US 4,658,829 A · Method and apparatus for pressure transducer calibration and simulation

Abstract

A method and apparatus for verifying the calibration of a pressure transducer in a pressure monitoring system and for isolating defective electrical components of the monitoring system. The apparatus includes a manually operable pressure cylinder for generating a known test pressure, a pressure calibration circuit coupled to the known test pressure for displaying on the device a calibrated output indicating the level of the known pressure, and a bypass pressure transducer also coupled to the known test pressure for transforming it into an electrical output signal to replace the transducer in the monitoring system as the source of electronically derived readable output in the monitoring system. The substitute pressure transducer includes a temperature compensation circuit and a semiconductor pressure diaphragm with a piezoresistive strain gauge formed thereon. One side of the diaphragm is coupled to the known test pressure and the other side thereof is referenced to atmosphere. The method and device disclosed have particular application in the medical arts to verify the calibration of and test the pressure transducer and cooperating electronic equipment in a direct patient blood pressure monitoring system.

Claims30

Dependent claims

In a pressure monitoring system having an on-line pressure transducer and a monitor for displaying an operator readable output electronically derived from said on-line pressure transducer, a device for selectively calibrating said on-line pressure transducer from known test pressures and for selectively bypassing said on-line pressure transducer to isolate defective electrical components of said pressure monitoring system, said device comprising:

(a) operator-variable means for generating a known test pressure;
(b) pressure calibration means coupled to said known test pressure for displaying on said device a calibrated output indicating the level of said known test pressure;
(c) bypass means for transforming said known test pressure into an electrical output signal of the type derived from said on-line pressure transducer in said monitoring system, said output signal corresponding to the level of said known test pressure;
(d) first output means selectively couplable to said monitoring system for applying said known test pressure to said on-line pressure transducer to produce on said monitor a first operator readable output so that said first operator readable output on said monitor can be checked against said calibrated output on said device when calibrating said monitoring system;
and
(e) second output means selectively couplable to said monitoring system for electrically bypassing said on-line pressure transducer with said bypass means, said output signal of said bypass means producing on said monitor a second operator readable output so that said second operator readable output on said monitor can be checked against said calibrated output on said device to isolate defective electrical components of said pressure monitoring system.

3 more elements

In a direct blood pressure monitoring system having an on-line pressure transducer referenced at a first side thereof to atmospheric pressure and coupled at a second side thereof through a fluid in a catheter adapted to be inserted into a circulatory vessel of a patient, and having a monitor for displaying an operator readable output electronically derived from said on-line pressure transducer, a device for selectively calibrating said on-line pressure transducer from known test pressures and for selectively bypassing said on-line pressure transducer to isolate defective electrical components of said pressure monitoring system, said device comprising:

(a) a manually operable pressure cylinder that generates a known test pressure;
(b) pressure calibration means coupled to said known test pressure for displaying on said device a calibrated output indicating the level of said known test pressure;
(c) a substitute pressure transducer coupled to said known test pressure and referenced to atmospheric pressure that transforms said known test pressure into an electrical output signal of the type derived from said on-line pressure transducer in said monitoring system, said output signal corresponding to the level of said known test pressure;
(d) a closeable output port connected to said pressure cylinder that selectively couples to said monitoring system to apply said known test pressure to said on-line pressure transducer in said monitoring system and to produce on said monitor thereof a first operator readable output, said first operator readable output reflective of the responsiveness of said monitoring system, inclusive of said on-line pressure transducer, to said known test pressure, so that said first operator readable output on said monitor can be checked against said calibrated output on said device in calibrating said monitoring system;
and
(e) an electrical receptacle connected to said substitute pressure transducer, said electrical receptacle capable of receiving a cooperating electrical plug at one end of a connection cable, the other end of said connection cable couplable electrically to said monitoring system so as to bypass said on-line pressure transducer with said substitute pressure transducer, said output signal of said substitute transducer producing on said monitor a second operator readable output reflective of the electrical responsiveness of said pressure monitoring system with said on-line pressure transducer thereof removed, so that said second operator readable output on said monitor can be checked against said calibrated output on said device to isolate defective electrical components of said pressure monitoring system.

3 more elements

In a pressure monitoring system having an on-line pressure transducer and a monitor for displaying an operator readable output electronically derived from said on-line pressure transducer, a device for selectively bypassing said on-line pressure transducer to isolate defective electrical components of said pressure monitoring system, said device comprising:

(a) operator variable means for generating a known test pressure;
(b) pressure calibration means coupled to said known test pressure for displaying on said device a calibrated output indicative of said known test pressure;
(c) bypass means for transforming said known test pressure into an electrical output signal of the type derived from said on-line pressure transducer in said monitoring system, said bypass means being capable of producing electrical output signals within a continuous range of values and said output signal corresponding to the level of said known test pressure;
and
(d) an electrical receptacle connected to said bypass means for receiving therein a cooperating electrical plug at one end of a connection cable, the other end of said connection cable couplable electrically to said monitoring system to replace with said output signal from said bypass means, said on-line pressure transducer as the source of operator readable output to said monitoring system, said output signal of said bypass means producing on said monitor an operator readable output reflective of the electrical responsiveness of said pressure monitoring system with said on-line pressure transducer thereof removed, so that said operator readable output on said monitor can be checked against said calibrated output on said device to isolate defective electrical components of said pressure monitoring system.

2 more elements

In a pressure monitoring system having an on-line pressure transducer and a monitor for displaying an operator readable output electronically derived from said on-line pressure transducer, a method for selectively calibrating said on-line pressure transducer from known test pressures and for selectively bypassing said on-line pressure transducer to isolate defective electrical components of said pressure monitoring system, said method comprising the steps of:

(a) generating a known test pressure;
(b) applying said known test pressure simultaneously to a pressure calibration means for displaying a calibrated output indicating the level of said known test pressure and to a substitute pressure transducer referenced to atmospheric pressure for transforming said known test pressure into an electrical output signal of the type derived from said on-line pressure transducer and said monitoring system, said output signal corresponding to the level of said known test pressure;
(c) selectively coupling said known test pressure to said on-line pressure transducer in said monitoring system to produce on said monitor thereof a first operator readable output, said first operator readable output reflective of the responsiveness of said monitoring system, inclusive of said on-line pressure transducer, to said known test pressure;
(d) checking said first operator readable output on said monitor against said calibrated output on said device to calibrate said monitoring system;
(e) selectively connecting said output signal of said substitute transducer to said monitoring system to replace said on-line pressure transducer with said substitute transducer as the source of said operator readable output to said monitoring system, said output signal of said substitute transducer producing on said monitor a second operator readable output reflective of the electrical responsiveness of said pressure monitoring system with said on-line pressure transducer thereof removed;
and
(f) checking said second operator readable output on said monitor against said calibrated output to isolate defective electrical components of said pressure monitoring system.

4 more elements

Dependencies are inferred from the claim text.

Method and apparatus for pressure transducer calibration and simulation

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Method and apparatus for pressure transducer calibration and simulation

Life of this patent

Abstract

Claims30