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 more than 23 years of commercial experience evaluating and designing usable, effective, and safe medical devices. He is a Certified Human Factors Professional, and as a member of the AAMI’s Human Factors Committee, is an contributor to HE:75. 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 the Lead Instructor and Subject Matter Expert for 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

As a partner and our Senior Technical Director, 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. Christina has a PhD in experimental psychology and ergonomics from North Carolina State University.


Corinna Proctor, MS

Corinna has nearly 20 years of experience employed in the field of Human Factors. She has worked in a variety of domains including medical hardware, health IT, and consumer / commercial IT product development. She has experience providing human factors expertise in the development of a variety of medical devices including Electronic Health Record (EHR) systems. Corinna holds a Master’s Degree in Cognitive Psychology from North Carolina State University.


Eric Shaver, PhD

Eric brings over a decade of human factors experience to the Human Factors MD Team.  He has spent a good portion of those years on the litigation side of human factors and safety in addition to product development.


Heather Colbert, BASc, PEng, CHFP

Heather is a licensed Professional Engineer and Certified Human Factors Professional. For the past 8 years, she has applied her human factors expertise to a wide variety of medical projects, including formative and validation studies.


Liz Mauer, MA

Liz 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.


Vince Velocci, MSc

Trained in Pharmacology, Physiology, Biomedical and Electrical Engineering, Vince has spent most of his 30-year professional career designing and evaluating medical software and devices. He has completed all manner of human factors projects, from contextual inquiry studies to formative and validation testing.


Danny Smith, MA

Danny holds a Master of Arts degree in Anthropology from the University of Montana. He supports activities including study planning and moderation, lab and customer support, and report review. Danny is pursuing a Master of Science degree in Human Factors in Information Design through Bentley University.


Sarah Ritvo, MA

Sarah brings a decade of experience in cognitive behavioural research, with a focus in the last five years on human-computer interaction (HCI) and human factors. She has been a member of the Executive Committee of Division 6 of the American Psychological Association and an invited speaker at several conferences, including the prestigious CHI (Human Factors in Computing Systems) conference. Sarah is a PhD candidate, and holds a MA in cognitive experimental psychology from York University.


Angela Hock, RN, BS, BSN

Angela has over 18 years experience in healthcare as a registered nurse. Her clinical experience includes: cardio, neuro, ortho, trauma, peds, dialysis, onc, surgery, resp, debility and medically complex patients. Angela holds degrees from Penn State University and University of NC at Charlotte.


David Rennie, BA

David has over 17 years of experience as a graphic designer. His background includes designing sales training materials for pharmaceutical companies, technical graphics, and marketing collateral.  He holds a Bachelor’s Degree in Graphic Design from Marymount University.


Aldous Silva, BA

Aldous has over 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 handheld mobile devices to high resolution touch screen workstations. Aldous also creates usable illustrations and Instructions For Use (IFU) and label designs for medical devices.


Marissa Karagiannis, BA

Marissa is a Project Facilitator. She holds a Bachelor’s degree in Health Communication and Public Health through The University of North Carolina at Charlotte. Marissa coordinates study logistics including recruitment, facilities, and data management.


Ashley Lance, BS

Ashley has over 18 years of experience in management and business administration. Ashley earned a Bachelor of Science in Business Administration in Marketing and a minor in International Business from Appalachian State University. She also is a member of the Epsilon Chi Omicron, the Honor Society in International Business.



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.