# US 2019/0167195 A1 · Systems and methods for performing diagnostic procedures for a volume clamp finger cuff > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167195 A1 - Document ID: US20190167195A1 - Status: Published application - Kind: A1 - Application number: 16/179,643 - Filed: 2018-11-02 - Published: 2019-06-06 - Earliest claimed: 2017-12-04 - Assignees: Edwards Lifesciences Corporation - Applicants: Edwards Lifesciences Corporation - Inventors: Blake W. Axelrod; Alexander H. Siemons; Virginia Qi Lin; Leah Paige Gaffney; Laura J. Livant - Web page: https://patentgrep.com/patent/US20190167195A1 ## CPC - A61B 5/6843: {Monitoring or controlling sensor contact pressure} - A61B 5/021: Measuring pressure in heart or blood vessels - A61B 5/02116: {of pulse wave amplitude (A61B5/02225 takes precedence)} - A61B 5/02241: {of small dimensions, e.g. adapted to fingers} - A61B 5/02255: {the pressure being controlled by plethysmographic signals, e.g. derived from optical sensors} - A61B 5/0261: {using optical means, e.g. infrared light} - A61B 5/0295: using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract Disclosed is a system to monitor a finger cuff connectable to a patient's finger to be used in measuring the patient's blood pressure by a blood pressure measurement system utilizing the volume clamp method and to measure the plethysmogram of the finger cuff. The system comprises the finger cuff that includes an enclosing portion that encloses a patient's finger. The enclosing portion includes a bladder and a light emitting diode (LED) and photodiode (PD) pair. The system further comprises a processor to: command applying pneumatic pressure to the bladder of the finger cuff from a low pressure to a high pressure; measure the plethysmogram of the finger cuff as the pressure increases from the low pressure to the high pressure; and determine fitness of the finger cuff on the patient's finger based on the measured plethysmogram. When the finger cuff is placed around the patient's finger, the bladder and the LED-PD pair aid the processor in measuring the plethysmogram. ## Claims ### Claim 1 A system to monitor a finger cuff connectable to a patient's finger to be used in measuring the patient's blood pressure by a blood pressure measurement system utilizing the volume clamp method and to measure the plethysmogram of the finger cuff, the system comprising: the finger cuff including an enclosing portion that encloses a patient's finger, the enclosing portion including a bladder and a light emitting diode (LED) and photodiode (PD) pair; and a processor configured to: command applying pneumatic pressure to the bladder of the finger cuff from a low pressure to a high pressure; measure the plethysmogram of the finger cuff as the pressure increases from the low pressure to the high pressure; and determine fitness of the finger cuff on the patient's finger based on the measured plethysmogram, wherein, when the finger cuff is placed around the patient's finger, the bladder and the LED-PD pair aid in measuring the plethysmogram. ### Claim 2 (depends on 1) The system of claim 1, wherein the processor is further to command releasing the pressure from the bladder and to observe pressure decay, and to measure the plethysmogram of the finger cuff throughout the pressure decay. ### Claim 3 (depends on 1) The system of claim 1, wherein determining the fitness of the finger cuff on the patient's finger comprises determining whether the finger cuff is loose, properly fitted, or too tight. ### Claim 4 (depends on 3) The system of claim 3, wherein determining whether the finger cuff is loose comprises: determining whether the pulsatility at a high end of the pressure is at least a predetermined percentage lower than a peak pulsatility. ### Claim 5 (depends on 4) The system of claim 4, wherein the processor is further to instruct an operator to reapply the finger cuff more tightly if the pulsatility at the high end of the pressure is not at least the predetermined percentage lower than the peak pulsatility. ### Claim 6 (depends on 3) The system of claim 3, wherein determining whether the finger cuff is properly fitted comprises: determining whether the pulsatility at a low end of the pressure is low. ### Claim 7 (depends on 3) The system of claim 3, wherein determining whether the finger cuff is too tight comprises: determining whether the pulsatility at a low end of the pressure is at least a predetermined percentage lower than a peak pulsatility. ### Claim 8 (depends on 7) The system of claim 7, wherein the processor is further to instruct an operator to loosen the finger cuff if the pulsatility at the low end of the pressure is not at least the predetermined percentage lower than the peak pulsatility. ### Claim 9 (depends on 6) The system of claim 6, wherein after the finger cuff is determined to be properly fitted, the finger cuff is used in measuring the patient's blood pressure by the blood pressure measurement system utilizing the volume clamp method. ### Claim 10 (depends on 1) The system of claim 1, wherein the processor is further configured to: determine whether blood volume of the patient's finger measured at the end of recovery time has returned to an initial value measured at the low pressure; and in response to determining that the blood volume of the patient's finger measured at the end of the recovery time has not returned to the initial value: determine that the patient's perfusion is too low for the blood pressure measurement system to operate properly, and instruct an operator to increase the patient's perfusion by warming the hand or to select a different pressure monitoring technology. ### Claim 11 A method to monitor a finger cuff connectable to a patient's finger to be used in measuring the patient's blood pressure by a blood pressure measurement system utilizing the volume clamp method and to measure the plethysmogram of the finger cuff, the finger cuff including an enclosing portion that encloses a patient's finger, the enclosing portion including a bladder and a light emitting diode (LED) and photodiode (PD) pair, the method comprising: applying pneumatic pressure to the bladder of the finger cuff from a low pressure to a high pressure; measuring the plethysmogram of the finger cuff as the pressure increases from the low pressure to the high pressure; and determining fitness of the finger cuff on the patient's finger based on the measured plethysmogram, wherein, when the finger cuff is placed around the patient's finger, the bladder and the LED-PD pair aid in measuring the plethysmogram. ### Claim 12 (depends on 11) The method of claim 11, further comprising: releasing the pressure from the bladder and observing pressure decay, and measuring the plethysmogram of the finger cuff throughout the pressure decay. ### Claim 13 (depends on 11) The method of claim 11, wherein determining the fitness of the finger cuff on the patient's finger comprises determining whether the finger cuff is loose, properly fitted, or too tight. ### Claim 14 (depends on 13) The method of claim 13, wherein determining whether the finger cuff is loose comprises: determining whether the pulsatility at a high end of the pressure is at least a predetermined percentage lower than a peak pulsatility. ### Claim 15 (depends on 14) The method of claim 14, further comprising: instructing an operator to reapply the finger cuff more tightly if the pulsatility at the high end of the pressure is not at least the predetermined percentage lower than the peak pulsatility. ### Claim 16 (depends on 13) The method of claim 13, wherein determining whether the finger cuff is properly fitted comprises: determining whether the pulsatility at a low end of the pressure is low. ### Claim 17 (depends on 13) The method of claim 13, wherein determining whether the finger cuff is too tight comprises: determining whether the pulsatility at a low end of the pressure is at least a predetermined percentage lower than a peak pulsatility. ### Claim 18 (depends on 17) The method of claim 17, further comprising: instructing an operator to loosen the finger cuff if the pulsatility at the low end of the pressure is not at least the predetermined percentage lower than the peak pulsatility. ### Claim 19 (depends on 16) The method of claim 16, wherein after the finger cuff is determined to be properly fitted, the finger cuff is used in measuring the patient's blood pressure by the blood pressure measurement system utilizing the volume clamp method. ### Claim 20 (depends on 11) The method of claim 11, further comprising: determining whether blood volume of the patient's finger measured at the end of recovery time has returned to an initial value measured at the low pressure; in response to determining that the blood volume of the patient's finger measured at the end of the recovery time has not returned to the initial value: determining that the patient's perfusion is too low for the blood pressure measurement system to operate properly, and instructing an operator to increase the patient's perfusion by warming the hand or to select a different pressure monitoring technology.