A capacitive micromachined ultrasonic transducer having a wide reception band is provided.

The capacitive micromachined ultrasonic transducer includes an element including a first sub-element and a second sub-element each including a cell. The cell includes a vibrating membrane that includes one of two electrodes formed with a spacing therebetween and that is vibratably supported. The capacitive micromachined ultrasonic transducer further includes a first detection circuit, a second detection circuit, and a combining circuit that combines a signal from the first detection circuit and a signal from the second detection circuit. The first sub-element is electrically connected to the first detection circuit, and the second sub-element is electrically connected to the second detection circuit. The first detection circuit and the second detection circuit have different cut-off frequencies.

A self-oscillating piezoelectric actuator drive circuit includes a integrating circuit; an inverter (INV1), inverters (INV2 and INV3) inverting an output signal of the inverter (INV1), sense resistors (Rs1 and Rs2) connected to output sides of the inverters (INV2 and INV3), a positive feedback resistor (Rfb2) feeding back an output signal of the inverters (INV2 and INV3) to the integrating circuit; and a negative feedback resistor (Rfb1) feeding back a voltage generated from the sense resistors (Rs1 and Rs2, Rs1<Rs2 in terms of a resistance value) to the integrating circuit. In a startup state, the sense resistor (Rs2) and the inverter (INV3) are selected, and in an operating state after the startup state, the sense resistor (Rs1) and the inverter (INV2) are selected.

The high voltage drive for the transducer of an ultrasonic transducer probe is provided by an active supply that monitors the high voltage supplied to the transducer by means of feedback, and responds to a decline in voltage during high voltage transmission by coupling charge from a capacitor to the high voltage supply line of the probe, thereby preventing a precipitous decline in the high voltage. Preferably the active supply and the capacitor are located in the probe connector enclosure.

Control consoles and methods for supplying a drive signal to a surgical tool are provided. The control console comprises a transformer with primary and secondary windings. The primary winding receives an input signal from a power source and induces the drive signal in the secondary winding to supply the drive signal to the surgical tool. A first current source comprising a leakage control winding is coupled to a path of the drive signal. The primary winding induces a first cancellation current in the leakage control winding to inject into the path of the drive signal to cancel leakage current. A sensor coupled to the path of the drive signal outputs a sensed signal to provide feedback related to leakage current. The sensor may connect to a second leakage current cancellation source and/or a fault detection stage. The power source may be variable and may also energize the second current source.

An aerosol separating module includes an ultrasonic vibrator configured to generate a ultrasonic wave, a surface acoustic wave vibrator configured to generate a surface acoustic wave, and a transfer element configured to transfer an aerosol forming substrate to at least one of the ultrasonic vibrator or the surface acoustic wave vibrator.

Provided is a control apparatus and control method for a capacitive electromechanical transducer with small decrease in transmission/reception efficiency, and with sets of transmission/reception characteristics with different frequency ranges. The apparatus has cells each including first and second electrodes facing each other via a gap; includes a driving/detecting unit and an external stress applying unit. The driving/detecting unit performs at least one of causing the second electrode to vibrate and transmit elastic waves by generating an AC electrostatic attractive force between the electrodes, and detecting a change of capacitance between the electrodes, the change being caused by the second electrode vibrating upon receipt of elastic waves. The external stress applying unit changes the external stress applied to the second electrode. The driving/detecting unit adjusts frequency characteristics by changing a parameter defining the frequency domain used in a transmitting/receiving operation, corresponding to the change of the external stress.

A control console for a powered surgical tool. The console includes a transformer that supplies the drive signal to the surgical tool. A linear amplifier with active resistors selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.

Amplifier architecture that allows low-cost class-D audio amplifiers to be compatible with ultrasonic signals, as well as loads presented by thin-film ultrasonic transducers. The amplifier architecture replaces the traditional capacitor used as an output filter in the class-D amplifier with the natural capacitance of the ultrasonic transducer load, and employs relative impedance magnitudes to create an under-damped low-pass filter that boosts voltage in the ultrasonic frequency band of interest. The amplifier architecture includes a secondary feedback loop to ensure that correct output voltage levels are provided.

A drive circuit includes a circuit for feedback oscillation connected to a vibrator to form a feedback oscillation circuit and including a high-pass filter, an oscillation circuit that outputs a periodic signal, and a control circuit that controls whether or not the periodic signal output by the oscillation circuit is supplied to the circuit for feedback oscillation under a condition that the feedback oscillation circuit operates, and controls to bring a state between a first node as an output node and a second node grounded of the high-pass filter into a non-conduction state when the periodic signal is supplied to the circuit for feedback oscillation and bring the state between the first node and the second node into a conduction state when the periodic signal is not supplied to the circuit for feedback oscillation.

A method for testing the integrity of a stack during ultrasonic welding, includes the steps of: (i) ultrasonically welding two or more work pieces with a stack, the stack including a convertor and a horn; (ii) measuring a frequency profile based on a vibration of the horn during the welding step; and (iii) comparing the measured frequency profile to a standard frequency profile to obtain an error rate, the error rate being indicative of a difference between the measured frequency profile and the standard frequency profile. A system employing the aforementioned method is also provided.