# US 7,611,471 B2 · Heart diagnosis system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,611,471 B2 - Document ID: US7611471B2 - Status: Granted - Kind: B2 - Application number: 10/477,606 - Filed: 2002-05-28 - Published: 2004-07-15 - Granted: 2009-11-03 - Earliest claimed: 2001-05-28 - Assignees: HD Medical Inc. - Inventors: Arvind Thiagarajan - Web page: https://patentgrep.com/patent/US7611471B2 ## CPC - A61B 7/04: Electric stethoscopes - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract The invention provides a method and apparatus for analysing a heart signal from a beating heart, the method comprising: collecting the heart signal, performing a cluster analysis of the signal to identify the first heart sound and the second heart sound, determining an energy envelope for each of a plurality of regions in the signal, determining the area of each of the energy envelopes, and classifying features in the signal by an analysis incorporating at least the areas, whereby one or more characteristics of the heart can be determined. ## Claims ### Claim 1 A method of analysing a heart signal from a beating heart comprising: collecting said heart signal; with a heart diagnosis system; and analyzing said heart signal with said heart diagnosis system by: identifying peaks within said heart signal, wherein the peaks are regions where the amplitude of said heart signal is higher than a predetermined level; calculating characteristic parameters of the peaks; clustering the peaks based on at least one of the calculated characteristic parameters of the peaks; eliminating any false peaks of said peaks due to artifacts and breathing sounds; identifying first heart sounds and second heart sounds based on the clusters of the peaks, and then identifying systoles and diastoles, wherein the identification of first heart sounds, second heart sounds, systoles and diastoles does not need external timing reference; dividing each of the identified systoles and diastoles into a plurality of regions and then determining an energy envelope for each of the plurality of regions; and determining an area for each of said energy envelopes; and classifying said heart signal by an analysis incorporating at least said areas. ### Claim 2 (depends on 1) A method as claimed in claim 1, wherein the analysis incorporating at least said areas comprises a step of comparing one or more of said areas with at least one other of said areas. ### Claim 3 (depends on 2) A method as claimed in claim 2, wherein the comparing of one or more of said areas with at least one other of said areas comprises steps of: determining one or more ratios, each comprising the ratio of one of said areas and another of said areas, and comparing said ratios with respective predetermined threshold values for said ratios, and thereby determining one or more characteristics of said heart signal. ### Claim 4 (depends on 2) A method as claimed in claim 2, wherein the comparing of one or more of said areas with at least one other of said areas comprises steps of: comparing one or more of said areas with respective predetermined threshold values for said areas, and thereby determining one or more characteristics of said heart signal. ### Claim 5 (depends on 1) A method as claimed in claim 1, further comprising step of: smoothing each of said energy envelopes. ### Claim 6 (depends on 1) A method as claimed in claim 1, wherein each of said energy envelopes is a Shannon's energy envelope. ### Claim 7 (depends on 1) A method as claimed in claim 1, wherein the step of determining the energy envelope comprises determining the energy envelope for the systolic region and for the diastolic region. ### Claim 8 (depends on 1) A method as claimed in claim 1, wherein the step of determining the energy envelope comprises determining the energy envelope for a plurality of regions within each of the systolic and diastolic regions. ### Claim 9 (depends on 1) A method as claimed in claim 1, wherein the step of determining the energy envelope comprises determining the energy envelope for at least three regions within the systolic region and for at least three regions within the diastolic region. ### Claim 10 (depends on 1) A method as claimed in claim 1, wherein said heart signal is a sound signal. ### Claim 11 (depends on 1) A method as claimed in claim 1, further comprising step of prompting a user for user input if unable to form a diagnosis, said user input including a user interpretation of said heart signal. ### Claim 12 (depends on 1) A method as claimed in claim 1, wherein the classifying of said heart signal includes detecting at least one of a systolic murmur, a diastolic murmur and a continuos murmur. ### Claim 13 (depends on 1) A method as claimed in claim 1, wherein the artifacts include motion artifacts. ### Claim 14 An apparatus for analysing a heart signal from a beating heart, said apparatus comprising: a detector for collecting said heart signal; data processing means for: receiving said heart signal from the detector; identifying peaks within said heart signal, wherein the peaks are regions where the amplitude of said heart signal is higher than a predetermined level; calculating characteristic parameters of the peaks; clustering the peaks based on at least one of the calculated characteristic parameters of the peaks; eliminating any false peaks of said peaks due to artifacts and breathing sounds; identifying first heart sounds and second heart sounds based on the clusters of the peaks, and then identifying systoles and diastoles, wherein the identification of first heart sounds, second heart sounds, systoles and diastoles does not need external timing reference; dividing each of the identified systoles and diastoles into a plurality of regions and then determining an energy envelope for each of the plurality of regions; and determining an area for each of said energy envelopes; and forming a classification of said signal by an analysis incorporating at least said area; and data output means for displaying said classification. ### Claim 15 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to compare one or more of said areas with at least one other of said areas. ### Claim 16 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to determine one or more ratios, each comprising the ratio of one of said areas and another of said areas, and to compare said ratios with respective predetermined threshold values for said ratios, and thereby determine one or more characteristics of said heart signal. ### Claim 17 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to compare one or more of said areas with respective predetermined threshold values for said areas, and thereby determining one or more characteristics of said heart signal. ### Claim 18 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is further operable to smooth each of said energy envelopes. ### Claim 19 (depends on 14) An apparatus as claimed in claim 14, wherein each of said energy envelopes is a Shannon's energy envelope. ### Claim 20 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to determine the energy envelope for the systolic region and for diastolic region. ### Claim 21 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to determine the energy envelope for a plurality of regions within each of the systolic and diastolic regions. ### Claim 22 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means is operable to determine the energy envelope for the energy envelope for at least three regions within the systolic region and for at least three regions within the diastolic region. ### Claim 23 (depends on 14) An apparatus as claimed in claim 14, wherein said heart signal is a sound signal. ### Claim 24 (depends on 14) An apparatus as claimed in claim 14, wherein said data processing means further includes means for prompting a user for user input and for receiving use input, and is operable to prompt said user for user input if unable to form a diagnosis, said user input including a user interpretation of said heart signal.