Lawrence A Blake

US Patent:

39811972, Sep 21, 1976

Filed:

Jun 23, 1975

Appl. No.:

5/589714

Inventors:

Clement Eugene Lieber - Yorba Linda CA
Lawrence Webster Blake - Costa Mesa CA

Assignee:

American Hospital Supply Corporation - Evanston IL

International Classification:

G01L 906

US Classification:

73398AR

Abstract:

Piezoresistive deflection-sensitive beam elements are encapsulated in a disc of elastomeric material which forms a fluid pressure responsive diaphragm. The beam elements are oriented within the diaphragm so as to be strained in tension or compression when the diaphragm is deformed by fluid pressure. The beam elements are connected in a bridge circuit to produce an electric signal which provides a fluid pressure indication or measurement, as in a blood pressure monitoring catheter.

US Patent:

39956237, Dec 7, 1976

Filed:

Feb 11, 1976

Appl. No.:

5/657141

Inventors:

Lawrence W. Blake - Costa Mesa CA
Clement E. Lieber - Yorba Linda CA
Harold J. C. Swan - Beverly Hills CA
William Ganz - Los Angeles CA

Assignee:

American Hospital Supply Corporation - Evanston IL

International Classification:

A61B 504

US Classification:

128 206E

Abstract:

The catheter is flow-directed through the heart of the patient by a balloon on its distal end to pass through the right atrium, right ventricle and into the pulmonary artery. A through lumen in the catheter tube is open at the distal end to monitor blood pressures in the pulmonary artery or a branch, or take blood samples. A thermistor proximal to the balloon permits monitoring of blood temperature in this region and thus allows the determination of cardiac output by the thermodilution technique. A second lumen has an orifice, which is characteristically located in the region of the junction of the superior vena cava and the right atrium, for pressure monitoring, infusion of liquid media, or blood sampling. A stylet in the second lumen assists in advancing the catheter and, by means of a sudden variation in stiffness, facilitates forming a sharp bend within the right ventricle to press distal electrodes against the myocardial wall which separates the left and right ventricles. Proximal electrodes on the catheter tube are positioned in the right atrium.