Abstract: A listening device for detecting audio frequency sounds and presenting them at increased sound levels to a user's ears. The listening device comprises a lighweight housing with a sound port disposed on a front wall and containing audio processing components for detecting input sound waves, amplifying them, and transferring them to bi-aural sound transfer means coupled to the housing. The bi-aural transfer means directs amplified sound to both ears of a device user simultaneously. The listening device is very lightweight and very compact, with the main housing being less than about 1 cubic inch in volumeThe listening device employs an acoustical connector on the front wall to allow efficient transfer of sound waves from a series of acoustical adapters, generators, and probes. One such probe is highly useful for automotive engine analysis and another is highly useful for medical applications.

Abstract: A displacement sensor for an electrocardiograph attaches a permanent magnet chip directly on a living body, and movement or vibration of the living body is sensed by measuring flux by said magnet. The electrocardiograph has a magnet assembly having an adhesive film mounting a permanent magnet at the center of the film supported on a bottom ring which has a plurality of upright walls with jaws, for detachably engaging the magnet assembly with a sensor body. The sensor body has saturable inductors which are placed in flux by said magnet and are coupled with a process circuit having an astable multivibrator with a collector load by said saturable inductors and a low-pass filter connected to the output of the multivibrator. The magnet assembly is first adhered on a living body, then, the sensor body is engaged with the same by engaging said jaws with a projection on the sensor body, then, the process circuit provides an output signal reflecting the movement of a living body.

Abstract: The stethoscope comprises a membrane (2) sensor (1) connected by a tube (3) to ear-pieces (8 & 9). The tube (3) traverses a casing (10) containing an electrical unit connected by a cable (12) to an electrical sensor (11). The electrical unit is sensitive to a given frequency range and comprises an electro-acoustic emitter (19) supplying acoustic signals into conduit (3) which are obtained in response to signals coming from the sensor (11) according to a predetermined scheme.

Abstract: A method and apparatus for reducing distortion of an acoustical waveform by locating a plurality of microspheres to interact with interfering acoustical waveforms.

Abstract: A displacement sensor or an electrocardiogram attaches a permanent magnet chip directly on a living body, and movement or vibration of the living body is sensed by measuring flux by said magnet. The displacement sensor has a magnet assembly having an adhesive film mounting a permanent magnet at the center of the film supported on a bottom ring which has a plurality of upright walls with jaws, for detachably engaging the magnet assembly with a sensor body. The sensor body has saturable inductors which are placed in flux by said magnet and are coupled with a process circuit having an astable multivibrator with a collector load by said saturable inductors and a low-pass filter connected to the output of the multivibrator. The magnet assembly is first adhered on a living body, then, the sensor body is engaged with the same by engaging said jaws with a ring on the sensor body, then, the process circuit provides an output signal reflecting the movement of a living body.

Abstract: A microprocessor based sound enhancement system in which frequencies outside of the auditory range of the human ear are translated into sound within the auditory range by translating each frequency component of the entire frequency spectrum of the input signal by a time scale compression factor. Preferably, a microprocessor transforms an electrical signal corresponding to the input signal into a frequency spectrum signal comprising frequency components having frequency, phase, and amplitude elements by performing a fast Fourier transform (FFT) operation on the input signal. The frequency components of this transformed signal are translated and the resulting translated frequency spectrum signal is transformed into a time varying output signal by performing an inverse FFT operation on the translated frequency spectrum signal. When heart pulses or similar periodic waveforms are monitored, the pulse rate of the signal is maintained in the output signal.

Abstract: An interference resistant biomedical transducer for monitoring the acoustic output of a patient's cardiac or respiratory system which provides a high degree of rejection of acoustic noise and spurious electromagnetic signals. The transducer comprises a piezoelectric diaphragm assembly having electrodes which produce a differential output signal. The transducer housing includes a massive metal disc and a compliant handle which provide a mechanical filter to remove undesired signals such as those related to motion of the patient and ambient acoustic noise.

Abstract: A stethoscope having a monophonic electrical sensor which feeds electrical signals corresponding to heart sounds to a transversal filter to produce pseudostereophonic signals at split outputs which may be used to power dual earphones for binaural listening. The electronic processing of the heart sounds in the transversal filter enables the listener to differentiate the different sounds of the heart.

Abstract: An electronic sound amplification stethoscope including a battery powered self-contained sound amplification circuit contained in a hand held connector housing inserted in the flexible sound conduit of the stethoscope. The circuit includes a miniaturized microphone for receiving sound waves from the stethoscope pickup head and a miniaturized speaker for transmitting amplified sound waves to the stethoscope headpiece. Both the microphone and speaker may be housed in the connector housing and are vibration insulated from the housing itself. The electronic circuitry and battery power source are located in compartments separated from the microphone and speaker. A LED light source is placed in series between the amplifier circuit and the power source such that the fluctuations in its intensity are directly proportional to the power surges in the circuit. The LED is thus a visual indicator of such body functions as respiration and blood flow.

Abstract: A diagnostic system comprising one or more stethoscopes and a diagnostic unit. Each stethoscope is used to pick up a sound, which is then transmitted in radio form via an antenna after amplification through an electric/audio transducer. The sound, after being received by the diagnostic unit, is compared in a computer for diagnosis of the symptoms. The result of the diagnosis is then transmitted through an antenna and received by the stethoscope for reference by its user.

Abstract: A displacement sensor for a living body provides an improved stethoscope and/or cardiogram. The apparatus has a diaphragm which is placed on the surface of a living body, a permanent magnet located on the diaphragm, an inductor arrangement located adjacent to the permanent magnet so that the saturable inductor changes its inductance according to movement or vibration of the magnet, a processor circuit which processes the inductance variation in the inductors to provide an electrical output signal for visual display and recording purposes, and a hollow sound tube which introduces an acoustic vibration sound of the diaphragm to the ears of a doctor. The present apparatus provides not only acoustic sound output but also visual display and a printed copy as a mechanocardiogram sensor.

Abstract: A battery source of dc voltage continuously energizes digital circuitry for controlling operation of analog signal processing circuitry including a microphone preamplifier, an automatic gain control amplifier, a bandpass section and an output buffer driving audio reproducing equipment. The analog signal processing circuitry is energized on select command from the battery source through a switched on power supply. Automatic operation of the gain control amplifier may be disabled and the bandpass section by-passed in response to other select commands.

Abstract: This invention relates in general to a method and apparatus for identifying specific medical conditions from detected stethoscopic sounds. More particularly, the invention relates to the processing of such sounds electronically and the display of the time-variations of the spectral composition of such sounds. The invention is embodied in an accessory package designed to enable a host computer to perform computerized stethoscopic analysis.

Abstract: A confined system of sound transmission from a frequency attenuation compensated source through plastic pneumatic tubes in series with liquid tubes of considerable length, transmitting audio to and through pneumatic headphones to the ear canals of the user. It is an audio system suitable for use in Nuclear Magnetic Resonance scanning environments and for use in CAT scan environments. The system includes a stereo program source playing into a stereo frequency compensation amplifier driving right and left loudspeaker pneumatic drivers feeding audio to and through long liquid tubes in series with pneumatic tubes extended to left and right earphones of plastic headphones worn by a patient in a scan room environment.

Abstract: An electronic stethoscope is disclosed having a palm sized electronic component case with operating switches provided on opposite sides of the case for ease of operation. The stethoscope includes a pickup head coupled to an electronic microphone by means of a flexible tubular acoustic member. A battery powered amplifier and filter circuit is provided within the component case and the amplified and filtered output of the microphone is coupled to a miniature speaker sealed within an airtight container within the case. A rotatable tubular member having radial apertures therein is coupled through the sealed container and out each side of the component case. A binaural headpiece is acoustically coupled to each end of the rotatable member and is thus free to rotate with respect to the case, allowing the stethoscope to fold for storage.

Abstract: An electronic stethoscope for reproducing at a user's ear as exactly as possible the sound pressure signals originating from a conventional diaphragm or bell type of chestpiece. The subject electronic stethoscope utilizes a signal processing approach which relies upon acousto-electronic feedback to provide an error or adjustment signal to amplifier gain control circuits. A pickup microphone detects audible sounds from a patient and produces an output signal representative thereof, and a variable gain amplifier amplifies the output signal of the pickup microphone. The amplifier drives an acoustic transducer in a headset which converts the amplified signal to audible sounds for audible detection by the user. A feedback microphone is placed near the acoustic transducer to detect the audible sounds produced thereby, and provides a feedback output signal.

Abstract: An electronic transducer in which the detected sounds are frequency multiplied to place them in a more favorable position for hearing within the auditory range, and in which lateral modulation by means of electrocardiogram signals is achieved to give a perception of physical space to the detected sounds.

Abstract: In an electronic stethoscope which includes a pickup head, a microphone, a tubular accoustic connection between the pickup head and microphone, an amplifier receiving an input from the microphone, a speaker coupled to the output of the amplifier, a binaural headpiece and tubes acoustically coupling the output of the speaker to the binaural headpiece, there is included a switch by means of which a momentary on operation can be achieved and a timer responsive to the switch to couple power to amplifier circuit, the timer adapted to shut power off after a predetermined period of time. Preferably the amplifier is an integrated circuit operational amplifier with a filter circuit which brings up lower frequencies interposed between the amplifier and speaker.

Abstract: A compact hybrid stethoscope comprises a detachable headpiece for picking up auscultory sounds, a flexible tubing pneumatically connected to the headpiece for transmitting the auscultory sounds, an amplifier unit pneumatically connected to the flexible tube for receiving the auscultory sounds and reproducing amplified auscultory sounds, and a pair of auricles pneumatically connected to the amplifier for transmitting the reproduced sounds to the user's ears. An automatic on/off timer switch is connected to the amplifier so that even if inadvertently left on, the on/off timer automatically switches off the hybrid stethoscope after a predetermined interval, thus saving electric power. A tone control is connected to the amplifier so that the user may listen to the particularly desired auscultory sounds, such as respiratory or cardiac sounds while eliminating certain other auscultory sounds.

Abstract: Sound monitoring apparatus is described which provides a slowed down version of the original sound, e.g. a heart beat without changing the quality of the sound as perceived by a trained listener such as a physician. The amount by which the sound is slowed down can be varied by the user. The original sound is converted to an analog electrical signal, digitized and electronically processed in a microprocessor-based circuit such that digital data corresponding to cycles of the analog signal are stored in a random access memory. The microprocessor reads out the digital data a predetermined number of times corresponding to a number of sound cycles according to the rate set by the physician. The digital data is reconstituted into sound which is composed of replicated sets of cycles of the original sound. The repetition rate of the heart-beat in the output sound is a fraction of the repetition of the heart-beat in the original sound but the sound quality appears the same to the physician as the pitch is invariant.

Abstract: An electronic stethoscope for monitoring prosthetic valves for hearts includes a casing to which the center portion of a spring member is mounted. A weighted housing is mounted to the ends of the spring member and contains an opening therethrough in which a magnetic circuit comprising a pole piece, magnet and coil are positioned. The air gap between the pole piece and magnet is varied as the relative distance between the center of the spring and housing vary in response to the operation of a prosthetic heart valve thereby resulting in an induced voltage in the coil which may be amplified and monitored.

Abstract: A portable differential stethoscope includes small microphone elements which are attached to the stethoscope heads to pick up acoustic signals from the body. The sounds picked up by the stethoscope heads include body noise signals as well as heartbeat signals. Each stethoscope head and microphone element provides an output which is amplified in an individual amplifier. The two amplified signals are inputted to separate terminals of a differential amplifier through a gain and balance control element. The differential amplifier outputs a difference signal which is amplified and inputted to an electrical headset or an electrical earphone element which is acoustically coupled to the conventional acoustic tube.