Medex, Inc.

Thomas P Frank

Charles Russell Patzer

Warren B Nicholson

Michael P Eland

John C Toomey

Dennis M Tomisaka

Wendell Thompson

Mark D Pfouts

Glen D Brunner

Jeffrey L Thompson

A pressure transducer (10) for measuring fluid pressure in a fluid path comprising a strain gauge circuit (37) of thick film piezoresistors formed on an alumina diaphragm (36) in a Wheatstone bridge configuration. Each resistance leg of the bridge typically includes a thick film measuring piezoresistor (R1A) to which selected thick film patch-in piezoresistors (R1B, R1C, R1D, R1E) are selectively connected to create a measuring resistance network (PN1). The measuring resistance network is adjusted to a predetermined resistance value to balance and optimize the electrical symmetry of the bridge. The pressure transducer (10) includes a mechanical stop member (46) located adjacent the alumina diaphragm (36) such that the fully deflected diaphragm contacts the stop thereby physically preventing the diaphragm from deflecting an amount that would cause the diaphragm to rupture.

Low cost pressure transducer particularly for medical applications

A sample site having a needleless connector access port including a flush mounted valve assembly which is readily accessible for wiping clean with a disinfectant. A male Luer connector may be operatively connected into the access port by a split Luer arrangement of female Luer connector portions adjacent the access port aperture. The split Luer arrangement does not generally obstruct wiping access to the access port and may include moveable connector portions to provide completely unobstructed wiping access thereto.

Needleless connector sample site

A transducer has a thick perimeter and an integral diaphragm extending across said perimeter, all formed of a thermoplastic resin. A thick mass is molded at the center of the diaphragm. Resistive elements formed of a conductive polymer are printed and baked on the diaphragm to form a Wheatstone bridge. The transducer is used as an accelerometer or load cell.

Transducer with conductive polymer bridge

In a blood pressure monitoring system, a transducer which is a conductive rubber tube having conductive terminals at each end,

Tubular pressure transducer

A reusable pressure transducer for use with a detachable dome. The pressure transducer includes a body having a recess with an opening covered by a flexible diaphragm. The body has a hole opposite the flexible diaphragm and a sensor placed over the hole. A dielectric gel fills the recess to transmit to the sensor variations in pressure imparted to the diaphragm.

Gel-filled blood pressure transducer

A pressure transducer has a thin central portion formed of a molded thermoplastic resin. A conductive polymer forms the resistive elements of a Wheatstone bridge printed and baked onto the molded substrate.

Pressure transducer with conductive polymer bridge

In a blood pressure monitoring system, a transducer which is a conductive rubber tube having conductive terminals at each end. The terminals are connected to a circuit for detecting changes in resistance of the tube. The internal surface of the tubing is coated with a dielectric material.

A system for calibrating a blood pressure transducer and monitor combination. The transducer assembly has a calibration resistor. The monitor cable has a housing which contains a switch and a shunt resistor. Electrical connections are provided to place the calibration resistor and shunt resistor in series with each other and in shunt across one leg of a transducer bridge to produce a reading of 100 mmHg on the monitor.

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Dublin, OH, United States of America

Thomas P Frank