# US 8,784,325 B2 · Apparatus and method for measuring blood pressure > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,784,325 B2 - Document ID: US8784325B2 - Status: Granted - Kind: B2 - Application number: 12/418,903 - Filed: 2009-04-06 - Published: 2010-05-06 - Granted: 2014-07-22 - Earliest claimed: 2008-11-03 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Youn-ho Kim; Kun-soo Shin - Inventors: Youn-ho Kim; Kun-soo Shin - Web page: https://patentgrep.com/patent/US8784325B2 ## CPC - A61B 5/022: by applying pressure to close blood vessels, e.g. against the skin; Ophthalmodynamometers - A61B 5/02225: {using the oscillometric method} - A61B 5/0225: the pressure being controlled by electric signals, e.g. derived from Korotkoff sounds - A61B 5/02255: {the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors} - A61B 5/021: Measuring pressure in heart or blood vessels - A61B 5/024: Measuring pulse rate or heart rate - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Provided are an apparatus and method for measuring blood pressure. The blood pressure measuring apparatus includes a pressure sensor detecting a sphygmus wave and pressure of a blood vessel in a subject, a pulse detecting unit detecting a peak-to-peak interval of the sphygmus wave of the subject, an optimum rate of pressure change detecting unit detecting an optimum rate of pressure change of the blood vessel by using the peak-to-peak interval of the sphygmus wave, a compression unit performing a compression operation in which the blood vessel is compressed at the optimum rate of pressure change detected by the optimum rate of pressure change detecting unit, or a decompression operation in which the blood vessel is compressed so as to be closed, and is then decompressed at the optimum rate of pressure change, and a blood pressure detecting unit detecting blood pressure of the subject, based on the sphygmus wave and the pressure of the blood vessel, which are detected in the compression operation or the decompression operation. ## Claims ### Claim 1 A blood pressure measuring apparatus comprising: a pressure sensor for detecting a sphygmus wave and pressure of a blood vessel in a subject; a pulse detecting unit for detecting a peak-to-peak interval of the sphygmus wave of the subject, which is detected by the pressure sensor; an optimum rate of pressure change detecting unit for detecting an optimum rate of pressure change of the blood vessel by using the peak-to-peak interval of the sphygmus wave; a compression unit for performing a compression operation in which the blood vessel is compressed at the optimum rate of pressure change detected by the optimum rate of pressure change detecting unit, or a decompression operation in which the blood vessel is compressed so as to be closed, and is then decompressed at the optimum rate of pressure change; and a blood pressure detecting unit for detecting blood pressure of the subject, based on the sphygmus wave and the pressure of the blood vessel, which are detected in the compression operation and the decompression operation; the pressure sensor being in operative communication with the pulse detecting unit, the optimum rate of pressure change detecting unit, the compression unit and the blood pressure detecting unit, and wherein the optimum rate of pressure change detecting unit detects the optimum rate of pressure change of the blood vessel by using information that the peak-to-peak interval of the sphygmus wave is inversely proportional to the optimum rate of pressure change of the blood vessel. ### Claim 2 (depends on 1) The blood pressure measuring apparatus of claim 1, wherein the compression unit compresses the blood vessel at a constant pressure so that the blood vessel is not closed to detect the peak-to-peak interval of the sphygmus wave. ### Claim 3 (depends on 1) The blood pressure measuring apparatus of claim 1, wherein the blood pressure detecting unit detects the blood pressure of the subject by using an oscillometric method. ### Claim 4 (depends on 1) The blood pressure measuring apparatus of claim 1, wherein the blood vessel is a radial artery of the wrist. ### Claim 5 (depends on 4) The blood pressure measuring apparatus of claim 4, further comprising a wrist band attached around the subject's wrist. ### Claim 6 (depends on 1) The blood pressure measuring apparatus of claim 1, further comprising a compression unit controlling unit for determining an optimum value of a control variable for driving the compression unit so that the compression unit is driven to correspond to the optimum rate of pressure change of the blood vessel. ### Claim 7 (depends on 6) The blood pressure measuring apparatus of claim 6, wherein the control variable is any one of a duty ratio, a current value or a voltage value of a signal input to the compression unit in order to drive the compression unit. ### Claim 8 (depends on 6) The blood pressure measuring apparatus of claim 6, wherein the compression unit controlling unit detects a plurality of values of the rate of pressure change of the blood vessel respectively corresponding to a plurality of values of the control variable, which are different from each other, and which determine a formula representing a relation between the control variable and the rate of pressure change of the blood vessel by using the plurality of values of the rate of pressure change of the blood vessel, and determines an optimum value of the control variable by substituting the optimum rate of pressure change for the rate of pressure change of the blood vessel in the formula. ### Claim 9 A blood pressure measuring method comprising: a pulse detecting operation in which a peak-to-peak interval of a sphygmus wave of a subject is detected from the sphygmus wave of the subject; an optimum rate of pressure change detecting operation in which an optimum rate of pressure change of a blood vessel is detected using the peak-to-peak interval of the sphygmus wave; a compression operation in which the blood vessel is compressed at the optimum rate of pressure change, or a decompression operation in which the blood vessel is compressed so as to be closed, and is then decompressed at the optimum rate of pressure change; and a blood pressure detecting operation in which blood pressure of the subject is detected based on the sphygmus wave and the pressure of the blood vessel of the subject, which are detected during the compression operation, wherein the optimum rate of pressure change detecting unit detects the optimum rate of pressure change of the blood vessel by using information that the peak-to-peak interval of the sphygmus wave is inversely proportional to the optimum rate of pressure change of the blood vessel. ### Claim 10 (depends on 9) The blood pressure measuring method of claim 9, wherein the pulse detecting operation comprises compressing the blood vessel at a constant pressure so that the blood vessel of the subject is not closed. ### Claim 11 (depends on 9) The blood pressure measuring method of claim 9, wherein the pulse detecting operation comprises detecting the blood pressure of the subject by using an oscillometric method. ### Claim 12 (depends on 9) The blood pressure measuring method of claim 9, wherein the blood vessel is a radial artery of the wrist. ### Claim 13 (depends on 9) The blood pressure measuring method of claim 9, wherein the compression operation is performed by a compression unit, and wherein the compression operation further comprises determining an optimum value of a control variable for driving the compression unit so that the compression unit is driven to correspond to the optimum rate of pressure change of the blood vessel. ### Claim 14 (depends on 13) The blood pressure measuring method of claim 13, wherein the control variable is any one of a duty ratio, a current value or a voltage value of an input signal input to the compression unit in order to drive the compression unit. ### Claim 15 (depends on 13) The blood pressure measuring method of claim 13, wherein the determining an optimum value of a control variable comprises detecting a plurality of values of the rate of pressure change of the blood vessel respectively corresponding to a plurality of values of the control variable, which are different from each other, determining a formula representing a relation between the control variable and the rate of pressure change of the blood vessel by using the plurality of values of the rate of pressure change of the blood vessel, and determining an optimum value of the control variable by substituting the optimum rate of pressure change for the rate of pressure change of the blood vessel in the formula.