摘要:
A system for detecting wear debris particulate from a medical implant within the body of a living animal is provided. The system includes an acoustic transmitter for transmitting acoustic energy from outside the body to a soft tissue region proximate the medical implant containing wear debris particles; an acoustic receiver located outside the body to detect resultant acoustic energy generated by the wear debris particles and produce a received signal indicative thereof; a processor for processing the received signal to evaluate at least one parameter associated with the wear debris particles; and an output for indicating the at least one parameter.
摘要:
Vibrational energy harvesting (VEH) structures that include resonant beams each having a fundamental resonance frequency and a parametric mode frequency and including at least one piezoelectric layer for generating electrical charge in response to each of fundamental-resonance excitation and parametric-mode excitation of that beam. Circuitry is provided for harvesting the electrical charge from the resonant beam. In some embodiments, the parametric mode frequency of the beam is tuned to be close to its fundamental resonance frequency so as to increase the effective bandwidth of a VEH structure. The effective bandwidth of a VEH structure can be further increased by tuning ones of multiple parametric-mode-enabled resonant beams to slightly different fundamental resonance frequencies and parametric mode frequencies.
摘要:
The aero-acoustic duster invention disclosed herein provides for high particle removal rate from surfaces with low energy expenditure relative to competing vacuum-based devices. The device removes particulate matter from a surface using a two-step process: 1. Acoustic radiation is used to break the adhesive bonds between dust and the surface, forcing particles into a mode where they continuously bounce up and down on the surface; and, 2. A bounded vortex is generated over the surface, with suction in the vortex center and jets for blowing air along the periphery. The jets are tilted in the tangential direction to induce vortex motion within the suction region. The vortex is said to be bounded because streamlines originating in the downward jets are entrained back into the central vortex.
摘要:
The aero-acoustic duster invention disclosed herein provides for high particle removal rate from surfaces with low energy expenditure relative to competing vacuum-based devices. The device removes particulate matter from a surface using a two-step process: 1. Acoustic radiation is used to break the adhesive bonds between dust and the surface, forcing particles into a mode where they continuously bounce up and down on the surface; and, 2. A bounded vortex is generated over the surface, with suction in the vortex center and jets for blowing air along the periphery. The jets are tilted in the tangential direction to induce vortex motion within the suction region. The vortex is said to be bounded because streamlines originating in the downward jets are entrained back into the central vortex.
摘要:
Vibrational energy harvesting (VEH) structures that include resonant beams each having a fundamental resonance frequency and a parametric mode frequency and including at least one piezoelectric layer for generating electrical charge in response to each of fundamental-resonance excitation and parametric-mode excitation of that beam. Circuitry is provided for harvesting the electrical charge from the resonant beam. In some embodiments, the parametric mode frequency of the beam is tuned to be close to its fundamental resonance frequency so as to increase the effective bandwidth of a VEH structure. The effective bandwidth of a VEH structure can be further increased by tuning ones of multiple parametric-mode-enabled resonant beams to slightly different fundamental resonance frequencies and parametric mode frequencies.