A multi-frequency ultrasound therapy apparatus is configured to operate at its center frequency and at the higher harmonic of its center frequency. The center frequency can be for the entire apparatus or for each ultrasound source element. At least one source element can generate ultrasound energy at its center frequency while, simultaneously, at least another source element can generate ultrasound energy at the higher harmonic of its center frequency. In addition, the same source element can generate ultrasound energy at its center frequency and the higher harmonic of its center frequency, respectively, but at different times. A data storage unit that stores encrypted and encoded data is disposed on the apparatus. The encoded data includes a unique identification code of the apparatus, the condition of use of the apparatus, the center frequency of each source element, the ultrasound efficiency of each source element, and/or other parameters relating to the apparatus.

A mask, according to an embodiment, comprises: a first wiring disposed on a first base layer; a piezoelectric element disposed on the first wiring; a second wiring disposed on the piezoelectric element; a second base layer disposed on the second wiring; a protective layer disposed between the first and second base layers and surrounding the first wire, the second wire, and the piezoelectric element; and a control unit which controls a driving frequency of the piezoelectric element. The control unit controls the driving frequency of the piezoelectric element in a frequency band defined as a first range, and the temperature of the piezoelectric element changes by means of the control of the driving frequency of the control unit.

An ultrasonic surgical tool system with a tip capable of simultaneously vibrating in plural modes. The system includes a console capable of supplying a drive signal to the tip that includes plural components. Each component has a frequency characteristic that is based in part on the equivalent of current through the mechanical components of the tip. The frequency components are different from each other. Based on the application of drive signal the tip undergoes non-linear vibrations.

A method of providing a haptic signal is described therein, the method comprising the steps of providing a first source signal, filtering a mid-range band of the first source signal for restricting a bandwidth of the first source signal to the mid-range band, integrating the filtered mid-range band of the first source signal to identify an amplitude of the filtered first source signal, providing a voltage control amplifier with a proportional calibrated voltage on a basis of the integration of the filtered first source signal for adjusting an amplitude of the filtered source signal, isolating a trans-conductance voltage control amplifier high impedance output from a second source signal with a buffer, filtering the filtered source signal with a low pass filter to identify original sub-frequencies of an audio program and combining the identified original sub frequencies of the audio program with transposed midrange frequencies in a haptic signal.

Control console for a powered surgical tool (310) that includes a transformer (250) with a secondary winding (264) across which the tool drive signal is present. Also internal to the transformer is a matched current source that consists of leakage control winding (246) and a capacitor. The current sourced by the matched current source at least partially cancels out leakage current that may be present.

The method and system uses ultrasound (US) transducers in contact with an inboard surface underwater portions of marine vessels or structures. By first digitally generating disruptive, multi-frequency, interfering US waveform signals (complex waveforms, typically replicating a Bessel function) and then converting the signals into analog, the transducers generate disruptive, multi-frequency, interfering US waveforms through the underwater portions of the marine vessels and structures which waveforms disrupt unwanted marine growth on the water-side of the vessel or structure. The digital signals, and also the analog signals, are complex waveform signals, typically produced with a Bessel function. The US transducers are either circular membrane transducers or surface transducers. A computer processor coupled to a memory, generates the complex waveform signals fed to the US transducers.

A method for identifying a mechanical impedance of an electromagnetic load may include generating a waveform signal for driving an electromagnetic load, the waveform signal comprising a first tone at a first driving frequency and a second tone at a second driving frequency. The method may also include during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receiving a current signal representative of a current associated with the electromagnetic load and a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load. The method may further include determining amplitude and phase information of the current signal responsive to the first tone and second tone, determining amplitude and phase information of the back electromotive force signal responsive to the first tone and second tone, and identifying parameters of the mechanical impedance of the electromagnetic load based on the amplitude and phase information of the current signal and the amplitude and phase information of the back electromotive force signal.

Transducer assemblies that can be used in acoustophoretic systems are disclosed. The acoustophoretic systems including the transducer assemblies and methods of operating the acoustophoretic systems are also disclosed. The transducer assemblies include a housing, a polymeric film attached to the housing, and a piezoelectric material attached to the polymeric film. The piezoelectric material is not attached to, and does not come in direct contact with, the housing. The piezoelectric material is configured to be driven by a drive signal to create a multi-dimensional acoustic standing wave. The piezoelectric material can be attached to the polymer film by an adhesive coating on the polymer film.

A mini subwoofer double drive low-frequency vibrator includes a base, an upper cover, a side cover, a flexible printed circuit, a coil, a magnetic body, a counterweight, a spring piece, an internal welding piece, an external welding piece, an insulating tape, and a buffer. The magnetic body and the coil includes a symmetrical double-driving structure at both upper and lower part to mutually offset components in a non-vibration direction of an electromagnetic force and cancel vibration noises. The spring piece adopts a V-shape structure to increase an effective length of a deformation zone and to make a response frequency even lower. Two V-shape springs are distributed symmetrically in a center, making an operation more stable. The buffer is adopted to enhance service life, for fear of a spring damage caused by high circuit voltage.

A driving device generates a driving signal and outputs the driving signal to a piezoelectric element, the driving signal having a waveform obtained by using, as a first modulated wave, a first low-frequency wave having a frequency of 1 Hz or more and less than 100 Hz, using, as a second modulated wave, a waveform obtained by modulating an amplitude of a second low-frequency wave having a frequency of 100 Hz or more and 300 Hz or less with the first modulated wave, and modulating a high-frequency wave having a frequency of 20 kHz or more and 100 kHz or less with the second modulated wave.