Forward and Black Flow Testing
Forward and Black Flow Testing

Heart Valve Testing – Steady Flow: Measured parameters

  • Strain
  • Measure of the transvalvular pressure gradient
  • Evaluate the Effective Orifice Area (EOA) of the valve
  • Measure of static leakage flow (transvalvular and paravalvular)
  • Measure maximum back pressure sustained by the valve

Heart Valve Testing – Steady Flow: Scope

  • Hydrodynamic performance of Artificial Heart Valves prosthesis
  • Hydrodynamic performance of valvular conduits
  • Hydrodynamic performance of Surgical and TAVI valves
  • Hydrodynamic performance of Biological, Polyester, Mechanical valves

Heart Valve Testing Steady Flow: Applicable standards

Heart Valve Testing Steady Flow: Associated tests

Heart Valve Testing – Steady Flow: Test method description

PHASE 1: STEADY FORWARD FLOW (DP) PERFORMANCE TESTING

During forward flow phase, prosthetic cardiac valves produce a pressure drop. The heart has to force against this pressure drop to move the blood through the valve. The highest the pressure drop is, the highest is the energy that the heart has to provide to the flow. The study aims to characterize pressure drop across the valves when subjected to a steady forward flow test.

TEST METHODE

TEST DESCRIPTION

PERFORMANCE PARAMETERS

1

Steady forward-flow testing (DP) Measurement of the pressure difference across the test valve and the standard nozzle over a flow range of 5 to 30 l/min in 5 l/min increments. Collecting and recording of at least five measurements at each flow rate.
  1. Measure of the transvalvular pressure gradient
  2. Evaluate the Effective Orifice Area (EOA) of the valve
       
PHASE 2: STEADY BACK FLOW (LEAKAGE FLOW) PERFORMANCE TESTING

When a prosthetic cardiac valve is closed due to an adverse pressure, some fluid is flowing back through the valve. The volume of fluid coming back during this phase will have to be compensated by an increase of ejection volume of the heart. The higher the back-flow, the higher the energy the heart has to provide to produce a supplementary forward flow. The study aims to characterize static leakage flow across the valves when subjected to different back pressures.

TEST METHODE

TEST DESCRIPTION

PERFORMANCE PARAMETERS

2

Steady back-flow leakage testing Measurement of the static leakage across the test valve and the standard nozzle at five equidistant back-pressures in the range of 40 to 200 mmHg. Collecting and recording of at least five measurements at each level of back pressure.
  1. Measure of static leakage flow
  2. Measure maximum back pressure sustained by the valve