Health Technology Assessment and Biomedical Engineering: Global trends, gaps and opportunities

The diffusion of medical devices is expanding at an astonishing rate. The increasing number of novel patents per year suggests this growth will continue. In contrast to drugs, medical devices are intrinsically dependent on the environment in which they are used and how they are maintained. This created an un- precedented global need for well-trained biomedical engineers who can help healthcare systems to assess them. The International Federation for Medical and Biological Engineering (IFMBE) is the global scientiﬁc society of biomedical engineers in oﬃcial relations with the United Nations World Health Organisation (WHO) and has been very active in promoting the role of the biomedical engineer in Health Technol- ogy Assessment (HTA). The IFMBE Health Technology Assessment Division (HTAD) is the IFMBE operative branch in this ﬁeld, promoting studies, projects and activities to foster the growth of this speciﬁc and very important science sector, including summer schools, training material, an HTA eLearning platform, HTA guidelines, awards and more. This article describes the vision, the mission and the strategy of the HTAD, with a focus on the results achieved and the impact this is having on global policymaking. This


Introduction
The past 10 years has seen a remarkable diffusion of Medical Devices (MDs). A proxy for future diffusion is the number of MD patent applications submitted per year [1] . While the yearly number of patent applications per pharmaceuticals and biotechnologies remains at a constant level year after year (about 60 0 0 novel patent applications per year since 2006), the number of patents for medical technologies only keeps growing at a remarkable rate, moving from 90 0 0 to more than 12,0 0 0 novel patent applications per year during the period 2006-2016 in Europe only [2] . Similar figures come from the United States of America (US), where patent filings show a significant uptrend from 2007 (about 22,000 applications) to 2018 (more than 34,0 0 0 applications). Should we consider this latter figure valid today, we could speculate that it equates to more than 93 novel patent applications per day, suggesting that while you are reading this manuscript three to four MD novel patent applications could have been filed. In addition, Health Technology Assessment (HTA) in connecting researchers to policy maker communities [9] .
In 2014 the World Health Organisation (WHO) stated that 't rained and qualified biomedical engineering professionals are required to design, evaluate, regulate, maintain and manage Medical Devices, and train on their safe use in health systems around the world ' [10] . In response to this statement, the European Economic and Social Committee (SEEC) engaged in close consultation with the European community of Biomedical Engineers represented by the European Alliance for Medical and Biological Engineering and Science (EAMBES) [11] . This discussion resulted in a study published in April 2015 (2015/C 291/07) in the Euro Lex (the official Journal of the European Union) stating that: ' Biomedical Engineering is not simply a subset of modern medicine. Modern medicine predominantly secures important advances through the use of the products of biomedical engineering ' [12] .
Referring to HTA knowledge, the Biomedical Engineering (BME) community has been lagging behind other healthcare scientific communities (e.g., pharma, medicine, health economy), in terms of available training, discussion fora and also in defining HTA as one of the core topics for BME. Although some universities had introduced HTA topics in their curricula, it was only in 2011 that HTA was proposed as a core topic for BME by a consortium of European Universities [13][14][15] endorsed by the International Federation of Medical and Biological Engineering (IFMBE) [16] .
This article describes the effort of the global community of Biomedical Engineers in talking these emerging challenges to foster the HTA culture among the BME community through the work of the Health Technology Assessment Division (HTAD) of the IFMBE between 2015 and 2018.

Global community of BME
The IFMBE is the global scientific society of Biomedical Engineers, federating 66 national societies from 60 different countries and 6 transnational societies (IEEE EMBS, EAMBES, ACCE, AAMI, CAHTMA and CORAL). These professional organisations represent the global interests in medical and biological engineering in the world. The IFMBE is also a Non-Governmental Organisation (NGO) in official relations with the United Nations World Health Organisation (WHO), which IFMBE serves as recognised stakeholder offering continuous support and expertise for delivering better and more accessible health care to the world, through a unique network of world leading experts of biomedical and clinical engineering.
The IFMBE governance is entrusted to five Officers (President, President-Elect, Past-President, Treasurer and Secretary General), which are elected by the IFMBE General Assembly during the World Congresses of Medical Physics and Biomedical Engineering. The officers are supported by the Administrative Council, whose members are in part elected during the General Assembly (4 members) and in part appointed ex-officio as Chairs of the Council of Societies, Fellows' Chapter and Divisions.
Important bodies of the IFMBE are the two Division: the IFMBE Health Technology Assessment Division (HTAD) [17] and the IFMBE Clinical Engineering Division (CED) [18] , which together account for a large part of the IFMBE activities and budget. Division board members are elected during the IFMBE General Assembly among candidates nominated by IFMBE Affiliated societies. Those members are considered to be experts of HTA or Clinical Engineering. Among those elected board members, seven per Division, the Chair, the Secretary and the Treasurer are then elected. They are responsible for coordinating the Divisions' activities and reporting about their achievements to the IFMBE Administrative Council.
It is worth remarking that the all activities and work done for the IFMBE is on voluntary base, and none of the AC or Division members is compensated for their contributions by the IFMBE.
The IFMBE Division can also propose to the IFMBE President two additional board members to be co-opted on the base of their expertise. Finally, both Divisions have a significant number of collaborators directly appointed by Division Chairs.
The IFMBE teamed up the International Organisation for Medical Physicists (IOMP) into a larger association named the International Union for Physical and Engineering Sciences in Medicine (IUPESM). These three organisations coordinate the World Congress on Medical Physics and Biomedical Engineering every three years. The forthcoming World Congress will be held in Singapore in late Spring 2021. IUPESM is a member of the International Science Council (ISC), an NGO in official relations with the UN UNESCO, bringing together 40 international scientific Unions and Associations and over 140 national and regional scientific organisations including Academies and Research Councils.

Method
Through a series of focus groups and scoping literature reviews, the IFMBE HTAD elected and co-opted members defined the IFMBE HTAD Vision, Mission and Strategy. Once these where defined, the IFMBE HTAD Chair discussed and agreed with the IFMBE Officers on a three-year plan and program of activities. A series of surveys and numerous focus groups were run along the years, aiming at involving international scholars, promoting the Division activities, getting feedback and for continuously improving ongoing activities.

Vision
The IFMBE HTAD vision is that biomedical engineers "should be constantly involved in HTA studies focusing on MDs, in order to better serve the ultimate beneficiary of healthcare and biomedical engineering: the patient". The Vision is based on three enabling values: • The expertise of Biomedical Engineers (unlike other HTA experts) spans across MD research, design, assessment and management; • biomedical engineering has a multi-disciplinary nature, considering that biomedical engineers are employed in MD research and manufacturing as well as in hospitals and healthcare agencies; • biomedical engineering has an inter-disciplinary nature, with BME students specifically educated in a wide range of topics, including physics, math, engineering, biology and medicine.

Mission
In order to achieve the above vision, the IFMBE HTAD performed a scoping review and a gap analysis, which resulted in the definition of four focus areas: • Training: due to the lack of specific training material and courses suitable for biomedical engineers, the Division aimed to develop specific training events and contents on HTA, based on BME educational needs and background, which are different from those of other HTA experts. • Research: reinforce the collaboration among BME scholars proactively involved in HTA research and studies. • Publications: in order to fill the dearth of publication fora (i.e., conference and journals) for HTA research outcomes, often due to lack of HTA experts in the BME community, the HTAD board decided to support the IFMBE Conference Organizers and journal editors, by helping them in identifying networks of local experts and by providing them with a direct support. • Events: organizing scientific events and workshops aiming at promotion collaboration among biomedical engineers, scientific societies with interest in HTA, policy makers and HTA stakeholders.

Strategy
In order to accomplish this mission, the IFMBE HTAD defined an articulated plan, made of 5 strategic goals further structured in 11 priority projects, aiming to overcome fragmentation and avoiding working "in silos": • Establishing periodical training events on HTA for biomedical engineers, • Developing and sharing free high-quality training material on HTA for biomedical engineers; • Reinforcing collaboration on HTA among biomedical engineers and other HTA experts; • Creating new spaces to facilitate BME publications on HTA; and • Preparing IFMBE recommendations and guidelines for HTA.
Ten priority projects of the HTAD were defined: (1) Organise HTA summer schools for biomedical engineers : starting a series of IFMBE Summer Schools on HTA, to be organised in different regions every 2 years; (2) Develop HTA training material : publishing high quality HTA didactic contents, which could respond to biomedical engineers' learning needs; (3) Launch eLearning platform : designing, refining and managing a web portal and an eLearning platform to spread HTA contents and promote BME experiences in HTA initiatives; (4) Foster HTA collaboration : fostering international collaboration among biomedical engineers active in HTA, supporting students and early career researchers' mobility by providing funds to set new collaborations and organizing writing sessions to apply for future grants on collaborative actions on HTA; (5) Support HTA strategic communication : aiming at reinforcing HTA related communication and exchange of experience and knowledge with other scientific societies, agencies and policy makers; (6) Preparing guidelines and recommendations : promoting studies in HTA areas of particular interest for biomedical engineers, including early HTA (pre-market HTA studies) and HTA for medical devices, to develop IFMBE guidelines for MDs assessment; (7) Fostering capacity building in LMICs : HTA-related capacity building in the LMICs (focusing on Africa in the first 3 years); (8) Continuous monitoring on biomedical engineering in HTA : a survey to monitor BME involvement in HTA; (9) Establishing and promoting IFMBE HTA Awards aiming at recognizing emerging BME talents in HTA, policy actions promoting BME involvement in HTA and individuals providing outstanding contribution to the promotion of biomedical engineering and (10) Supporting the WHO in the area of HTA of MDs by providing BME knowledge Each project was coordinated by a division elected or co-opted member together with a team of collaborators. Many projects were run in strict collaboration with ongoing projects led by partner institutions, in order to avoid duplications and maximise communication and impact.

Ethical approvals
When required, ethical approvals where sought at the home institutions of project coordinators.

HTA summer schools for Biomedical Engineers
The first IFMBE HTAD Summer School was held in the UK, at the Warwick University in September 2015. The course was structured in three days. The first day an introduction to underlying concepts of HTA was offered, or ganised in three topics: evidence generation in medicine; systematic literature review; fundamentals of health economics. The second day was dedicated to the HTA of MD, introducing the main difference between medical devices and other healthcare technologies, and presenting methodological implications and existing tools, which could be used to assess medical devices. The third and last day was focused on two relevant topics for biomedical engineers: early stage HTA and Multi-Criteria Decision Making (MCDA) for HTA. Each day was organised in two sessions: frontal lectures were held in the morning, while the afternoon was open for practical group work facilitated by lecturers and tutors. Lectures were given from professors coming from seven countries: Croatia, Italy, Luxemburg, The Netherlands, Spain, UK and USA. The second Summer School was held at the University of Patras, Greece, in September 2107, following the same structure of the first edition ( Fig. 1 ).
Further details and the detailed programs are published on the IFMBE HTAD website [17] .

HTA training material
This project aimed at developing HTA training material, specifically designed considering the needs of biomedical engineers. A quick survey run in 2015 revealed that many biomedical engineers struggled using training material that was conceived for other scholars. The survey has identified five main aspects perceived as gaps: limited use of equations and schematic workflows; poor attention and limited examples on MDs; widespread use of verbose paragraphs; lack of attention to pre-market HTA, which is topic of great interest for many BME scholars; little or no attention to methods and tools (e.g., MCDA) to assist decision-making in healthcare.
All the lecturers participating to the IFMBE HTAD Summer Schools, agreed to create and share handouts specifically meant for an engineering audience. In addition, all the lectures given during those two summer schools where videotaped and became eLearning objects.
A gap-analysis revealed which essential HTA topics were missing from the two summer schools. IFMBE HTAD elected, co-opted and collaborator members volunteered to videotape lectures or keynotes given to IFMBE conferences to complete the missing subjects. This resulted in a significant production of novel HTA training material specifically designed for BME. Part of this material is freely accessible via the IFMBE HTAD eLearning platform, while the handouts are under review for publication on an upcoming openbook.

eLearning platform
The HTA didactic material produces is freely available on the IFMBE HTA eLearning platform, accessible via the IFMBE HTAD website [17] . It contains more than 30 h of HTA lectures organised in nine sections each composed by a variable number of presentations: (1) Introduction to HTA: this section contains basic and advanced lectures to fundamental topics of HTA and health economics: Launched in September 2016, the eLearning platform has had a significant and fast-growing number of users, from the entire world ( Fig. 2 ), 76 different users from 14 countries in August 2017,

HTA collaborative
The HTAD has supported several face-to-face meetings, often held during IFMBE conferences in order to facilitate experts' participation, given their busy agenda.
In order to prepare the IFMBE recommendation on the HTA of MDs, two focus groups were organised ( Fig. 3 ): 15 IFMBE HTAD members and collaborators were invited for a 2-day structured focus group convened in 2016 November 26th and 27th, at the School of Engineering at the University of Warwick; the second focus group was convened in Tampere, Finland, in June 16th, 2017.

HTA strategic communication
This project was conceived for fostering HTA-related communication and exchange of experience and knowledge among the BME community as represented by the IFMBE and other scientific societies, agencies and policy makers. This project, as many others, was run in strict collaboration with other IFMBE Divisions and working groups, IFMBE affiliated societies, IFMBE HTAD collaborators and partner institutions. This activity was focused on three main actions: • Collecting evidence to support the ongoing discussion among the IFMBE, WHO, UN ILO (United Nation International Labour Organisation) and the European Parliament for stronger recognition of BME as a profession. • Establishing stable collaboration among the European biomedical engineering community and the European Parliament, aiming at mutual informing on political and other initiatives regarding medical devices regulation, management and assessment and fostering the ongoing discussion among relevant European and African institutions with the purpose of promoting the harmonisation of directives and regulations on medical devices, medical facilities and healthcare professionals. Regarding the stronger recognition of BME as a profession, the IFMBE has had an intensive discussion with the WHO aiming at ensuring that this profession will be listed in the next edition of the ILO International Standard Classification of Occupation (ISCO). The ILO global repository of occupations is recognised by UN member states, and consequently transferred to nationally regulations. The current version of this classification is the ISCO-08, which was adopted through a resolution of a Tripartite Meeting of Experts on Labour Statistics held in December 2007 and subsequently endorsed by the Governing Body of the ILO in March 2008. According to ISCO, BME is listed in the category 2149 ' Engineering professionals not elsewhere recognised' . That BME is not yet classified in the classification of occupations as an independent occupation has hindered its recognition at several national levels generating lack of harmonised regulations (e.g., no harmonised professional requirements for pursuing this profession in public hospitals in Europe). In order to appreciate this difference, readers could compare the difference levels of professional recognition and regulation of BME and medical physics in different European countries.
One of the reasons for ILO not considering BME in the ISCO-08 classification in 2008 was the lack of worldwide evidence on the number of biomedical engineers employed as either engineering or medical professionals. In fact, the ILO policy is to consider for the ISCO classification a new occupation, if and only if, there is evidence that more than 10 0,0 0 0 professionals are employed. In order to meet the ILO requirement, the chairs of the IFMBE HTAD and Clinical Engineering Division met in Brazil with WHO representatives for MDs in September 2017 and designed a survey aiming at acquire the number of biomedical engineers employed in the profession worldwide. This survey was structured ( Fig. 4 ) with the goal of optimizing the number of inquiries and maximize the collection of evidence supporting the numbers of employed biomedical engineers. The survey was then administered by WHO [19] , which published the results in October 2018 [20] , giving evidence of more than one million of biomedical engineers and biomedical technicians employed in 79 different countries.
At the European level, the IFMBE HTAD worked in strict collaboration with the EAMBES (European scientific society of biomedical engineers) aiming at supporting the European institutions by providing technical support for policy initiatives regarding medical devices, medical facilities and related human resources. This collaboration was also functional to foster the promotion and stronger recognition of BME as an independent occupation in Europe and to establish the European Community of BME as valuable stakeholder for the development and revision of future European Regulations on medical devices. Since 2014, this activity resulted in significant achievements.
In April 2015, the IFMBE Division and the EAMBES supported the European Economic and Social Committee (EESC) report on BME in publishing the first European report on BME social and economic impact [12] . This was actually a significant milestone, which first stated in the official Journal of the European Union the importance of biomedical engineers and the great economic and social impact BME is having in Europe. Moreover, this publication facilitated further contacts with the European Parliament and the European Commission.
Following the EESC publication, the IFMBE HTAD supported the preparation of two parliamentary questions tabled by two Italian Members of the European Parliament (MEPs), Ms Lara Comi and Mr Nicola Caputo, in July 2015. The former, asking the Commission to explain why unlike the USA, the EU research and innovation program Horizon 2020 does not have a dedicated space for supporting BME research [21] , obtained a written answer from the Commission in October 2015 [22] . The latter, asking the Commission to explain why BME is not listed among the professions that are officially classified by the European Commission [23] , obtained a written response from the Commission in December 2015 [24] . Those two parliamentary questions raised significant attention around BME needs in Europe, resulting in the launch of the first Euro Parliament Interest Group on Biomedical Engineering (EPIG on BME) , on 31st of May 2016 ( Fig. 5 ). The EPIG on BME aimed at working with the European Commission for support the recognition of BME in Europe and focusing on 4 strategic goals: • ensuring that BME will be classified in the next revision of the European Commission Professional Qualifications Directive; • recognizing BME scientific organisations as official stakeholders in the Medical Devices Coordination Groups, which is the group responsible for medical devices legislation revision in Europe; • recognizing BME as an independent research area, creating independent panels in forthcoming funding European funding schemes and • fostering collaboration among relevant European and African institutions aiming at harmonizing regulations on medical devices, medical facilities and relevant human resources.
Since its launch, the EPIG on BME got outstanding support from 8 MEPs elected in five EU member countries: Nicola Caputo (Italy), Lara Comi (EPP, Italy), Jens Gieseke (Germany), Neena Gill (UK), Lojze Peterle (Slovenia), Marijana Petir (Croatia), Davor Škrlec (Croatia) and Cécile Kyenge (Italy). The EPIG on BME worked intensively on those four points, achieving significant results presented in the last EPIG on BME meeting held in October 2018. Among others, one of the most impressive was the introduction of the BME profession in the European Skills, Competences and Occupation (ESCO) database, which is an equivalent of the UN ILO ISCO, and, likewise, was not yet listing BME as an independent occupation since 2016 [25] .
While this manuscript is being written, a new EU legislature has been elected and has been officially in place for 2 months. Linking the newly-elected MEPs with the BME community has started aiming at giving continuity to this very positive experience.
Regarding BME in LMICs, in collaboration with WHO, the IFMBE has also been proactively involved in fostering BME in Africa, creating the first IFMBE African BME working group, which was launched in the Africa Union Headquarters in January 2018 ( Fig. 6 ) [26] . HTA has been one of the core topics for this African working group since its launch.

Guidelines and recommendations
As the first important topic, the HTAD members decided to focus on HTA of MDs. It is quite well known that differences among MDs and other healthcare technologies are substantial, and using the same methods to assess different healthcare technologies may lead to misleading conclusions. Starting from the table proposed in [7] , the HTAD working group performed a systematic analysis on which key element of MDs lifecycle should be considered in a HTA studyand on how MDs interact with medical facilities and how this interaction may hinder HTA conclusions. In order to achieve consensus on those elements and their importance, an electronic Delphi study was lunched, involving 32 experts from 17 countries, 25% of which were experienced clinical engineers and 70% HTA experts. A grey literature review was performed, aiming at exploring how existing guidelines on HTA of MDs consider those factors. As a result [27] , nine recommendations where given, with the purpose of improving the assessment of MDs: (1) Ensure that all reasonable maintenance, installation, and ongoing facility costs are incorporated in the economic evaluation, or explicitly state the hypothesis of the study conducted.
(2) Describe the maintenance and installation organisational model considered in the economic evaluation (e.g., internal clinical engineering service). (3) Understand and describe explicitly in the HTA report all possible maintenance, installation, and operational costs considered. (4) Obtain additional insights on the maintenance required, and capture maintenance impact during the HTA process by using appropriate methods of contextual inquiry.
(5) Use both pre-market and post-market data to capture impact of context of use variables (i.e., user, tasks, physical and social environment) on HTA outcomes. (6) Conduct a risk assessment by using appropriate and validated tools or standards. (7) Simulate and use appropriate statistical methods to analyse the different types of evidence on the effectiveness and safety of the medical device. (8) Conduct, when necessary, a simulation of use to empirically analyse safety in use and define procedures of risk reporting and processes to mitigate residual risks. (9) Conduct an analytic assessment to estimate "what if" the minimum requirements are not met.

Capacity building in LMICs
The HTA Division members focused on supporting existing collaborations with the aim of: (1) performing scoping exercise for better understanding the real needs of Africa in terms of BME and clinical engineering; (2) ensuring that ongoing initiatives properly consider HTArelated topics.
Over 24 months, the division supported (co-sponsored) five field studies in SSA countries (Benin, Ethiopia and South Africa) and established proactive collaboration with the IFMBE African Working Group on BME. In addition, the division facilitated focus groups and electronic surveys involving world-leading scholars with experience of HTA, clinical engineering, medical device and medical settings. As a result, the division produced a series of evidence-based data, which demonstrated for the first time that the majority of researches on MDs in Africa are focused on economic and competence constrains. Conversely, very little attention has been given to how medical devices interact with the settings in which those are operationalised. This is mainly due to the fact that, although the majority of global population is still diagnosed and treated in low-sources settings, more than 90% of MD market is in high-income countries, namely in Europe, USA and Japan [28] . Thus, MDs are designed giving for granted that their installation and maintenance will be performed according to high-income medical facility standards. Therefore, MDs are not resilient to lowincome medical settings. Accordingly, the division planned a series of training events aiming at informing African biomedical engineers on the international standards given as granted from MD designers with the purpose of increasing their capability to: • recondition MDs, making them more resilient to African working conditions (e.g., temperature, dust, humidity; nonspecialised users; • contribute to the definition of international standards on MDs; • be proactively involved in the design of medical devices and in use ICT to support MD maintenance [29] . The first two training events were piloted in Benin (May 2017 and January 2018) at the University of Abomey-Calavi. Two more events, namely summer schools, are planned for 2019 and 2020 in Uganda and Benin, respectively.

Continuous monitoring on BME in HTA
The HTA Division runs several surveys and focus groups aiming at involving international scholars, globally promoting the division activities, informing on current projects and acquiring feedback for continuously improving their execution. Those surveys were strictly coordinated with the other priority projects and researches running in partner institutions. When required, ethical approvals were sought at the project coordinator ethical committee. Five major electronic surveys have been implemented since 2015: • BME recommendation for HTA of MDs [27] , • A survey aiming at identifying factors that may hinder MD safety and effectiveness in low-resource settings [3] , • A survey aiming at identifying the key priorities and finding consensus on the priority topics to be discussed with the European Parliament aiming at fostering the recognition of BME profession in Europe, • A survey aiming at acquiring the number of BME and clinical engineers worldwide and • A survey aiming at comparing the qualifications required to work as a clinical engineer in European public hospitals.
The results of these surveys have been published or submitted for publication elsewhere. Nonetheless, the overarching results achieved by this project was to highlight the importance of sociological methods in engineering, if necessary. Moreover, those surveys also emphasised the need for more evidence-based clinical engineering for building consensus and defining international standards regarding medical devices and medical locations.

IFMBE HTA awards
The HTA Division decided to recognize individuals and organisations that contributed to the promotion and support of BME in HTA. Two awards were delivered from June 2015 to June 2018.
The IFMBE HTAD Policy Award, awarded to policy makers that gave significant contribution to the recognition of BME, was granted to the Member of the European Parliament Nicola Caputo for his outstanding contribution to the recognition of BME profession and for establishing the first European Parliament Interest Group on Biomedical Engineering (EPIG BME) in the European Parliament.
The IFMBE HTAD Award for Outstanding Contribution, awarded to recognize outstanding contributions to promote or consolidate BME involvement in HTA, was awarded to Edgardo Maria Iozia for authoring the EESC report on BME impact in EU (2015/C 291/07).

Reinforce the collaboration between IFMBE and WHO on HTA
IFMBE collaborates with the WHO in matters on biomedical engineering and medical devices. As a NGO in official relations with WHO, the IFMBE hosts a seat in the WHO General Assembly. The IFMBE has supported the producing several WHO reports and technical books, and has been actively involved in organisation of WHO international events on health technologies. Since 2012, the IFMBE Division has extended this collaboration to HTA related activities. For instance, the IFMBE members have been continuously involved in organisation of the WHO Global Fora on Medical Devices, by giving plenary speeches, organising workshops on HTA of medical devices and HTA in LMICs, chairing the tracks on HTA, organising joint events in collaboration with both, the WHO and the European Parliament [3] .

Conclusions
Medical devices are intrinsically dependent on the environment in which they are used. Consequently, HTA of medical devices is also intrinsically dependent on the environment where a medical device is required to work and this affects the generalisation of use of HTA reports across countries, in contrast with pharmaceuticals. HTA for medical devices should therefore find its own way and models of conductance to respond to the large and ever-expanding variety of technologies involved. Medical devices are becoming increasingly essential at all stages of healthcare delivery (i.e., prevention, diagnosis, treatment, rehabilitation, patient management, end of life). Therefore, HTA agencies in Europe and beyond are increasing their human resources experienced in MDs. WHO recommends employing experts of MDs such as biomedical engineers in HTA agencies.
The activities described in this manuscript had a significant impact among the biomedical engineering community and beyond, consolidating the concept that HTA is a core topic for biomedical engineering and that biomedical engineers are crucial actors of HTA, especially in regards to medical devices. A proxy for this change in BME culture is the number of papers, round tables, sessions and tracks dedicated to HTA to biomedical engineering events and conferences. For instance, reviewing the proceedings of the last four editions of the IUPESM World Congress on Medical Physics and Biomedical Engineering, held in the past 12 years respectively in Munch [30] , Beijing [31] , Toronto [32] and Prague [33] , the number of papers focusing on HTA has grown exponentially. All the IFMBE conferences organised in Europe since 2016, had at least a whole track dedicated to HTA. Simultaneously, other international societies focusing on HTA (e.g., HTAi, ISPOR, INAHTA) recognised biomedical engineers relevance to HTA and included BME speakers and topics to conferences they organizing, and a collaborative cross-societies working group has been established to foster global cooperation among those organisations and the WHO [34] . This is also having a direct impact on other biomedical and clinical engineering areas, which are paying unprecedented attention to HTA topics. This is certainly the case of recent studies advocating in favour of a more evidence-based approach to health technology management [35] and clinical engineering [36] .
Nonetheless, more training opportunities and learning material on HTA specifically addressing BME learning needs is clearly needed. The fact that the number of users of the IFMBE eLearning platform has been growing exponentially in the past 3 years is a significant proxy for this demand.
The collaboration with the European Parliament, the EESC and the WHO has been incredibly welcome, suggesting that there is a real need for biomedical engineers to provide valuable inputs to the policy-makers. Moreover, the collaboration with the WHO and the European Commission for fostering stronger recognition of BME profession has given tangible results beyond our initial expectation. The inclusion of BME in the ESCO has also been another important milestone in the journey of biomedical engineering, paving the way to more structural inclusion of biomedical engineers in the European initiatives (e.g., creating a BME panel in framework for excellence in research in Horizon Europe, consulting European BME scientific societies as stakeholder for forthcoming regulations on medical devices). Moreover, it is clear that more regulation is required in terms of who-can-do-what on MDs, in the best interest of patient safety and quality of life, especially now that healthcare services are becoming so dependent upon MDs.
In 2016, the WHO concluded that Biomedical Engineering professionals can be found in 129 of 194 Member States of WHO, based on the input from biomedical engineers proactively involved in national scientific BME societies and professional organisations [ 8 ]. In 2017, the Survey designed by the IFMBE in collaboration with WHO demonstrated that we can rely on one million of biomedical engineers and technicians employed in 79 countries worldwide.

Declaration of Competing Interest
The authors have no conflict of interest

Acknowledgement
The activities described in this paper have been supported by the IFMBE. LP acknowledge support received via the EPSRC IAA grant ( EP/R511808/1 ) titled Grant titled 'Health Technology Assessment (HTA) of Medical Devices (MDs) in low-and middle-income countries (LMIC)' and via the GCRF funded project titled 'Supporting the harmonisation of regulations on medical devices and medical locations among Sub-Saharan African regions and Europe'.

Ethical approval
Not required.