging. The coolant flow modelling and optimisation software tools developed by Thompson and Summers during Knowledge Transfer Partnership project KTP009868 have: (i) enabled the company to understand how twist-drill geometry affects overall cooling performance, reliability, and tool life; (ii) been instrumental in the development of the High-Performance Multi-Material Drills, which provide a step-change in reliability. Since their launch in March 2020, these have resulted in sales of [text removed for publication] up to September 2020. Despite the launch being seriously affected by COVID-19, the company estimate that their superior functionality will eventually result in annual sales of [text removed for publication].

The project led to an important culture change in the company through the provision of new knowledge, training and software tools to over 60 Sandvik technical staff in Sheffield, Coventry, Rovereto (Italy), and Sandviken (Sweden). The company now values flow modelling so highly that it has established a new R&D Modelling and Simulation team to provide flow modelling resources to the wider Sandvik Group and that this “ has been justified and formed based on the flow modelling research carried out on this KTP” [B].

Impact of Flow Modelling of Pharmaceutical Manufacturing Systems on GSK (confirmed by Statement [C])

This UoA’s flow modelling research in pharmaceutical manufacturing has “ enhanced significantly GSK’s scientific understanding of semi-solid and colloidal systems”. It has been used by GSK to develop process understanding and to optimise the performance of the handling of white soft paraffin; rotor-stator mixers and mixer scraper blades; and, in the cleaning of systems used in production of creams and ointments. Furthermore, the training materials and courses that Kapur has delivered to over 150 GSK technical staff, in person and remotely, have led to “ substantial improvements in the technical capabilities of GSK staff” in process engineering and flow modelling.

Impact of Flow Modelling on the NHS

NHS Ambulance Services (confirmed by Statement [D]):

Our research published in [5] convinced the Yorkshire Ambulance Service (YAS) to commission new, more aerodynamically-efficient ambulances. Since July 2013, YAS have operated 43 of these new vehicles, which have achieved an improvement in the average fuel efficiency from 16–18 miles per gallon to 26 miles per gallon, with savings of [text removed for publication] in fuel costs per annum. Our research [5] has been incorporated into the UK design specification for ambulance design, offering reductions in fuel consumption [text removed for publication], and ambulance manufacturer Cartwright has implemented the design for Yorkshire emergency response vehicles. It was also a recommended innovation in Lord Carter’s review of Ambulance Services (Ref. [5] is cited on p 52): https://improvement.nhs.uk/documents/3271/Operational_productivity_and_performance_NHS_Ambulance_Trusts_final.pdf

COVID-19 (confirmed by Statement [E]):

Kapur worked with Leeds NHS Trust to apply his flow modelling expertise to optimise design modifications to Continuous Positive Airway Pressure (CPAP) machines and to develop an innovative air-driven Venturi valve to improve treatment of COVID-19 patients. The modified CPAP machines were used to treat >30 patients successfully in the first wave and were ready for use in the later COVID-19 waves. The valve places less burden on hospital infrastructure than other available designs, including efficient oxygen utilisation, and provides crucial additional treatment capacity should patient numbers outstrip existing CPAP and ventilator provision. These approaches and equipment have been adopted by other NHS Trusts.

Impact of Flow Modelling on Chemical Flow Reactors (confirmed by Statement [F])

Asynt Ltd created a commercial flow chemistry platform based on Kapur’s prototypes [6], creating [text removed for publication] sales between January 2019 and October 2020. This is significant for an SME and enabled them to secure [text removed for publication] to bring further flow chemistry technologies to market, benefitting a wider group of chemists, and providing additional employment in the UK machining industries.

Intelligent Speed Assistance Required as a Mandatory Safety Feature on all new Vehicles ...

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Political
Is this case study continued from a case study submitted in 2014?: Yes

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1. Summary of the impact

Speeding is a major factor in road deaths and serious injuries. Intelligent Speed Assistance (ISA) is the vehicle safety technology that discourages and curtails speeding by limiting vehicles to the speed limit, unless overridden by the driver. University of Leeds research on the behavioural and safety benefits of ISA played a major role in informing, and delivering, European Union legislation in 2019 that mandates all new motor vehicles sold in the EU from 2022 to be equipped with ISA. According to the European Transport Safety Council, the package of mandated vehicle safety measures in this legislation, which includes ISA, is forecasted to save 25,000 fatalities and 140,000 serious injuries over 15 years.

2. Underpinning research

From 2001 to 2011, researchers in the Institute for Transport Studies at the University of Leeds (ITS Leeds) studied the benefits of Intelligent Speed AssistanceFootnote:

ISA was formerly termed ‘Intelligent Speed Adaptation’, but that name has fallen into disuse. (ISA) systems through conducting large-scale trials and analysing the resulting data. ISA systems allow a vehicle to monitor the permitted or recommended maximum speed for the road by coding speed limits into an in-vehicle digital road map that is combined with a positioning system (e.g. GPS). This can be supplemented by on-vehicle cameras that read the roadside speed limit signs. For a given section of road the system can: advise speeding drivers to slow down (Advisory ISA, also termed ‘Speed Limit Information’); curtail the ability to speed (Overridable or Assisting ISA); or prevent acceleration beyond the legal maximum (Non-overridable ISA).

Real-world trials on driver behaviour and assessment of wider impacts

The outcomes of a wide-ranging three-year UK government-funded study—the EVSC project, carried out by ITS Leeds and the Motor Industry Research Association (MIRA)—were delivered in 2000. This included on-road studies of driver behaviour in a car fitted with an ISA system. MIRA researchers integrated sensor and actuator technologies into the vehicle and created digital maps for test routes. ITS Leeds researchers carried out the on-road tests and analysed the vehicle data to determine the effects of ISA on behaviour and accident risk [1]. Using microsimulation techniques, they also examined the subsequent impacts of ISA-equipped vehicles on other traffic, and found that the effects of ISA would be cumulative if more than 60% of vehicles were equipped with the technology. Given the observed changes in speed, ISA would have a substantial impact on injuries and fatalities and was highly favourable in cost-benefit terms [2].

In 2003, the growing evidence on the benefits of ISA led to a large-scale trial (‘Field Operational Test’) named ‘ISA-UK’ funded by the Department for Transport (DfT). The system, unique at the time (and now emulated in the ISA specification adopted in European Union legislation), was an Overridable/Assisting ISA automatically-enabled at ignition-on, with electronic control to curtail speed to the speed limit, combined with a visual interface to the driver. The trial involved adaptation of 20 cars by MIRA, and collected data on 79 drivers living and working in urban and rural settings (previous studies only covered urban roads). The project logged more than 400,000 miles of driving, with over 200,000 miles using an ISA linked to mapping data and technology provided by Navigation Technologies (NAVTEQ, now HERE).

This trial showed that all categories of drivers, including those who admitted a tendency to speed, improved their speeding behaviour when driving with Overridable/Assisting ISA across a variety of road categories. Indeed, the effects tended to be larger for speed-intenders, with for example a 27% reduction in motorway speeding and a 10% reduction in urban speeding accompanied by a very substantial overall reduction in high-speed driving. The ITS Leeds team also predicted the likely safety impacts, which were found to be substantial, particularly regarding serious injuries and fatalities. The research analysed alternative paths to implementation and showed that ISA was highly positive in cost-benefit terms over the 60 year period required by DfT appraisal guidance, and especially for the ‘stronger’ forms of the technology that directly curtail or limit speeds to the legal maximum [3].

Environmental studies and further analysis of impacts

In 2007, Carsten and his team received funding from the Commission for Integrated Transport and the Motorists’ Forum to remodel the data generated by the large-scale trial, using up-to-date national fuel models to analyse the impact of ISA on emissions and fuel economy. Goodman carried out a detailed assessment of the effect of ISA on CO₂ emissions and fuel economy, finding that speed limitation generated an immediate 5% fuel saving for motorway driving. A national survey of around 18,000 households devised by Chorlton and Hess revealed substantial support for ISA implementation and indicated that drivers were generally willing to pay up to £100 for an ISA system [4, 5]. A revised safety prediction and cost-benefit analysis, carried out by Carsten with Lai and Tate, was an additional element of the project [4, 6].

Prior to leaving the University, Carslaw, Chorlton, Goodman, Lai and Wardman contributed to the original research as part of the ITS Leeds research team.

4. Details of the impact

Vehicles currently fitted with ISA. As documented in our REF2014 Impact Case Study and corroborated by Euro NCAP, ITS Leeds research strongly influenced Euro NCAP to incorporate ISA in its safety rating scheme via its ‘Safety Assist’ protocol, and in that protocol to give extra credit to Overridable/Assisting ISA as opposed to a purely advisory ISA system. The Euro NCAP decision in January 2013 stimulated leading manufacturers such as Ford and Volvo to offer such ISA on many of their models. Ford offers Overridable/Assisting ISA on almost all of its cars and vans and has stated that 95% of purchasers, for whom the system is an option, take it up (Thomas Lukaszewicz, Ford Research & Advanced Engineering Centre, Germany: https://vimeo.com/172579013 at 7 minutes, 48 seconds). Consequently, hundreds of thousands of vehicles are already on the road with Overridable/Assisting ISA.

**Mandatory fitting. ** In parallel with this voluntary take-up, there has been swift progress on moving towards mandatory incorporation of ISA into new vehicles across Europe, with ITS Leeds research playing a prominent role on providing the evidence to justify the decision.

In 2014, the responsible authority for European vehicle regulation (DG GROW of the European Commission) began a series of studies into enhancing the safety of road users through compulsory use of a variety of crash-avoidance systems. Until then, vehicle standards, as embodied in the ‘General Safety Regulation’ and ‘Pedestrian Safety Regulation’, which set the minimum standards for new vehicles sold across Europe, had focused primarily on occupant protection in the event of a crash, as well as on prevention of serious injury to pedestrians in the event of a frontal collision. The Commission was now investigating what would be the benefits and costs of fitting a variety of new crash avoidance and crash mitigation technologies, so-called ‘Active Safety’ systems. This initial study was based on information in the open literature, and the study report issued in March 2015 rated ISA as one of the most promising Active Safety systems (reference [A], page 39). In the detailed assessment of the research evidence on the impact of ISA (pages 104 to 107),16 out of 30 citations in the text, covering virtually every aspect of the evidence on ISA, are to ITS Leeds research.

In December 2016, the Commission issued a Communication to Parliament, Council and other EU bodies indicating that it was minded to propose regulation, including fitting ISA to all new passenger and goods vehicles (M and N vehicle types) [B]. ITS Leeds research was cited in support, and the discussion of the safety impact and costs and benefits also cited ITS research (footnotes 12, 14 and 15). The Communication also strongly specified, on page 10, that the favoured system was an overridable/assisting one (here termed ‘voluntary’), i.e. the configuration trialled in the ISA-UK project.

In May 2017, the Commission published its detailed cost-effectiveness study on the choices to be made in revising the General Safety Regulation and Pedestrian Safety Regulation [C]. This cited input from ITS Leeds (page 98), and reported that values from ITS Leeds studies (pages 100 and 101) could provide the required information on the safety effectiveness of ISA for cars (vehicle category M1) and light trucks (vehicle category N1).

Finally, in May 2018, the European Commission announced its package of measures for safe, clean and connected mobility, termed ‘Europe on the Move III’ ( https://tinyurl.com/ybzj8j9d). For safe mobility, a central policy was that new vehicles be fitted with advanced safety features. The justification for the vehicle proposals can be found in Section 2 ‘Safe Mobility’ of the Commission’s Communication [D]. The package of vehicle safety measures that was introduced in this proposed legislation included fitting ISA to all passenger vehicles and light, medium and heavy trucks. The detailed text (reference [E], page 24) defines the minimum requirement for ISA as follows: “ (a) it shall be possible for the driver to feel through the accelerator pedal that the applicable speed limit is reached or exceeded; (b) it shall not be possible to switch off or supress the system.” In other words, what was to be legislated was not merely Overridable/Assisting ISA, but an ISA that defaults to being enabled, i.e. the system trialled and reported in the 2000s in the ITS Leeds ISA-UK project.

Overcoming industry pressure. The Association of European Vehicle Manufacturers (ACEA) campaigned to persuade the European Parliament to replace Overridable/Assisting ISA with a less effective warning system, i.e. Speed Limit Information or Advisory ISA. Carsten spoke at a workshop organised by the Committee on the Internal Market and Consumer Protection (IMCO) of the European Parliament on 29 November 2018, confirming the high acceptance for the overridable/assisting system found in the UK trials, and wrote to the IMCO members stating that the predicted impact of Overridable/Assisting ISA on serious injuries and fatalities was more than four times that of Advisory ISA (Speed Limit Information). On 21 February 2019, the committee voted overwhelmingly to retain Overridable/Assisting ISA in the vehicle safety package, and Overridable/Assisting ISA is specifically written into the final legislation, which passed in April 2019 [F, G]. In November 2019, the legislation was formally approved by Council and thus became law [H].

The Director of the TRL Academy corroborates that ‘ the ITS outputs on ISA were the most influential independent set of studies and helped us to come to our recommendation to the European Commission to require mandatory fitment of ISA to all passenger and freight vehicles’ [I].

In summary, evidence from ITS Leeds research played a ‘crucial role’ and a ‘crucial body of evidence’ [I] in the decision-making process leading to European Union legislation in 2019 that mandates all new motor vehicles sold in the EU from 2022 to be equipped with ISA, and also prevented the legislation from being weakened under pressure from manufacturers. The safety benefits are core to the decision to adopt the package of vehicle safety measures that include the ISA system; the underlying prediction is 25,000 prevented fatalities and 140,000 prevented serious injuries across the EU Member States in the period 2021 to 2037 [J].

5. Sources to corroborate the impact

European Commission, ‘Benefit and Feasibility of a Range of New Technologies and Unregulated Measures in the Fields of Vehicle Occupant Safety and Protection of Vulnerable Road Users’, DG GROW, Brussels (2015). https://doi.org/10.2769/497485 Describes the benefits and costs of ISA (Appendix A.3, pages 104–107); 16 out of 30 citations in the text are to ITS Leeds research.
European Commission, Commission Staff Working Document Accompanying the document Report from the Commission to the European Parliament and the Council ‘Saving Lives: Boosting Car Safety in the EU’, SWD(2016) 431 final, DG GROW, Brussels (2016). https://tinyurl.com/ycv97tde Discussion of the safety impact of ISA cites ITS Leeds research. References 12, 14 and 15 are to ITS Leeds research. Reference 13 ( https://ec.europa.eu/transport/road_safety/sites/roadsafety/files/newspdf/speed_limitation_evaluation_en.pdf ) cites ITS Leeds work on pages 34, 38–40, 57, 95, 185, 189, and 190.
European Commission, ‘In depth cost-effectiveness analysis of the identified measures and features regarding the way forward for EU vehicle safety: final report’ DG GROW, Brussels (2017). https://doi.org/10.2873/748910 ITS Leeds research on the safety impacts of ISA for cars (vehicle category M1) and light trucks (vehicle category N1) is cited on pages 98, 100 and 101.
European Commission, ‘Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions—Europe on the Move, Sustainable Mobility for Europe: safe, connected, and clean’ (2018). https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:52018DC0293
European Commission, Proposal for a Regulation of the European Parliament and of the Council on type-approval requirements for motor vehicles (2018). https://eur-lex.europa.eu/resource.html?uri=cellar:f7e29905-59b7-11e8-ab41-01aa75ed71a1.0003.02/DOC_1&format=PDF
European Commission, Press Release, 26 March 2019. Road safety: Commission welcomes agreement on new EU rules to help save lives. https://ec.europa.eu/commission/presscorner/detail/en/ip_19_1793
European Transport Safety Council, Press Release, 16 April 2019. European Parliament backs new vehicle safety standards. https://etsc.eu/european-parliament-backs-new-vehicle-safety-standards/
European Council, Press Release, 8 November 2019. Safer cars in the EU. https://www.consilium.europa.eu/en/press/press-releases/2019/11/08/safer-cars-in-the-eu/
Letter from the Director of the TRL Academy, Wokingham, RG40 3GA, UK, 14 January 2021.
Presentation by the Director of the TRL Academy, 6 June 2018. The importance of the GSR for the future of vehicle safety: Results of the Impact Assessment study. https://etsc.eu/wp-content/uploads/Richard_Cuerden_06062018.pdf

Mapping Hazardous Infectious Faecal Wastes

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Societal
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

[100 words]**

Lack of access to safe sanitation affects 2.6 billion people, particularly in low/middle income countries. Political and engineering bias towards ‘global north’-style centralised sewerage, despite most people depending on distributed on-site sanitation, results in large investments actually benefitting very few people. University of Leeds research develops tools that generate accessible whole-city visualisations of safe and unsafe (i.e. hazardous and infectious) human excreta flows and identify policy and institutional gaps requiring investment. Our research has influenced investments in over 100 global cities, maximising public health benefits for over one million people, and are embedded in institutional planning covering a population of 2.4 billion.

2. Underpinning research

[500 words]**

In 2011 the University of Leeds was commissioned by the World Bank to start collaborative research to inform their $10 billion investment in Urban Sanitation. We identified that many of these investments failed to improve the faecal sludge management (FSM) systems that accounted for 80–100% of services in most low- and middle-income (LMIC) cities. The portfolio was instead dominated by investments in centralised sewerage that benefitted very few people. We also found that institutional analyses failed to address the full range of sanitation services, hiding critical problems, and highlighted the need for practical tools to analyse the status of sanitation in a city and better target investment.

Two tools were developed [1]: the ‘Service Delivery Assessment’ (SDA) Scorecard showing the underlying drivers of the sanitation performance, and the ‘Shit-Flow Diagram’ (SFD), which visually represents the resulting excreta flows. Together, they enable a comparative assessment of policy environments, budgeting and financial performance, human resources, and regulation. Uniquely, they bridge the disciplinary gap between engineers (who understand the processes) and planning/finance professionals (who wish to place sanitation investments into a wider systems framework). The SFD works well for technical and non-technical audiences, and the SDA helps those wanting to identify key policy and investment bottlenecks (Figure 1). In tandem, they promote investment in infrastructure integrated with necessary institutional frameworks, avoiding the wasted funds and poor public health outcomes that characterise many planning interventions.

| | In 2014 the SDA and SFD were honed through twelve city case studies, co-produced with local stakeholders [2], identifying typical modes of failure and associated interventions. The cities were characterised into a three-tier typology based on their SDA score and the proportion of human excreta that is safely managed. The work demonstrates: how city planners can overcome their specific challenges; that investments in infrastructure without | | --- | --- | | Figure 1 Bill Gates showing a SFD at the Reinvented Toilet Expo, Beijing, 2018 [L]. ||

adequate policies and operational funds for services will be unsuccessful; and, that comprehensive FSM systems will be needed in most LMIC cities. This (and Evans’ wider portfolio e.g. Refs. [3] and [4]) led to Evans participating in the development of the United Nations methodology for estimating access to safely managed sanitation in the Sustainable Development Goal (SDG) framework, refining the SFD approach for use in global monitoring (see e.g. Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (WHO and UNICEF, 2018), https://washdata.org/report/jmp-methodology-2017-update; a SFD features on page 11).

The newest SFD paper looked at progress with the roll out of the SFD, its accompanying graphics generator and manual, and the 100+ SFD reports published since 2014 [5]. Analysis of 39 cities identified five critical technical failure modes associated with the degrees to which containment, emptying, discharge, delivery and treatment of faecal sludge are achieved. Identifying these gives clear direction as to which processes and infrastructures are causing a city to miss the SDG goals for safely managed sanitation for all (see also Ref. [2]). The paper develops a set of standard intervention packages to effectively improve sanitation services in low-resource settings. A further phase of the SFD project, funded by the Bill and Melinda Gates Foundation (PI Evans, OPP1210665, US$790k) currently underway at the University of Leeds will strengthen the tools and ensure that their use is institutionalised.

3. References to the research

[1] Peal A, Evans BE, Blackett I, Hawkins P, and Heymans C. Fecal Sludge Management: analytical tools for assessing FSM in cities. Journal of Water, Sanitation and Hygiene for Development 4(3), 371–383 (2014). https://doi.org/10.2166/washdev.2014.139

[2] Peal A, Evans BE, Blackett I, Hawkins P, and Heymans C. Fecal Sludge Management: a comparative assessment of 12 cities. Journal of Water, Sanitation and Hygiene for Development 4(4), 563–575 (2014).https://doi.org/ 10.2166/washdev.2014.026

[3] Balasubramanya S, Evans B, Hardy R, Ahmed R, Habib A, Asad N S M, Rahman M, Hasan M, Dey D, Fletcher L, Camargo-Valero M A, Rao K C, and Fernando S. Towards sustainable sanitation management: Establishing the costs and willingness to pay for emptying and transporting sludge in rural districts with high rates of access to latrines. PLoS ONE 12(3) e0171735 (2017). https://doi.org/10.1371/journal.pone.0171735

[4] Bartram J, Brocklehurst C, Bradley D, Muller M, and Evans B. Policy review of the means of implementation targets and indicators for the sustainable development goal for water and sanitation. npj Clean Water 1(1), 3 (2018). https://doi.org/10.1038/s41545-018-0003-0

[5] Peal A, Evans B, Ahilan, S, Ban R, Blackett I, Hawkins P, Schoebitz L, Scott R, Sleigh A, Strande L, and Veses O. Estimating Safely Managed Sanitation in Urban Areas; Lessons Learned from a Global Implementation of Excreta-Flow Diagrams. Frontiers in Environmental Science 8, Article 1 (2020). https://doi.org/10.3389/fenvs.2020.00001

All of the above journals are internationally recognised with rigorous review processes and international editorial boards. The quality of the underpinning research being at least 2* is demonstrated by all five references.

Prior to leaving the University, Ahilan and Veses contributed to the original research in Ref. 5 as members of Evans’ research group in the School of Civil Engineering.

4. Details of the impact

Impacts on practitioners and delivery of professional services: The SFD and SDA have brought rigour to investment decisions around urban sanitation, raising its profile and steering funds towards technical interventions that actually improve outcomes, replacing interventions based on standard budget allocations and outdated master plans [A, B, C]. They had an immediate impact on policy discussions at the World Bank, being formalised in their toolkit for urban sanitation planning [A]. After the work was presented at the 2013 Stockholm World Water Week, meetings between the University of Leeds, the World Bank, the Federal Government of Germany (Deutsche Gesellschaft für Internationale Zusammenarbeit) [A, B, C] led to a partnership that formed the Bill and Melinda Gates Foundation (BMGF) funded ‘SFD Promotion Initiative’ (SFD-PI) ( https://sfd.susana.org/about/the-sfd-promotion-initiative).

In 2015, the world committed to the Sustainable Development Goals (SDGs). SFDs are incorporated in the design of data collection and reporting protocols for the WHO/UNICEF Joint Monitoring Programme for Water, Sanitation and Hygiene (JMP) [D, 5], mandated by the UN to report on SDG6.1 and 6.2 including urban sanitation. Evans participated in the development of a methodology for estimated access to safely managed on site sanitation as Chair of the Advisory Group [D]. SFD/SDA concepts are integrated into the World Health Organisation normative ‘Guidelines on Sanitation and Health’ [E] and listed as key components in the urban sanitation guidelines of e.g. the NGOs Water and Sanitation for the Urban Poor (WSUP) [C] and WaterAid [F], and the Asian Development Bank [C, G].

Impacts on understanding and learning: The SuSanA website ( https://tinyurl.com/yxvkyx6a) develops and transparently archives city-level SFDs. Over 120 reports, currently covering a population of 140 million people, are freely available allowing planners, academics and funding agencies to target sanitation-related decisions and investments using a globally-recognised standard [A, C]. The SFD-PI training events have reached an estimated 8,000 professional and government staff [B], improving analysis of existing sanitation constraints at the local level using the publicly available graphic generator tool with accompanying materials. Work by practitioners who have benefitted from the training has been presented at e.g. Stockholm World Water Week and the World Bank Spring Meetings.

Impacts on public policy and services: From its inception, the impact of the SFD graphic on non-technical stakeholders has been to cause shock and dismay at the unaccounted faecal waste within their cities, leading national governments to institutionalise the SFDs into their sanitation planning programmes. In India, SFDs have been imbedded in the government’s scaling up of urban sanitation as part of the Swachh Bharat Nirmal programme, and more than 700 cities have developed City Sanitation Plans based on the SFD approach [H]. In South Africa more than eight cities have used SFDs as part of their planning process, and the government is now working in partnership with their Water Research Commission, and the Indian Centre for Science and the Environment, requiring all municipal governments to prepare SFDs as the basis for funding decisions from the central government [H]. Indonesia has institutionalised the SFD, with every municipality required to produce one as part of their city sanitation plans [I].

Impacts on the health and wellbeing of people: There is an extremely low level of access to safely managed sanitation services in cities and towns in the global south. The SFD tool can unlock enormous public health benefits through improved targeting of sanitation investments. SFDs are now widely used in World Bank Project Appraisal Documents; for example, to target an investment of US$115M in Mozambique, and US$65M in Zambia [A]. The Asian Development Bank has also extensively used the SFD tool to optimise sanitation investments in Indonesia, Nepal, the Philippines, Papua New Guinea and Vietnam [G]. The SFD/SDA report for Nairobi was produced by a coalition of stakeholders supported by Evans over the course of nine months. It re-evaluated the status of sanitation in the city, potentially improving the lives of nine million people. Newspaper headlines [J] prompted by the report catalysed a clear policy shift [K].

In 2018 Bill Gates announced that the World Bank Group and the BMGF had “committed to work together to unlock at least $1billion in investments in innovative sanitation solutions to help address the urgent challenge of 2.6 billion people around the world living without access to sanitation services” [B]. In his speech at the Beijing Toilet Expo attended by hundreds of Chinese and international sanitation experts, he used the image of an SFD to visualise his point regarding the problems of unsafe urban sanitation (Figure 1) [B, L].

5. Sources to corroborate the impact

[A] Letter from the Lead Water and Sanitation Specialist, Water Global Practice, The World Bank, Washington, DC 20433 USA, 20 January 2021.

[B] Letter from the Sr. Program Officer, WSH Program, Bill & Melinda Gates Foundation, Seattle, WA 23350 USA, 26 January 2021.

[C] Letter from the Head of Project – Sustainable Sanitation, Deutsche Gesellschaft für Internationale Zusammenarbiet (GIZ), 53113 Bonn, Germany, 26 January 2021.

[D] Letter from the Unit Head, WASH, Dept. of Environment, Climate Change and Health, World Health Organisation, 28 October 2020.

[E] ‘Guidelines on Sanitation and Health’, World Health Organisation (2018), p29 et seq, p68 et seq. https://apps.who.int/iris/bitstream/handle/10665/274939/9789241514705-eng.pdf?ua=1

[F] ‘Comparison of tools & approaches for urban sanitation September 2016’, Water Aid (2016). https://washmatters.wateraid.org/publications/urban-sanitation-tools-and-approaches

[G] Letter from the Chief Sector Officer, Sustainable Development and Climate Change Department, Asian Development Bank, Manila, Philippines, 1 February 2021.

[H] Letter from the Senior Director & Academic Director, School of Water & Waste Centre for Science and Environment, New Delhi-110 062, India, 21 October 2020.

[I] Letter from the Director of Housing and Settlements, Directorate Housing and Settlements, National Development Planning Agency (BAPPENAS), Jakarta 10310, Republic of Indonesia, 21 January 2021.

[J] ‘Where does your 'shit' go? 66% of Nairobi human wase unaccounted for’, Nairobi Star, 5 July 2018. https://www.the-star.co.ke/news/2018-07-05-where-does-your-shit-go-66-of-nairobi-human-waste-unaccounted-for/

[K] Letter from the Co-Founder, Sanergy Inc, Brookline, MA 02446, USA, 26 October, 2020.

[L] Bill Gates, Speech at Reinvented Toilet Expo, Beijing, China, 6 November 2018, Paragraph 20. https://www.gatesfoundation.org/Media-Center/Speeches/2018/11/Reinvented-Toilet-Expo

Radio Frequency Power Combiners for Mobile Communication Systems

Submitting institution: The University of Leeds
Unit of assessment: 12 - Engineering
Summary impact type: Technological
Is this case study continued from a case study submitted in 2014?: No

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1. Summary of the impact

Research at the University of Leeds has underpinned the development and manufacture of radio frequency (RF) power combiners by Radio Design Ltd for use in mobile communication systems. Radio Design industrialised the Leeds research, training design engineers in the new technology, and designing devices for volume production. [text removed for publication]

2. Underpinning research

Since 2000, the University of Leeds developed a new research activity in the School of Electronic and Electrical Engineering led by Professor Ian Hunter FREng on the development of microwave filters for the rapidly expanding mobile communications market. As cellular networks became deployed more widely, there was a need for interference rejection filters for base stations with bandwidths of <1 MHz at centre frequencies of 1–4 GHz. Hunter conducted research into the development of filters with significant dissipation loss, and non-uniform Q filters. This new technique took low-Q structures into account, avoiding reduction in skirt selectivity, and this was then extended to transmission-mode filters with elimination of the requirement for a circulator [1]. Based on this research, Leeds received funding from two Technology Strategy Board projects with TWI (Cambridge) to develop filter designs (‘Adept-Sip’ Ref. 461348, £398,401, 1/05/2006–31/10/2009; and, ‘PPM2’ Ref. 475416, £325,000, 1/06/08–31/11/11), as well as research grants with the Defence Technology Centre for Electromagnetic Remote Sensing to support applications in the defence sector.

In response to the development of LTE and 4G systems by cellular radio operators, there was a growing need to develop directional channel combining filters. Hunter commenced a collaborative research programme with Radio Design Ltd in 2010 following their recognition of the commercial significance of Hunter’s work on cascaded directional filters in providing the theoretical concepts underpinning new filtering technology. Radio Design Ltd furthermore supported and co-funded Hunter’s appointment to a Royal Academy of Engineering Research Chair in 2012, and is currently employing him on a part-time basis following his retirement from the University in 2018.

Working with Radio Design Ltd, Hunter developed a theoretical synthesis technique for the design of directional filters for 4G power combining systems showing that parallel connected networks could be implemented with non-uniform Q filters [2], enabling transversal directional filters to be realized for channel combining [3]. This new design approach enabled a device called a ‘four port combiner’ to be constructed, which allows two radio frequency channels to be combined onto a single antenna, even if the two channels are very close in frequency. The four port combiner enables two cellular operators to share a single antenna by integrating their base stations to such a combiner, or a single operator to combine two different cellular systems (e.g. 4G and 5G) to the same antenna. This enables considerable savings in both cost and the infrastructure required for base stations, as well as reducing the consequential environmental impact. Ref. 3 reports a miniaturisation of the combiner by a factor of two or more in volume. The research was subsequently extended to the synthesis of multi-band filters [4].

This work was patented by Radio Design Ltd with Hunter [5,6], and used to underpin the series of successful products described in section 4.

Pollard and Rhodes both retired from the University during this period, but contributed to the research presented in Refs. 1 and 2, respectively, in collaboration with Hunter.

4. Details of the impact

Radio Design Ltd designs and manufactures single- and multi-band RF filters and combiners for cellular radio systems, focusing on: inter-operator and technology sharing; tower mounted amplifiers; interference reduction; and, the provision of test equipment. The company currently has around 470 employees, mostly in the UK and India, with a turn-over of ~£28M per annum.

In 2010, Radio Design Ltd. recognised the commercial significance of Hunter’s RF filter research at the University of Leeds and, in particular, its application to the development of miniaturised combiners that allow two radio frequency channels to be combined onto a single antenna, even if the two channels are very close in frequency.

Radio Design Ltd subsequently industrialised the Leeds research, training their design engineers in the new technology, upgrading their in-house filter design software and designing devices for volume production. Since 2015, [text removed for publication] products have been shipped based on the designs and simulations undertaken by Hunter and his group at the University of Leeds [text removed for publication] [A].

Specifically, these products comprise [B]:

• RD0569 800 MHz same band combiner with 5 MHz bandwidth

• RD0615 800 MHz same band combiner with 10 MHz bandwidth (adjacent spectrum)

• RD0630 900 MHz same band combiner with 5 or 10 MHz bandwidth

• RD0730 800 MHz same band combiner with 10 MHz bandwidth (non-adjacent spectrum)

• RD0784 1800 MHz same band combiner

The 5 MHz bandwidth products have a narrower guard band than the 10 MHz bandwidth products. In all cases, the combiner guard band is less than the unoccupied spectrum between adjacent carriers.

[text removed for publication]

Two granted patents associated with products RD0569, RD0615, RD0630 and RD0784 list Professor Ian Hunter among the inventors [5, 6]. Radio Design Ltd have a further patent application for product RD0730 (GB2566182) awaiting examination [text removed for publication] [A].

The University of Leeds has not only supported the design of new products at Radio Design Ltd, but has also provided highly skilled PhD-trained engineers from Hunter’s research group who have been recruited by the company. [text removed for publication].

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