Audiological Engineering Corporation

Adient Medical, Inc.

Other

David Franklin

Michael Steele

Michael Hogan

Mitchell Donn Eggers

Raymond Kirk

Jeremy Durack

Joseph Steele

Paul G Hughes

Michael Wollowitz

John Simpson

Joseph Franklin

The present invention relates generally to a method and apparatus for deploying and/or retrieving an object (e.g., a vena cava filter) in a cavity (e.g., a vena cava) using a system configured to: (i) maintain grip of the unsheathed object in the cavity until deliberately released, (ii) prevent premature release of the object in the cavity, and/or (iii) facilitate retrieval by first everting said object, then withdrawing the object through a guiding catheter (e.g., retrieval via eversion).

Method and apparatus for deploying and retrieving objects in a cavity

The present invention relates generally to a method and apparatus for deploying and/or retrieving a vena cava filter in a vena cava using a system configured to: (i) maintain grip of the unsheathed filter in the vena cava until deliberately released, (ii) prevent premature release of the filter in the vena cava, and/or (iii) facilitate retrieval by first everting the filter, then withdrawing the filter through a guiding catheter (e.g., retrieval via eversion).

Spread-spectrum technology, either direct sequence or frequency hopping, or a combination of the two, is used for transmitting audio signals one way and control signals two ways over an RF channel(s) to reduce interference with/from other RF transmissions and enabling use of multiple such systems in close proximity without requiring pre-selection of transmission frequencies. Alternatively, multiple channels with appended access codes may be used, wherein interference or loss of clear signal results in automatic switching to another channel. The control signals accompany the transmitted audio signal at some time in the transmission interval, or previous to the beginning of the transmission interval, and constitute a coded control message allowing a unique connection. In some cases the encoding keys may only occur at the beginning of the desired message, while in other cases the two-way control signals may continue throughout the interval of the message link.

Method and system for delivering from a loudspeaker into a venue

An RF-type amplification system, such as a classroom amplification system, employs technology adapted from a cordless telephone system to overcome interference. The amplification system includes a portable remote unit ( ) and a base unit ( ). Remote unit ( ) includes: a microphone ( ) for detecting a voice and generating corresponding voice signals; a transmitter ( ) which generates RF signals containing the voice signals as well as control signals provided by the central processing unit ( ) of remote unit ( ), and an antenna ( ) for transmitting the RF signals and for receiving RF signals from base unit ( ). Base unit ( ) includes an antenna ( ) which receives the RF signals transmitted by the remote unit and a receiver ( ) which detects the RF signals and separates the RF signals into the voice signals and control signals. The control signals are identified by a code detector ( ) of base unit ( ) and evaluated by a CPU ( ). If the values of the control signals are as expected, the voice signals are processed through a speech network ( ) and provided at a communications interface to an audio power amplifier ( ) which amplifies the voice signals and supplies the voice signals to speakers which audibly project the voice signals as sound. Base unit ( ) further includes a transmitter ( ) for generating RF signals containing control signals, but no voice signals, that are transmitted to remote unit ( ), thereby effecting one-way transmission of voice signals and two-way transmission of control signals between remote unit ( ) and base unit ( ).

Method and apparatus for improving classroom amplification systems and other RF-type amplification systems

Improved signal to noise ratio to help speech comprehension in a noisy environment is accomplished by selectively downwardly expanding a speech and noise composite signal when the speech signal is absent, thereby lowering signal components which represent noise. An expansion control signal is extracted from the composite input signal. Operation is based on the assumption that when noise alone is present, the input signal amplitude is less than some reference level and that when speech and noise are present together, the input signal amplitude is greater than the reference level. The response rates of gain changes are quite rapid, and do not introduce distortion or other audibly noticeable artifacts of the processing. The amount of downward expansion of the noise alone is small compared to noise gates to further reduce processing artifacts. The methods of realization include use of, in combination and alone, analog compressors and expanders, analog expanders in combination with voltage clamps and/or automatic level control circuits, two-quadrant multipliers in conjunction with digital control, entirely digital means for obtaining the requisite sensing and gain control, and expandor designs that are analogs of conventional filter designs where the notion of amplitude replaces frequency. Automatic noise suppression may be employed to pre-process the input signal, thereby rendering the control circuit self adjusting for better performance over a wide range of background sound levels. Various microphone, preferably providing directional characteristics, may be used to reduce noise levels in the received input signal.

Method and apparatus for improving effective signal to noise ratios in

Inexpensive wideband transducers convert low frequency components (i.e., approximately 50 Hz through 800 Hz) of an audio signal to mechanical vibrations at the same frequencies so that the vibrations may be perceived at the user's skin, typically at a hand or finger. The transducer may be a small permanent magnet moving coil loudspeaker with most of the diaphragm cone removed to minimize soundwave generation, or it may be a small d.c. or stepping motor arranged to have its drive shaft rotated in alternate directions through small angles corresponding to signal amplitude. Vibrations may be applied to the user's hand through a hand-held case vibrating with the motor, or to a finger via a contactor extending outside the case from the motor or loudspeaker. The transducer has particular utility in conjunction with closed captioned in television programs to enhance appreciation of speech therein while also training the user in utilizing the transducer. One or more fixed frequency transducers may additionally be employed vibrations at a single frequency representing all of the higher frequency components in the audio signal.

Method and apparatus for tactile transduction of acoustic signals from

Directional hearing in noisy environments is enhanced using small conventional microphones. In one embodiment a conventional first order bidirectional gradient microphone is employed in connection with a barrier to produce sound shadow at the rearward end of the microphone. In other embodiments such as hearing assistive devices worn on a person's head or body, the head or body of that person serves as the barrier. The result is a significant reduction in gain for all frequencies of acoustic energy emanating from generally rearward of the microphone. The sound shadow creates an apparent change of direction of arrival for rearwardly arriving acoustic energy, thereby making it appear to the microphone that the sound is approaching from the high attenuation 90.degree. direction. Two spaced bidirectional microphones worn on a person's body may be positioned to take advantage of this effect while simulating binaural hearing in an assistive listening device. A similar directional result is obtained with two conventional cardioid microphones mounted on a common casing to face in opposite directions. Electronic circuitry subtracts the output signal of the rearward facing microphone from the output signal of the forward facing microphone to render the combination highly directional. Case noise and other mechanical vibrations modulating the two output signals are nulled out in the subtraction process.

Method and apparatus for reducing background noise in communication

A tactile aid for deaf individuals includes a conveniently wearable array of vibration transducers mounted on a flexible carrier strip so as to be positionally biased toward the individuals's skin. Each transducer includes an enclosed magnetically vibratable cantilevered beam, an angled mounting slot to effect the positional bias mounting on the strip, and contact pads rather than conventional pin connectors to both reduce mass and facilitate electrical connection to contact pads on carrier strips in the form of printed circuit boards. Received acoustic signals are processed in at least first and second formant circuits each sub-divided into plural sub-bands corresponding to the number of transducers. In each formant circuit the corresponding formant frequency and amplitude are measured, averaged over a predetermined number of cycles, and a voltage corresponding to the measured amplitude is provided on a corresponding sub-hand channel to pulse width modulate a pulse train employed to excite the transducers. Spectral resolution can be increased by averaging the amplitude/frequency measurements over fewer cycles. Glottal pulses in the speech signal are monitored to provide a glottal rate signal at a stepped down frequency related to the actual glottal rate. The channel amplitude is modulated by the glottal signal to cause alternation of transducer excitation at the related glottal rate. Additional formants may be detected to derive additional information in the excitation signal.

Method and apparatus for sound responsive tactile stimulation of deaf

A circuit for suppressing background noise of a continuous nature while enhancing speech signals, or signals having the transient temporal qualities of speech, includes a signal multiplier which, in the preferred embodiment, receives the composite audio signal along with a control signal present only when the speech component of the audio signal is present. The control signal may be derived from an AGC circuit having a slow attack, fast decay characteristic to establish a quiescent output level from the AGC amplifier in the absence of speech. An envelope detector is biased to provide a zero output amplitude in response to the quiescent amplifier output level. Speech components appearing in the amplifier output signal are then envelope-detected and filtered to provide the control signal. Alternatively, the control signal can be derived by envelope-detecting the audio signal, filtering the detected signal to remove its d.c. component representing the continuous noise, and then detecting and filtering again. In still another embodiment, the control signal acts upon a constant amplitude instead of the audio input signal in order to provide a speech-responsive tactile vibration for the deaf.

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Somerville, MA, United States of America

David Franklin