Steady Flow Testing – Hydrodynamic Performance

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.

Includes: Steady Forward flow testing, Steady back flow leakage testing, Stent Post Deflection, Migration, and Burst Testing

Test Procedure

Steady Forward-Flow Testing 

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.

Performance parameters:

• Measure of the transvalvular pressure gradient
• Evaluate the Effective Orifice Area (EOA) of the valve

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 physiological range recommended by the ISO 5840 standard for the adult and pediatric population as well as right and left heart conditions. Collecting and recording of at least five measurements at each level of back pressure.

Performance parameters:

• Measure of static leakage flow

Burst Pressure

Pressure at which device failure occurs.

Static Migration

Pressure at which devices migrates.

Equipment

• Steady Flow test bench
• Pump
• Data acquisition system ±15mV with Software
• Calibrated Standard nozzles
• Calibrated thermometer
• Calibrated Manometer
• Calibrated Flow Meter
• Thermo-regulated tank

Measured Parameters

• Mean transvalvular pressure gradient at each flow rate
• Effective Orifice Area (EOA) of the valve at each flow rate
• Mean static leakage flow rate (transvalvular and paravalvular) at each back pressure

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 5840-1:2021
  Cardiovascular implants — Cardiac valve prostheses — Part 1: General requirements

• NF EN 12006-1
  Non active surgical implants – Particular requirements for cardiac and vascular implants – Part 1 : heart valve substitutes

Related Tests

• Pulsatile Flow Testing – Hydrodynamic Performance
• Accelerated Wear Testing (AWT)
• Steady Flow Testing – Stent Post Deflection

OLE0911, OLE0912, OLE0920, OLE0937