Abstract:
A stethoscope capable of eliminating unwanted sounds and method thereof, the stethoscope and method thereof mainly use a stethoscope head containing a sensor and a signal processing circuit. By way of detecting and judging whether the stethoscope head arrives on correct stethoscopic position by the sensor, unwanted sounds generating by frictions, translations, or collisions during the stethoscopic process can be effectively eliminated such that the stethoscopic quality can be improved. Thus, a doctor can use less time and spirit to make a correct diagnosis for a patient with least unwanted interference sounds.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a stethoscope capable of eliminating unwanted sounds, and more particularly, to stethoscope capable of effectively eliminating unwanted sounds generating by frictions, translations, or collisions during an auscultatory process for improving auscultation quality by the use of a stethoscope head containing a sensor and a signal processing circuit. 
     BACKGROUND OF THE INVENTION 
     Analysis of heart, lung and vascular disorders by means of noninvasive auscultation has long been a very useful tool for medical diagnosis of ailments. By using a stethoscope, a physician would listen to the heart sounds, chest sounds or other body sounds to identify sounds associated with abnormalities. The stethoscope has proven to be a valuable instrument for the transmission of these sounds to the examining physician. However, identifying specific murmurs, like identifying heart sounds, is difficult. Developing the skill to make a proper analysis takes years of study and practice. In addition, it has been recognized that there is a need for amplifying certain frequency areas relative to those which are effectively reproduced by a stethoscope so as to provide physicians with improved sound quality for enhancing diagnosis of abnormalities. 
     Conventional stethoscope had been invented and used for over 190 years since Year 1816 while electronic stethoscopes was developed not until Year 1922. Modern electronic stethoscopes can improve sound quality and provide visual indication of heart sounds or chest sounds, such as cardiophonography. However, early electronic stethoscopes, which are composed of vacuum tubes or transistors, are typically expensive and bulkier than conventional stethoscopes. Accordingly, electronic stethoscopes can only begin to replace the dominant role of conventional stethoscopes after the rapid development of IC technology at the end of 20 th  century. Nevertheless, most electronic stethoscopes currently available on the market are analog electronic stethoscopes that are still lacking of the convenient of a conventional stethoscope. 
     In a prior-art electronic stethoscope disclosed in U.S. Pub. No. 2005/0157888 A1, entitled “Electronic Stethoscope with Piezo-Electrical Film Contact Microphone”, the auscultatory sounds are first being amplified and then the amplified sounds are sent to a filter for eliminating unwanted sounds. Although the aforesaid electronic stethoscope is able to eliminate unwanted sound in an auscultatory process, it is still imperfect that the elimination is realized by a very complex signal processing operation and apparatuses, and a physician using the referring stethoscope to perform an auscultatory process is still bothered by ambient noises, e.g. a bumping sound of a collision happening in the vicinity of the auscultatory being performed. 
     Therefore, it is in need of a stethoscope capable of effectively eliminating unwanted sounds generating by frictions, translations, or collisions during an auscultatory process for improving auscultation quality by the use of a stethoscope head containing a sensor and a signal processing circuit, such that a physicians can exercise a diagnosis of abnormalities with less effort and time and without being interfered by noises. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a stethoscope capable of effectively eliminating unwanted sounds in an auscultatory process, which utilizes a sensor and signal processing circuit embedded in a stethoscope head of the stethoscope to determine whether the stethoscope head is located at a proper position for the auscultatory process while effectively eliminating unwanted sounds generating by frictions, translations, or collisions during the auscultatory process. 
     It is another object of the invention to provide a stethoscopic method with noise elimination ability, which is characterized in that: the tilting of a stethoscope head or the angular variation of the stethoscope head per time unit is detected and measured by a sensor embedded inside the stethoscope head; an evaluation is made using a polling means for determining whether the detected angular velocity or the inclination angle is larger than a threshold value; if so, a stethoscope is enabled to stop the gathering of auscultatory sounds or enter a power-saving mode as it is determined that the stethoscope head is not located at a proper position for an auscultatory process to be performed; otherwise, the stethoscope is enabled to start the gathering of auscultatory sounds for performing the auscultatory process while unwanted sounds generating by frictions, translations, or collisions are eliminated. 
     To achieve the above objects, the present invention provides a stethoscope apparatus and method, which are capable of effectively eliminating unwanted sounds generating by frictions, translations, or collisions during an auscultatory process for improving auscultation quality by the use of a stethoscope head containing a sensor and a signal processing circuit, such that a physicians can exercise a diagnosis of abnormalities with less effort and time and without being interfered by noises. 
     Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a stethoscope capable of eliminating unwanted sounds according to the present invention. 
         FIG. 2  is a schematic diagram showing a sensor of a stethoscope capable of eliminating unwanted sounds according to a first preferred embodiment of the present invention. 
         FIG. 3  is a schematic diagram showing a sensor of a stethoscope capable of eliminating unwanted sounds according to a second preferred embodiment of the present invention. 
         FIG. 4  is a flow chart illustrating the steps of a stethoscopic method of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For your esteemed members of reviewing committee to further understand and recognize the fulfilled functions and structural characteristics of the invention, several preferable embodiments cooperating with detailed description are presented as the follows. 
     Please refer to  FIG. 1 , which shows a stethoscope capable of eliminating unwanted sounds according to the present invention. The stethoscope  100  is comprised of: a stethoscope head  110 , a signal processing circuit  120  and a headset  130 . Wherein. The stethoscope head  110  further comprises a microphone  112  and a sensor  114 ; the signal processing circuit  120  further comprises: a micro processor  122 , an operational amplifier with recording circuit  124 , a low-pass filter  126  and an accentuator  128 . The micro processor  122  is capable of controlling the operations of the operational amplifier with recording circuit  124 , the low-pass filter  126 , the accentuator  128 , the sensor  114 , and the microphone  112  while connecting thereto, and simultaneously is polling the detection of the sensor  114  actively at any time for using the result of the detection to control the starting/stopping of the gathering of the auscultatory sound by the microphone  112 . Moreover, the micro processor  122  can also be connected to a keyboard/LCD  125  for using the same as I/O device. If the detection of the sensor  114  satisfies a specific condition for enabling the gathering of the auscultatory sound, the stethoscope head  110  is assumed to be placed exactly at a specific position suitable for an auscultatory process to be performed. During the auscultatory process, the auscultatory sound, gathered by the microphone  112 , amplified by the operational amplifier  124 , filtered by the low-pass filter  126 , and having one&#39;s characteristics frequency band being emphasized by the accentuator  128 , is sent to the headset  130  to be used by a physician in an auscultatory process. 
     Please refer to  FIG. 2 , which is a schematic diagram showing a sensor of a stethoscope capable of eliminating unwanted sounds according to a first preferred embodiment of the present invention. In  FIG. 2 , the sensor  114  is an angular velocity sensor being positioned directly on a printed circuit board (PCB)  115 , and is enabled to detect an angular variation measured between a specific position where the auscultatory process is performed and a planar surface where the sensor  114  is placed, while comparing the detected angular variation with a threshold value configured in the sensor  114  to determine whether the stethoscope head  114  is located at the specific position suitable for an auscultatory process to be performed. In a preferred aspect, if the detected angular variation is larger than the threshold value, the stethoscope head  110  is assumed to be still in the process of moving toward the specific position and not yet arrive, and thus the gathering of the auscultatory sound is stopped for eliminating unwanted sounds to be received thereby; if the detected angular variation is smaller than the threshold value, the stethoscope head  110  is assumed to be placed exactly at the specific position, and thus the gathering of the auscultatory sound is started. 
     Furthermore, the sensor  114  of  FIG. 2  can be an angle sensor, which is capable of detecting an inclination angle measured between a planar surface where the sensor is placed and a reference position, while comparing the detected angle with a threshold value to determine whether the stethoscope head  114  is located at the specific position of the auscultatory process. In a preferred aspect, if the detected inclination angle is larger than the threshold value, the stethoscope head  110  is assumed to be placed on a table and not being used in an auscultatory process, and thus the gathering of the auscultatory sound is stopped for saving power; if the detected inclination angle is smaller than the threshold value, the stethoscope head  110  is assumed to be used in an auscultatory process, and thus the gathering of the auscultatory sound is started. In addition, the sensor  114  of  FIG. 2  can be a pressure sensor, which is capable of detecting a pressure difference between the pressure measured at a specific position where the auscultatory process is performed and that at a planar surface where the sensor is placed, while comparing the pressure difference with a threshold value to determine whether the stethoscope head  114  is located at the specific position of the auscultatory process. In a preferred aspect, if the detected pressure difference is smaller than the threshold value, the stethoscope head  110  is assumed to be still in the process of moving toward the specific position and not yet arrive, and thus the gathering of the auscultatory sound is stopped for saving power; if the detected angular pressure variation is larger than the threshold value, the stethoscope head  110  is assumed to be placed exactly at the specific position, and thus the gathering of the auscultatory sound is started. 
     Please refer to  FIG. 3 , which is a schematic diagram showing a sensor of a stethoscope capable of eliminating unwanted sounds according to a second preferred embodiment of the present invention. In  FIG. 3 , the sensor  114  is an optical sensor, being comprised of a light emitter  115 , a light receiver  116 , a light grating  117  and a roller  118 . Wherein, the light emitter  115  is used for discharging a light beam; the light receiver  116  is used for receiving the light beam and thus is positioned at a location corresponding to that of the light emitter  115 ; the light grating  117  is sandwiched between the light emitter  115  and the light receiver  116  to be used for controlling the propagation of the light beam; and the roller  118  is connected to the light grating while being sandwiched between the light emitter  115  and the light receiver  116 . As the moving of the stethoscope head  110  is bringing along the roller  118  to enable the light grating  117  to rotate therewith, the optical sensor is enabled to measure a variation of continuity as it is detecting the propagating of the light beam passing through the rotating light grating  117  so as to use the measured variation of continuity for enabling the micro processor  122  to determine whether the stethoscope head  110  is located at the specific position suitable for an auscultatory process to be performed. 
     Please refer to  FIG. 4 , which is a flow chart illustrating the steps of a stethoscopic method of the present invention. The flow starts at step  400 . At step  400 , a stethoscope is activated, and then the flow proceeds to step  410 . At step  410 , a sensor of the stethoscope compares a value detected thereby with a designated threshold value to determine whether the stethoscope head is located at a specific position suitable for an auscultatory process to be performed; if so, the flow proceeds to step  420 ; otherwise, the flow proceeds to step  415 . In step  415 , the gathering of an auscultatory sound is stopped while a micro processor is enabled to keep on pulling the detection result of the sensor; if a latest pulling specified that the stethoscope head is located at a specific position suitable for an auscultatory process to be performed, the flow proceeds back to step  410 . At step  420 , the gathering of the auscultatory sound is started, and then the flow proceeds to step  430 . At step  430 , an auscultatory process can be performed. 
     To sum up, the present invention provides a stethoscope apparatus and method, which are capable of effectively eliminating unwanted sounds generating by frictions, translations, or collisions during an auscultatory process for improving auscultation quality by the use of a stethoscope head containing a sensor and a signal processing circuit, such that a physicians can exercise a diagnosis of abnormalities with less effort and time and without being interfered by noises. 
     While the preferred embodiment of the invention has been set forth for the purpose of disclosure, modifications of the disclosed embodiment of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.