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Automatic Blood Pressure Measuring

IP.com Disclosure Number: IPCOM000096483D
Original Publication Date: 1963-Jun-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Anderholm, FR: AUTHOR [+4]

Abstract

Blood pressure is automatically measured by pressurizing cuff 10 to approximately 300 millimeters of mercury in approximately five seconds so as to occlude the flow of blood in finger 15. A pressure strain gage transducer 20 provides a continuous indication of system pressure furnished by pump 25.

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Automatic Blood Pressure Measuring

Blood pressure is automatically measured by pressurizing cuff 10 to approximately 300 millimeters of mercury in approximately five seconds so as to occlude the flow of blood in finger 15. A pressure strain gage transducer 20 provides a continuous indication of system pressure furnished by pump 25.

Operation of pump 25 is controlled by a cam, not shown, so that after cuff pressure reaches 300 millimeters of mercury, the pressure in cuff 10 is reduced at the rate of six millimeters per second. Light from light source 16 passes through finger 15 and light transmissive pressure cuff 10 to photocell 17. With cuff 10 at zero pressure impulses are emitted by photocell 17. However, no impulses are emitted when cuff 10 is pressurized to 300 millimeters of mercury.

As pressure falls in cuff 10 at a linear rate to a point where blood can flow from finger 15, systolic pressure is reached. As blood flows from finger 15, a first pulse is emitted by photocell 17 to pulse amplifier 30 to provide an indication of systolic pressure. The amplified pulse is transferred to start conversion unit 35, which controls analog to digital converter 36, and to start printout unit 40. Converter 36 sets up printer 45 which prints out under control of unit 40. Converter 36 receives its analog input from DC amplifier 50, which is connected to transducer 20. Hence, the digital value of systolic pressure is printed.

The first pulse passed to amplifier 30 is also t...