An apparatus includes a current source, an electronic circuit and a circuit board. The current source is configured to flow an electrical current having a selected frequency between a pair of electrodes coupled to a medical probe. The electronic circuit is configured to measure a single-ended voltage relative to ground that is formed on at least one of the electrodes in the pair in response to the electrical current, and, based on the measured voltage, to assess physical contact between the at least one of the electrodes and tissue. The circuit board includes the current source and the electronic circuit, and includes a layout that produces, at the selected frequency, a predefined capacitance between the current source and ground, thus forming a reference for measurement of the single-ended voltage.

Disclosed is a method of detecting a short circuit in the jaws of an end effector of a surgical instrument. The method includes applying a sub-therapeutic electrical signal to an electrode located in the jaws of the end effector. The sub-therapeutic electrical signal comprises a sequence of exploratory waveforms comprising pulsed current and voltage waveforms. The method includes detecting a shorted electrode when a measured electrical parameter in the jaws of the end effector is less than a predetermined value and modifying electrical current applied to the shorted electrode by the RF generator.

Disclosed is a method of adapting energy modality due to a short circuit or tissue type grasped in the jaws of an end effector of a surgical instrument. The method includes selecting an electrode in an array of segmented electrodes during a pre-energy activation cycle. The method includes applying a sub-therapeutic electrical signal to the selected electrode to differentiate between a shorted electrode and low impedance tissue grasped in the jaws of the end effector. The method includes determining the selected electrode is shorted based on a measured electrical parameter received by the control circuit after applying the sub-therapeutic electrical signal and blending monopolar and bipolar RF energy. The method includes determining that the selected electrode is shorted and switching output energy of the RF generator between monopolar and bipolar RF energy.

An electrosurgical generator and associated methods determine a real part of the impedance of treated tissue. The electrosurgical generator includes an output stage, a plurality of sensors, and a controller that controls the output stage. The controller includes a signal processor that determines an RMS voltage, an RMS current, an average power, and a real part of the impedance of the treated tissue based on measured voltage and current by using a plurality of averaging filters. The controller controls the output stage to generate electrosurgical energy based on at least the determined real part of the impedance.

Control systems and methods for delivery of energy that may include control algorithms that prevent energy delivery if a fault is detected and may provide energy delivery to produce a substantially constant temperature at a delivery site. In some embodiments, the control systems and methods may be used to control the delivery of energy, such as radiofrequency energy, to body tissue, such as lung tissue.

A surgical instrument includes an ultrasonic waveguide extending through a body assembly. An ultrasonic blade connects to the ultrasonic waveguide. A clamp arm assembly of the surgical instrument is able to move from an opened position for receiving a tissue toward a closed position for clamping the tissue. The clamp arm assembly includes a clamp body and a clamp pad facing the ultrasonic blade. A clamp arm actuator of the surgical instrument is able to move from a first position toward a second position to direct the clamp arm assembly from the opened position toward the closed position. A modular coupling of the surgical instrument connects to the clamp pad such that at least the clamp pad can be disconnected relative to the ultrasonic blade for replacement thereof.

Various embodiments are directed to battery unit for use with surgical instruments. The battery units may comprise a plurality of cells and include a translatable discharge drain. When attached to the surgical instrument, the discharge drain may electrically connect an anode of the battery unit to a cathode of the battery unit, for example, via a resistive element in order to drain the battery unit.

Various embodiments are directed to battery unit for use with surgical instruments. The battery units may comprise a plurality of cells and include a translatable discharge drain. When attached to the surgical instrument, the discharge drain may electrically connect an anode of the battery unit to a cathode of the battery unit, for example, via a resistive element in order to drain the battery unit.

A method for controlling a user interface of a modular energy system. The modular energy system comprises a header module and a display screen on which the user interface is displayed. The modular energy system can detect attachment of a first module thereto, control the user interface to display one or more first user interface elements corresponding to the first module, detect attachment of a second module to the modular energy system, control the user interface to resize the one or more first user interface elements to accommodate display of one or more second user interface elements corresponding to the second module, and control the user interface to display the one or more second user interface elements. The various UI elements can correspond to the particular module type that is being connected to the modular energy system.

A method of operating a modular surgical system including a control module, a first surgical module, and a second surgical module is disclosed. The method includes detachably connecting the first surgical module to the control module by stacking the first surgical module with the control module in a stack configuration, detachably connecting the second surgical module to the first surgical module by stacking the second surgical module with the control module and the first surgical module in the stack configuration, powering up the modular surgical system, and monitoring distribution of power from a power supply of the control module to the first surgical module and the second surgical module.