Pulsatile Flow Testing – Hydrodynamic Performance

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 Procedure

Aortic, mitral, pulmonary or tricuspid heart valve prosthesis samples (or cardiac repair devices) undergoing testing are mounted in the active test position (atrioventricular/semilunar) of the Pulse Duplicator and a companion valve is mounted in the opposite test position (atrioventricular/semilunar). The test loop is filled with a blood analog solution. Heart valve test samples are then subjected to a pulsatile flow that is intended to simulate physiologic conditions. Measurements of the various chamber pressures and the flow through the test position are obtained. The results are used to determine the pressure drops through the valve during the forward flow phase of the cycle and the regurgitant volumes of fluid during the closing and leakage phases of the cycle.

The goal of the test is to evaluate, using a pulse duplicator which produces pressure and flow waveforms that approximate physiological conditions:

• The pressure difference at four simulated cardiac outputs (2, 3.5, 5 and 7l/min) at a single simulated heart rate (70 cycles/min) as specified in ISO 5840 and ISO 5910
• The regurgitant volume at three different (averaged over the cardiac cycle) back-pressures (Hypotensive, normotensive, severe hypertensive), at three simulated heart rates (45, 70 and 120 cycles/min) at a normal cardiac output (5 l/min) as specified in ISO 5840 and ISO 5910

In accordance with ISO 5840-3:2021 additional testing can be performed for transcatheter devices including using a simulated calcium nodule, migration testing, and various challenge cases as appropriate based on the device design.

Equipment

• ViVitro Pulse Duplicator (Pulse Duplicator + Superpump + Superpump controller)
• Data Acquisition system including ViViTest Software
• Flow Meter
• Pressure transducers
• Heat bath
• Calibrated manometer
• Calibrated thermometer
• Companion valve (ViVitro spring loaded disc valve)

Measured Parameters

Obtain key indicators of valve performance including regurgitant fraction, effective orifice area, and numerous others. In addition to pass/fail information in accordance with ISO 5840, these methods can show design parameters such as minimized paravalvular leakage, transvalvular leakage, closing volume, leakage volume, and forward flow pressure drop. Along with quantitative data, ViVitro can provide qualitative high speed video and high resolution photography of a device while operating, providing key information on valve performance.

Optional:

• Geometric Orifice Area (valve opened)
• Regurgitation Orifice Area (valve closed)
• Assess kinematics of valve leaflets

Scope

• Surgical Valves: SAVR, SMVR, SPVR, STVR
• Transcatheter Valves: TAVI / TAVR, TMVI / TMVR, TPVI / TPVRTMVR, TTVR / TTVI  and any other transcatheter valve
• Biological, Polymeric, mechanical valves, tissue engineered
• Artificial heart valves prosthesis
• Venous valves
• Valvular conduits
• Any valvular prosthesis
• Any cardiac repair device

Service Levels

• Fast Track
• Standard Service
• Full Service
• Full Service with ISO 17025

Applicable Standards

• ISO 5840-2:2021
  Cardiovascular implants — Cardiac valve prostheses — Part 2: Surgically implanted heart valve substitutes

• ISO 5840-3:2021
  Cardiovascular implants — Cardiac valve prostheses — Part 3: Heart valve substitutes implanted by transcatheter techniques

• ISO 5910:2018
  Cardiovascular implants and extracorporeal systems — Cardiac valve repair devices

Related Tests

• Steady Flow Testing – Hydrodynamic Performance
• Experimental Flow Field Assessment – Digital Particle Image Velocimetry (DPIV)
• Experimental Flow Field Assessment – Echo Doppler – Bernoulli’s Equation Verification
• Accelerated Wear Testing (AWT)

OLE1714