Pulsatile flow system for developing heart valves

• US 5,899,937 A
• Filed: 03/05/1997
• Issued: 05/04/1999
• Est. Priority Date: 03/05/1997
• Status: Expired due to Term

• Current Assignee: Cryolife Incorporated
• Original Assignee: Cryolife Incorporated
• Inventors: Goldstein, Steven, Black, Kirby S.
• Primary Examiner(s): Isabella, David J.
• Assistant Examiner(s): SNOW, BRUCE EDWARD
• Application Number:
  US08/812,303
• Time in Patent Office: 790 Days
• Field of Search: 623/1, 623/2, 623/3, 623/900, 623/901, 623/66, 73/37, 73/865.6
• US Class Current: 623/2.11
• CPC Class Codes: A61F 2/2415 Manufacturing methods
• CPC Class Codes: A61F 2/2472 Devices for testing
• CPC Class Codes: C12M 21/08 for producing artificial tissue or for ex-vivo cultivation of tissue prostheses A61F2/00, grafts A61L27/00
• CPC Class Codes: C12M 29/12 Pulsatile flow

Abstract

A closed, sterile pulsatile flow loop for studying tissue valves. The system provides both a tool to examine heart valve leaflet fibroblast function and differentiation as these are affected by mechanical loading, as well as an apparatus to provide heart valves seeded with suitable cells. The sterile pulsatile flow system provides a left heart duplicator, which exposes viable tissue valves to a dynamic flow environment imitating that of the aortic valve.

Claims

1. An apparatus for subjecting implant heart tissue to a physiologic pulsatile flow, comprising:

a piston-type pump;

a flexible elastomeric bladder containing a fluid that is mounted inside of a fluid-filled chamber, the pump serving to displace the fluid within the chamber so as to simulate a pulsatile flow within the bladder and to shield the fluid within the bladder from contamination by the pump, wherein the fluid within the bladder is a blood-analog suitable for providing living cells in heart tissue with nutrients;

a fluid conduit leading from the bladder to a test section adapted to contain at least one aortic valve sample containing living cells;

a fluid conduit leading from the test section to a downstream compliance and resistance element;

a gas exchanger in communication with the blood-analog fluid for providing the at least one aortic valve with proper levels of gases;

a heat exchanger in thermal communication with the blood-analog fluid; and

a fluid conduit leading from the compliance and resistance element to the bladder;

wherein the apparatus provides pulsatile flows from a range of pressure regimes and fluid flow regimes.

2. An apparatus as set forth in claim 1, wherein the apparatus provides pulsatile flows having physiologic systolic and diastolic pressures.

3. An apparatus as is set forth in claim 1, further comprising a waveform generator for controlling the piston pump.

4. A bioreactor for studying the effects of physical inputs to heart valve leaflet biochemical functions, comprising:

a pump;

a flexible elastomeric bladder containing a fluid that is mounted inside of a fluid-filled chamber, the pump serving to displace the fluid within the chamber so as to simulate a pulsatile flow within the bladder and to shield the fluid within the bladder from contamination by the pump, wherein the fluid within the bladder is a blood-analog suitable for providing living cells in valvular heart tissue with nutrients for a period of time sufficient to study the mechanical effect of physiologic pumping on live cells;

a fluid conduit leading from the bladder to a test section adapted to contain natural aortic valve samples mounted in parallel;

a fluid conduit leading from the test section to a downstream compliance and resistance element;

a gas exchanger in communication with the blood-analog fluid for providing the natural aortic valves with the proper levels of gases;

a heat exchanger in thermal communication with the blood-analog fluid; and

a fluid conduit leading from the compliance and resistance element to the bladder;

wherein the apparatus provides pulsatile flows from a range of pressure regimes and fluid flow regimes to the heart valves so that the effect of such regimes on cells within the heart valves can be studied.

5. An apparatus as set forth in claim 4, wherein the apparatus provides pulsatile flows having physiologic systolic and diastolic pressures.