Abstract: A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fHt at a temperature T defined by fHt=(vt/2?)(?(A/voL)) were vt is the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vo is the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of ?(A/voL) at a rate and in a manner that balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2?)(?(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range, thereby holding the value of fH substantially constant across the temperature range.

Abstract: A buzzer includes a piezoelectric diaphragm and a housing enclosing the diaphragm and defining a resonating chamber. The chamber includes a sound port and has an optimal resonating frequency fHt at a temperature T defined by fHt=(vt/2?)(?(A/voL)) were vt is the velocity of sound waves in air at a temperature T, A is the effective area of the sound port, vo is the volume of the resonating chamber, and L is the effective length of the sound port. A temperature compensating member moves in response to changes in temperature to change the value of ?(A/voL) at a rate and in a manner that balances the change in 1/vt across that same temperature range, thereby reducing changes in the product (vt/2?)(?(A/voL)) and consequently reducing any changes that would otherwise occur in fHt across that temperature range, thereby holding the value of fH substantially constant across the temperature range.

Abstract: In one embodiment, an endoscope has a proximal end portion opposite a distal end portion. A view port is included at the distal end portion to view an internal body region through a passageway of a patient's body. Also located at the distal end portion are one or more piezoelectric elements operable in one mode to determine position of the distal end portion relative to internal body region and operable in a second mode to ablate tissue of the internal body region. The endoscope carries a balloon positioned about the one or more piezoelectric elements to selectively hold the distal end portion in a desired position in the passageway.

Abstract: In one embodiment, an endoscope has a proximal end portion opposite a distal end portion. A view port is included at the distal end portion to view an internal body region through a passageway of a patient's body. Also located at the distal end portion are one or more piezoelectric elements operable in one mode to determine position of the distal end portion relative to internal body region and operable in a second mode to ablate tissue of the internal body region. The endoscope carries a balloon positioned about the one or more piezoelectric elements to selectively hold the distal end portion in a desired position in the passageway.

Abstract: An apparatus for ablating tissue within a treatment region includes an ultrasound treatment transducer (36, 36′) for orienting at a first longitudinal orientation and a first angular orientation (40, 42) within the treatment region (26), for orienting at the first longitudinal orientation and a second angular orientation (40, 42) within the treatment region, and for orienting at a second longitudinal orientation and the first angular orientation (40, 42) within the treatment region, and a drive system for exciting (via conductors 46) the transducer (36, 36′) to ablate tissue (60) oriented adjacent the first longitudinal orientation and the first angular orientation within the treatment region (26), adjacent the first longitudinal orientation and the second angular orientation within the treatment region (26), and adjacent the second longitudinal orientation and the first angular orientation within the treatment region (26), respectively.

Abstract: An apparatus for ablating tissue within a treatment region includes an ultrasound treatment transducer (36, 36′) for orienting at a first longitudinal orientation and a first angular orientation (40, 42) within the treatment region (26), for orienting at the first longitudinal orientation and a second angular orientation (40, 42) within the treatment region, and for orienting at a second longitudinal orientation and the first angular orientation (40, 42) within the treatment region, and a drive system for exciting (via conductors 46) the transducer (36, 36′) to ablate tissue (60) oriented adjacent the first longitudinal orientation and the first angular orientation within the treatment region (26), adjacent the first longitudinal orientation and the second angular orientation within the treatment region (26), and adjacent the second longitudinal orientation and the first angular orientation within the treatment region (26), respectively.