Heart Valve Replacement and Repair

Study the durability (repeated opening and closing) of a heart valve prosthesis under accelerated conditions.

ViVitro Labs calcification testing is available for cardiovascular devices including prosthetic valves and conduits and other cardiovascular devices that contain tissue, or may be susceptible to calcification.

A contactless optical gauging machine is used to measure dimensional attributes of the device.

Durability testing is intended to determine the in-vitro lifetime, the anticipated failure modes, and  potential failure consequences (e.g. immediate total loss of  function or gradual degradation of  function).

Dynamic Failure Mode (DFM) testing is used together with Accelerated Wear Testing (AWT) to provide a  thorough assessment of durability. Since AWT is a “test to success” approach meaning samples are intended to survive the test, DFM testing is a “test to failure” approach which is intended to characterize potential durability-related failure modes.

A measurement at which pressure a device begins to migrate under pulsatile flow conditions.

An assessment of the effects of post-implant dilatation on the leaflets and frame should be conducted if this is an expected use condition to which the (novel) heart valve substitute will be exposed.

Our ex-vivo beating heart simulator is used to test transcatheter devices when realistic anatomy is required.

Using Digital Particle Image Velocimetry (DPIV),  pulsatile flow conditions in the immediate vicinity of the device can be analyzed to determine the viability of cardiovascular devices meeting regulatory standards. Triggers for disease (such as shear stresses and regions of stagnation) can be quantified with a high degree of accuracy. Advanced methods, including proper orthogonal decomposition, also capture the implicit fluid mechanical phenomenon of interest.

The goal of the test is to determine, in vitro, for a specific artificial cardiac valve the value of the coefficient K in the Bernoulli equation, ΔP = K (Vd2 – Vp2).

Hydrodynamic Performance Pulsatile Flow Testing – Forward flow and regurgitant performance of the device will be assessed under physiological pulsatile flow conditions. Key indicators of valve performance such as Effective Orifice Area (EOA) and regurgitant fraction (RF) are determined.

Test specimens are exposed to X-Ray levels necessary for the imaging system and the product or material. Digital analysis method is used to produce the images in accordance with the equipment manufacturer’s instructions. Radiopacity of the device is determined by qualitatively comparing X-ray image(s) of test sample and a user-defined standard with or without the use of a body mimic.

Real-time wear testing (RWT) is intended to match physiological loading conditions as closely as possible as to what would be obtained in a real patient. Due to the viscoelastic nature of some materials, Accelerated Wear Testing may actually under test devices, so RWT can be used to identify frequency dependent failure modes.

A measure of the resistance to sewing ring dehiscence. Failure may result from sutures, suture retention failure, fabric tensile strength failure, fabric weave failure, or fabric seam failure.

Before conducting other evaluations, test samples should undergo all the steps a finished device would go through before being implanted in the patient.

Devices can be subjected to various physiological pulsatile flows and pressures.

Hydrodynamic Performance Steady flow testing determines the forward and reverse flow performance characteristics of a valve in a simple and highly controlled manner. While no formal acceptance criteria exists for steady flow testing, it can be useful in confirming results of pulsatile flow testing.

The deflection of the stent lateral struts (post) is measured when subjected to different back-pressures.