Abstract:
A diagnostic system for collecting, processing, recording and analyzing sounds associated with the physiologic activities of various human organs. The system includes a plurality of transducers placed on the body surface at the operator&#39;s discretion. The transducers are coupled to analog/digital signal processing circuitry for enhancement of the desired signal and exclusion of ambient noise. An A/D converter digitizes the incoming data and transmits data, which is divided into a multitude of discrete blocks, received over very finite intervals of time, to a computer workstation and moved through an analysis program sequentially. The program is displayed as a series of icons which depict operations that the program performs and which allow the operator to reprogram the system at any time. The data is finally displayed in graphical format and stored in memory as the program processes each block sequentially.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/785,357 filed on Mar. 23, 2006, the contents of which are incorporated herein by reference. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to the field of diagnostic methods and systems, and particularly to the acquisition and analysis of physiological auditory signals. 
     BACKGROUND OF THE INVENTION 
     Throughout this application, various publications are referenced. The disclosures of these publications in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein. 
     Auscultation of the lung and heart is probably the most widely used physical diagnostic method in respiratory and cardiac disease. However, due to the limitations of the human auditory system, auscultation has such low sensitivity and specificity that many physicians no longer rely solely on it as a diagnostic tool. Although digital acquisition and analysis of physiologic sounds has the potential to be of tremendous diagnostic/therapeutic benefit to patients, the medical community has been slow to embrace this technology. In order to overcome this obstacle, any system for digital acquisition and analysis of physiologic sounds must be lightweight and easy for individuals without technical expertise to operate and modify. In addition, all generated results must be presented in a format that allows for rapid interpretation and correlation with important physiologic values obtained from other tests. A description of the prior art and their perceived shortcoming relevant to the objectives of the present invention follows herein. 
     Physiologic sounds may be captured electronically, processed, and transmitted back to the clinician thus enabling the human auditory system to obtain greater information conveyed by the signal. For example, U.S. Pat. No. 5,774,563 discloses a device for acquiring physiologic sounds. Electronic circuitry embedded in the device enables the operator to filter and amplify the incoming signal. Furthermore, this device also allows the user to listen to the post-processed signal through implementation of earpieces. However, no plan is described for enabling clinicians of ordinary ability to modify the system. Thus, the effective frequency range measured by this device is 70-480 Hz, which is essentially unalterable, has minimal clinical applications. In addition, this system does not provide a means for digital acquisition/display/analysis of the recorded signal, which serves to severely limit the use of this device in a clinical setting. Other forms of analogous art, which are based on these same principles, share similar disadvantages. 
     Analogous inventions in the art have depicted devices capable of acquiring, processing and digitally recording/analyzing physiologic signals. U.S. Pat. No. 6,139,505 discloses an electronic stethoscope for the digital acquisition and analysis of physiologic sounds. The device consists of a microphone, which can be embedded inside conventional chest pieces. After amplification and filtering, the signal is transferred to an analogue to digital converter (A/D converter) for computer analysis. The system disclosed contains a modifiable number of independent transducers to record physiologic sounds at any particular location, which the operator desires. The device allows for amplification/filtering of the recorded signal, store these recordings in memory, perform root mean square (RMS) and time expanded waveform analysis, and display data on a monitor for visual analysis/printing. This device is also fairly easy to modify/upgrade/repair and includes a built in program for analyzing respiratory sounds and generating a probable diagnosis based on this information. 
     However, this device does not disclose a method to enable the physicians to listen to the sound as it is being recorded, but instead, requires them to discern phases of the respiratory cycle simply by inspection of the time expanded waveform. The patent describes a method by which physiologic sound may be processed and transmitted to a computer workstation using analogue circuitry which is bulky and not easily customized thus limiting the device&#39;s practical application. Further, no information is given about how this device can be used for higher level analysis (such as performance of Fourier Transformation or wavelet) of the desired signal, only time expanded waveform analysis and RMS of the complete spectrum are illustrated. These quantities give incomplete information regarding the sound and the program is not easily operated/modified by a clinician of ordinary skill. Lastly, no method is outlined by the inventors for reducing the corruption of the data from inadvertent pickup of ambient noise or superimposed signals emitted from other organs in close proximity to the transducer. The probable diagnosis product available with this device is also extremely limited since it provides no quantitative information regarding the degree of functionality of the desired organ system. Although Murphy&#39;s electronic stethoscope represents significant improvement from analogous art as a system for the display and analysis of physiologic sounds, the limitations of this device as described above decrease its usefulness in a clinical setting. 
     Additional devices have been patented which attempt to provide more sophisticated means for mathematically analyzing physiologic sounds and transmitting results to remote locations. One such example can be found in U.S. Pat. No. 6,699,204, which illustrates a device for recording physiologic sound using multiple sensors that are secured to a patient via a harness. Physiologic sound can be recorded by the sensors and relayed to a processing station for filtering/amplification using analogue circuits. The signal is then transferred to a sampler Ech (sound card) for digital recording via analogue circuitry or modem (not shown). With the aid of a specialized calculation manager (Matlab® for example), the device can evaluate a set of transformed intensity levels, each associated with a predetermined sound frequency and means for storing each transformed intensity level in correspondence with an associated frequency for the purpose of displaying these intensity levels, transformed on the basis of frequencies as a spectral representation of the auscultation sound. 
     The device depicted by Kehyayan et al. is a further improvement over analogous art since it provides an accurate spectral representation of the auscultation sound as the intensity varies with time. However, a physician of ordinary ability cannot be expected to have the technical expertise necessary to easily operate and/or modify this analysis program in order to examine a wide array of physiologic sounds. Also, no plan is outlined by the inventor for preventing extraneous sounds (from ambient noise or sound emitted from other organs) from influencing the results displayed on the spectral plots. Lastly, the spectral plots contain too much information for a clinician to interpret in a timely manner. Thus, it is unlikely that the invention proposed by Kehyayan will be useful in a practical setting, and thereby widely embraced by the medical community. 
     SUMMARY OF THE INVENTION 
     It has been proven that organs in the human body emit characteristic physiologic signals when they are functioning in the absence of pathology. It is an object of the present invention to provide an improved system for accurately assessing organ (particularly lung) function and thereby facilitating the diagnosis of certain diseases based upon digital recording, processing and analysis of these physiologic sounds. 
     One of the main obstacles to widespread acceptance of electronic stethoscopes is that these devices are too cumbersome, and also, too complicated for health care professionals to operate in a professional setting. Thus, it is a further object of this invention to provide a compact, customizable device. But most important, the device will be an improvement over analogous art by providing a simple interface which allows medical professionals with limited technical background to easily manipulate vital parameters such as block length, overlap, sampling rate, low/high pass filtering, adjusting the Fast Fourier Transformation (FFT) and RMS analysis to cover any component of the frequency spectrum, and applying data windows without the need for computer programming knowledge. 
     Another object of this invention is to boost the accuracy of recording physiological sounds by providing the physician with an efficient method of eliminating background noise (which is either present in the ambient environment and/or emitted by other body organs in the vicinity of the transducer) from the desired signal in real time. Accomplishing this task will not only lead to greater accuracy in the measurement of physiologic sounds, but it will also allow the device to operate with a greater degree of autonomy when compared to analogous art. 
     Lastly, acoustic signals from human organs occur over many different frequency ranges (depending on the specific organ and any pathology present) and are often of minimal intensity. Therefore, detecting differences in these signals between normal physiologic and pathologic states over a finite time interval for any given organ requires a system of mathematical analysis with greater sensitivity than that described in many versions of analogous art. Thus it is an additional objective of this device to provide a means for adjusting the frequency band in the Power Spectrum Density (PSD), which the RMS values are calculated from. The PSD results from performing the FFT on the digital data corresponding to the audio signal. 
     As noted above, this invention relates to a system for recording and analyzing physiologic sounds to provide the clinician with information relating to functional status of the organ being examined. This information may provide clues, that when combined with other elements of a diagnostic workup (history, physical exam, lab tests, medical imaging, etc.) may facilitate the diagnosis of various disease states (pulmonary disease for example). Consistent with other forms of analogous art, the system includes a plurality of transducers, such as microphones embedded in small rubber tubes coupled to a thin plastic diaphragm(s) which may be placed at pre-selected sites on the patient using either light pressure or a harness of some type. Physiologic signals of interest vibrate the plastic diaphragm, which transmits the sound by moving air molecules in the tube. The transducers detect these sounds and convert them into electrical signals. The system contains a preamplifier that not only increases the intensity of the incoming electrical signal, but also polarizes the transducers with an electromotive force (preferably 48 Volts) applied equally to both inputs to the sensor with respect to ground (phantom power). In order to provide this polarizing potential high voltage commercial alternating current is converted to high voltage direct current. This voltage is applied to same wires that carry the audio signal. Since the preamplifier can supply such high voltage (unlike many computer sound cards available commercially) this invention can make use of transducers with higher signal to noise ratios than those used in analogous art. Furthermore, portability may be maximized by supplying the phantom power through a rechargable battery. 
     The system also includes a digital signal processor for conditioning the signal (filtering, gating, limiting, or excluding background noise). In the preferred embodiment of the invention, analogue circuitry or a digital signal processor employing Super Harvard Architecture (SHARC) can be added for additional filtering, expansion, compression or conversion of the processed signal back to sound energy thereby enabling the operator to hear the altered sound in real time. After processing, the analogue signals generated by the transducers are converted into digital data and transferred to a computer workstation. In order to increase the portability of this device, digital data may be transmitted to the workstation over wireless internet. A further advantage of utilizing a SHARC processor is that optimal settings for detecting sound from a variety of sources may be stored in memory for instantaneous recall by the operator. These aforementioned settings which are programmed into the SHARC processor may enable the claimed invention to acquire properties of sound transmission which are identical to a conventional acoustic stethoscope. This is important because acoustic stethoscopes remain popular in clinical settings due to the fact that a tremendous amount of research has already been done with them and the steadfast hesitancy among health-care professionals to abandon their use of these devices. 
     The computer station includes a microprocessor, input/output circuitry, and random access memory for data storage, one or more input devices (such as a keyboard or mouse), a modular interface with many different graphical displays of incoming data, and one or more output devices (such as a printer, monitor or modem for transmission over the Internet). 
     Executing on the computer is an application program constructed from a set of modular elements synthesized using a graphical programming language. The application program collects the data and organizes it into discrete sections (blocks) before moving it through though a series of modules. By clicking on any specific module with the mouse, the operator can set the sampling rate, block size and overlap. Furthermore, the operator may elect to further high/low pass filter the data digitally or apply a mathematical window analogous to FFT processing in order to minimize distortion of calculated results. 
     After breaking the signal into multiple blocks (which correspond to discrete time intervals) and then pre-processing these blocks, the program calculates the power spectrum density of the portion of the signal contained in each block using the FFT. After calculation the computer displays the results graphically as a plot of Intensity vs. Frequency. These results are updated continuously as the PSD is calculated anew for each incoming block and the results of the previous block are saved in memory. 
     As the PSD is calculated for each incoming block, the computer may exclude portions of the PSD that are outside the selected thresholds specified by the operator. This is possible because the program may contain a trigger, which enables the operator to exclude portions of the spectrum, which are not of interest with a simple mouse click. Once the PSD is determined, the program calculates the root mean square (RMS) value of the signal in the frequency band(s) chosen by the operator. The computer performs this calculation on each incoming block and displays the data as a list during the time of operation. This method is highly advantageous to the clinician since it takes a very complicated quantity (the PSD of each block that gives information about the power of all frequency components in the block) and converts it into a simple quantity (RMS), while still relaying the necessary information about the signal to the clinician. Secondly, by performing these calculations on each incoming block of the data, the properties of the signal outlined above can be analyzed as they vary over time. The clinician can then use this information about an organ&#39;s spectral characteristics to assess its degree of functionality in a quick, inexpensive, accurate and non-invasive manner. The analysis program illustrated in the present invention can be used either as a stand alone application or in combination with a number of additional program elements which may include patient&#39;s electronic medical records. As a result, this system has the potential to dramatically improve efficiency in the healthcare system and clinical outcomes for patients. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of the present invention may be further illustrated by referencing the following description and corresponding drawings, in which: 
         FIG. 1  provides a general overview of the preferred embodiment of the present invention. 
         FIG. 2  is an illustration of the computer station component of  FIG. 1 . 
         FIG. 3A  illustrates a block diagram of the preferred embodiment of the signal conditioning station. 
         FIG. 3B  illustrates a block diagram of the digital signal processor described in the preferred embodiment. 
         FIG. 3C  illustrates a block diagram of elements utilized in data conversion and transfer incorporated within the preferred embodiment. 
         FIGS. 4A-L  illustrates a variety of operations which may be performed on the acquired data by the digital signal processor. 
         FIG. 5  illustrates a display of the RMS values for the incoming signal (ambient noise) received from the test microphone. These values can be helpful in quantifying the effect of ambient noise on the calculation of the RMS values of the desired signal. 
         FIG. 6  is a flow chart of the data collection and analysis program. Each icon represents an operation which is performed on incoming data and selecting a corresponding icon can modify these operations. 
         FIGS. 7A and 7B  represent time expanded waveforms of physiologic sounds. 
         FIG. 8  is a graphical representation of the power spectrum density calculated using the Fast Fourier transformation from an incoming data stream representative of physiologic sounds received by the transducer positioned over the heart. 
         FIG. 9  depicts the sequential display of RMS values calculated from the PSD after processing for heart sounds. This data may then be used to assess the degree of functionality of the target organ. 
         FIG. 10  depicts the PSD calculated from tracheal breath sounds using the FFT. 
         FIGS. 11A and 11B  depict the sequential display of RMS values calculated from the PSD after processing of the tracheal breath sound. 
         FIGS. 12A-12C  depict the sequential display of values corresponding to the maximum frequency  12 A and corresponding intensity  12 B/ 12 C from the desired portions of the PSD after processing of the incoming signal from the heart. Data is displayed as it is obtained from each incoming block. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  provides an overview of the sound recording and analysis system of the present invention. This system includes a transducer  1 , such as an analogue condenser microphone, which can be placed at various sites around the patient to listen to sounds emitted by different organs. It should be understood that the system could be expanded to include additional transducers  1  if desired so that data from multiple sites can be collected concurrently. To isolate the sensors from external sounds (and thereby improve signal to noise), they may be embedded in the tubing/chest pieces of conventional stethoscopes. The transducer(s)  1  may be held against the surface of the patient with mechanical pressure applied by the operator, adhesive tape or suitable strapping to prevent movement during the data acquisition process. 
     Leads  2  extending from the sensors are balanced cables with XLR inputs  97  that connect to a signal conditioning station. A suitable signal conditioning circuit for use in the present invention could be the Eurorack 1202, a sound mixer  3  made by Behringer. This station performs many important functions. First, it supplies the electromotive force needed to polarize the transducer  1 . In the preferred embodiment, the mixer  3  converts standard alternating current (120 volts) into direct current (48 volts). It has been proven that to accurately record physiologic sounds, it is important to have a transducer  1  with a high signal to noise ratio and a flat frequency response. These types of sensors may demand high voltages, which are not readily supplied by analogous art that utilizes sound cards built into most commercially available personal computers  9  or batteries. 
     The voltage is then supplied to the sensor through both XLR inputs  97  equally with respect to ground (phantom power)  93 . The audio signal is transmitted through these same inputs approximately 180 degrees out of phase of each other thereby ensuring a balanced signal. Balanced signals are less corrupted by ambient noise relative to unbalanced ones. Inside the stethoscope tube, sound energy generated from organs inside the body is converted into an electrical signal by the microphone. This electrical signal (which is a representation of the sound) is then transmitted to the mixer  3  though the same leads  2  that supply the voltage in the manner described previously. To further prevent this desired signal from being corrupted by external electric/magnetic fields, the cables may be shielded. The mixer  3  may have additional ports to receive electrical signal from additional sensors. In addition, phantom power  93  may be supplied via alkaline (such as the ART Phantom Power Adapter), or other rechargeable 9 volt batteries. 
     Once the electrical signal is received by the mixer  3 , it may be amplified  255  and/or filtered  256 . In the preferred embodiment the mixer contains circuitry  383 , which can act as a high pass filter (80 Hz)  256  and/or low pass filter (12 kHz)  256 , although other frequencies are possible. It should be noted that the invention gives the operator the ability to bypass this processing if they choose. After amplification/filtering, the signal may be sent to a headset  4  where it is converted back to sound energy, thereby enabling the operator to listen to the sound as it is recorded. The signal may also be sent for recording on cassette tapes or it can be sent to a digital signal processor (DSP)  5 . One such example is the DEQ 2496, a digital equalizer with Super Harvard Architecture (SHARC) signal processors  76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90  and specialized software, made by Behringer which is depicted in  FIGS. 3A and 3B . 
     The digital processor  5  performs the fast Fourier transformation on the signal and displays both the discrete frequency bands and the power of the signal in each band (power spectrum density)  621 , as shown in  FIGS. 8 and 10 , for example. One of ordinary skill in the art will understand that the waveforms shown in  FIGS. 8 and 10  (as well as other waveforms, such as  FIG. 12A ) are merely exemplary, and that the ordinate or Y-axis demonstrates relative values, such as decibel (dB) shown, as well as other measures of PSD, such as, but not limited to, RMS. From here, the operator can selectively amplify/attenuate components of the signal in any frequency band from 20-20000 Hz (similar to an equalizer)  612 - 615 . Unwanted signal can be excluded by compressing  615  (the processor reduces the intensity of all signal components with a volume that is greater than desired) or expanding  615  (reducing the intensity of all frequency components with an intensity less than that desired by the operator) frequencies detected by the transducer  1 . Of note, the device can function as a noise gate and/or limiter if compression/expansion is performed to a maximum degree. All operations undertaken by the digital signal processor  5  to alter the incoming audio signal can be displayed via LCD, and device operations  612 - 620  and  622 - 623  may be saved in memory by device operation  620  for instant recall by the operator at some future time. The adjustment of stereo width function  623  may or may not be necessary. It is understood that specific operations  612 - 619  of the digital signal processor  5  may cause the invention to acquire properties of sound transmission similar to conventional acoustic stethoscopes. This characteristic of the claimed invention is a valuable attribute, since a tremendous body of research has already been conducted in the analysis of physiologic auditory signals using said acoustic stethoscopes. Secondly, it is well known that such conventional stethoscopes are still widely popular in the market place. Specifically, settings contained in the digital signal processor  5  may allow clinicians to measure blood pressure values, grade cardiac murmurs (I-VI) and listen to other physiological sounds in a manner which correlates well with findings obtained from a conventional acoustic stethoscope. The ability to perform compression/expansion is an improvement over other forms of analogous art since it allows the device to record physiologic sounds from the human body without having to constantly be directed to by the operator. However, it should be noted that the device might set up so that it is required to be directed by the operator before making recordings. 
     Furthermore, the digital signal processor  5  contains a test transducer  1 , which can be deployed by the operator if desired. This test transducer  1  may be affixed to body surface or exposed to the ambient environment. The test transducer  1  records sounds from sources that might corrupt the signal being recorded from the organ of interest. This may include noise present in the ambient environment or sound emitted from other organs in the vicinity of the target organ. The power spectrum density 621 of these ambient signals can be used to calculate and display  622 A the corresponding RMS values for the signal as demonstrated in  FIG. 5 . The components of the undesired signal, which interfere with the signal of interest, are effectively quantified in real time. The DSP  5  may transmit data directly to a computer workstation  9  for further analysis via cable or wireless internet connection  16 ,  17 . This is a significant improvement over analogous art because it can be used to remove ambient noise that contains identical frequency components to those of the target organ, thus producing a much clearer signal from the target organ in addition to enabling the clinician to obtain standardized measurements regardless of the noise level present in the ambient environment at the time of measurement. The processing methods may include (but is not limited to) graphic  612 , parametric  613 , digital  614  and/or dynamic equalizers  615 , as well as signal compression/expansion/boosting/cutting and feedback destruction  622  or bypassed altogether  616 . 
     After this additional processing, the signal from each analogue output is transmitted to an analog-to-digital converter (A/D converter)  6 , which may or may not be part of the computer station  9 . The A/D converter  6  converts the processed audio information into a digital data stream for transmission to the workstation  9 . One advantage of employing a SHARC processor  5  is that digital data may be transmitted to the computer workstation  9  over wireless internet  16 , 17 . This process can be achieved by coupling the SHARC processor  5  to a modem  16  with a WiFi PC card (not shown). Digital data acquired during stethoscope operation may be transferred to a WiFi Access Point/Router  17 , and afterward, sent to a modem  16  via CATS cable or WiFi USB adapter. 
     The sampling rate used in digitizing the data may be adjusted by the operator and should be greater than 44.1 KHz with a bit rate preferably greater than 24 bits per sample. The A/D converter  6  is preferably multi-channel which may contain an additional preamp such as the Edirol UA-25 sold by the Roland Corporation.  FIG. 3  is a schematic of all of the hardware components which comprise the preferred embodiment of the invention (components for transmission of data over a wireless network are not shown).  FIG. 3A  illustrates a first portion of a first schematic connected to a second portion of the first schematic, illustrated in FIG.  3 A(cont.), through lines (a)-(f).  FIG. 3C  illustrates a first portion of a third schematic connected to a second portion of the third schematic, illustrated in FIG.  3 C(cont.), through lines (g)-(v). A suitable workstation  9  may be a personal computer of the E-machines series as sold by Lenovo, comprising a microprocessor  12 , input/output circuitry  10 , and memory for data storage  13 , one or more input devices (such as a keyboard  8  or mouse  7 ), a modular interface with many different graphical displays of incoming data as depicted in  FIG. 6 , and one or more output devices such as a printer  15 , monitor  14  or modem  16  for transmission over the Internet. As shown in  FIG. 1 , input/output circuitry  10 , microprocessor  12 , and memory for data storage  13  are interconnected via bus  11 . However, it should be understood that other models may be substituted. These computers are controlled and coordinated by operating system  16 A, such as Microsoft Windows XP or other system. The operating system  16 A may also comprise a window manager  17 A, printer manager  18  and additional device managers  21  in addition to one or more device drivers  19 , 20 , 22  in order to allow the computer workstation  9  to interface with hardware components. 
     In the present invention digital data from the A/D converter  6  is transmitted to input/output (I/O) circuitry  10  of the computer via USB cable JK 1 .  FIG. 2  illustrates the interaction of software elements on the computer workstation  9  with the application programs  210 , 220 , 230  and operating system  16 A relationships shown by arrows  306 , 307 , 308  via system calls. The program ( FIG. 6 ) is organized by a series of graphical icons that are provided via specialized data acquisition software such as DASY LAB 9.0, a product manufactured and sold by Capital Equipment. Each icon, constructed using a graphical programming language, represents a command(s) for the workstation  9  to perform. This program  210  is fully customizable since simply inserting/deleting icons in the flow diagram can make new programs. All commands given to the analysis program by the clinician are accomplished via simple keyboard  8  entries or mouse  7  “clicks”. Thus, knowledge of computer programming languages (which many health care personnel do not possess) is not a required prerequisite for proper operation of the instant device. 
     Prior to first listening to the sound the clinician chooses the sampling rate by clicking on a tab marked “experimental setup.” The A/D input icon  404  receives data via I/O circuitry  10 . The Recorder Icon  407  displays the time-expanded function of the incoming signal illustrated in  FIGS. 7A and 7B  in accordance with the description set forth in U.S. Pat. No. 3,990,435. The clinician then clicks the Filter icons  405 , 406  in order to select frequencies where the signal can be high/low pass filtered digitally. Some examples include digital high/low pass filtering, application of a windowing function to incoming data analogous to PSD calculation, adjustment of sample rate, block size, degree of overlap and recording time. Through the use of these icons, the clinician may also determine the characteristic (Butterworth, Bessel, etc.) and order of the digital filter. The clinician will click the Data Window Icon  408 , to select the desired block length, appropriate mathematical window to fit the data with, and determine the degree of overlap (if any) between successive blocks. The FFT icon  409  in the program  210  instructs the computer to calculate the FFT on the portion of the signal represented by each block. The Y/T Icon  413  enables the clinician to view a display of the PSD on a monitor  14  for each block after it is calculated as illustrated in Figures  FIGS. 8 and 10 . By clicking the FFT max icon  410 , the clinician can specify the frequency range within the PSD where both the frequency of maximum intensity and its magnitude may be calculated as illustrated in Figures  FIGS. 12A ,  12 B and  12 C. These quantities may be displayed by the icon marked “Digital Meter”  411  or List icon  412 . By clicking the Trigger Icon, the clinician can determine which frequency components of the PSD will be excluded from the RMS calculation (not shown). 
     Since different body organs emit sound in different frequency ranges, the ability to adjust the frequency range is vital if one hopes to construct a single device that can be used to analyze sounds from all of the different organs (not just lung). The Statistics Icon  414  instructs the computer to calculate the RMS value of the signal in the desired frequency range set by the digital high/low pass filters  405 , 406  or Trigger Icon in the specified range. The List Icon  415  displays the RMS value sequentially as it is calculated from each incoming block as shown in  FIGS. 10 and 12 . Additional modules may be added to the program  210  for the purpose of determining the magnitude of the change in RMS values with respect to time at a given anatomic position. These RMS values, either as displayed by the List Icon  415  or when combined with additional analysis programs  220 , 230  on the workstation  9 , give the attending physician a mechanism for comparing the intensity of physiologic sound recorded by the sensor in any desired frequency range and over any duration of time. 
     In operation, the sensors  1  are affixed to any part of the body surface according to the discretion of the clinician. The system is then initialized and data is transmitted to application program  210 , as the patient inhales/exhales, sound is converted to audio signals which may be amplified/filtered/processed before being relayed to both the clinician and the application program  210  in the computer workstation  9 . At any instant in time (if the physician hears an interesting sound) the physician can start the digital recording by clicking the Recorder Icon  407 , a green arrow in the upper left hand corner of the screen. After the signal of interest is no longer audible, the physician may stop recording by clicking the red square icon or specifying the duration of recording via the “Stop” icon  416 . The computer recording may be influenced by the DSP  5  via compression/limiting  615  or equalization  612 , 613 , 614  as described above. After recording is complete, the clinician may click the list icon  415  to obtain a columnar display of the desired RMS values. Review of this list may give the clinician valuable information regarding the degree of functionality/pathology present in certain organs (lung, heart, bowel, etc.). The settings and/or outputs of the PSD (calculated from the Y/T icon  413 ), Time Expanded Waveform  407 , FFT Maximum  410 , Filters  405 , 406  and List  412 , 415  can all be saved in memory  13 , printed on paper via printer  15  or transmitted via modem  16  to another computer  9  though the internet. It should be understood that additional icons may be added to the program in  FIG. 6  if additional data manipulation is desired. In addition, program settings for analysis of auditory signals from two or more different sources (organs, ambient noise, etc.) such as the heart and trachea ( FIGS. 9 and 11 ) may be combined, thereby enabling the operator to analyze discrete frequency bands within a signal. For instance, if an observed physiologic sound is composed of sounds from the trachea and heart superimposed on each other, the operator may combine modules from  FIGS. 9 and 11  into a single program that will separately analyze the signals from each source simultaneously. If there exists overlap, additional methods may be deployed to separate out the overlapping frequency components of the two or more sources. 
     Lastly, data generated from this analysis program  210  may be integrated with numerical/text data contained in a patient&#39;s electronic medical records  220 . The integration of data among these programs  210 , 220 , 230  can be directed by an operator using a mouse  7 , keyboard  8  or other input. U.S. Pat. Nos. 6,944,821 and 6,154,756 demonstrate two such methods for performing said integration of data contained on multiple program elements. Additional software programs  230  may combine data from the analysis program  210  and electronic medical records  220  for the purposes of assessing target organ functionality, characterization of pathology if present, and generating accurate predictions regarding the degree of functionality of the target organ system in the near future. 
     A description on the preferred embodiment of the invention outlines a very specific method for analysis of physiologic sounds. The device as claimed is capable of variants and it should be appreciated by one skilled in the art that substitution of materials and modification of details can be made without departing from the spirit of the invention.