# US 12,599,311 B2 · Device for measuring a pressure differential > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,599,311 B2 - Document ID: US12599311B2 - Status: Granted - Kind: B2 - Application number: 17/920,905 - Filed: 2021-04-23 - Published: 2023-06-15 - Granted: 2026-04-14 - Earliest claimed: 2020-04-24 - Assignees: Clinical Technology Limited - Applicants: Clinical Technology Limited - Inventors: Gwilym Alban Davies; Brian Stewart Hoyle - Web page: https://patentgrep.com/patent/US12599311B2 ## CPC - A61B 5/03: Measuring fluid pressure within the body other than blood pressure, e.g. cerebral pressure {; Measuring pressure in body tissues or organs (determining bladder or urethral pressure A61B5/205)} - A61B 5/036: {by means introduced into body tracts (A61B5/032 and A61B5/035 take precedence)} - A61B 5/6848: {Needles} - A61B 2560/0223: of calibration, e.g. protocols for calibrating sensors - A61B 2562/0247: Pressure sensors - A61B 2562/028: Microscale sensors, e.g. electromechanical sensors [MEMS] - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A device for measuring a pressure differential comprises a tube, at least one pressure sensor and a processor. The tube comprises a closed insertion portion for insertion into a body, the insertion portion having an insertion end and an internal bore in communication with ambient pressure via an opening in the tube. The sensor is located in or on the insertion portion and comprises an internally facing region in communication with the bore and an externally facing region in communication with an exterior of the tube. The processor is configured to provide a stimulus, which may be an electrical stimulus, to the pressure sensor so that when the stimulus is provided, the pressure sensor provides a measurable response wherein the processor correlates the response with the pressure differential between the exterior of the tube and the bore. The measurable response may be indicative of a change in pressure differential between the exterior of the tube and the bore. There may be a plurality of pressure sensors, in which case at least two of the sensors may have different resonant frequencies at the same pressure differential. The insertion portion may comprise at least one aperture sealed by at least one pressure sensor. The pressure sensor may comprise an electromechanical or micro-electromechanical material and may comprises a piezoelectric and/or electrocapacitive sensor. The externally facing region of the pressure sensor may comprise a coating, which may be electrically insulative. ## Claims ### Claim 1 A device for measuring a pressure differential comprising: a tube comprising a closed insertion portion for insertion into a body, the closed insertion portion having an insertion end, and an internal bore which is in communication with ambient pressure via an opening in the tube; at least one pressure sensor located in or on the closed insertion portion, the at least one pressure sensor comprising an internally facing region which is in communication with the internal bore and an externally facing region which is in communication with an exterior of the tube; and a processor configured to provide a stimulus to mechanically excite the at least one pressure sensor so that when the stimulus is provided, the at least one pressure sensor provides a measurable resonant response, wherein the processor correlates the measurable resonant response with the pressure differential between the exterior of the tube and the internal bore. ### Claim 2 (depends on 1) The device according to claim 1, in which the at least one pressure sensor is located proximal to the insertion end. ### Claim 3 (depends on 1) The device according to claim 1, comprising a plurality of pressure sensors, in which at least two of the plurality of pressure sensors have different resonant frequencies at a same pressure differential. ### Claim 4 (depends on 1) The device according to claim 1, in which the externally facing region of the at least one pressure sensor is aligned with the exterior of the tube. ### Claim 5 (depends on 1) The device according to claim 1, in which the closed insertion portion comprises at least one sealed aperture, in which each aperture is sealed by at least one pressure sensor. ### Claim 6 (depends on 1) The device according to claim 1, in which the at least one pressure sensor comprises an electro-mechanical or micro-electromechanical (MEMs) material. ### Claim 7 (depends on 1) The device according to claim 1, in which the at least one pressure sensor comprises a piezoelectric pressure sensor or an electro-capacitive pressure sensor. ### Claim 8 (depends on 1) The device according to claim 1, in which the stimulus comprises an electrical stimulus. ### Claim 9 (depends on 1) The device according to claim 1, in which the measurable resonant response is an electrical response. ### Claim 10 (depends on 1) The device according to claim 1, in which the measurable resonant response is indicative of an electrical impedance of the at least one pressure sensor. ### Claim 11 (depends on 1) The device according to claim 1, in which the measurable resonant response is indicative of a resonant frequency of the at least one pressure sensor. ### Claim 12 (depends on 1) The device according to claim 1, in which the measurable resonant response is indicative of a change in pressure differential between the exterior of the tube and the internal bore. ### Claim 13 (depends on 1) The device according to claim 1, further comprising a user-holdable portion which is in connection with the tube, in which the internal bore is in communication with ambient pressure via the user-holdable portion. ### Claim 14 (depends on 13) The device according to claim 13 in which the user-holdable portion comprises a penetration restraint mechanism operable to limit a penetration depth of the tube. ### Claim 15 (depends on 1) The device according to claim 1, in which the tube is a needle. ### Claim 16 (depends on 1) A method of measuring a pressure differential using the device according to claim 1, the method comprising the steps of: providing a stimulus to mechanically excite the at least one pressure sensor so that the pressure sensor provides a measurable resonant response; measuring the measurable resonant response, wherein the measurable resonant response is indicative of the pressure differential between the exterior of the tube and the internal bore, the internal bore being in communication with ambient pressure via the opening in the tube; and correlating the measurable resonant response with the pressure differential between the exterior of the tube and the internal bore. ### Claim 17 (depends on 16) The method according to claim 16 further comprising the step of calibrating the device, the step of calibrating the device comprising the sub-steps of: providing a stimulus to mechanically excite the at least one pressure sensor whilst maintaining the externally facing region of the at least one pressure sensor at ambient pressure so that the at least one pressure sensor provides a measurable resonant calibration response indicative of the pressure differential between the exterior of the tube and the internal bore; measuring the measurable resonant calibration response; and correlating the measured resonant calibration response with a pressure differential of zero. ### Claim 18 (depends on 16) The method according to claim 16 in which the stimulus is an alternating and/or pulsed electrical stimulus. ### Claim 19 (depends on 16) The method according to claim 16 in which a frequency of the stimulus is varied. ### Claim 20 (depends on 16) The method according to claim 16 in which a frequency of the stimulus is increased or decreased from a first frequency to a second frequency.