Dr. Zahra (Parisa) Motamed directs the Cardiovascular Research Group and is an Assistant Professor in the Department of Mechanical Engineering at McMaster University in Hamilton, ON. She is also a research affiliate faculty member at the Institute for Medical Engineering & Science and Harvard-MIT Biomedical Engineering Center at MIT in Cambridge, MA. Dr. Motamed is a mechanical engineer with more than two decades of experience in using computational and experimental mechanics to solve problems ranging from industrial product development to understanding functions of biological systems in healthy and diseased conditions. Dr. Motamed has more than 14 years of experience in experimental and computational studies of cardiovascular diseases and devices from basic science to clinical research.
ViVitro Labs Applications Manager, Rob Fraser, recently spoke with Dr. Motamed about her work developing diagnostic and predictive tools and regulatory medical device testing machines for complex ventricular-valvular-vascular disease (Complex VVVD) and transcatheter valve intervention.
Rob Fraser Please tell us about your current work.
Dr. Zahra Motamed In Canada, one in every four deaths is a result of cardiovascular disease. Social and economic consequences associated with cardiovascular disease is major – they cost the Canadian economy $22 billion every year in physician services, hospital costs, lost wages and decreased productivity. In addition, Ontario is home to 22% of Indigenous peoples of Canada. Indigenous people in Canada have a significantly higher likelihood of developing heart disease and heart attack. With heart disease rates as much as 50% higher than in the general Canadian population, the overall cardiovascular health of Indigenous people is far worse.
Non-invasive, image-based patient-specific diagnostic and predictive tools and realistic regulatory medical device testing machines
I want to emphasize the word “non-invasive”, because I believe that if it’s based on invasive input parameters or invasive actually data, I don’t think it is really meaningful for patients with cardiovascular diseases to have weekly, sometimes daily, basis follow ups. So first, the main objective is non-invasive and image-based patient-specific diagnostic tools.
- Diagnostic tools. Cardiology is fluid dynamics. Abnormal hemodynamics and biomechanics lay at the base of the initiation and progression of cardiovascular disease. Flow quantification can be greatly useful for accurate and early diagnosis, but we still lack proper diagnostic methods for many cardiovascular diseases because the fluid-dynamics methods that can be used as engines of new diagnostic tools are not yet well developed.
- Predictive tools. Although the ability to predict fluid dynamics and biomechanics following an intervention can have significant impacts on saving lives, predictive tools are rare. These tools predict the effectiveness of interventions, allowing systematic testing for possible clinical solutions, and thereby enabling personalized interventions. Despite remarkable advances in patient-specific, multi-material 3-D printing and medical imaging, these are not predictive tools on their own.
Clinical predictive tools enable cardiologists to study the effects of intervention scenarios on the function of the cardiovascular system of the patient before performing an irreversible procedure on the body. Despite its importance, there exists no quantitative predictive tool that can predict detailed blood flow conditions after intervention in a patient-specific manner. We are developing a non-invasive predictive tool that shouldn’t pose any risk to the patient and this is also happening computationally and experimentally right now.
- Regulatory cardiovascular device testing machines. Companies developing and manufacturing cardiovascular devices require realistic testing machines for validating and optimizing their new devices. FDA recommends that in addition to evaluating local efficacy of a cardiovascular device, the evaluations should also include investigations of its hemodynamic effects remote from the site of placement (global effect). A realistic regulatory testing machine, therefore, should investigate and quantify the effects of medical devices on both local and global hemodynamics under real human body conditions. Despite its importance, there exists no realistic regulatory testing machine that can satisfy these requirements.Realistic testing machines need to be developed based on patient-specific clinical hemodynamic input parameters (hemodynamic metrics and imaging) and need to be validated with patient-specific clinical outcomes (hemodynamic metrics and imaging). In the absence of such testing machines to quantify local and global hemodynamics, medical-device companies currently rely heavily on animal testing and human trials, which in turn greatly increase the time-to-market and cost-to-market for new devices. It is notable that animal testing has limitations, i.e., animals and their related physiologic attributes may not provide a test system that offers a best attempt at simulating the human application.
Rob Fraser There is lots of synergy and overlap between those three goals, how is the work going?
Dr. Zahra Motamed Currently, we develop diagnostic and predictive tools as well as regulatory medical device testing machines for the most general and fundamentally challenging cardiovascular condition: complex ventricular-valvular-vascular disease (Complex VVVD) and transcatheter valve intervention. Complex VVVD represents conditions in which multiple ventricular, valvular and vascular pathologies have mechanical interactions with one another wherein physical phenomena associated with each pathology amplify the effects of others on the cardiovascular system. Until recently, the only possible choice for high-risk patients with valvular diseases was surgical replacement of the valve, which has a high mortality rate. Transcatheter valve replacement is an emerging minimally invasive procedure and is a growing alternative for patients with valvular diseases across a broad risk spectrum.
The interesting point is that when we develop something for a diagnostic tool, we can use it for predictive, we can use it even for regulatory testing machine, both computationally and experimentally. So therefore, they are covering both in terms of methodology.
Rob Fraser What are the reactions to your work?
Dr. Zahra Motamed It was very well received – we have highly active collaborations with clinicians, radiologists, and interventional cardiologists both nationally and internationally. To connect with the end users of our research, my lab is currently collaborating with Canadian medical device companies.
The potential end users and direct beneficiaries of the technologies developed in our research are policy makers, clinicians, various industries (biomedical devices, pharmaceuticals, manufacturers of medical devices and medical imaging equipment, and high-precision surgery equipment) and individual users (e.g., wearable monitoring devices). We plan to reach out to Canadian regulatory agencies to ensure that outcomes of this research remain relevant to those who will form the user community.
Rob Fraser Has ViVitro labs helped you with this work?
Dr. Zahra Motamed Absolutely! My lab is building 3 different cardiovascular simulators for different test purposes. For these developments, my lab needs a pump that creates reliable physiological cardiac flows for various cardiovascular diseases and their related medical devices. The ViVitro SuperPump is a digitally controlled hydraulic piston pump that creates cardiac flows for cardiovascular devices and diseases. Unsurpassed in reliability, functionality, and versatility, the ViVitro SuperPump’s digital technology provides maximum control with precision accuracy. Moreover, cardiovascular simulation that will be developed in Motamed lab, should be adapted to operate free from pathogenic microorganisms. For this purpose, to keep the cells alive during the cardiac cycle loading, this cardiovascular simulator should be temperature-controlled and operate with a sterile medium instead of water. The ViVitro SuperPump and its accessories, in our knowledge, are the only equipment on the market that have the above-mentioned capabilities.
Rob Fraser What are your plans for the future?
Dr. Zahra Motamed Extending these objectives to the other cardiovascular diseases, interventions and devices. Complex valvular and ventricular disease is really very sophisticated from an engineering perspective. By starting with the most complicated situation in the entire circulatory system, with minimal effort, we can solve the problems for the rest of the vascular system.
Rob Fraser Do you have advice for our readers?
Dr. Zahra Motamed One piece of advice comes from my own experience. I changed the field that I was working in. Initially I was working on internal combustion engineering for my master and my nine years of industrial experience, and now 15 years since I switched to cardiovascular science. So I have just one advice, just tackle scientific and engineering challenges in this field – a small improvement in clinics, can save lives of many patients with cardiovascular diseases. This is a very important field which evolves every day especially in minimally invasive trans-catheter interventions. If you have an impactful idea, do not be afraid to take a stand.
Read about other Cardiovascular Pioneers here.