I.5 Developing custom patient-specific anatomical models for a flow simulator and particle image velocimetry (PIV) testing

Bench-top anatomical modeling is an integral part of medical device development, as it enables designers and researchers to investigate how the devices they manufacture interact with the anatomy. At [Fortune 500 global medtech company], bench-top modeling could feature simulated-use or functionality testing. Simulated-use testing allows the designers, researchers, or physicians to mimic the intended use and/or test the functionality of the medical device. For heart disease related devices (e.g heart valves), simulated-use platforms will seek to mimic the pressure, and flow conditions of the cardiovascular system using a mock circulatory loop or pulse duplicator (PD). The PD facilitates the study of heart valve device characteristics and device parameters in a predictable, controlled, and reproducible manner. The ViVitro Pulse Duplicator system is a commercially available PD and is used to assess the hydrodynamics of prosthetic heart valves.

Beyond pressures and flow rates, the detailed flow properties (local and downstream of a heart valve) provide different insight into the valve hemodynamics and could increase understanding of hemolytic and thrombogenic potential of devices. Particle image velocimetry (PIV) is a flow quantification technique that is recognized as a gold standard for fluid velocity measurements. PIV is optical imaging based and allows for the assessment of the displacement of tracer particles seeded into the working fluid and flowing through an optically accessible region of interest (ROI).

Currently, the ROI in the ViVitro PD system is based on ideal and averaged geometrical dimensions of the anatomy (Figure 1). Although this is useful in its current form, patient-specific modeling is critical. A patient specific model allows the ability to assess the device deployment and anchorage, analyze the effects of deployment on leakage, and most importantly the patient-specific hemodynamics after device implantation. As such, there exists a need to customize the ROI to simulate patient-specific anatomical geometries.

Figure viewable at link

https://docs.google.com/document/d/1IcyB6u5PycvAxkNqtKKBNLAoTBQf5LQ2/edit?usp=sharing&ouid=102395378220494226356&rtpof=true&sd=true

Figure 1: Diagram showing the ViVitro PD and PIV system used for imaging

The goal of this project is to develop a process of creating bench-top patient specific anatomical models (Customized ROI), which are optically clear for PIV studies, and will be amenable to the in-house ViVitro Pulse Duplicator system.

Challenge:

Develop a method/process that allows the creation of varied patient anatomies for PIV testing using the ViVitro PD.

Deliverables:

• Materials and method considerations that will allow the creation of optically clear parts for PIV
• Patient-specific anatomy CAD
• Segmentation and basic simplifications done to model
• Fixtures included on model geometry to ensure it connects to the ViVitro PD
• Prototypes for preliminary PIV testing

Deliverables from [Company]:

• Weekly virtual meetings with GT Team
• [Company] Team will provide details about PIV and the ViVitro pulse duplicator
• [Company]  Team will supply necessary images, dimensions, and CAD files of current ViVitro PD
• [Company]  Team will conduct PIV testing and will also host GT students visit to MN to conduct PIV testing