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Mock Circulatory Loop to Generate Variable Adult Heart Conditions for Evaluating Mechanical Circulatory Support Devices

Catalog of Regulatory Science Tools to Help Assess New Medical Devices 


This regulatory science tool is a lab method used for simulating target clinical use patient conditions on the bench using a mock circulatory loop in conjunction with the ISO 14708-5 standard specifications for circulatory support devices.


Technical Description

This regulatory science tool (RST) is a benchtop left heart mock circulatory loop (MCL) that may be used to simulate well-defined heart failure and healthy adult patient conditions in a reproducible manner. This RST may also assist in evaluating the hydrodynamic performance of mechanical circulatory support (MCS) devices and complements the recommendations in Clause 6.6 and Annex B of ISO 14708-5:2020 “Implants for surgery – Active implantable medical devices – Part 5: Circulatory support devices." [1

The RST consists of: a) a User Manual [2] for building the MCL and simulating the test conditions, and b) Technical Recommendations [3] complimentary to the ISO 14708-5:2020 specifications for conducting MCL testing.

Intended Purpose

The purpose of this RST is to support the in vitro design evaluation and hydrodynamic performance characterization requirements of MCS devices described in Clause 6.6 of ISO 14708-5:2020 “Implants for surgery – Active implantable medical devices – Part 5: Circulatory support devices." [1]. More specifically, this RST is applicable to left ventricular assist devices (LVADs) or systems (LVASs) with Product Code: DSQ. The RST provides recommendations and a user manual for standardized MCL simulations of relevant clinical use conditions including left heart failure and normal left heart hemodynamics to characterize the performance of LVADs. Evaluation of the MCS device itself under the recommended simulated use conditions is outside the scope of this tool.


Verification and validation (V&V) activities for the RST include test fluid characterization, sensor calibration, frequency response filter characterization, MCL simulations of the recommended target test conditions, and MCL repeatability testing. A summary of the V&V activities is provided in [4] and detailed test results are reported in the peer-reviewed publications by D’Souza et al., 2024 [5], and Contarino et al., 2023 [6].


  • The technical limitations of the RST are described in the peer-reviewed publication by D’Souza et al., 2024 [5].
  • The test system described in the RST is limited to only evaluating left heart hemodynamics and heart failure disease states and is thus primarily applicable to evaluations of LVADs or LVASs.
  • Additional device-specific V&V activities will be required for LVAD or LVAS evaluation using this RST. Acceptance criteria for the simulated outputs have not been established by this RST, such that a future correlation study with clinical evidence is needed for determining acceptable metrics.

Supporting Documentation

  1. ISO 14708-5 Implants for surgery — Active implantable medical devices — Part 5: Circulatory support devices. 2020.
  2. User Manual: Mock Circulatory Loop (MCL) Setup and Testing
  3. Technical Recommendations
  4. Summary of V&V Activities
  5. D'Souza GA, Rinaldi JE, Meki M, Crusan A, Richardson E, Shinnar M, Herbertson LH. Using a Mock Circulatory Loop as a Regulatory Science Tool to Simulate Different Heart Failure Conditions. J Biomech Eng. 2024 Jan 1;146(1):011004. doi: 10.1115/1.4063746.
  6. Contarino C, Chifari F, D'Souza GA, Herbertson LH. Validation of a Multiscale Computational Model Using a Mock Circulatory Loop to Simulate Cardiogenic Shock. ASAIO J. 2023 Nov 2. doi: 10.1097/MAT.0000000000002062.


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