Abstract: Various implementations include in-ear wearable audio devices. In certain implementations, the in-ear audio devices include an eartip with a body having first and second ends, an inner wall extending between the first and second ends defining a hollow passage to conduct acoustic energy, and a deformable outer wall connected to the inner wall of the body at the first end and tapering away from the inner wall toward the second end, where the deformable outer wall is functionally graded from the first end to the second end to comply with an entrance of an ear canal of a user. In additional implementations, the eartip includes a retaining structure, and at least one of the inner wall or the outer wall of the body, or the retaining structure, has an integral electronic component and/or an electronic component signal trace.

Abstract: An improved method for adaptively cancelling acoustic feedback in hearing aids and other audio amplification devices. Feedback cancellation is limited to a frequency band that encompasses all unstable frequencies. By limiting the bandwidth of the feedback cancellation signal, the distortion due to the adaptive filter is minimized and limited only to the unstable feedback regions. A relatively simple signal processing algorithm is used to produce highly effective results with minimal signal distortion.

Abstract: An improved method for adaptively cancelling acoustic feedback in hearing aids and other audio amplification devices. Feedback cancellation is limited to a frequency band that encompasses all unstable frequencies. By limiting the bandwidth of the feedback cancellation signal, the distortion due to the adaptive filter is minimized and limited only to the unstable feedback regions. A relatively simple signal processing algorithm is used to produce highly effective results with minimal signal distortion.

Abstract: A method and apparatus to regulate the inflation of objects. To start inflation, the apparatus couples a fluid source to the object via a plenum. Concurrent with inflation, the apparatus substantially continuously measures pressure within the plenum using a sensor sufficiently proximate the object such that pressure measured by the sensor is substantially similar to pressure within the object. When measured pressure exceeds a target pressure by a prescribed margin, the apparatus stops inflating. While inflation is stopped, the apparatus reads pressure measured by the sensor and deflates the object as needed to reduce measured pressure to the target pressure.

Abstract: A surgical cassette having an aspiration chamber with a bubble separating structure. The bubble separating structure facilitates accurate, reliable measurement of the fluid level in the chamber.

Abstract: A method for operating a peristaltic pump having a molded flow channel contained on an elastomeric sheet that is bonded or mechanically attached to a rigid substrate. The pump head rollers are mounted radially from the axis of rotation of the pump motor and compress the elastomeric flow channels against the rigid substrate. During reflux, the pump head is positioned so that at least one of the rollers compresses the elastomeric flow channel at the input end of the peristaltic pump. Such an operation minimizes the amount of the elastomeric sheet that is exposed to high transient pressures.

Abstract: A method and apparatus to regulate the inflation of objects. To start inflation, the apparatus couples a fluid source to the object via a plenum. Concurrent with inflation, the apparatus substantially continuously measures pressure within the plenum using a sensor sufficiently proximate the object such that pressure measured by the sensor is substantially similar to pressure within the object. When measured pressure exceeds a target pressure by a prescribed margin, the apparatus stops inflating. While inflation is stopped, the apparatus reads pressure measured by the sensor and deflates the object as needed to reduce measured pressure to the target pressure.

Abstract: An acoustic fluid level sensor for use in a chamber contained in a surgical cassette. The sensor has an ultrasound transducer mounted on the outside of the bottom of a fluid chamber and is acoustically coupled to the chamber. The transducer sends a pulse ultrasound signal through the chamber and any liquid in the chamber. The signal is reflected back by the air/liquid interface and captured by the transducer. The time required for the signal to travel to and from the transducer will vary with the amount of fluid in the chamber and is indicative of the level of fluid in the chamber.

Abstract: A fluid level sensor for use in a chamber contained in a surgical cassette. The sensor has a pair of parallel conductor that project vertically into the chamber forming an open circuit. When surgical fluid contained within the chamber touches the conductor, the circuit is completed and AC voltage or current is passed through the conductor circuit. The conductivity of the circuit can be measured and related to the depth of fluid covering the conductors using laboratory-generated data or in situ calibration of the cassette.

Abstract: An improved surgical cassette for controlling intraocular pressure during ophthalmic surgery.

Abstract: A surgical cassette having an aspiration chamber or infusion chamber with a sensing portion and a storage portion. The sensing portion has a small transverse cross sectional area and facilitates accurate fluid level measurements. The storage portion has a larger transverse cross sectional area to facilitate fluid storage.

Abstract: A microsurgical system capable of controlling aspiration via a vacuum control mode, a suction control mode, or a flow control mode.

Abstract: A microsurgical system capable of controlling aspiration and detecting an occlusion via monitoring a change in either suction flow rate or suction impedance.

Abstract: An improved method for adaptively cancelling acoustic feedback in hearing aids and other audio amplification devices. Feedback cancellation is limited to a frequency band that encompasses all unstable frequencies. By limiting the bandwidth of the feedback cancellation signal, the distortion due to the adaptive filter is minimized and limited only to the unstable feedback regions. A relatively simple signal processing algorithm is used to produce highly effective results with minimal signal distortion.

Abstract: The insertion effects of hearing aids are determined and compensated to restore the ability to have directional hearing in individuals wearing hearing aids. In one aspect a method involves finding the ratio of the unaided head related transfer function to the aided head related transfer function and then designing a hearing aid filter that is the inverse of that derived insertion effect, thereby restoring the ability to hear interaural differences in aided systems both in level and in time of arrival to improve hearing in the presence of noise. The insertion effects can be derived either through frequency domain analyses, using the above-mentioned transfer function calculations and measurements, or in another aspect through time domain analyses, using optimal filter calculations and measurement obtained using a successive data acquisition system that is subsequently time aligned by recording trigger pulses with the data.