A method comprising: receiving, by an electronic device, a first signal having a first frequency; identifying, by the electronic device, at least one of a strength of the first signal or a signal-to-noise ratio of the first signal; outputting, by the electronic device, a second signal having a second frequency that is different from the first frequency, the second signal being output based on at least one of the strength of the first signal or the signal-to-noise ratio of the first signal; receiving the second signal by the electronic device; and detecting whether the electronic device is at least partially immersed in a liquid based on the received second signal.

A method comprising: receiving, by an electronic device, a first signal having a first frequency; identifying, by the electronic device, at least one of a strength of the first signal or a signal-to-noise ratio of the first signal; outputting, by the electronic device, a second signal having a second frequency that is different from the first frequency, the second signal being output based on at least one of the strength of the first signal or the signal-to-noise ratio of the first signal; receiving the second signal by the electronic device; and detecting whether the electronic device is at least partially immersed in a liquid based on the received second signal.

The invention provides an improved acoustic energy generating apparatus that includes an improved backing structure. The improved backing structure employs protrusions that are not located in a uniform pattern along a forward side surface of the backing structure, to realize improved re-direction of acoustic energy towards a forward direction relative to the acoustic energy generating apparatus.

The invention provides an improved acoustic energy generating apparatus that includes an improved backing structure. The improved backing structure employs protrusions that are not located in a uniform pattern along a forward side surface of the backing structure, to realize improved re-direction of acoustic energy towards a forward direction relative to the acoustic energy generating apparatus.

Some surgical instruments become partially or fully disabled at a device firmware level after being used in a surgical procedure in order to prevent overuse or abuse of the surgical instrument that could create patient safety concerns. A reconditioning device may be used by the end user of such a surgical instrument to perform diagnostics and reconditioning of the surgical instrument so that the surgical instrument may be placed back into service without the direct intervention of the manufacturer. The reconditioning device provides power to the surgical instrument, analyzes device usage history, activates and tests the surgical instrument cutting and gripping functions, and measures electrical characteristics and mechanical characteristics of the surgical instrument. Gathered data is used to determine if the surgical instrument may be safely reconditioned for further use. If reconditioning is possible, the device will be reconfigured for safe use, reactivated, and then sterilized for subsequent re-use.

Disclosed are a device and a method for testing impedance characteristic and expansion performance of a sound absorption material. The device includes a first cavity and a second cavity which are both sealed. The first cavity is communicated with the second cavity through a slit channel. The second cavity is used for placing a sound absorption material therein. The device further includes a sound excitation source whose sounding face is located in the first cavity and used to provide a testing sound pressure. The device further includes two sound pickup sensors whose sound pickup surfaces are respectively arranged in the first cavity and the second cavity and respectively used to detect sound pressure in the first cavity and the second cavity. The device further includes a material for enclosing the first cavity and the second cavity is a hard sound insulation material.

Disclosed are a device and a method for testing impedance characteristic and expansion performance of a sound absorption material. The device includes a first cavity and a second cavity which are both sealed. The first cavity is communicated with the second cavity through a slit channel. The second cavity is used for placing a sound absorption material therein. The device further includes a sound excitation source whose sounding face is located in the first cavity and used to provide a testing sound pressure. The device further includes two sound pickup sensors whose sound pickup surfaces are respectively arranged in the first cavity and the second cavity and respectively used to detect sound pressure in the first cavity and the second cavity. The device further includes a material for enclosing the first cavity and the second cavity is a hard sound insulation material.

A sensor device, including a sensor having a sound transducer to emit sonic waves and convert received sonic waves to electrical signals. A sensor evaluation unit carries out surrounding-area monitoring during a normal operation of the sensor, by evaluating electrical signals of the sound transducer. During a monitoring mode of the sensor, a monitoring unit of the sensor device measures an impedance of the sound transducer for different excitation frequencies of excitation signals produced with a signal generator of the sensor device. The sensor device includes a first and a second signal path, which are each connected to the sound transducer and are connectable to the signal generator. To reset the sensor from normal operation to the monitoring mode, a first control unit of the sensor device is configured to decouple the signal generator from the first signal path and to connect it to the second signal path.

A sensor device, including a sensor having a sound transducer to emit sonic waves and convert received sonic waves to electrical signals. A sensor evaluation unit carries out surrounding-area monitoring during a normal operation of the sensor, by evaluating electrical signals of the sound transducer. During a monitoring mode of the sensor, a monitoring unit of the sensor device measures an impedance of the sound transducer for different excitation frequencies of excitation signals produced with a signal generator of the sensor device. The sensor device includes a first and a second signal path, which are each connected to the sound transducer and are connectable to the signal generator. To reset the sensor from normal operation to the monitoring mode, a first control unit of the sensor device is configured to decouple the signal generator from the first signal path and to connect it to the second signal path.

Methods, systems, and devices for determining an acoustic parameter of a downhole fluid using an acoustic assembly. Methods include transmitting a plurality of pulses; measuring values for at least one wave property measured for reflections of the plurality of pulses received at at least one acoustic receiver, including: a first value for a first reflection traveling a first known distance from a first acoustically reflective surface having a first known acoustic impedance, a second value for a second reflection traveling a second known distance substantially the same as the first known distance from a second acoustically reflective surface having a second known acoustic impedance, and a third value for a third reflection traveling a third known distance from a third acoustically reflective surface having a third known acoustic impedance substantially the same as the second acoustic impedance; and estimating the acoustic parameter using the values.