An amplifier system may include a first feedback loop coupled between an output of an amplifier to an input of a modulator for regulating an output voltage driven at the output of the amplifier to a first terminal of a load of the amplifier system, a sense resistor for sensing a physical quantity associated with the amplifier, a second control loop coupled to the sense resistor such that the sense resistor is outside of the second control loop, the second control loop configured to regulate a common-mode voltage at a second terminal of the load, and a common-mode feedforward circuit coupled to the sense resistor and configured to minimize effects of a signal-dependent common-mode feedback of the sense resistor.

The present invention is a portable hand-held battery-operated therapeutic ultrasonic device that is specifically designed for clinical applications in muscle and joint pain management. The present invention generates stepwise high resolution, high frequency microprocessor-based signal to drive piezo-crystals for applying on the skin of the user. It makes use of a novel electronic driving technology that enables it to generate therapeutically combinations of acoustic intensities from 0 to 2 W/cm.sup.2 and with 80-85% efficiency. It is a lightweight device and can be programmed wirelessly by a physician/professional to be used at home by a patient.

A vibration structure includes a fixing member; a voltage expansion/contraction member that is deformed in a first direction by a voltage; a first vibration member that is elastically coupled to the fixing member to vibrate in the first direction with respect to the fixing member; and a second vibration member that is elastically coupled to the first vibration member to vibrate in the first direction with respect to the first vibration member. The voltage expansion/contraction member is supported by the fixing member and the first vibration member or the second vibration member. A vibration of the first vibration member is superposition of a first vibration at a first resonance frequency and a second vibration at a second resonance frequency, a vibration of the second vibration member is superposition of the first vibration and the second vibration, and the second resonance frequency is a multiple of the first resonance frequency.

Methods of mitigating current overload of an ultrasonic system having an ultrasonic stack under load at startup are provided. The methods include beginning an ultrasonic cycle in the ultrasonic system having the ultrasonic stack that runs a closed loop phase control through the weld cycle by ramping up the power of the ultrasonic stack under load. During ramping up of the power of the ultrasonic stack under load, a controller lowers the phase to a negative phase. After ramping up the power of the ultrasonic stack under load is complete, the controller raises the phase to 0 degrees and the ultrasonic stack is operating at steady state and with the phase at 0 degrees.

A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, comprising applying energy during a series of short burst periods, the short burst periods interspersed by short rest periods. The method and apparatus further comprise delivering minimal energy during a long off period, the long off period comprising a relatively long period when minimal energy is applied, wherein one long off period follows each pulsed energy on period. The short burst periods and the short rest periods are relatively brief in duration as compared with the long off period.

A piezoelectric system for ultrasonic thermotherapy and electrotherapy comprises a first piezoelectric element, a proof mass, a second piezoelectric element and an output unit. The proof mass is disposed between the first piezoelectric element and the second piezoelectric element. The first piezoelectric element is powered by a power source to generate oscillation, which is transferred by the proof mass to the second piezoelectric element so as to cause the second piezoelectric element to move and generate power. The output unit comprises a connecting surface and a tip surface. The output unit is electronically connected with the second piezoelectric element, wherein the connecting surface is connected with the first piezoelectric element and the tip surface is formed in a tapered shape. The oscillation from the first piezoelectric element and the power generated by the second piezoelectric element are output through the tip surface.

An immersive system includes a processing device. The processing device is communicated with an interface device and an electronic display in a head mounted display device. The interface device includes a haptic feedback circuit. The haptic feedback circuit is configured to induce a haptic feedback. The interface device includes a haptic feedback circuit. The haptic feedback circuit is configured to induce a haptic feedback. The processing device is configured to provide an immersive content to the electronic display. The processing device is configured to identify a simulated object corresponding to the interface device in the immersive content, and identify an interaction event occurring to the simulated object in the immersive content. The processing device is configured to determine a vibration pattern according to the interaction event and the simulated object, and control the haptic feedback circuit to induce the haptic feedback according to the vibration pattern.

A fluid device includes a chamber that is provided with an inlet and an outlet opened at different positions on an X axis and is formed with a flow path space in which a fluid is caused to flow from the inlet to the outlet, a first ultrasonic element configured to generate a standing wave in a direction along an X axis in the fluid in the chamber, a driver configured to drive the first ultrasonic element, and a drive controller configured to control the driver such that a drive voltage applied to the first ultrasonic element is reduced over time.

An ultrasound diagnosis apparatus includes a transformer, a first power source, a second power source, and a switching unit. The transformer includes a primary winding and a secondary winding, and drives an ultrasound transducer based on a voltage generated in the secondary winding. The first and second power sources cause a potential difference. The switching unit switches a connection path between the primary winding and at least one of the first and second power sources to a first connection path that connects the first power source to one end of the primary winding and the second power source to the other end, a second connection path that connects the first power source to the other end and the second power source to the one end, or a ground connection path that connects the first power source or the second power source to the ground through the primary winding.

The present disclosure provides three-dimensional (3D) printing systems, apparatuses, software, and methods for the production of at least one requested 3D object. The 3D printer includes a material conveyance system, filtering system, and unpacking station. The material conveyance system may comprise transporting pre-transformed (e.g., powder) material against gravity, by directional conveyance (e.g., of a bounceable platform), and prolonged uninterrupted sieving while minimizing sieve blinding. The 3D printing described herein comprises facilitating non-interrupted (e.g., curbs interruptions of) material dispensing through a component of the 3D printer, such as a layer dispenser.