153224 results about "Electrical current" patented technology

The present invention provides a system for implementing surgical procedures which includes an ultrasonic surgical hand piece having an end-effector, a console having a digital signal processor (DSP) for controlling the hand piece, an electrical connection connecting the hand piece and the console, and a memory, such as an EEPROM (Electrically Erasable Programmable Read Only Memory), disposed in the electrical connection. The console sends a drive current to drive the hand piece which imparts ultrasonic longitudinal movement to the blade. The console reads the memory and authenticates the hand piece for use with the console if particular or proprietary data are present in the memory. Moreover, to prevent errors in operating the hand piece, the memory can store certain diagnostic information which the console can utilize in determining whether the operation of the hand piece should be handicapped or disabled. Furthermore, the memory can be used to reprogram the console, if needed.

Surgical devices, systems and methods for treating tissue are provided. An exemplary surgical device comprises a tip portion including first and second jaws each having a tissue grasping surface, at least one of the jaws being movable toward the other jaw. The tissue grasping surface of each jaw has includes an electrically insulative surface. The device also includes first and second electrodes connectable to different terminals of an RF generator to generate electrical current flow therebetween, with each of the electrodes having an electrode surface. One of the electrode surfaces is located on one of the jaws separated from one edge of the tissue grasping surface, and the other of the electrode surfaces is located on one or the other of the jaws separated from the other edge of the tissue grasping surface. The device also includes at least one fluid passage being connectable to a fluid source.

A bipolar surgical instrument that includes opposing grips that can engage the tissue. A current is delivered from an electrosurgical power source to electrodes disposed on the grips to cauterize the tissue. The electrode configurations provide efficient cauterization of the tissue. In some embodiments, the positive and negative electrodes will be offset from each other to prevent shorting and to provide a thin line of coagulation heating to the gripped tissue. In some embodiments the electrodes are removably coupled to the grips through nonconductive sleeves. In some embodiments, the first electrode is disposed in a groove and the second electrode is disposed on a boss.

A motor control device selectively turns on or off a drive transistor in-accordance with a PWM control signal Sp, such that a drive current Im supplied to a motor is adjusted. The device also samples and holds a motor current Sm for obtaining a motor current value Ih. With reference to the motor current value Ih, the device protects the motor from an overcurrent. Sampling and holding of the motor current Sm is performed for a sampling and holding time Ts. The sampling and holding time Ts corresponds to a time period between a first point in time when the level of the PWM control signal Sp is switched for turning off the drive transistor and a second point in time that precedes the first point in time by a predetermined period. As a result, the motor current value Ih is detected with high accuracy.

A method and apparatus for calculating current lost through a patient during a treatment of a patient using an electromagnetic energy delivery system is disclosed. The system generates electromagnetic energy, contacts a skin surface of the patient, transfers the electromagnetic energy to tissue beneath the surface of the skin, detects a value of at least one characteristic of the electromagnetic energy utilizing synchronous undersampling, and calculates the current lost through the patient. The characteristic measured may be a value of current of the electromagnet energy. An adjustable matching network may be utilized to maximize power to the tissue of the patient. Values of the impedance of the matching network may be utilized to determine the electromagnetic energy delivered to the tissue of the patient. A current correction factor is determined from the impedance of the matching network and utilized to calculate the current lost through the patient.

A surgical instrument is disclosed, the instrument including: a handle assembly; a jaw assembly including a staple cartridge containing a plurality of staples and an anvil to form the plurality of staples upon firing; a lockout mechanism configured to prevent reuse of the jaw assembly; a drive assembly at least partially located within the handle and connected to the jaw assembly; a motor operatively coupled to the drive assembly; and a controller operatively coupled to the motor, the controller configured to control supply of electrical current to the motor and to monitor a current draw of the motor, wherein the controller is further configured to terminate the supply of electrical current to the motor in response to a drop in the current draw.

A biopsy device and method for operating the biopsy device are disclosed. The method of operating the biopsy device can include varying the translational speed of a cutter independently of the speed of a motor driving translation of the cutter. The method can also include providing close loop control of a fluid system, such as a vacuum system, associated with the biopsy device. The method can also include control of a cutter motor including comparing an actual motor current with a predetermined motor current.

An ultrasonic coagulation and cutting apparatus includes: an ultrasonic transducer for a treatment using ultrasonic vibrations on body tissue; a probe for transmitting generated ultrasonic vibrations to the distal end thereof; a movable gripping member for cooperating with the outer surface of the probe in gripping therebetween body tissue; an operation unit operated to move the gripping member; an operation transmitting member for transmitting the operation of the operation unit to the gripping member; and high frequency power supply connecting portions for electrically connecting the probe and the gripping member to predetermined portions of a high frequency power supply for a treatment using high frequency current on the body tissue. At least coagulation of the body tissue using high frequency current is started in a first gripping state. Cutting of the body tissue using ultrasonic vibrations generated by the ultrasonic transducer is started in a second gripping state.

An inductive power systems transfers energy by inductively coupling a source coil on a power source to a receiver coil on a power portion of a power adapter. The source current is received in the power adapter and converted to direct current for transmission to a computer system. Wireless communication between a power source and the power adapter is provided. A wireless communication arrangement provides for authentication of devices that are allowed by a source to be powered.

A treatment tool for performing a treatment for a curative procedure with ultrasonic waves, high frequency current and so on is provided with an identifier formed of a resistor or the like for indicating the type of the treatment tool. A medical instrument such as an ultrasonic wave output apparatus discriminates the type of a treatment tool connected thereto from the identifier to automatically set operating parameters such as an output value suitable for the treatment tool and to associatively operate an ancillary medical instrument such as a perfusion / aspiration apparatus depending on the treatment tool, thereby reducing extra work such as manual setting to allow for a smooth treatment.

Various embodiments provide compositions that exhibit positive temperature coefficient of resistance (PTCR) properties for use in thermal interactions with tissue—including thermal sensing and I2R current-limiting interactions. Embodiments also provide tissue-engaging surfaces having PTCR materials that provide very fast switching times between low resistance and high, current-limiting resistance. One embodiment provides a matrix for an electrosurgical energy delivery surface comprising a PTCR material and a heat exchange material disposed within an interior of the matrix. The PTCR material has a substantially conductive state and a substantially non-conductive state. The heat exchange material has a structure configured to have an omni-directional thermal diffusivity for exchanging heat with the PTCR material to cause rapid switching of the PTCR material between the conductive state and non-conductive state. Preferably, the structure comprises a graphite foam having an open cell configuration. The matrix can be carried by tissue contacting surfaces of various electrosurgical devices.

An object is to improve accuracy of tightening torque and to shorten time necessary for fastening a screw in an impact type screw fastening device that uses an electric motor as a rotation driving source. A control method for the impact type screw fastening device that uses an electric motor as a rotation driving source includes the steps of driving the motor to rotate by supplying current to the motor intermittently so that torque exerted on a load by rotation of the motor becomes like pulses on the time axis, and controlling the current of every time of each pulse so that an increment of every time of each pulse of the torque after the torque reaches a target approach torque TQN that is a first set value becomes smaller than that before it reaches the target approach torque TQN.

An improved hand-held fastener driving tool is provided with an adjustable torque limiting control. The tool is portable, and is electrically powered using either a battery pack or a power cord as a power source. The tool drives collated fasteners (e.g., screws) into solid objects. The motor current is measured to determine the amount of torque being applied to a screw by the motor and mechanical drive components. As the screw bottoms out, the motor torque increases to a point where it exceeds the user-adjusted torque limiting control. The motor is automatically turned off at that point, thereby preventing the screw from being stripped.

An electrochemical analyte sensor formed using conductive traces on a substrate can be used for determining and / or monitoring a level of analyte in in vitro or in vivo analyte-containing fluids. For example, an implantable sensor may be used for the continuous or automatic monitoring of a level of an analyte, such as glucose, lactate, or oxygen, in a patient. The electrochemical analyte sensor includes a substrate and conductive material disposed on the substrate, the conductive material forming a working electrode. In some sensors, the conductive material is disposed in recessed channels formed in a surface of the sensor. An electron transfer agent and / or catalyst may be provided to facilitate the electrolysis of the analyte or of a second compound whose level depends on the level of the analyte. A potential is formed between the working electrode and a reference electrode or counter / reference electrode and the resulting current is a function of the concentration of the analyte in the body fluid.

A surgical system and associated method for sealing the passageway of a fluid-carrying vessel with a diameter up to 5 millimeters comprises an electrosurgical generator capable of delivering electrosurgical power, a surgical instrument electrically connected to the electrosurgical generator and adapted to transfer electrosurgical power from the electrosurgical generator to a pair of end effectors disposed at a distal end of the surgical instrument. The system also includes a power control circuit for controlling the delivery of radio frequency energy to the vessel through the end effectors, wherein the delivery of the radio frequency energy to the vessel comprises, raising the output current to a range below 1.75 Amperes RMS and the output voltage to a range below 135 Volts RMS. Radio frequency energy is applied to the vessel for a period of time while the power is held approximately constant. The flow of radio frequency energy is terminated when the impedance of the vessel being sealed reaches a predetermined level.

Systems, methods, and apparatus for providing power to an electrosurgical instrument. In particular, a power supply is disclosed in which non-sinusoidal (e.g., pulsed) constant frequency voltage having a variable amplitude is passed to an LC circuit to produce a quasi-sinusoidal current in the LC circuit. The constant driving frequency can be one half the resonant frequency of the LC circuit allowing the LC circuit to operate as an impedance, and thus limit current spikes and arcing. The frequency and phasing of the driving voltage also enables the LC circuit to discharge energy back into a power provider of the power supply so that energy does not build up in the LC circuit. These features result in less severe current spikes and arcing, as well as reduced cutoff times.

A motor driving method for driving a direct-current (DC) motor, designed for avoiding a reverse current induced by the Back Electromotive Force (BEMF), includes providing a driver circuit for driving the DC motor; comparing a signal level of a terminal of the DC motor and a predetermined voltage value to produce a comparing result; and controlling a specific lower gate switch to avoid the occurrence of a reverse current of the DC motor according to the comparing result.

An expert system manages a power grid wherein charging stations are connected to the power grid, with electric vehicles connected to the charging stations, whereby the expert system selectively backfills power from connected electric vehicles to the power grid through a grid tie inverter (if present) within the charging stations. In more traditional usage, the expert system allows for electric vehicle charging, coupled with user preferences as to charge time, charge cost, and charging station capabilities, without exceeding the power grid capacity at any point. A robust yet accurate state of charge (SOC) calculation method is also presented, whereby initially an open circuit voltage (OCV) based on sampled battery voltages and currents is calculated, and then the SOC is obtained based on a mapping between a previously measured reference OCV (ROCV) and SOC. The OCV-SOC calculation method accommodates likely any battery type with any current profile.

A drilling device prevents recurrence of an overload condition after occurrence of the overload condition, thereby improving operability and safety in the drilling device. A motor for rotating a drill is connected to an AC power source through a motor control unit, a current detector, and a power switch. A magnet is also connected to the AC power source through the power switch and a full-wave rectifier. The motor control unit rotationally drives the motor on the basis of a signal sent from a main control unit according to a state in which a motor start switch is on. The main control unit controls the motor control unit to gradually reduce a supply voltage to the motor when the motor becomes overloaded, to gradually increase the voltage to the normal power supply condition when the overload condition is vanished, and to stop power supply to the motor if the overload condition continues for a predetermined period.