System and method to simulate hemodynamics
A system for hemodynamic simulation comprises a vessel having properties of a blood vessel, a reservoir containing a quantity of fluid, tubing connecting the vessel and reservoir, and at least one pump for circulating the fluid within the system. Fluid can be tissue culture medium or blood analog fluid, and the vessel may include mammalian cells attached to its inside. A drive system, comprising two reciprocating drive shafts that are coupled by a cam, enables the uncoupling of pulsatile flow and pulsatile pressure to provide independent control over wall shear stress and circumferential strain. The shaft drives two pumps that are 180 degrees out-of-phase and are connected upstream and downstream of the vessel, and effect this uncoupling.
1 . A system configured to produce biomechanical conditions, comprising:
a specimen chamber;
a first pump system operatively coupled to the specimen chamber;
a steady flow pump operatively coupled to the specimen chamber and the first pump system; and
a reservoir operatively coupled to the specimen chamber, wherein the first pump system and the steady flow pump are configured to generate pressure and flow conditions in the specimen chamber.
2 . The system of claim 1 , wherein the specimen chamber, the first pump system, the steady flow pump and the reservoir are configured to allow fluid to flow therethrough.
3 . The system of claim 2 , wherein the specimen chamber is configured to receive a specimen therein for exposure to at least one predetermined three-dimensional hemodynamic condition.
4 . The system of claim 2 , wherein the biomechanical conditions comprise an in-vivo hemodynamic environment.
5 . The system of claim 4 , wherein the first pump system and the steady flow pump are used to produce prescribed longitudinal shear stress and circumferential strain conditions in the specimen unit.
6 . The system of claim 5 , wherein the longitudinal shear stress and circumferential strain conditions produce a prescribed stress phase angle therebetween.
7 . The system of claim 6 , wherein the stress phase angle is greater than 100 degrees.
8 . The system of claim 2 , wherein the fluid is at least one of substantially liquid, substantially gas, a liquid combined with a solid, a liquid combined with a gas, a gas combined with a solid, and a liquid combined with a solid and a gas.
9 . The system of claim 1 , further comprising at least one downstream pump coupled to a downstream end of the specimen chamber and selectively operated out of phase with at least one pump of the first pump system.
10 . The system of claim 9 , further comprising an external pump coupled to the specimen chamber and configured to dynamically generate an oscillatory variation in pressure or flow in the specimen chamber.
11 . The system of claim 10 , wherein the pumps each comprise piston or bellows pumps, oscillatory pump, occluders or the like.
12 . The system of claim 1 , further comprising a drive system unit configured to control the pumps, wherein the drive system unit includes at least one of a cam mechanism; a multi-bar linkage mechanism; a solenoid; a stepper motor; an electric motor; a linear ball actuator; a belt-driven actuator; or a chain-driven actuator between two of the plurality of pumps.
13 . The system of claim 1 , wherein the system is configured to produce a plurality of dynamic in-vivo biological conditions.
14 . A method for producing biomechanical conditions, comprising:
providing a specimen chamber;
providing at least one pump operatively coupled to the specimen chamber;
providing a steady flow pump operatively coupled to the specimen chamber and said at least one pump; and
operatively coupling a reservoir to at least one of the specimen chamber, the steady flow pump and said at least one pump.
15 . The method of claim 14 , providing a continuous flow path through the specimen chamber, the steady flow pump, said at least one pump and the reservoir, and wherein the specimen chamber is configured to receive a specimen therein for exposure to at least one predetermined hemodynamic condition in the flow path.
16 . The method of claim 14 , wherein the biomechanical conditions comprise re-producing at least one in-vivo hemodynamic environment.
17 . The method of claim 14 , further comprising producing prescribed longitudinal shear stress and circumferential strain conditions in the specimen unit using the at least one pump and the steady flow pump.
18 . The method of claim 17 , wherein the longitudinal shear stress and circumferential strain conditions produce a prescribed stress phase angle therebetween, and wherein the stress phase angle is greater than 100 degrees.
19 . The method of claim 14 , further comprising:
providing an upstream pump and a downstream pump coupled to the specimen chamber and operated selectively out of phase therebetween; and
dynamically generating an oscillatory variation in external pressure or flow in the specimen chamber.
20 . The method of claim 14 , wherein the biomechanical conditions reproduce three-dimensional hemodynamic conditions.