# US 11,896,421 B2 · Monitoring blood distribution in a subject > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,896,421 B2 - Document ID: US11896421B2 - Status: Granted - Kind: B2 - Application number: 16/967,555 - Filed: 2019-02-05 - Published: 2021-03-25 - Granted: 2024-02-13 - Earliest claimed: 2018-02-08 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Franciscus Hendrikus Van Heesch; Nico Maris Adriaan De Wild; Rick Bezemer; Igor Wilhelmus Franciscus Paulussen - Web page: https://patentgrep.com/patent/US11896421B2 ## CPC - A61B 8/06: Measuring blood flow - A61B 8/488: {involving Doppler signals} - A61B 8/5223: {for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012)} - G16H 50/30: for calculating health indices; for individual health risk assessment - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA ## Abstract A system for monitoring blood distribution in a subject, the system comprising a processor(38) responsive to Doppler ultrasound data representing arterial blood flow in at least two different locations of the subject, such as the neck and the arm, to obtain velocity (C, B1, B2, B3) or volumetric flow rate at each location, to monitor changes in a predetermined function of the blood flows, and to provide an output indicative of the monitored changes which may result from blood volume centralization. This can indicate the onset of hypovolemia or hypervolemia. ## Claims ### Claim 1 A system for monitoring blood distribution in a subject, the system comprising: a processor adapted to: receive Doppler ultrasound data representing a first arterial blood flow value at a first location and a second arterial blood flow value at a second location of the subject; perform a first comparison of the first arterial blood flow value and the second arterial blood flow value, wherein the first comparison comprises calculation of a ratio between the first arterial blood flow value and the second arterial blood flow value, wherein the ratio is associated with the blood distribution in the subject; perform a second comparison of the ratio to a first threshold associated with hypovolemia and to a second threshold associated with hypervolemia; detect the hypovolemia, when the ratio is greater than the first threshold; detect the hypervolemia when the ratio is less than the second threshold; and generate an output indicative of the hypovolemia when the ratio is greater than the first threshold and indicative of the hypervolemia when the ratio is less than the second threshold. ### Claim 2 (depends on 1) The system according to claim 1, wherein the first arterial blood flow value comprises an arterial blood flow velocity integrated over a period of a heart beat of the subject. ### Claim 3 (depends on 1) The system according to claim 1, wherein the processor is responsive to a measure of a diameter of the artery at the first location, and wherein a volumetric rate of flow of the blood is based on the diameter and a flow velocity. ### Claim 4 (depends on 3) The system according to claim 3, wherein the first arterial blood flow value comprises the volumetric flow rate integrated over a period of a heart beat of the subject. ### Claim 5 (depends on 1) The system according to claim 1, comprising a fluid management system configured to: provide fluid to the subject; and control a provision of the fluid responsive to the output indicative of the hypovolemia or the hypervolemia. ### Claim 6 (depends on 1) The system according to claim 1, wherein the processor is configured to generate an output indicative of a cardiac output of the subject, based on blood perfusion in at least the first location obtained by integrating over time a blood flow velocity at the first location multiplied by a diameter of the artery at the first location. ### Claim 7 (depends on 1) The system according to claim 1, comprising at least two Doppler ultrasound probes configured to measure an arterial blood flow velocity in the at least the first location and the second location of the subject and to provide the Doppler ultrasound data to the processor. ### Claim 8 (depends on 1) The system according to claim 1, comprising at least one Doppler ultrasound probe configured to image an artery at one of the the first location or the second location of the subject to provide to the processor a diameter of the artery. ### Claim 9 (depends on 8) The system according to claim 8, comprising a subject monitor configured to display the output indicative of the hypovolemia or the hypervolemia. ### Claim 10 (depends on 1) The system according to claim 1, wherein the Doppler ultrasound data represents a plurality of first arterial blood flow values at the first location and a plurality of second arterial blood flow values at the second location, and wherein the processor is further adapted to monitor the ratio over time based on the plurality of the first arterial blood flow values and the plurality of the second arterial blood flow values. ### Claim 11 (depends on 10) The system according to claim 10, wherein the processor is further adapted to: detect, based on the monitoring of the ratio over time, an onset of the hypovolemia or an onset of the hypervolemia. ### Claim 12 (depends on 10) The system according to claim 10, wherein the ratio comprises a mean of the plurality of first arterial blood flow values over a mean of the plurality of second arterial blood flow values. ### Claim 13 (depends on 1) The system according to claim 1, comprising a speaker configured to sound an alarm corresponding to the output indicative of the hypovolemia or the hypervolemia. ### Claim 14 A method of monitoring blood distribution in a subject, comprising: receiving Doppler ultrasound data representing a first arterial blood flow value at a first location and a second arterial blood flow value at a second location of the subject; performing a first comparison of the first arterial blood flow value and the second arterial blood flow value, wherein the first comparison comprises calculation of a ratio between the first arterial blood flow value and the second arterial blood flow value, wherein the ratio is associated with the blood distribution in the subject; performing a second comparison of the ratio to a first threshold associated with hypovolemia and to a second threshold associated with hypervolemia; detecting the hypovolemia when the ratio is greater than the first threshold; detecting the hypervolemia when the ratio is less than the second threshold; and generating an output indicative of the hypovolemia when the ratio is greater than the first threshold and indicative of the hypervolemia when the ratio is less than the second threshold. ### Claim 15 (depends on 14) The method according to claim 14, wherein the first location and second location of the subject are at substantially different distances from a heart. ### Claim 16 (depends on 15) The method of claim 15, wherein the first location comprises a carotid artery, and wherein the second location comprises a brachial, femoral or radial artery. ### Claim 17 (depends on 14) The method of claim 14, comprising at least one of: displaying the output indicative of the hypovolemia or the hypervolemia on a subject monitor; or sounding an alarm corresponding to the output indicative of the hypovolemia or the hypervolemia with a speaker. ### Claim 18 A non-transitory computer readable medium comprising a plurality of instructions stored thereon, wherein, when executed by a processor, the plurality of instructions is configured to cause the processor to: receive Doppler ultrasound data representing a first arterial blood flow value at a first location and a second arterial blood flow value at a second location of a subject; perform a first comparison of the first arterial blood flow value and the second arterial blood flow value, wherein the first comparison comprises calculation of a ratio between the first arterial blood flow value and the second arterial blood flow value, wherein the ratio is associated with a blood distribution in the subject; perform a second comparison of the ratio to a first threshold associated with hypovolemia and to a second threshold associated with hypervolemia; detect the hypovolemia when the ratio is greater than the first threshold; detect the hypervolemia in the subject when the ratio is less than the second threshold; and generate an output indicative of the hypovolemia when the ratio is greater than the first threshold and indicative of the hypervolemia when the ratio is less than the second threshold.