Jeremy A. Brown

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The results of a study of the three-dimensional vibration of two dry human skulls in response to harmonic excitation are presented. The vibratory response exhibits three distinct types of motion across the range of audible frequencies. At low frequencies below 1000 Hz, whole-head quasi-rigid motion is seen. At the middle frequencies between 1000 and 6000(More)
OBJECTIVE To evaluate optimal placement of the Floating Mass Transducer of the Vibrant Soundbridge (Med-El, Innsbruck, Austria) against the round window membrane, particularly the impact of interposed coupling fascia and of covering materials. METHOD : Six fresh human cadaveric temporal bones were used. After mastoidectomy, posterior tympanotomy and(More)
The bone-anchored-hearing-aid (BAHA) transduces airborne sound into skull vibration. Current bilateral BAHA configurations, for sounds directly facing listeners, will apply forces that are in-phase with each other and directed roughly towards the center of the head. Below approximately 1000 Hz the two cochleae respond in approximately the same direction and(More)
Digital transmit and receive beamformers for a 45-MHz, 7-element annular array are described. The transmit beamformer produces 0- to 80-Vpp monocycle pulses with a timing error of less than +/-125 ps. Up to four adjustable transmit focal zones can be selected. The dynamic receive beamformer uses a variable frequency sampling technique in which the frequency(More)
OBJECTIVE To compare the performance of a subcutaneous piezoelectrically actuated hearing aid (SPAHA) with the bone-anchored hearing aid (BAHA) and assess its effectiveness as a treatment option for conductive loss and single-sided deafness (SSD). BACKGROUND To validate the use of the SPAHA as a bone conduction implant, its performance was compared with a(More)
HYPOTHESIS To illustrate the ability of high frequency ultrasound (HFUS) using a transducer array to demonstrate a variety of simulated clinical scenarios involving the ossicular chain. BACKGROUND HFUS (>20 MHz) is a relatively new area of ultrasonic imaging that provides an order of magnitude better image resolution than the conventional low-frequency(More)
Ultrasonic power transfer using piezoelectric devices is a promising wireless power transfer technology for biomedical implants. However, for sub-dermal implants where the separation between the transmitter and receiver is on the order of several acoustic wavelengths, the ultrasonic power transfer efficiency (PTE) is highly sensitive to the distance between(More)
Imaging techniques currently used in the clinic to inspect ears in patients are generally limited to views terminating at the tympanic membrane (TM) surface. For imaging past the TM, methods such as computed tomography are typically used, but in addition to disadvantages such as being costly, time consuming, and causing radiation exposure, these often do(More)
Ultrasonic power transfer is a promising alternative to electromagnetic induction for providing wireless power to active implanted medical devices. In a portable ultrasonic power link for devices like cochlear implants, there is a key requirement for an inverter circuit that is capable of driving the transmitting piezoelectric transducer with high(More)
A 50MHz array-based imaging system was used to obtain high-resolution images of the ear and auditory system. This previously described custom built imaging system (Brown et al. 2004a, 2004b; Brown and Lockwood 2005) is capable of 50 microm axial resolution, and lateral resolution varying from 80 microm to 130 microm over a 5.12 mm scan depth. The imaging(More)
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