US 4,598,579 AGranted

Portable instrument to test pressure/flow of ventricular shunt valves

AssigneeCordis Corporation

InventorsJoel Cummings, Michael D. Hooven

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Abstract

A portable instrument system is provided for the testing of pressure and flow characteristics of implantable ventricular shunt valves using a gaseous testing fluid that may be drawn from the testing environment. The system includes a rate pump having a control mechanism that provides a variety of selective constant flow rates so that the valve characteristics can be determined under various operating conditions. Fluid communication is provided between the pump, the valve and a pressure sensing device such that the pressure sensing device receives the same pressure and flow rate that the valve does. Typically, the pressure sensing device is a gauge transducer that utilizes atmospheric pressure as a reference point and senses the changes in the gas pressure in the valve, relaying the pressure readings to a digital display or chart recorder.

Claims18

Dependent claims

A portable instrument for testing the pressure and flow characteristics of an implantable valve with a gaseous testing fluid in a substantially liquid-free testing atmosphere, said valve having an inlet port, an outlet port and a fluid passageway connecting said inlet port and said outlet port, the fluid passageway having a valve element for controlling the flow of fluid through the fluid passageway, the system comprising, in combination:

means for pumping a gaseous testing fluid through the valve at a predetermined flow rate;
means for maintaining the flow rate of the testing fluid at a constant rate while pumping said testing fluid through said implantable valve;
means for directing the testing fluid both to said implantable valve and to a single pressure sensing device, said pressure sensing device receiving the testing fluid at the same predetermined flow rate as that received by said valve;
said pressure sensing device including a single pressure transducer having a diaphragm therein, one side of said diaphragm being mechanically coupled to said fluid directing means and the opposite side of said diaphragm being exposed to the testing atmosphere, whereby said transducer measures the difference in pressure between said testing atmosphere and the gaseous testing fluid directed to said valve and said diaphragm, said pressure sensing device further including means for producing an electrical output signal indicative of the testing fluid pressure within said valve passageway;
and
means for conditioning the electrical signal for reception by means for indicating the testing fluid pressure level in said valve passageway.

3 more elements

A method for the testing of the pressure and flow characteristics of a surgically implantable valve with a gaseous testing fluid in a substantially liquid-free testing atmosphere, said implantable valve being of the type that has a valve inlet port, a valve outlet port and a fluid passageway connecting said inlet and outlet ports, the fluid passageway having a valve element for controlling the flow of fluid through the fluid passageway, comprising the steps of:

pumping a gaseous testing fluid across the valve element at a predetermined flow rate;
maintaining the flow rate of the testing fluid at a constant rate while pumping said testing fluid through said implantable valve;
providing a single pressure sensing device including a gauge pressure transducer having a diaphragm therein, one side of said diaphragm being exposed to said valve testing atmosphere;
directing the testing fluid both to the implantable valve being tested and to the opposite side of said pressure transducer at the same predetermined flow rate;
producing an electrical output signal indicative of the pressure of the testing fluid across said valve element;
conditioning the electrical signal for reception by a means for indicating the level of pressure of the testing fluid across the valve element, and
indicating the pressure of the testing fluid across the valve element.

4 more elements

Dependencies are inferred from the claim text.