MXPA05013006A - Method and system for analyzing cardiovascular sounds - Google Patents

Abstract

A method and system for analyzing sounds originating in at least a portion of an individualâÇÖs cardiovascular system. N transducers, where N is an integer, are fixed on a surface of the individual over the thorax. The ith transducer is fixed at a location xi and generates an initial signal P(xi,t) indicative of pressure waves at the location xi;for i=1 to N. the signals P(xi,t)are processes so as to generate filtered signals in which at least one component of the signals P(xi,t)not arising from cardiovascular sounds has been removed. The filtered signals may be used for generating an image of the at least portion of the cardiovascular system.

Description

METHOD AND SYSTEM FOR ANALYZING CARDIOVASCULAR SOUNDS FIELD OF THE INVENTION This invention relates to medical devices and methods, and more particularly to those devices and methods for analyzing body sounds. BACKGROUND OF THE INVENTION Body sounds are routinely used by physicians in the diagnosis of various diseases. A doctor can place a stethoscope on a person's chest or back and monitor breathing or heart rate to detect upsetting lung or heart sounds (this is abnormal or unexpected). The identification of pulmonary or cardiac upwelling sounds often provides important information about pulmonary or cardiac abnormalities. It is also known to place one or more microphones on a person's chest or back and record lung sounds. U.S. Patent No. 6,139,505 describes a system, in which a plurality of microphones are placed around the chest of a patient. The recordings of the microphones during inhalation and exhalation are displayed on a screen or printed on paper. The recordings are then visually examined by the doctor in order to detect lung disease in the patent. Kompis et al (Chest, 120 (4), 2001) writes a system in which M microphones are placed on a patient's chest, and lung sounds are recorded. The recordings generate M linear equations that are solved using the least squares adjustment. The solution of the system is used to determine the place in the lungs where the sound source detected in the recordings is located. US Patent 5,285,788 discloses a system for tissue imaging by ultrasound having an acoustic transducer and means for image formation to produce tissue images. The system also includes means of Doppler imaging to produce a scanned acoustic image of moving tissue that is shown superimposed on the ultrasound image. SUMMARY OF THE INVENTION In the following description and set of claims, two explicitly described, calculable or measurable variables are considered that are considered equivalent when the two variables are proportional to each other. The present invention in one of its modalities provides a system and a method to record and analyze the cardiovascular sounds produced in the cardiovascular system. The system includes a plurality of N transducers (microphones) configured to be attached to an essentially planar region R of the person's back or chest on the person's chest. The positions in the region R are indicated by means of bidimensional vectors x = (x1, x2) in a two-dimensional coordinate system defined in the region of the plane R. The transducer is the transducer for i = the N, is fixed in the position x in the region R and generates a signal, denoted here with P (Xi, t) that indicates that the pressure waves in the body are reaching x ±. The transducers are typically embedded in a matrix that allows them to be easily fixed on the individual's skin. Such a matrix can typically be in the form of a vest or garment to be easily placed on the individual's chest. As can be appreciated, different matrices can be used for individuals of different sizes, for different ages, sexes, etc. The N signals (Px_¡., T) are processed by means of signal processing circuits. According to the invention, the signals are filtered to remove one or more components of the signals that do not arise from cardiovascular sounds (for example respiratory tract signals). Cardiovascular sounds are typically in the range of 6 to 45 HZ, while respiratory tract sounds are typically in the range of 100 to 400 Hz. Thus respiratory sounds can be eliminated from the signals by filtering the signals, by example with a filter passes bands between 15 and 45 Hz. The N filtered signals (also indicated here with P (xi, t)) can be processed in order to diagnose the state of the cardiovascular system of the individual. This can be done by means of automatic differential diagnosis in which the processing results are compared to the functions or parameters previously stored in databases which are known to indicate various disorders in the body region. Filtered signals can also be processed to generate an image of the individual's cardiovascular system. The results of this processing are displayed on a screen, for example using a grayscale scale, as demonstrated in the following examples. In the image, it can be analyzed visually or automatically to detect a disease in the cardiovascular system similar to the analysis of images obtained by other methods of imaging, such as X-rays (scintigraphy) or ultrasound images (echocardiography). A region or region of the cardiac or cardiovascular system in an image shown to be suspect include a pathological condition, can be identified in the image, and this can be done in a plurality of ways, for example by means of different colors, different patterns, or by means of a written text or by any other means. The term "pathological condition" refers to a deviation from the normal healthy condition of the cardiovascular system. This includes murmurs and other hemodynamic irregularities cardiac effusion, narrowing of the blood vessels, and other spaces containing lesions in the cardiovascular system, etc. Additionally a time slot can be divided into a plurality of sub-intervals, and each sub-interval is processed separately. An image of the cardiovascular system for each of these sub-intervals can then be determined and displayed sequentially on the screen device. This generates a movie that shows dynamic changes that occur in the cardiovascular system over a period of time. This allows to see the systoles and diastoles of different parts of the heart during the heartbeat. In a preferred embodiment, the processing includes determining from N signals an average acoustic energy arising from the cardiovascular sounds, denoted here with V (x ^ tl f t2), at least one x position in the R region during a time interval from t__ to t2. The term "acoustic energy" at a point is used here to refer to a parameter that indicates or approximates the product of the pressure and velocity of mass propagation at that point. In one embodiment, an average acoustic energy over a time interval from t__ to t2 is obtained at a position of one of the microphones using the algebraic expression where i is the position of the microphone. In a more preferred embodiment, the processing includes obtaining the average acoustic energy P (x, t?, T2) during a time interval ranging from t2 to t2 in a plurality of positions x% of the microphones, for example using the equation (1), and then calculate P (x, tl r t2), at other points x by means of the interpolation of "P (x?, Ti, t2) using any known interpolation method. Interpolation is done to obtain an average acoustic energy P (x, tl r t2) at a position x = (x1, x2) on the surface R using the algebraic expression: where g (x xl rs) is a kernel that satisfies »= (3) -? s is approximately equal to 1. (4) and where x ± = (XÍ ^ XÍ2) is the position of the ninth microphone and s is a selectable parameter. For example, the nucleus can be used The system can optionally contain a screen to display the P function. The P function can be displayed on the screen, for example using a scale of gray levels, as demonstrated in the examples that follow. A two-dimensional graphical representation of the P function produces an image of the cardiovascular system. In the image, anatomical features of the heart such as atria can be observed, ventricles, septic walls. The image can be analyzed for the detection of a problem in the cardiovascular system similar to the analysis of the images obtained by other methods of imaging such as X-rays (scintigraphy) or ultrasound (echocardiography). A region or regions of the heart or cardiovascular system shown in an image that is suspected includes a pathological condition, can be identified in the image and this can be in a plurality of ways, for example by means of different colors, by means of patterns, or by • means of a written text or by any other means. The term "pathological condition" refers to a deviation of 5 from the normal healthy condition of the cardiovascular system. This includes murmurs and other hemodynamic irregularities cardiac effusion, narrowing of the blood vessels, and other spaces containing lesions in the cardiovascular system, etc. In addition, a time interval may be divided into a plurality of sub-intervals, and an acoustic energy per means P determined in the region R for two or more of the sub-intervals. An image of P for each of these sub-intervals can then be determined and displayed sequentially in the display device. This generates a movie that shows dynamic changes that occur in the cardiovascular system over a period of time. For example, transducers can be placed on the chest or back of a person and the average acoustic energy P can be determined according to the invention for a plurality of subintervals during one or more heartbeats. A movie can be obtained for each of these sub-intervals and displayed sequentially to generate a movie showing them. changes in the acoustic energy of the heart during the heartbeat. One This allows you to see the systoles and diastoles of different parts of the heart during the heartbeat. Signals P (xj, t) can also be subjected to additional analysis to detect abnormal heart sounds. The present invention also provides a storage device for a program that can be read by a machine, which tangibly includes a program of instructions executable by the machine to perform the steps of the method to determine at least a time interval, a function of acoustic energy P arising from cardiovascular sounds using an algorithm that includes at least one signal P (x ±, t) indicative of pressure waves at a point x ± on a body surface. The present invention also provides a computer program product comprising a computer-usable medium having a computer readable program code which analyzes the sounds in at least a portion of the cardiovascular system, the computer program comprising: program code computer readable to cause the computer to determine, for at least a certain period of time, an acoustic energy function P that < ^ > arise from the portion of the cardiovascular system. P is determined or in an algorithm that includes at least one signal P (x ±, t) which indicates the pressure waves at a point x¿ on a body surface. The invention thus provides a system for analyzing sounds that originate in at least a portion of an individual's cardiovascular system comprising: (One) N transducers, where N is an integer, each transducer is configured to be fixed on a surface of the individual on the thorax, the i th transducer is fixed at a point x ± y generates an initial signal P (x rt) indicative of the pressure waves at the point x ¿for i = the N; and (Two) a processor configured to receive the signals P (Xj_, t),? to filter the signals P (x ±, t) to generate filtered signals in which a component of the signals P (x ±, t) 'that does not arise from cardiovascular sounds have been eliminated. The invention thus further provides a system for analyzing sounds that originate in at least a portion of an individual's cardiovascular system comprising: (a) N transducers, where N is an integer, each transducer is configured to be fixed on a surface of the individual on the thorax, the i th transducer is fixed in a place x ± y generates an initial signal P (x ±, t) indicative of the pressure waves at the point x ±, for i = the N; and (two) a processor configured to receive the signals P (xí r t) and to generate an image of at least a portion of the cardiovascular system. The invention further provides a method for analyzing the sounds that originate in at least a portion of a person's cardiovascular system consisting of: (One) fixing on the surface of a person on the thorax, N transducers where N is an integer, the i th transducer is set at a point x ± y to generate an initial signal P (xft) that indicates the pressure waves at the point x ± for 1 = 1 to N; and (Two) process the signals P (x ±, t) to generate filtered signals in which at least one component of the P (x ±, t) signals that arise from the cardiovascular sounds has been removed. The invention thus provides a method for analyzing sounds originating in at least a portion of the cardiovascular system of a person comprising: (One) Fixing on a person's surface on the thorax, N transducers, where N is in whole , the ith transducer is set at a point x ± y to generate an initial signal P (x ± rt) that indicates the pressure waves at the point x ± for i = the N; and (Two) process the signals P (x ±, t) to generate an image of at least a portion of the cardiovascular system. The invention thus further provides a device for storing programs by a machine, which includes in a tangible manner a program of instructions executable by the machine to analyze sounds that originate in at least a portion of the person's cardiovascular system, consisting of: process N initial signs P (x ± ft), where N is an integer the initial signals are indicative of the pressure waves at the point x¿ for i = the N, start generating filtered signals in which at least one component of the signal P (x ±, t) that does not arise from cardiovascular sounds have been eliminated. The invention also provides a computer program product comprising a computer-usable medium having a computer readable program code which analyzes the sounds in at least a portion of the cardiovascular system, which comprises: processing N initial signals P ( x ±, t), where N is an integer the initial signals are indicative of the pressure waves at the point x ± for i = the N, start generating filtered signals in which at least one component of the signal P (x ± ft) that does not arise from cardiovascular sounds have been eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS In order to understand the invention and see how it can be put into practice, a preferred embodiment will be described, in the form of a non-limiting example, with reference to the accompanying drawings, in which: Figure 1 shows a system for obtaining and analyzing cardiovascular sounds according to one embodiment of the invention. Figure 2 shows a flow chart for performing a method for analyzing cardiovascular sounds according to an embodiment of the invention; Figure 3 shows the places of the transducers on the person's back to analyze cardiovascular sounds; Figure 4 shows successive frames of a heart film of a healthy person during a heartbeat; Figure 5 shows successive frames of a film of the heart and lungs of a person during a respiratory cycle. DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a system generally indicated with 100 for analyzing body sounds in a three-dimensional region of a person's body according to an embodiment of the invention. A plurality of N sound transducers 105, of which four are shown, are applied to a flat region of the skin of the chest or of the back of a person 110. The transducers 105 can be any type of sound transducer such as a microphone a Doppler shift detector. The transducers 105 can be applied to the subject by any means known in the art for example using an adhesive, suction or fixation strips. Each transducer 105 produces an analog voltage signal 115 which indicates pressure waves reaching the transducer. The analog signals 115 are digitized by a multi-channel digital-to-analog converter 120. The digital data signals P (x ± rt) 125 represent the pressure wave at the point x ± of the i th transducer (i = the N) in the moment t. The data signals 1245 are input to a memory 130. The data entries to the memory 130 are accessed by a processor 135 configured to process the data signals 125. The signals 125 can be eliminated by noise when filtering the components that they have frequencies outside the range of body sounds in the body region, for example, vibrations due to the movement of individuals. Each signal 125 may also be subject to filtering passes bands in such a way that only the components in the signal within the range of cardiovascular sounds. The signal can be divided into frequency bands and each band is analyzed separately. An input device such as a computer keyboard 140 or a mouse 145 is used to enter relevant information relating to the examination such as personal details of the individual 110. The input device 140 can also be used to input values at times t ± and t2 . Alternatively, the times can be determined automatically in an analysis of the respiratory phase of the signals P (xl rt) performed by the processor 135. The processor 135 determines the average acoustic energy P (xr t?, T2) during the time interval of t ± and t2 at least one point x in the region R in a calculation involving at least one of the signals The average acoustic energies are stored in the memory 130 and can be displayed in a display device 1560 such as a CRT screen for the diagnosis by a doctor. The processor 135 can also perform the automatic differential diagnosis by comparing the function P to the functions stored in the memory and known to indicate various problems in the body region. Figure 2 shows a flow chart for carrying out the method of the invention according to one embodiment. In step 200 the signals P (xl f t) are obtained from N transducers placed at predetermined points x ± for i from 1 to N in the region R on the body surface. In stage 205, the values of whether they are input to the processor 135 using the input devices 140 or 145, or are determined by means of the processor. In step 210, an average acoustic energy P (x, t ±, t2) is determined at least at point x in the region R during the time interval t ± y t_ ?. In step 220 the average acoustic energy is shown on the screen 150 for at least one value of x. In step 230, it is determined whether a function P must be determined during another time interval. If affirmative, the process returns to stage 205. Otherwise the process ends. It will also be understood that the system according to the invention can be a computer programmed in an appropriate manner. Similarly, the invention contemplates a computer program that is read by a computer to execute the method of the invention. The invention also contemplates a memory that can be read by a machine, which includes in a tangible way a program of instructions executable by the machine to execute the method of the invention. EXAMPLES The system and method of the invention were used to analyze cardiovascular sounds in an individual. Example 1 Figure 3 shows recordings of signals during a heartbeat in an individual. A two-dimensional coordinate system was defined on the individual's back. As shown in Figure 3, 48 transducers were placed on the individual's back on the thorax, at locations indicated by circles 300. Curves 305 show the presumed contours of the lungs and curve 306 shows the assumed contour of the lungs , and curve 306 shows the assumed contour of the heart. As can be seen, the transducers were colored in a regular orthogonal network with separation between the transducers in the vertical and horizontal directions of 2.5 cm. The signals P (x? R t) of each transducer were then recorded during a heartbeat. Each signal is filtered using a filter passes bands of 6-45 Hz in order to eliminate the sounds of the respiratory tract. The beat was divided into intervals of 0.1 second in duration, and for each interval P (x, tl f t2) was obtained using the previous equations (1) and (2) with the nucleus g of equation (5) with s = 36 pixels. Figure 4 shows the images obtained by representing the obtained functions P (xr tl f t2) by shading by gray levels. The images can be displayed on the screen 150 in rapid succession to produce a heart film during a heartbeat. The film can be analyzed to determine the values of the basic parameters of cardiac function, such as left ventricular end-diastolic volume (LVED), left ventricular end-systolic volume (LVES), left ventricular end-diastolic volume (RVED) , the final systolic volume of the left ventricle (RVES), the final diastolic diameter of the left atrium (LAED), the final diastolic diameter of the right atrium (LAES), the thickness of the wall of the intraventricular septum (systolic and diastolic), and the derivable parameters of these parameters such as the left ventricular input volume, the cardiac output of the left ventricle, the execution fraction, the fractional shortening of the left ventricle, the thickening of the inter ventricular septum. The film can also be analyzed in order to detect carious defects such as valvular dysfunction and cardiac arrhythmia. Example 2 The signals P (x?, T) were obtained from each transducer as described in example 1, and then recorded during a respiratory cycle including approximately 5 beats. Each signal was divided into two sub-signals P? (x?, t) and P2. { x? , t) of different frequency bands. The sub signal P? (xl r t) was obtained by filtering the signal using a 6-40 Hz band pass filter. The P-sub signal tx r t) was obtained by filtering the signal using a 100-150 Hz bandpass filter. The P? (xl f t) consists mainly of heart sounds, whereas the sub signal P2 (x?, t) consists mainly of lung sounds. The sub signal P? (x?, t) was analyzed by means of the method of the invention, and the sub-signal P2 (xl rt) was analyzed as described in the co-pending US patent application 10 / 338,742 of the same applicant filed on January 9. of 2003, the signal P2 (x?, t) was divided into intervals of 0.25 seconds in duration, and the signal P? (x, t) was divided into intervals of 0.1 second in duration. For each interval, the functions P (xf tl f t2) and P (x, tl r t2) were obtained from P __ (xbt) and P2 (Xt) respectively, using equations (1) and (2) above with the nucleus g of equation (5) with s = 36 pixels. The two functions are preferably displayed simultaneously in a screen device by means of intensity shading, using a different color for each function. Figure 5 shows the images obtained by representing the functions (xr tl f t) and P (xr t?, T2) simultaneously by means of shades of gray level. The images can be displayed on the screen device 150 in rapid succession to produce a heart film during a heartbeat. The film can be analyzed to determine the values of cardiac performance parameters, such as cardiac output and blood ejection fraction. The film can also be analyzed in order to detect cardiac defects such as valvular dysfunction and cardiac arrhythmia.

Claims (48)

1. CLAIMS 1. A system for analyzing sounds originating in at least a portion of the cardiovascular system of an individual comprising: (One) N transducers, where N is an integer, each transducer is configured to be fixed on a surface of the individual on the thorax, the i th transducer is fixed at a point x ± y generates an initial signal P (x ± rt) indicative of the pressure waves at the point x ± for i = N; and (Two) a processor configured to receive the signals P (x ±, t), and to filter the signals P (x ±, t) for general filtered signals in which a component of the signals P (x ±, t) that does not arise from cardiovascular sounds have been eliminated.
2. 2. The method according to claim 1 wherein the sounds of the respiratory tract have been eliminated.
3. 3. The method according to claim 1 in which the initial signals are filtered by means of a filter passes bands between 15 and 45 Hz.
4. The system according to claim 1 in which the processor is further configured for generating an image of at least a portion of the cardiovascular system from at least one of the filtered signals.
5. The system according to claim 1 wherein the processor is configured to generate an image of at least a portion of the cardiovascular system during a plurality of times during a plurality of successive time intervals, and displaying the images successively on the screen.
6. 6. The system according to claim 1, further comprising a bidi-ensional screen.
7. 7. The system according to claim 4, wherein the processor is further configured to display an image of at least a portion of the cardiovascular system in a display device.
8. The system according to claim 1, wherein the processor is further configured to determine the average acoustic energy P (xr tl r t2) arising from the cardiovascular system in at least one position x during a time interval from a first time t2 to a second time t2, P is determined in an algorithm that includes at least one of the processed signals.
9. The system according to claim 8, wherein the processor is further configured to compare the average acoustic energy P to one or more predetermined functions F and determine a function F0 from among the F functions most similar to P.
10. 10. The system according to claim 9 in which the processor is further configured to make a diagnosis based on the determined function.
11. The system according to claim 9 in which the average acoustic energy P during the time interval from ti to t2, is determined at a point xi of a transducer using the algebraic expression: j 5 (*, f) dt (1)
12. 12. The system according to claim 8 in which the function P is determined at one or more points x in an algorithm comprising: (One) determining an average acoustic energy P (xf t? F t2) during a time interval of ti to t2, in a plurality of points x ± of the transducers; and (Two) determine an average acoustic energy P (x, t?, t2) in at least one point x by means of the interpolation of the determined P (xr t?, t2).
13. The system according to claim 12, wherein the average acoustic energy P (x, t, t2) is determined during a time interval of ja t_ ?, at a plurality of x ± points of the transducers using the algebraic expression: P (x?, Fr) = \ P2 (Xi.t) dt 1.
14. The system according to claim 12 in which the average acoustic energy is determined at at least one point x by means of the interpolation of the P (x, t?, T2) determined using the algebraic expression: Píx i =) = £ < xt /?) g (x,.:. s) (2) where g (x, x?, s) is a core that satisfies imadamente equal to l. (4)
15. 15. The system according to claim 12 wherein g (x, xlrs) is the core
16. 16. The system according to claim 8, wherein the processor is further configured to display the average acoustic energy P (xrtlrt) on the screen.
17. The system according to claim 1, wherein the processor is configured to determine the average acoustic energy during a plurality of successive time intervals, each average acoustic energy is determined using an algorithm that includes at least one of the signals P (x ±, t).
18. 18. The system according to claim 17, wherein the processor is configured to sequentially display on the display device a representation of each determined average acoustic energy.
19. 19. The system according to claim 1 in which the processor determines a plurality of successive time intervals, each average acoustic energy is determined using an algorithm that includes at least one of the signals P (x ±, t).
20. The system according to claim 1 in which the processor is configured to: (One) for each of the one or more frequency bands, (twenty seven) subjecting the signals P (x ±, t) to filtering passes bands in the frequency band; and (ab) determining an average acoustic energy function for the frequency band based on at least one of the filtered signals.
21. The system according to claim 20, wherein the processor is configured to display one or more of the average acoustic energy functions determined for a frequency band on a screen.
22. 22. A system for analyzing which originates in at least a portion of an individual's cardiovascular system comprising: (a) N transducers, where N is an integer, each transducer is configured to be fixed on a surface of the individual on the thorax , the i th transducer is fixed • in a place x ± y generates an initial signal P (x ±, t) indicative of the pressure waves at the point x ±, for i = N; and (two) a processor configured to receive the signals P (x ±, t) and to generate an image of at least a portion of the cardiovascular system.
23. 23. A system for analyzing which originate in at least a portion of the cardiovascular system of an individual comprising: (One) fixing on the surface of a person on the thorax, N transducers where N is an integer, the i th transducer is fixed at a point x ± y generate an initial signal P (x ±, t) indicating the pressure waves at the point x ± for i = N; and (Two) process the signals P (x ±, t) to generate filtered signals in which at least one component of the P (x ±, t) signals that do not arise from cardiovascular sounds has been removed.
24. 24. The method according to claim 23 in which the sounds of the respiratory tract are filtered from the initial signals.
25. 25. The method according to claim 23 in which the initial signals are filtered by means of a filter passes bands between 15 and 45 Hz.
26. 26. The method according to claim 23 further comprising generating an image of at least a portion of the cardiovascular system from at least one of the filtered signals. 5.
27. The method according to claim 23 further comprising generating an image of at least a portion of the cardiovascular system for a plurality of times during a plurality of successive time intervals, and displaying the images successively on the screen.
28. The method according to claim 26, further comprising displaying an image of at least a portion of the cardiovascular system in a display device.
29. 29. The method according to claim 23 further comprising determining the average acoustic energy P (x, t ?, t2) arising from the cardiovascular system in at least one position x during a time interval from a first time ta second time tr P is determined in a 0 algorithm that includes at least one of the processed signals.
30. 30. The method according to claim 29 further comprising comparing the average acoustic energy P to one or more predetermined functions F and determining a function FQ of the F functions most similar to P.
31. 31. The method according to claim 30 in which the processor is further configured to make a diagnosis based on the determined function.
32. 32. The method according to claim 29 in which the average acoustic energy P during the time interval from tj to t2r is determined at a point x ± of a transducer using the algebraic expression:
33. 33. The method according to claim 29 in which the function P is determined at one or more points x in an algorithm comprising: (One) determining an average acoustic energy P (x, t, t2) during a time interval of tat, in a plurality of points x ± of the transducers; and two) . determine an average acoustic energy P (x, t?, t2) in at least one point x by means of the interpolation of the determined P (x, t?, t2).
34. 34. The method according to claim 33, wherein the average acoustic energy P (x, t?, T2) is determined during a time interval of tj at, at a plurality of points x ± of the transducers using the expression Algebraic: P (xi, t?, T) =] pl (xt) dt
35. 35. The method according to claim 33 in which the average acoustic energy is determined at at least one point x by means of the interpolation of the P ( x, t?, t2) determined using the algebraic expression: where g (x, X? r s) is a core that satisfies g = É (3) ds g x ^ s) is approximately equal to l. (4)
36. 36. The method according to claim 35 in which g (x, x?, S) is the core
37. 37. The method according to claim 29, further comprising displaying the average acoustic energy P (x, t?, T2) on the screen.
38. 38. The method according to claim 23, further comprising determining the average acoustic energy during a. plurality of successive time intervals, each average acoustic energy is determined using an algorithm that includes at least one of the signals P (Xi, t).
39. 39. The method according to claim 38, further comprising sequentially displaying on the display device a representation of each determined average acoustic energy.
40. 40. The method according to claim 23 further comprising determining a plurality of successive time intervals, each average acoustic energy is determined using an algorithm that includes at least one of the signals P (x ±, t).
41. 41. The method according to claim 23 further comprising: (c) for each of the one or more frequency bands, (ca) subjecting the signals P (x, t?, T2) to filtering passes bands in the frequency band; (cb) determining an average acoustic energy function for the frequency band based on at least one of the filtered signals.
42. 42. The method according to claim 41, further comprising displaying one or more of the average acoustic energy functions determined for a frequency range on a screen.
43. 43. A method for analyzing sounds that originate in at least a portion of an individual's cardiovascular system comprising: (One) Fixing on a surface of a person on the thorax, N transducers, where N is in whole, the transducer The last one is fixed at a point x ± y and generates an initial signal P (x ±, t) that indicates the pressure waves at the point x ± for i = N; and (Two) process the signals P (x ±, t) to generate an image of • at least a portion of the cardiovascular system.
44. 44. A processor configured to receive signals P (x ±, t) and from them generate an image of at least a portion of the cardiovascular system.
45. 45. The use of the method of claim 23 for diagnosing a "cardiovascular problem" 46.
46. The use according to claim 44 wherein the disease is selected from the group comprising at least cardiac arrhythmia and cardiac valve problems.
47. A device for storing programs by a machine, which includes in a tangible way a program of instructions executable by the machine to analyze sounds that originate in at least a portion of the cardiovascular system of the person, which consists of: processing N initial signals P (x ±, t), where N is an integer the initial signals are indicative of the pressure waves at the point x ± for i = the N, start generating signals filtered in the which at least one component of the signal P (x ±, t) that does not arise from cardiovascular sounds have been eliminated.
48. 48. A computer program product comprising a computer-usable medium having a computer readable program code to analyze sounds originating in at least a portion of the person's cardiovascular system, which. consists of: processing N initial signals P (x ±, t), where N is an integer the initial signals are indicative of pressure waves at the point x ± for i = N, start generating filtered signals in which when minus one component of the signal P (x ±, t) that does not arise from cardiovascular sounds have been eliminated.