Our Team

The core Human Factors MD team consists of:


Tim Reeves, PhD CHFP 

Tim is the Managing Director of Human Factors MD and founded the company in early 2001. He has twenty years of commercial experience evaluating and designing usable, effective, and safe medical devices. He is a Certified Human Factors Professional, and a member of the AAMI’s Human Factors Committee. He has been an invited speaker at several professional meetings, including the AAMI/FDA sponsored Human Factors and Patient Safety for Medical Devices and the first IBC’s conference on Human Factors and Combination Products. Tim is also a member of the teaching faculty for the AAMI’s popular Human Factors for Medical Device Design course. Tim has a PhD in cognitive psychology and human factors from the University of Toronto.


Christina Mendat, PhD

Christina is a Partner and the Senior Technical Director. She has conducted numerous formative and summative studies, and led clients successfully through regulatory approval process. For Human Factors MD, Christina provides technical oversight to our HF team and is an expert at translating research findings such as user needs, requirements, product strengths and weaknesses into compelling design directions and solutions. She brings over a decade of experience in human factors having spent more than 5000 hours in surgical suites, medical device usability studies, and outpatient facilities. She has presented papers to the Human Factors and Ergonomics Society and the American Psychology Society and has been providing multiple workshops and lectures on navigating the latest standard, HE75, and human factors integration in quality management systems to groups including PDA (Parenteral Drug Association), ISPE (International Society for Pharmaceutical Engineering), and ASQ (American Society for Quality). Christina has a PhD in experimental psychology and ergonomics from North Carolina State University.


Eric Shaver, PhD

Eric is the Director of Human Factors.  In this role, he contributes technically to all human factors activities throughout the product development life cycle.  This includes participating in ideation sessions, understanding users needs, creating design requirements, providing input on early prototypes, developing device labeling, leading formative and summative usability studies, and conducting expert reviews. Prior to joining Human Factors MD, Eric was the Human Factors Lead at FUJIFILM SonoSite where he oversaw all human factors efforts across five product lines.  He has also worked as a consultant to a variety of industries where he specialized in the design and evaluation of safety information, organizational behavior, and training development and presentation on safety and human factors-related topics.  Eric holds a PhD in Ergonomics Psychology from North Carolina State University and is a full member of the Human Factors and Ergonomics Society (HFES).


Johanna Schoss, PhD

Johanna is a Senior Consultant.  Johanna has over 20 years of experience working in experience design and has focused the last five years on medical devices and products, including combination products, biologics, generic equivalents for in-home and clinical use. Her passions are contextual inquiry and workflow analysis. Johanna holds a doctorate in anthropology from the University of Chicago.


Vince Velocci, MSc

Vince is the Director of User Experience.  Trained in Pharmacology, Physiology, Biomedical and Electrical Engineering at the University of Toronto, Vince has spent most of his 30-year professional career designing and evaluating medical software and devices.


Heather Colbert, BASc, PEeg, CHFP

Heather is a Senior Consultant. She is also a licensed Professional Engineer and Certified Human Factors Professional. She has applied her human factors expertise to a wide variety of medical projects, including formative and summative studies.


Liz Mauer

Liz is a Senior Consultant. She has over 15 years of diverse experience in human factors research, design, and testing. She has particular expertise in planning, conducting, and analyzing findings from user research studies and translating those findings into directions for useful, usable, and desirable products. She is also experienced in applying the requirements of IEC 62366, HE75, and various FDA Guidance documents to support the development of safe and effective medical products. Liz holds a Masters Degree in Human-Computer Interaction from Carnegie Mellon University.


Aldous Silva, BA

Aldous is the Creative Director.  He has 18 years experience as a visual design professional, including 15 years consulting with Human Factors MD.  He has created highly-usable visual designs for software user interfaces for a wide range of medical applications ranging from hand-held mobile devices to high resolution touch screen workstations.  Aldous’ design portfolio includes award-winning creative designs for print, web, and software user interfaces.  His work has been featured in the Toronto Design Exchange.


Angela Hock, RN, BS, BSN

Angela is a Clinical Consultant. Angela has over 18 years experience in healthcare as a registered nurse. Her clinical experience includes: cardiology, neurology, orthopedics, trauma, pediatrics, dialysis, oncology, surgery, respiratory, debility and medically complex patients. She holds degrees from Penn State University and the University of North Carolina State at Charlotte.


Kendra Vair-Haley, BA

Kendra is the Manager of Project Logistics.  Kendra holds a Honors Bachelor of Arts from Wilfred Laurier University and was experienced supporting large research teams prior to joining Human Factors MD. Kendra manages much of the coordination for our user-based research and usability testing projects, including IRB approvals, recruitment, facilities, and data management.


Bob Williamson, BASc

Bob is an Interaction Designer.  He holds a Bachelor of Applied Science in Systems Design Engineering from the University of Waterloo, with a Management Sciences option. He has been a creative force for over 20 years as a user experience designer, product architect, and process usability specialist. His experience covers the gamut of human-machine interaction from personal mobile apps to medical device implants, clean-room automation, and robotic surgery. Bob is a patented inventor, having been awarded multiple patents for user interaction designs in the United States and Canada.



Based on the individual project, we create project teams using associates with the skills required to meet your needs, from behavioral research, to software prototyping, to graphic design. This ensures you access the skills and expertise of a large firm, but with the flexibility, focus, and attention that’s unique to a small one.