The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 03, 1978
Filed:
Dec. 08, 1976
William J Williams, Ann Arbor, MI (US);
Weisman & Allen, Madison Heights, MI (US);
Abstract
A method and apparatus for making blood pressure measurements is disclosed particularly adapted to automated measurements of systolic and diastolic blood pressure values. The method includes detecting the rate of change of pressure values existing in an inflatable occluding cuff encircling an extremity of the subject, in whom the blood pressure measurements are to be taken, as the pressure in the occluding cuff is varied from a pressure sufficiently high to completely occlude blood flow to the extremity, to a pressure value in which blood flow takes place in the extremity substantially unaffected by the encircling inflatable cuff. The rate of change of pressure is disclosed as precipitously increasing at a cuff pressure value corresponding to a systolic blood pressure and precipitously declining at a cuff pressure corresponding to diastolic pressure, with the onset of a precipitous increase and decrease detected in order to ascertain the systolic and diastolic pressure values respectively. The particular arrangement disclosed features a rate-of-change-of- pressure transducer which produces a signal directly corresponding to the rate of change of pressure. The transducer includes a pressure responsive moveable element such as a diaphragm subjected to the varying cuff pressures, which element is drivingly connected to a magnetic core surrounded by an electrically conductive coil, the rate of movement of the magnetic core with respect to the encircling coil inducing an emf in the electrical coil corresponding to the rate of change of pressure to which the diaphragm is subjected, which signal is used to detect the systolic and diastolic cuff pressure values as described.