The Johner Institute Consulting Team

We ourselves are people who, from the heart, are passionate about developing medical software and have years of experience in this field. We have participated in countless audits, as auditees as well as a companion for companies. With us, you can discuss the latest technologies and software architecture as well as the automation of your test process.

We have a very good understanding of medicine and medical terminology. We are experts in this area because we mainly operate in the healthcare industry and it is so to say, our main focus. With this specific knowledge, we can also carry out risk analyses and provide the interface for clinical testing.


Christian Johner PhD

Diploma in Physics

The physicist graduate, Christian Johner, is the founder and owner of the Johner Institute for Healthcare IT. He is an internationally renowned expert for medical software. As a professor in several universities, his lectures are in the field of software architecture, software engineering, software quality assurance and medical computer science. His consulting focus is in the lean implementation and implementation of quality management systems, processes and tools.

Find out more on the profile page of Christian Johner.

Immanuel Bader

M.Sc. Information Technologies in Healthcare

Immanuel Bader is Chief Executive Officer of the Johner Institute North America Inc. 


Annett Arndt

Diploma in Information Technology Business Administration

Being a long-standing consultant and managing director of companies in the field of software applications, Mrs. Arndt knows what is important in the design and adaption of processes. Her expertise in setting up quality management systems and creating technical documentation is based on the introduction of an innovative medical device which she led as the responsible quality manager. At Johner Institute, Mrs. Arndt focuses on technical documentation of medical software and health software.

Claudia Schmitt

Diploma in Engineering

At the Johner Institute, Claudia Schmitt supports and advises our customers in the field of standard-compliant software development according to IEC 62304, the establishment of quality management systems according to ISO 13485.

As a medical informatics engineer, she has been involved in the development and approval of medical devices for more than 15 years. With her experience as a quality management representative, she can empathize and understand where the problems exist and may arise. With much pleasure and her relevant experience in ISO 9001, ISO 13485, IEC 62304, she would like to support companies to realize their idea and vision.

Astrid Schulze

Diploma in Economics

As a Dipl. economist and labor economist, Astrid Schulze keeps an overview before delving into details of the regulations on the approval of active medical devices in Europe and North America. For more than two decades, she has successfully advised companies on quality management according to 13485 and on the market launch of their medical devices and software in her own company. Astrid Schulze supports the regional presence of Johner Institute in the Berlin-Brandenburg area in terms of quality management and technical documentation.

Robert Dick-Hambeck

Diploma in Precision Mechanics and Microtechnology

Robert Dick-Hambeck has been intensively involved in the development and market approval of medical devices for more than 15 years. As a graduate engineer for precision engineering, he has worked for manufacturers for 10 years and as a consultant for 8 years. Therefore, his knowledge of international regulations, especially MDD/MDR, 21 CFR, and the "Guidance" documents, as well as the relevant standards, such as IEC62304, IEC62366, ISO13485, ISO14971, IEC60601, is accordingly deep. He supports the Institut as a generalist with the set-up of complete QM systems, the improvement of processes, the definition of product definition and approval strategies, as well as the creation of technical documentation. He is an expert for modular damage and IT security risk management.

Claudia Volk

M.Sc. Agriculture, Food Science and Business

Claudia Volk aims several years of experience as a Quality and Regulatory Affairs Manager in regulated industries. She started in the field of food production and then worked as Quality Management Representative for an IVD manufacturer. In that role she established, developed and audited Quality Management Systems and also implemented digital Quality Management tools. Working now at Johner Institute, she is helping our customers with setting up and improving their Quality Management Systems.

Christian Rosenzweig

Diploma in Biomedical Engineering

As an engineer specializing in biomedical engineering, Christian Rosenzweig started his professional career in basic development of complex active medical devices. He has then worked for more than 10 years in software development for medical devices. His daily work with regulatory requirements finally led him to quality management. In this field, he gained international experience as a quality management officer under ISO 13485 in a large corporation. He supports the consulting team at the Johner Institute.

Daniel Reinsch

Diploma in Electrical Engineering

As an electrical engineer, Daniel Reinsch spent many years as a software developer and software sub-project manager developing safety-critical software for medical devices and writing the technical documentation for it. At the Johner Institut location Berlin he supports customers regarding the technical documentation of medical device software (IEC 62304, ISO 13485, ISO 14971). His goal is to ensure that the compilation of the technical documentation does not become an obstacle in the development of safety-critical software, but rather serves as a support.

Dirk Bethäußer

M.A. Health Management

After finishing his studies, Dirk Bethäußer worked for many different medical device manufacturers in the field of quality management. In doing so, he has built up QM systems, maintained and continually refined them. He supports the customers of the Johner Institut with the setup, implementation, and maintenance of QM systems. In addition, he supports the customers with the certification according to the EN ISO 13485. Before his work at the Johner Institut, he has already audited QM systems.

Sven Wittorf

M.Sc. Information Technologies in Healthcare

Sven Wittorf has been part of the Johner Institute since 2006 and started as a consultant on software development processes. His passion is the question of how regulatory requirements can be mapped in coherent data concepts in order to make the processes on the part of manufacturers and notified bodies more efficient on the one hand and to increase the quality of the documentation and thus also of the products on the other.
After founding the sister company Medsoto together with Christian Johner in 2012, he is now devoting himself to this issue as part of the research group at the institute.

Alexander Wassel

M.Sc. Information Technologies in Healthcare

After graduating with his bachelor degree in 2017, Alexander Wassel got in touch with the Johner Institute for the first time. He then decided to participate in the master program 'IT in healthcare'. In addition to his studies, Alexander also worked as a software developer focused on web applications and cloud infrastructures. Alexander supports our clients with all questions regarding medical software. Besides being a software expert, Alexander is also playing handball sucessfully in Austria's National Handball League for more than ten years.

Maria Keller

M.Eng. Print and Media Technology

Maria Keller supports our customers in quality management out of our Berlin office. In particular, her focus lies on developing and improving QM systems, including the integration of digital tools to manage the entire QM and development documentation.
Prior to joining Johner Institute, she was quality manager at a start-up in the field of active implants. There, she was responsible for the QMS certification pursuant to
ISO 13485.

Markus Gerhart

M.Sc. Computer Science

Markus Gerhart has been supporting the Johner Institut since almost the beginning. As one of the first employees, he was and is allowed to help to design the processes and values of the Johner Institut. He supports the customers of the Johner Institut in the field of consulting and is especially responsible for the management of the Consulting Circle as well as for consulting with the focus on strategy development, medical device software, risk management and quality management systems.

Dr. Marc Paul

Dipl. Computer Science

Marc Paul is a computer scientist and worked on the topic of system-supported integration of UE into the SE process during his doctorate. Afterwards, he was responsible for the standard-compliant development and approval of products at an international IVD manufacturer. He then worked as QMB and head of QM and RA at a medium-sized medical device manufacturer. At the Johner Institute, he is currently leading the IT project "Digital Approval Platform".

Sarah Gruber

Diploma in Biotechnology

Sarah Gruber is an engineer for biotechnology and works in the area of product safety. As an expert in chemical characterization and biocompatibility, she supports our customers with her experience on necessary tests from development to approval of medical devices.

Dr. Sandra Brecht

Dipl.-Ing. Mechanical Engineering

Sandra Brecht enjoys supporting our clients in establishing, maintaining and continuously improving viable and efficient quality management systems for the benefit of the company and its employees.

Before joining the Johner Institute, she was a quality management representative for a quality management system certified according to EN ISO 13485 and ISO 9001 at the Technical University of Munich for several years.

There she not only advanced quality management with joy and commitment, but also developed medical devices for minimally invasive surgery herself.

Alexander Thern

Diploma in Physics

With Alexander Thern, the institute has been able to win a lead auditor for the Quality Management Standard ISO 13485. He shares the common vision of lean quality systems that contribute to real improvement in quality and more cost-effective development and production. Alexander Thern looks back on many years of consulting and audit practice.

Alexander Thern holds the seminars for the Johner Institute: "PRRC Person responsible for regulatory compliance", “Medical device consultant” and "Internal Auditor", as well as a two day seminar on ISO 13485 on request. Alexander Thern has lived in England and speaks fluent English. All Seminars are available in English as inhouse Seminars. Alexander Thern is a freelancer of the Johner Institute.

Team Auditgarant

Matthias Weiss

B.Sc. Health Informatics

Matthias Weiss already supported the Johner Institute during his studies of health informatics. Since successfully completing his studies, he has been an integral part of the Auditgarant team. He supports the team as Technical Product Owner in the technical development of the Auditgarant and in customer support. He enjoys developing solutions for complex topics in order to make the Auditgarant even more intuitive and user-friendly. Exact project planning and quality assurance as well as precisely specified requirements are particularly important to him.

Benedikt Tölle

M.Sc. Biomedical Engineering

Benedikt Tölle is a medical physicist with a master's degree in Biomedical Engineering and has programmed software in a medical context during his studies. Before joining the Johner Institute, he was part of two MedTech start-ups (Active Implantable and SaMD), where he was responsible for establishing a QM system according to ISO 13485 and supervising product development from a regulatory perspective.

Mr. Tölle supports our customers in setting up QM systems, implementing risk management, and creating technical files.

Sebastian Lettau

M.Sc. Computer Science

Sebastian Lettau first completed his degree in business informatics in Konstanz and then continued with his master in computer science. Already during his master thesis, he designed a software to support the post-market surveillance of medical devices.

He supports our customers in developing standards-compliant medical devices, laying his focus on medical software. He creates, improves and checks software files as well as the general technical documentation and helps to set up ISO 13485-compliant QM systems.

Team Sales

Florian Wettlaufer

Dipl. Logistics

As a logistics graduate with a focus on business administration, Florian Wettlaufer has gained extensive experience in the areas of sales, customer success management, and resource planning.
At the Institute, as an Account Executive, he is responsible for bringing our customers together with the right experts and solutions at all times so that they can achieve their respective goals quickly and reliably.

Johannes Luz

Restaurant professional

Johannes Luz has been with us at the Johner Institute since 2021. For his dual studies in the field of digital health management, the Institute is his partner. partner at his side. With his high striving for quality and willingness to communicate, he now supports the Johner Institute in the area of marketing and sales. Previously, he worked as a sommelier and restaurant manager in the upscale gastronomy.

Martin Uiffinger

B.A. Business Administration/ Service Management

Martin Uiffinger holds a degree in business administration and has gained various audit and compliance experience in renowned consulting and financial services companies. He has also built up a B2B sales company with over 1,800 customers.
At the institute, he leads the sales team and is responsible for ensuring that every interested party gets clarity as quickly as possible as to whether and how we can help with a suitable solution.

Marcel Heimerl

Banking specialist

Marcel Heimerl learned the trade of a customer service with solutions in need of explanation in his bank training.
As an Account Executive, Marcel Heimerl accompanies our customers through the institute from the idea of a medical product to its implementation. Here he takes care of linking projects with the right experts, developing solutions and being there for our customers as a constant contact person.

Team Marketing

Dr. Anja Segschneider

M.A. Media Science

Dr. Anja Segschneider holds degrees in law and media studies and earned her doctorate in genetic engineering law. She has worked in the media for more than ten years and has reported on science issues throughout the EU.

Daniel Weidler

Bachelor of Arts

"Good communication design uses rule-based design while incorporating contemporary conventions. Very good communication design occasionally breaks out of this to create surprising, inspiring experiences."

Team IVD

Andreas Kalchschmid-Lehmann

M.Sc. Stem Cells and Regeneration

Andreas Kalchschmid-Lehmann is an expert in in vitro diagnostics with more than 17 years of practical experience in molecular diagnostics. He is the author of the book "ISO 13485 – Obstacle or Opprotunity", and has relevant experience in other QM systems, including ISO 17025, ISO 15189, and MDSAP. As a laboratory manager, he gained detailed knowledge of processes in a routine diagnostic laboratory, and as a former quality manager he knows how to successfully set up and live a QMS for IVDs. He worked as a product specialist and lead auditor at a large notified body, where he assessed IVD technical documentations and QM systems.

Dr. Catharina Bertram

Diploma in Biochemistry

Catharina Bertram supports Johner Institute’s customers in placing their in vitro diagnostic (IVD) medical devices on the market. She is an expert in the performance evaluation of IVD medical devices. Catharina contributes to the product-specific preparation of our customers‘ technical documentation and advises on strategic issues focusing on IVD assays and IVD software, particularly AI-based software. With a Ph.D. in biochemistry, she gained years of industry experience and now transfers her expertise to practical concepts for implementing regulatory requirements. As branch and laboratory manager of a pharmaceutical start-up, she contributed to all QM-related processes. Furthermore, she was involved in the development of various in vitro diagnostic products.

Katrin Schnetter


Katrin Schnetter is our expert for IVD software. She has more than 15 years of experience in the introduction and certification of QM systems according to EN ISO 13485 and in the implementation of software development processes in a regulated environment. Ms. Schnetter supports our customers with the introduction of standards-compliant processes according to IEC 62304, IEC 62366 and ISO 14971. She assists our customers with the approval of the IVD software and guides you safely through the audits.

Dr. Sebastian Grömminger

Diploma in Biology 

Sebastian Groemminger is molecular biologist and expert in the field of molecular genetic in-vitro diagnostics. At Johner Institute, he supports clients in the certification, development and maintenance of QM systems according to EN ISO 13485, as well as in the implementation of the standards EN 62304 and EN ISO 14971, and the approval of in-vitro diagnostics.

Following his doctorate in the field of virus-associated tumor development at the Helmholtz Centre in Munich, he played a decisive role in the development, practical implementation, approval, and performance evaluation of non-invasive prenatal examination methods. With his experience in development and diagnostic routine, he has taken over Quality Management and Regulatory Affairs. 

Dr. Sophie Bartsch

Diploma in Biology

Sophie Bartsch holds a doctorate in biology and has extensive knowledge and several years of experience in routine molecular diagnostics. During her time at an accredited laboratory, she additionally established NGS-based workflows. Prior to joining the Johner Institute, she was responsible for the development of a molecular biological assay as laboratory manager. Thereby, she worked in close cooperation with bioinformaticians for the identification of new biomarker candidates via machine learning models. Sophie Bartsch holds a doctorate in biology and has extensive knowledge and several years of experience in routine molecular diagnostics. During her time at an accredited laboratory, she additionally established NGS-based workflows. Prior to joining the Johner Institute, she was responsible for the development of a molecular biological assay as laboratory manager.

Ulrich Hafen

Diploma in Biology

Ulrich Hafen is our specialist on regulatory requirements for medical laboratories. He assists manufacturers of in-house IVDs in complying with the IVDR requirements. He also supports IVD users and manufacturers in establishing and maintaining QM systems according to ISO 15189, Rili-BÄK Part A as well as ISO 13485 and is also a certified QMR and supplier auditor.

After studying biology in Constance and Innsbruck, Ulrich conducted research on the development of Parkinson's disease at Helmholtz Zentrum München. He then worked as a quality manager in an in-vitro diagnostics start-up and in a mid-size medical technology company.

Janos Hackenbeck

M.Eng. medical physics

Janos Hackenbeck studied medical physics. With many years of experience in software quality assurance and in setting up software projects under IEC 62304 and ISO 13485, he is an expert in the development of medical device software.

Based in Berlin, he supports clients of the Johner Institute with a focus on the compliant development of software in the field of IVD medical devices.

His incentive lies in the implementation of regulatory requirements in efficient and lived development processes in order to remove hurdles in the realisation of innovative medical devices with compliant and at the same time lean documentation.

Dr. Juliane Havlicek

M.Sc. Pharmaceutical Biotechnology

Dr. Juliane Havlicek is a biotechnologist and gained years of industry experience as a team leader. She was involved in the development of various in vitro diagnostic tests (IVDs). Her focus was on the implementation of regulatory requirements for their approval. She supports Johner Institute's clients regarding the performance evaluation of their IVDs.

Dr. Tina Priewasser

Dipl. Ing. (FH) Software Engineering - Bioinformatics

Tina Priewasser holds a PhD in Bioinformatics and did postdoctoral research on the simulation of sequence evolution. Afterwards, Tina gained more than 8 years of experience in a biotech start up, which later became an international diagnostics company in the field of liquid biopsy for cancer diagnosis. She was responsible for the evaluation of data from different analytical methods like PCR or NGS and a standard compliant software development of IVDs. At the Johner Institute, Tina supports clients in the technical documentation of software as a medical device or as part of an IVD.

Team Clinical Affairs

Dr. Bettina Martin

M.Sc. Molecular Biology

Dr. Gisela Knopf

General practitioner

Lea Wettlaufer

M.Sc. Biology

Dr. Martin is a Molecular Biologist and completed her PhD in the field of Neuroimmunology at the Max Planck Institute in Munich. During her studies, she worked as a scientist at the German Cancer Research Center and at the University of Brisbane in Australia. Since 2019, she is leading the Clinical Affairs Circle at the Johner Institute, helping medical device manufacturers plan and conduct clinical evaluations. She is focusing on the automation and digitization of clinical data. Dr. Martin was a patient herself and experienced the importance of medical devices firsthand. Since then, she has been passionate about Johner's vision to create and apply knowledge to bring safe, effective and affordable medical devices to market.

As a specialist in general medicine, Gisela Knopf is the medical advisor at the Johner Institute. With her broad medical expertise, which she owes to her many years of clinical and general practice experience in conservative as well as operative specialties, she ensures medical and clinical consistency of clinical evaluations and studies. In addition, she has many years of experience in study design, "Good Clinical Practice" and the associated regulatory and legal systems. Thus, she combines the demanding scientific and formal standards with the needs of practice, conducts training, and works constructively in the area of clinical evaluations and clinical trials.

Lea Wettlaufer is a molecular biologist. While writing her master’s dissertation, she worked in molecular oncology research with a focus on therapy resistance in lung cancer cells. She is a certified Clinical Research Associate. Prior to joining Johner Institute, she has worked in a CRO specializing in writing clinical evaluations. Therefore, her expertise lies within the field of clinical trials and clinical evaluation. At Johner Institute, she supports our customers in creating clinical evaluations according to MEDDEV 2.7/1 rev. 4.

Dr. Nadine Jurrmann

Diploma in Biology

Dr. Johannes Goldmann

Diploma in Biology

Dr. Hanna Lutz

M.Sc. Chemistry

Nadine Jurrmann holds a doctorate in biology and has been working for a medical device manufacturer for more than six years. There, she has been responsible for the preparation of clinical evaluations. Her tasks further included the planning, execution, and evaluation of PMCF studies on the newly developed medical devices. Thus, her expertise lies in post market surveillance and clinical evaluation. At the Johner Institute, she supports our customers in creating clinical evaluations compliant with MEDDEV 2.7/1 rev. 4.

Dr. Johannes Goldmann is a qualified biologist and holds a PhD in pharmaceutical biology/immunology. He worked for more than six years in stem cell research and in routine operations at the Institute for Transfusion Medicine and Immunohematology in Frankfurt am Main. There he was employed as a study coordinator for several clinical phase III studies in the field of "pathogen inactivation of blood preparations" and knows the challenges in the development of medical products from own experience. He gained additional experience in the sale of drugs for different indications during his six-year field work for a pharmaceutical company in Berlin. His focus is now on the clinical evaluation of medical devices according to MEDDEV 2.7/1 rev. 4, as well as in the assessment and analysis of PCMF data.

Hanna Lutz is a chemist and completed her PhD in the field of biophysical chemistry at the Georg-August-University Göttingen. During her four-year PhD, she intensively studied biochemical processes in the active actin cortex and their influence on the mechanical properties of cells. During this time, she gained a variety of experience and expertise in scientific working methods. At the Johner Institute, she supports our clients in the creation of MDR compliant clinical evaluation files and post market surveillance of differently classified medical devices.

Team Usability

Ann-Kathrin Dessel

M.Sc. Psychology

Christopher Seib

M.Eng. Chemische Technologie

Dr. Nils Becker

Diploma in Biology

Ann-Kathrin Dessel is passionate about the optimal and holistic interaction between humans and technology and is motivated to support the development of appropriate product solutions. In her master's degree in psychology, she specialized in human-machine interaction and completed this with her master's thesis - an explorative analysis of current user-centered design practice. At the Johner Institut she supports customers in planning and conducting usability tests and in creating usability documents according to IEC 62366.

Christopher Seib is an engineer for chemical technology with a special focus on instrumental analytics. After his studies, he acquired several years of experience in the areas of quality management according to ISO 13485 and regulatory affairs of both in-vitro diagnostics and implantable medical devices. He advises customers of the Johner Institute on all issues related to the international approval of medical devices and supports them in meeting this challenge.

Nils Becker is a Dipl. biologist. Conducting his doctorate, he researched the molecular mechanisms of neural plasticity. Prior to joining Johner Institute, he was involved in regulatory affairs, usability, and technology transfer.

At Johner Institute, he supports customers in the planning and execution of usability tests as well as in the creation of usability documents pursuant to IEC 62366.

Dr.-Ing. Philipp Schleer

M.Sc. Medical Engineering

Sophia Schwaeppe

M.Sc. Psychology

Wolfgang Schneider

Diploma in Psychology

Philipp Schleer studied mechanical engineering and focused on medical technology during his master's degree. In the course of his doctorate, he discovered his passion for human-machine interaction when he developed and evaluated assistance systems for robotic surgery from a usability perspective. At the Johner Institute he supports customers in the planning and implementation of usability tests, the introduction of usability processes and the documentation according to IEC 62366.

Sophia Schwaeppe is a psychologist and during her studies, she focused on human factors engineering. On behalf of the Fraunhofer Institute, she researched user requirements for the area of smart home development. At the Johner Institute, she supports customers in planning and conducting summative and formative evaluations. As well as in creating usability documents according to IEC 62366.

Wolfgang Schneider is a Dipl. psychologist and has been advising companies as a usability expert for over 20 years (heuristic evaluations based on standards, walkthroughs, usability tests, workplace observations, documentations).

He is involved in the responsible standardization committees of DIN/ISO (amongst others as editor of part ISO 9241-125 - visual representation of information) and the DKE (IEC 62366-1/-2). He worked as an author, e.g. for DGUV Information Softwareergonomie and the publisher Beuth. He supports Johner Institute in terms of usability.

Team International Regulatory Affairs

Luca Salvatore

M.Sc. Computer Science

Margret Seidenfaden

Diploma in Medical Engineering

Katharina Keutgen

B.Eng. Medical Technology

Luca Salvatore helps our customers both in writing the technical documentation and authorisation documents and in creating QMS. As an informatics professional, he was involved in university based medical products startup as software developer at the beginning and later on as quality manager.

Before joining Johner Institute, he has done QMS audits and is now engaged in a standard committee DKE 811.3.1 (Medical Software, responsible for IEC 62304, etc)

Margret Seidenfaden supports the Johner Institut customers regarding questions and challenges concerning international product approval. She studied medical technology and business administration and focused on quality management and regulatory affairs. In these areas ,she worked for two medical device manufacturers. Her passion, however, is dedicated to diverse regulatory issues surrounding medical devices and the manufacturers’ challenges in international product approval processes. Before joining the Johner Institut and among others, she was responsible for the planning, implementation, and monitoring of worldwide registrations.

After her graduation in Biomedical Engineering and her studies of Regulatory Affairs Management, Katharina Keutgen worked many years in the development and regulatory affairs management of heart-lung machines and vascular access devices. She gained comprehensive regulatory knowledge, supported development projects from idea to market release, compiled 510(k)s as well as Technical Documentations according to MDD and MDR for class III devices and was deeply involved in the actualization of the QM System for complying with the requirements of the MDR.
As a member of the International Regulatory Affairs Team, she supports customers in international approvals and questions concerning the regulatory strategy

Dr. Manuela Reinhold

Dpl. Human Biology

Manuela Reinhold studied human biology and supports the clients of the Johner Institute in all regulatory issues concerning medical devices as well as in the development of international approval strategies. After her time as a scientist, she initially worked in the development and regulatory affairs departments of various medical device manufacturers. She prepared technical documentation in accordance with MDD and MDR and supervised the approval for a wide variety of products in classes I to III. During this time, she gained extensive experience in setting up a quality management system in accordance with ISO 13485 and was intensively involved in the implementation of regulatory requirements.

Team Johner Institute Switzerland

Mario Klessascheck

Diploma in Electrical Engineering

Urs Müller

M.Sc. Computer Science

Mario Klessascheck is a Dipl. engineer and has been passionately "married" to the medical technology industry since his studies. His focus lies on medical systems engineering and the associated topic of functional safety. In this context, Mr. Klessascheck supports development teams with his technical and methodological knowledge in the practical implementation of the requirements of IEC 60601-1 and co. He likes to think outside the box and applies proven analog concepts such as ones from the field of mechanical engineering.

Based on his experience gained in numerous projects, Mr. Klessascheck has developed a powerful framework for medical systems engineering. This framework combines the aspects of people, technology, methods, and processes and enables teams to sustainably master regulatory and technical challenges.

Additionally, Mr. Klessascheck also teaches risk management in development at the Berne University of Applied Sciences. He is member of the association of Certified Professionals for Medical Software. 

Urs Müller works as a consultant in Johner's Swiss office and supports customers and projects in the areas of product development and development of production equipment for medical technology with a focus on verification, validation (CSV) and software development.

Since graduating in computer science, Urs has been moving in the service environment of software development, first as a test automator/tester and later as a team leader in an engineering company with focus on medical device development. Quality-driven development is in Urs' blood and he likes to share his enthusiasm for it with colleagues and customers.

Team Johner Institut New Zealand

Annett Arndt

IT business economist

After completing her studies in computer science, Annett Arndt gained extensive knowledge in the field of industrial software applications as a consultant and managing director of companies for many years. During her work as a quality and process manager, she was solely responsible for the introduction of an innovative medical product and therefore knows what is important in the development of regulatory strategies, the creation of technical documentation or the establishment of quality management systems. As Managing Director of Johner Institute New Zealand, Mrs. Arndt continues to focus on software as a medical device and supports customers in New Zealand and Australia.

Team Johner Medical

Dr. Dennis Hummel

Diploma in Biology

Due to his doctorate in Psychology and as a biologist with a focus on neuroscience, Dennis Hummel has always been interested in human behavior patterns. In numerous projects and activities in the areas of IT and business development, he gained in-depth knowledge in the architecture, operationalization and optimization of business processes. For Johner Medical, he supports customers in establishing regulation-compliant processes within the framework of quality management systems according to EN ISO 13485 in connection with the implementation of technical solutions for QM systems, technical documentation and post-market surveillance.

Dimitrios Kaloulis

M.Sc. Biomedical Engineering

Dimitrios Kaloulis, as a member of the Johner Medical team, supports customers in the preparation of technical documentation and the establishment of QM systems in accordance with MDR 2017/745 and ISO 13485. With a degree in Mechanical Engineering and an M.Sc. in Biomedical Engineering, as well as experience in industry and research, he has extensive expertise in supporting our customer projects.

Margarita Rozhdestvenskaya

Diploma economist

Margarita Rozhdestvenskaya has headed the EU representation of a non-European manufacturer of active medical devices for the last 8 years. On his behalf, she was the contact person for the authorities within the EU. It was her responsibility to check the completeness and conformity of the technical documentation as well as to fulfill the notification and reporting obligations. With her broad experience, she supports the customers of Johner Medical as a certified auditor for QM systems. More precisely in the legal marketing of medical devices in Europe according to ISO 13485, by taking on the role of the safety officer for medical devices or the responsible person and by writing and checking the technical documentation.

Pierre Jäger

M.Sc. Electrical Engineering

Since the beginning of his career in 2009, Pierre Jäger has been involved in the development of security-critical systems. As a system engineer and project quality manager, his main focus is the implementation of regulations and standards in development projects. For the past three years his core field is mainly product development in the area of medical technology, especially software development and verification compliant with IEC 62304, ISO 13485, ISO 14971.

In the Johner Institute, Pierre is responsible for our customers in the field of quality management and creating technical documentation

Stefanie Hasler

B.Sc. Sport Sciences/ Usability Engineer (cert.)

Stefanie Hasler has a degree in sports sciences. After graduating, she went to work for a young medical device manufacturer. There she was instrumental in the certification of the QMS according to ISO 13485. Stefanie developed an interest and from that a passion for the usable development of software and hardware for medical devices. She decided to take a part-time certificate course to become a usability engineer. Since then, she has strived to design simple and user-friendly medical devices that also meet all necessary regulatory requirements. At Johner Medical, she is involved in testing and further designing electronic QMS together with their users.

Andreas Kaffer

Diploma in Software Engineering

Andreas Kaffer studied software engineering and has many years of experience in software development. Before his time at Johner Medical, he worked for several years as an Agile Coach and Scrum Master and supported agile teams and companies in the introduction of Scrum and the establishment & optimization of agile processes and procedures.

At Johner Medical, he supports the establishment of regulation-compliant agile processes for the development of quality management systems as well as in the development of tool-chains and workflows for these QM systems.

Lisa Wittmayer

M.Sc. Medical Physics

Lisa Wittmayer supports the product management of the digital quality management system at Johner Medical. She studied biomedical engineering and medical physics and spent time abroad at the University of Melbourne and Harvard Medical School. After her studies, she initially worked as a research assistant and project manager at the University of Heidelberg. From research, she founded a medical technology startup in 2018 and took over as CEO before joining Johner Medical in March 2022.

Vanessa-Alexandra Vasile

B.Sc. Health Informatics

Vanessa Alexandra Vasile already supported the consulting team of the Johner Institute during her studies of health informatics at the HTWG in Konstanz. Since successfully completing her studies, she has become an integral part of the Johner Medical team. She supports the team as a consultant for electronic documentation systems and regulatory tasks in the medical device industry. With a lot of joy and enthusiasm she supports customers in the compliant approval of their medical devices. Above all, good and timely customer support is very close to her heart.

Dr. Bernhard Gerstenecker

Diploma in Biology

Bernhard Gerstenecker has a PhD in microbiology and has been involved in all aspects of IVD systems for his entire professional life. For about 25 years, he has developed immunochemical reagents and assays, set up and further developed QM systems and dealt with regulatory affairs requirements. Since 2010, he has been employed in the IVD device industry as Quality Manager and Regulatory Affairs Manager.

Bernhard Gerstenecker worked for the Johner Institute as a freelancer for many years and has been working for Johner Medical in a permanent position since December 2021.

Team Research

Dr. Angela Nickel

M.Sc. Biology

Dr. Heidi Seibold

M.Sc. Statistics

Dr. Irina Idler

Diploma in Biology

Angela Nickel holds a PhD in developmental biology and therefore has a very good understanding of molecular and morphological correlations. Prior to joining the Johner Institute, she was project manager for a support program assisting companies in the implementation of the MDR and IVDR. Driven by the desire to optimize the regulations for medical devices, she is a member of our research group Regulatory Science. Her aim is to collect evidence-based data and to derive concrete recommendations for legislators and other stakeholders.

Heidi Seibold is a biostatistician and developed machine learning methods for application in personalized medicine. After her PhD at the University of Zurich, she conducted research at LMU, Bielefeld University, and Helmholtz Zentrum München and led the Open AI in Health research group at Helmholtz AI from fall 2020. She is an advocate for open and reproducible science and received the "AI Newcomer of the Year 2021" award from the German Informatics Society for her work on Open Science in AI and Medicine. At the Johner Institute, she is driving advancements in teaching and research. This includes a podcast where she collects and discusses ideas for the future of teaching and research.

Irina Idler is a molecular biologist and didactician with experience as a clinical affairs manager. After her PhD on the development of a vaccine against malaria tropica, she worked for more than ten years at the German Cancer Research Center in the field of basic oncological research and precision medicine. There, she taught regulatory and ethical content at the graduate school. In addition, she has one year of basic didactic training at the teacher training seminar in Weingarten. As Clinical Affairs Manager she was responsible for the implementation of clinical studies for medical devices in an advisory capacity. Irina is course director for the Regulatory Affairs course and is responsible for the smooth running and high quality of the course content. She is particularly concerned with the best possible professional and personal development of the students.

Team Digital Post Market Services

Dr. Andrea Seeck

PhD in Medical Engineering

Katharina Knossalla

B.Eng. Biomedical Engineering

Franziska Reichel

M.Sc. Microbiology

Andrea Seeck holds a PhD in Medical Engineering and has many years of experience in the field of Clinical & Regulatory Affairs. Since April 2017, she has been a consultant at the Johner Institute and now heads the Digital Post-Market Services department. Together with her team, she advises customers of the institute on all questions and concerns related to post-market surveillance. She focuses on the efficient use of the latest technologies to design the process in a way that ensures the supply of safe and useful medical devices to the global healthcare system.

After completing her studies in biomedical engineering, Katharina Knossalla has already worked as a consultant for medical devices for three years. She has experience in technical documentation (MDR), clinical evaluations according to MEDDEV 2.7/1 and premarket notifications in the USA (510(k)). With her enthusiasm for digitalization/automation and her extensive knowledge in dealing with international databases, she now supports customers at Johner Institute in implementing post-market surveillance requirements.


Franziska Reichel, a microbiologist, worked in infection biology during her thesis. There, she explored the pathogen Staphylococcus aureus and new antibacterial substances. After completing her studies in Tübingen, she now supports the Johner Institute in the area of Regulatory and Post Market Radar.

Jasmin Schemberg

M.Sc. Medical Engineering

Colin Strasdat

M.Sc. Biological Sciences

Jasmin Schemberg completed her studies in medical engineering. During her thesis, she supported a manufacturer in the implementation of electronic instructions for use. Thereby, she discovered a passion for the regulation of medical devices. Since then, she has been supporting the Johner Institute in the Regulatory Radar.

Colin Strasdat graduated in biology with a focus on disease biology. After graduating from the University of Konstanz, he is now full of energy to support the Johner Institute in the area of post market radar. His goal is to provide efficient and precise support to our customers, thereby achieving a sustainable positive impact for them and their products.

Team Internal Services

Ana Lajn

Assistant tax consultant

Anna Ivanova

Financial accounting specialist

Sabine Wentworth-Paul

Dipl. Business Administration

As a specialist in financial accounting, Ana Lajn is an important contact person for the accounting department at the Johner Institute. Next to her work in accounts receivable for the Johner Institut, she is completing a degree in social work.

Anna Ivanova is as a specialist for financial accounting, the first point of contact for all accounting questions. As an integral and important part of the Internal Service Team, she is responsible for accounts receivable and dunning.

After graduating, she worked for almost 20 years in the field of tax consultancy and auditing as a team leader and most recently as Head of Finance and Accounting in a medium-sized international group. She is responsible for finance and accounting at the Johner Institute in Germany and for our foreign subsidiaries and ensures clarity in our Johner Institute's world of figures. She also enjoys optimising processes and is the contact person for tax and accounting issues.

Christiane Fischer

B.A. Communication Design

Daniela Reitmeier

Hotel manageress

Daria Salvatore


Our corporate design is her milieu. During and after her studies in media and communication design, Christiane Fischer gained experience at various agencies and publishing houses. Today she supports us in the design of all kinds of media that represent the institute internally and externally. From the website to seminar materials to business stationery and many other topics, she assists her colleagues in design and implementation.

Daniela Reitmeier supports Internal Services in ensuring that all administrative processes run smoothly. Another major task is the seminar administration, where she is in charge of the seminar administration. She plans and organizes the seminars at all Johner Institute locations and is responsible for the all-round support of our seminar participants in Constance.

Daria Salvatore is part of the Seminar Admin Team and takes care of the well-being of the seminar participants at our location in Frankfurt am Main. In addition, she supports Internal Service with accounts receivable and accounts payable.

Désirée Lüttich

M.Sc. Human Resource Management

Mareike Jäger

Hotel manageress

Nadine Kaffer

Event Manager

Désirée Lüttich holds master's degrees in sociology and human resource management. With the conviction that employees make up the success of every company, she is in charge of the HR department. With a great deal of passion and commitment, she ensures that we find new specialists quickly and accurately. In addition, she accompanies the induction of our new colleagues and enables our team to be ready for action quickly.

Mareike Jäger supports Internal Services in Frankfurt in Facility Management. Here she is the contact person and first point of contact for all matters relating to the Frankfurt office. She is responsible for the smooth running of the office and looks after the well-being of our employees and guests. She also supports the team in seminar administration.

Nadine Kaffer has been working as an event manager in the field of medical technology since 2008. In close collaboration with Prof. Dr. Christian Johner, she developed the innovative concept of the Medical Device Days in Berlin. In 2019, the Speed Consulting Conference took place for the first time and has since become an integral part of the Institute's annual continuing education and networking events. She is a regular employee at the Institute now since June 2021 and organizes the Institute Day in addition to the Medical Device Days Berlin. Another focus of her work is study course management.

Philipp Koppenhagen

M.Sc. Computer Science

Susanne Montau


Susanne Exler

Diploma in administration

Philipp Koppenhagen is a computer scientist specializing in business process and IT management. He has been overseeing Auditgarant since its early times and is therefore very familiar with anything concerning Auditgarant. For our customers, he creates technical documentation and supports them in setting up QM systems.

After 20 years of experience as a bank clerk at a large banking institution, Susanne Montau is very familiar with payment transactions. In the Internal Service Team, she keeps an eye on all incoming and outgoing payments and ensures that all invoices are paid on time.


With more than 20 years of experience in personnel selection and development, management diagnostics and test design, Susanne Exler is the contact person for all internal HR questions at the Johner Institute. She also supports our customers with the selection of new employees. Together with our specialists, she develops diagnostic procedures such as subject-specific aptitude tests and case studies, which allow us to determine the professional competence and personality traits of applicants.

Isabelle Pflug

B.A. International Business

Isabelle Pflug studied International Business with a focus on Human Resource Management and Francophone World. After two semester abroad in London and Martinique, she entered the world of human resources. At Johner Institut she accompanies the complete recruiting process and ensures our candidate care. She particularly enjoys getting in touch with different people and supporting applicants and colleagues.

Team Development and Infrastructure

Anastasiia Kuziuberdina

B.Sc. Applied Computer Science

Anastasiia Kuziuberdina studied Applied Computer Science at the University of Duisburg-Essen and brings many years of experience in software testing and test automation development from her time as a working student. With her eye for detail and her high quality orientation, she supports the software development & infrastructure team as a software tester in performing overall system / environment tests as well as designing test plans, test designs and test procedure specifications.

Bernd Huber

M.Sc. Computer Science

After his studies Bernd Huber worked for several years in the software industry on the development of online shops and online survey platforms. With his fascination and passion for web applications, he supports the Software Development & Infrastructure team in further developing existing software as well as developing new software solutions.

Julia Kaibach

B.Sc. Health Informatics

Julia Kaibach already supported the development team of the Johner Institute during her bachelor thesis. After successfully completing her studies in health informatics at the HTWG in Konstanz, she is a permanent member of the development team and takes care of the development of new tools and the maintenance of the website.

Maximilian Fletschinger

B.Sc. Business Informatics

Already during his studies, Maximilian Fletschinger supported the Software Development & Infrastructure Team of the Johner Institute.

After his graduation in Business Informatics with a focus on software and system development, he is now responsible for the development of new software solutions as well as the support of existing ones.

Perla Gjoka

M.Sc. Computer Science

Perla Gjoka studied Computer and Information Science at the University of Konstanz. Directly after completing her studies, she joined Johner-Institut. Perla already worked as a Software Developer during her Master Studies and gained the necessary experience needed to support our developing team. Her focus is the enhancement of existing Software and the development of new ones.

Philippe Renner

B.Sc. Business Informatics

As part of his bachelor's thesis, Philippe Renner worked with the Johner Institute to develop the concept of a digital tool for conducting clinical trials. Since graduating with a focus on software and systems development, he has been supporting the team in maintaining and expanding the IT infrastructure as well as developing new and existing software solutions.

Raphael Sterk

B.Sc. Business Informatics

Raphael Sterk worked during and after his studies in the software industry, including the development of online shops and the integration of systems in companies. With his enthusiasm and expertise in software development and the technology behind it, he supports the Software Development & Infrastructure team in the further development of existing software as well as the development of new software solutions.

Tino Weber

B.Eng. Industrial Engineering

During and after completing his bachelor's degree, Tino Weber worked on the native app development with a focus on real-time synchronization. With his distributed systems expertise and passion for web applications, he supports the the Software Development & Infrastructure team in the support and further development of existing existing as well as the development of new digital products of the Johner Institute.


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