# US 10,945,702 B2 · Doppler ultrasound system for diagnosing carotid stenosis > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,945,702 B2 - Document ID: US10945702B2 - Status: Granted - Kind: B2 - Application number: 14/906,966 - Filed: 2014-07-02 - Published: 2016-06-09 - Granted: 2021-03-16 - Earliest claimed: 2013-07-24 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Krishnamoorthy Palanisamy; Sushanth Govinahallisathyanarayana; Rajendra Singh Sisodia; Nagaraju Bussa; Shankar Mosur Venkatesan; Shriram Sethuraman; John Petruzzello; Ajay Anand; Shiwei Zhou; Ramon Quido Erkamp; Vikram Basawaraj Patil Okaly - Web page: https://patentgrep.com/patent/US10945702B2 ## CPC - A61B 8/06: Measuring blood flow - A61B 8/0891: {for diagnosis of blood vessels} - A61B 8/4483: {characterised by features of the ultrasound transducer} - A61B 8/483: {involving the acquisition of a 3D volume of data} - 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 diagnostic ultrasound system for carotid artery diagnosis has a two dimensional array probe with a low element count and relatively large element size which can cover an area of the carotid artery at its bifurcation. The elements are operated independently with no phasing, and detect Doppler flow spatially beneath each element. The system produces maps of carotid blood flow in two or three dimensions and can assemble an extended view of the flow by matching segments of the carotid flow as the probe is moved over the vessel. Once the carotid artery has been localized, the degree of stenosis is assessed by automated measurements of peak systolic velocity and blood flow turbulence. ## Claims ### Claim 1 A Doppler ultrasound system for diagnosis of a carotid artery comprising: a probe that comprises a two dimensional non-phased transducer array of ultrasound transducer elements arranged in rows and columns of transducer elements, the transducer elements further being canted at a Doppler angle away from orthogonal to the carotid artery when the probe is disposed over the carotid artery, the transducer elements disposed in an overlying layer of transducer lens material; a beamformer coupled to the transducer elements of the non-phased transducer array and adapted to (i) independently actuate each transducer element, in a firing sequence of the transducer elements, to transmit pulses into a body in a pulsed wave mode and sequentially cover a range of depths and (ii) to receive Doppler signals independently from beneath each transducer element in response to the transmitted pulses, wherein the pulse wave mode provides depth resolution of the received Doppler signals; a Doppler processor, coupled to the beamformer and responsive to the received Doppler signals for producing Doppler values for each transducer element; a spectral Doppler processor, responsive to the Doppler values for producing a spectral Doppler profile; a peak systolic velocity (PSV) estimator responsive to the Doppler values, which produce estimates of peak systolic velocity; a turbulence estimator, responsive to the spectral Doppler profile, for producing estimates of flow turbulence; and a stenosis detector for producing an indication of stenosis as a function of (i) peak systolic velocity estimates and (ii) turbulence estimates. ### Claim 2 (depends on 1) The Doppler ultrasound system of claim 1, wherein the turbulence estimator further comprises an estimator for producing estimates of flow turbulence which are related to broadening of the spectral Doppler profile. ### Claim 3 (depends on 2) The Doppler ultrasound system of claim 2, wherein the stenosis detector is further operable to distinguish a carotid bifurcation from a carotid stenosis. ### Claim 4 (depends on 3) The Doppler ultrasound system of claim 3, wherein the stenosis detector distinguishes the carotid bifurcation by a normal peak systolic velocity of 125 cm/s or less and high turbulence, and distinguishes the stenosis by a high peak velocity of 125 cm/s or greater and high turbulence. ### Claim 5 (depends on 1) The Doppler ultrasound system of claim 1, wherein the spectral Doppler profile further comprises spectrogram; and wherein the spectral Doppler processor is still further configured for extracting an envelope of the spectrogram. ### Claim 6 (depends on 5) The Doppler ultrasound system of claim 5, wherein the spectral Doppler processor is still further configured for extracting an upper trace of the spectrogram and a lower trace of the spectrogram. ### Claim 7 (depends on 6) The Doppler ultrasound system of claim 6, wherein the turbulence estimator is responsive to the extraction of the upper and lower traces of the spectrogram to estimate turbulence by using an area of the spectrogram between the upper and lower traces in proportion to an area of the spectrogram under the upper trace. ### Claim 8 (depends on 1) The Doppler ultrasound system of claim 1, further comprising a vessel localization processor, responsive to the Doppler values for each transducer element and their spatial relationship to a carotid artery for producing a carotid artery vessel map. ### Claim 9 (depends on 8) The Doppler ultrasound system of claim 8, further comprising a Doppler angle estimator, responsive to the carotid artery vessel map, for estimating a Doppler angle. ### Claim 10 (depends on 9) The Doppler ultrasound system of claim 9, wherein the Doppler values produced by the Doppler processor further comprises velocity values, and wherein the PSV estimator produces estimates of the peak systolic velocity from (i) the estimated Doppler angle and (ii) a maximum value of the velocity values. ### Claim 11 (depends on 10) The Doppler ultrasound system of claim 10, wherein the maximum value of the velocity values is computed from the spectral Doppler profile. ### Claim 12 (depends on 1) The Doppler ultrasound system of claim 1, wherein the spectral Doppler profile is not displayed by the non-imaging Doppler ultrasound system. ### Claim 13 (depends on 1) The Doppler ultrasound system of claim 1, wherein the indication of stenosis further comprises an estimate of a degree of stenosis ranging from (i) normal to (ii) total occlusion. ### Claim 14 (depends on 1) The Doppler ultrasound system of claim 1, wherein the Doppler ultrasound system is configured to operate in a probe placement mode, comprising the steps of: activating a subset of the ultrasound transducer elements and acquiring a Doppler spectrum from the subset of Doppler ultrasound elements; computing a sum-plot integration of Doppler power in a selected frequency range; and identifying a transducer element in the subset of ultrasound transducer elements that is directly above a vessel from the magnitude of sum-plot values. ### Claim 15 (depends on 14) The Doppler ultrasound system of claim 14, wherein the probe further comprises at least one indicator providing an indication of a direction to adjust the probe or an indication that the probe is correctly positioned over a carotid bifurcation. ### Claim 16 (depends on 14) The Doppler ultrasound system of claim 14, wherein the Doppler ultrasound system further configured to operate in a vessel mapping mode, comprising the step of producing a grid-like map of the location and position of the carotid artery beneath each element of the probe. ### Claim 17 (depends on 1) The Doppler ultrasound system of claim 1, wherein the transducer elements are at least 3 mm by 3 mm in size. ### Claim 18 A method for diagnosis of stenosis in a carotid artery comprising the steps of: determining placement of a Doppler ultrasound probe comprising a two-dimensional array of non-phasing ultrasound transducer elements based on indications from the probe; independently actuate each transducer element of the two-dimensional array of non-phasing ultrasound transducer elements, in a firing sequence of the transducer elements, to transmit pulses into a body in a pulsed wave mode and sequentially cover a range of depths receive Doppler signals independently from beneath each transducer element in response to the transmitted pulses, wherein the pulse wave mode provides depth resolution of the received Doppler signals; producing Doppler values for each transducer element; producing a spectral Doppler profile from the Doppler values; producing estimates of peak systolic velocity from the Doppler signals; producing estimates of flow turbulence from the Doppler signals; and producing an indication of stenosis as a function of (i) peak systolic velocity estimates and (ii) turbulence estimates. ### Claim 19 (depends on 18) The method of claim 18, wherein the Doppler profile comprises a spectrogram and producing a turbulence estimate comprises: extracting an upper and a lower trace from the spectrogram and; calculating turbulence as an area of the spectrogram between the upper and lower traces in proportion to an area of the spectrogram under the upper trace.