Abstract: An electrosurgical instrument includes a housing, an elongated shaft, and an end-effector assembly. The proximal end of the shaft is operably associated with the housing. The end-effector assembly is operably coupled to the distal end of the shaft and includes first and second jaw members. Each of the first and second jaw members includes a sealing plate and a bipolar electrode. Either one or both of the first and second jaw members is movable from a position in spaced relation relative to the other jaw member to at least one subsequent position wherein the sealing plates cooperate to grasp tissue therebetween. The electrosurgical instrument includes a semiconductor switch operably coupled to at least one of the sealing plates and at least one of the bipolar electrodes. The semiconductor switch is configured to enable user selection between energizing the at least one sealing plate or the at least one bipolar electrode.

Abstract: The invention provides a system for evaluating a patient featuring: 1) an ECG-measuring system connected to the patient and configured to sense ECG information from the patient; 2) a data-acquisition system interfaced to a vital sign-monitoring system configured to sense vital sign information from the patient during an electro-physiology (EP) procedure; and 3) an external software system interfaced to both systems. The external software system includes a first software interface that receives ECG information measured from the patient by the ECG-measuring system, and a second software interface that receives vital sign and EP-related information from the data-acquisition system measured from the patient during an EP procedure. A database stores physiological and EP-related information measured from the patient before, during, and after the EP procedure.

Abstract: A treatment system includes a power source for heat generation which outputs power for heat generation, a grasping member having a heating element which applies the power for heat generation as thermal energy to a living tissue, and a control section which performs constant temperature control on the power source for heat generation on the basis of temperature of the heating element, and controls the power source for heat generation so as to finish application of the thermal energy and complete treatment if the power for heat generation becomes not more than predetermined threshold power which is independent of a type of the living tissue or if a rate of decrease in the power for heat generation becomes not more than a predetermined threshold rate.

Abstract: Optical energy-based methods and apparatus for sealing vascular tissue involves deforming vascular tissue to bring different layers of the vascular tissue into contact each other and illuminating the vascular tissue with a light beam having at least one portion of its spectrum overlapping with the absorption spectrum of the vascular tissue. The apparatus may include two deforming members configured to deform the vascular tissue placed between the deforming members. The apparatus may also include an optical system that has a light source configured to generate light, a light distribution element configured to distribute the light across the vascular tissue, and a light guide configured to guide the light from the light source to the light distribution element. The apparatus may further include a cutting member configured to cut the vascular tissue and to illuminate the vascular tissue with light to seal at least one cut surface of the vascular tissue.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The electrosurgical generator includes impedance sensing circuitry which measures impedance of tissue, a microprocessor configured to determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid, and an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue.

Abstract: An electrosurgical generator may reduce unintended tissue damage by improving regulation of output power. The electrosurgical generator may control the power during a cycle, and react to a change in power if arcing occurs. Voltage sources, especially, demonstrate the tendency to have large, uncontrolled power excursions during normal electrosurgical use. The magnitude of the power excursions may be dependent on various factors. An exemplary electrosurgical generator control scheme reduces or minimizes the thermal spread by accurately supplying the specified power within a few cycles. Additionally, fast and accurate regulation provided by the constant voltage mode reduces or minimizes unintentional tissue charring. Thus, reduced thermal spread and charring should result in better surgical outcomes by reducing scarring and decreasing healing times.

Abstract: An electrosurgical system is disclosed. The electrosurgical system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue. The electrosurgical generator includes impedance sensing circuitry which measures impedance of tissue, a microprocessor configured to determine whether a tissue reaction has occurred as a function of a minimum impedance value and a predetermined rise in impedance, wherein tissue reaction corresponds to a boiling point of tissue fluid, and an electrosurgical instrument including at least one active electrode adapted to apply electrosurgical energy to tissue.

Abstract: A surgical instrument includes an end effector including first and second jaw members movable relative to one another between a first, spaced-apart position and a second position proximate tissue. In the second position, the jaw members cooperate to grasp tissue therebetween. A first optical fiber is disposed within the first jaw member and is configured to provide a first signal, and a second optical fiber is disposed within the first jaw member and is configured to provide a second signal. A controller is coupled to the first and second fibers and is configured to determine the temperature and the strain of the first jaw member as a function of the first and second signals, respectively.

Abstract: A biopsy needle having a longitudinal channel formed within an inner conductor of a coaxial antenna is disclosed. The coaxial antenna terminates in a rigid insertion tip e.g. a ceramic cone that is insertable into biological tissue. Microwave energy (e.g. having a frequency of 1 to 100 GHz) delivered to the coaxial antenna is emitted at the insertion tip. The insertion tip may be arranged to match the impedance of the coaxial antenna to a predetermined tissue impedance. The emitted radiation can be used to measure properties of or treat (e.g., ablate) tissue at the insertion tip. Needle biopsy apparatus is also disclosed, in which a microwave energy is controllably delivered to a needle from a microwave generator. The apparatus may include an impedance tuner to dynamically match the impedance of the needle with tissue at the insertion tip.

Abstract: An electrode structure and a mechanism for automated or user-selected operation or compensation of the electrodes, for example to determine tissue coverage and/or prevent arcing between bottom electrodes during electrocautery is disclosed.

Abstract: A method and system for assessing lesion formation in tissue is provided. The system includes an electronic control unit (ECU). The ECU is configured to acquire values for first and second components of a complex impedance between the electrode and the tissue, and to calculate an index responsive to the first and second values. The ECU is further configured to process the ECI to assess lesion formation in the tissue.

Abstract: System and methods of an electrosurgical controller having multiple modes of operation that are configured for treatment of a specific targeted tissue type and the electrosurgical effect desired where the treatment and effect are provided by a single controller and an electrosurgical probe. The electrosurgical controller includes an integrated fluid control apparatus or pump where activation of the controller allows for selective energy delivery and corresponding fluid volume flow rates. The electrosurgical probe includes a fluid transport lumen and is in communication with the controller and the pump for operation of the probe in the various user selected modes with accompanying energy delivery and fluid control directed to the desired treatment and surgical effect.

Abstract: Lesion size or volume prediction shortly after the onset of an ablation procedure can inform or control the ablation procedure. The prediction and/or control is made without regard to an actual detected temperature in the vicinity of the ablation electrodes. As a consequence, the system has utility with irrigated catheter constructions and other situations in which local irrigation in the vicinity of an ablation site would otherwise interfere with a prediction or control scheme that solely relies upon temperature measurements.

Abstract: Until now, ohmic consumers have been used to abruptly complete the output signal in RF surgical generators. Considering an RF surgical generator comprising a power supply with at least one storage capacitor and a controllable switching device with at least one energy storage device (e.g., a transformer) by which an RF output signal that can be delivered to an RF surgical instrument is generated, it is suggested herein that a regenerative device be provided between the energy storage device and the storage capacitor. Furthermore, a control mechanism is used for controlling the switching device and the regenerative device such that, if the RF output signal is to be completed, the regenerative device is energized for at least part of the time, and the energy storage is at least partially discharged in the storage capacitor.

Abstract: A system for controlling a treatment device generates a graphical interface that visually prompts a user in a step-wise fashion to use the treatment device to perform a process of forming a pattern of lesions that extends both circumferentially and axially in different levels in a body region. The graphical interface displays for the user a visual record of the progress of the process from start to finish and guides the user so that so that individual lesions desired within a given level are all formed, and that a given level of lesions is not skipped.

Abstract: An electrosurgical probe including a probe body which defines a longitudinal probe axis. The electrosurgical probe also includes a first and second conductive electrode, each disposed along the probe axis. The surface area of the first conductive electrode is greater of the surface area of the second conductive electrode. The ratio of the surface area of the first conductive electrode to the surface area of the second conductive electrode may be adjustable. Another aspect of the present invention is an electrosurgical probe having a probe body which defines a single longitudinal probe axis. The electrosurgical probe of this aspect of the invention further includes more than two electrodes operatively disposed at separate and distinct positions along the axis of the probe body. The electrodes may be selectively connected to one of or a combination of a stimulation energy source, an ablation energy source or a ground for either energy source.

Abstract: A power-supply system has a power converter configured to generate a high-frequency power signal and supply the high-frequency power signal to a load such as a plasma or gas laser process. The power converter includes a digital-to-analog converter (DAC) configured to generate an analog signal from a digital signal, an amplifier path in which the generated analog signal is amplified, and a logic-circuit unit coupled upstream of the DAC and configured to generate the digital signal and supply the generated digital signal to the DAC. The logic-circuit unit includes a signal-data buffer storing a signal-data value for generating a shape of the analog signal, an amplitude-data buffer storing an amplitude-data value for influencing an amplitude of the analog signal, and a multiplier configured to multiply the signal-data value by the amplitude-data value.

Abstract: An electrosurgical generator is disclosed. The generator includes a radio frequency output stage configured to generate a radio frequency waveform and a sensor circuit configured to measure a property of the radio frequency waveform during a predetermined sampling period to determine whether an arc event has occurred. The generator also includes a controller configured to determine a total charge and/or total energy deposited by the radio frequency waveform during the predetermined sampling period associated with the arc event. The controller is further configured to adjust the output of the electrosurgical generator based on at least one parameter to limit arcing.

Abstract: A system for monitoring ablation size is provided and includes a power source including a microprocessor for executing at least one control algorithm. A microwave antenna is configured to deliver microwave energy from the power source to tissue to form an ablation zone. An ablation zone control module is in operative communication with a memory associated with the power source. The memory includes one or more data look-up tables including data pertaining to a control curve varying over time and being representative of one or more electrical parameters associated with the microwave antenna. Points along the control curve correspond to a value of the electrical parameters and the ablation zone control module triggers a signal when a predetermined threshold value of the electrical parameter(s) is measured corresponding to the radius of the ablation zone.

Abstract: This invention relates generally to apparatus and methods for tightening tissue of the female genitalia by heating targeted connective tissue with radiant energy, while cooling the mucosal epithelial surface over the target tissue to protect it from the heat. Embodiments include a handle and treatment tip that has both an energy delivery element and a cooling mechanism. The handle may be a two-handed handle allowing control even while rotating and maneuvering the treatment around the genital opening. The apparatus or system may also include an integrated controller, which may confirm tissue contact without applying RF energy, based only on the temperature of the applicator and the time since the last application of energy from the applicator.

Abstract: Single-use electrical leads for a nerve stimulator are disclosed. The nerve stimulator has a “test mode” that determines a current value for treatment, and a “therapy mode” that administers treatment with the chosen current value. Preferably the fuse is electrically isolated from the leads that contact the patient.

Abstract: Apparatus, consisting of a probe, configured to be inserted into a body cavity, and an electrode having an outer surface and an inner surface connected to the probe. The apparatus also includes a temperature sensor, protruding from the outer surface of the electrode, which is configured to measure a temperature of the body cavity.

Abstract: A method for suppressing arc formation during an electrosurgical tissue treatment procedure includes the steps of supplying pulsed current from an energy source to tissue and measuring the pulsed current supplied from the energy source. The method also includes the steps of comparing an instantaneous measured pulse to a predetermined threshold and controlling the pulsed current supplied from the energy source based on the comparison between the instantaneous measured pulse and the predetermined threshold.

Abstract: A method and apparatus that utilizes a force-time integral for real time estimation of lesion size in catheter-based ablation systems. The apparatus measures the force exerted by a contact ablation probe on a target tissue and integrates the force over an energization time of the ablation probe. The force-time integral can be calculated and utilized to provide an estimated lesion size (depth, volume and/or area) in real time. The force-time integral may also account for variations in the power delivered to the target tissue in real time to provide an improved estimation of the lesion size. In one embodiment, the force metric can be used as feedback to establish a desired power level delivered to the probe to prevent steam popping.

Abstract: A method and system for detecting microbubble formation during a radiofrequency ablation procedure. The method includes measuring an impedance of a pair of electrodes, at least one electrode in the pair of electrodes being coupled to a treatment assembly of a medical device. Radiofrequency ablation energy is transmitted between the pair of electrodes. The transmission of radiofrequency ablation energy between the pair of electrodes is terminated when after a predetermined period of time the measured impedance in either of the electrodes in the pair of electrodes is a predetermined percentage above a measured minimum impedance and a measured power is above a predetermined power threshold. An alert is generated indicating at least one of the formation and release of microbubbles proximate the pair of electrodes.

Abstract: A system for performing a surgical procedure includes a source of energy, a surgical instrument, and an impedance matching network. The source of energy is an electrosurgical generator or a microwave generator. The surgical instrument is coupled to the source of energy and receives the energy therefrom. The surgical instrument is adapted to treat tissue with the energy. The impedance matching network is interposed along a path of the energy and matches an input impedance of the source of energy to an output impedance (or thereabouts).

Abstract: A circuit for controlling the discharging of stored energy in an electrosurgical generator includes a pulse modulator which controls an output of a power supply. At least one comparator is configured to provide an error signal to the pulse modulator based on a comparison between an output signal generated by the power supply and a feedback signal generated in response to the application of energy to tissue. A discharge circuit is configured to control the discharge of the output of the power supply to an inductive load disposed in parallel with the output of the power supply based on the comparison between the output signal and the feedback signal. The discharge circuit provides a rapid response and time rate control of the delivered electrosurgical energy by controlling the power supply and delivered RF energy in real time, based on a feedback signal generated in response to the application of energy to tissue.

Abstract: A system and method for assessing effective delivery of ablation therapy to a tissue in a body is provided. A three-dimensional anatomical map of the tissue is generated and displayed with the map defining a corresponding volume. An index is generated corresponding to a location within the volume with the index indicative of a state of ablation therapy at the location. The index may be derived from one or more factors such as the duration an ablation electrode is present at the location, the amount of energy provided, the degree of electrical coupling between an ablation electrode and the tissue at the location and temperature. A visual characteristic (e.g., color intensity) of a portion of the anatomical map corresponding to the location is then altered responsive to the index.

Abstract: A method is disclosed for delivering energy to a region of tissue within a patient's body using a medical treatment system. The medical treatment system comprises an energy delivery device coupled to an energy source. Energy is delivered through the energy delivery device positioned within the patient's body. An energy delivery parameter associated with the delivery of energy by the medical treatment system is monitored and if one or more values of the energy delivery parameter exceed a predetermined magnitude threshold, one or more errors are detected. The extent of the detected errors is determined or assessed and the delivery of energy is controlled if the extent of the errors detected exceeds a sensitivity threshold before the expiry of a predetermined time period.

Abstract: The invention relates to a method for medical treatment of a mammal, preferably a human, by applying pulsed radiofrequency (PRF) stimulation intravascularly. More particularly, said method has as effect that it boosts the immune system and/or that it relieves pain. In a preferred embodiment, the disease or condition to be treated is caused or accompanied by immunodeficiency, more preferably the disease or condition is selected from the group of cancer, infectious diseases, immunosuppression or otherwise caused immunodeficiencies. Also auto-immune diseases and conditions associated with allostatic load are preferred for treatment with the method of the invention. In an also preferred embodiment, the PRF stimulation is applied together with vaccination.

Abstract: A medical system is provided, including an ablation system having at least one ablation element and a sensor, a generator operable to deliver radiofrequency ablation energy to the ablation element. A power supply defines a duty cycle and provides a voltage to the generator, and the power supply has a duty cycle modulator and an amplitude modulator. A processor is connected to the power supply, the generator, and the sensor. The processor obtains a feedback signal from the sensor, and adjusts the duty cycle modulator and the amplitude modulator according to the feedback signal.

Abstract: A treatment system includes a power source for heat generation which outputs power for heat generation, a grasping member having a heating element which applies the power for heat generation as thermal energy to a grasped living tissue, a storage section storing a power decrease pattern which is a prediction about a change state of the power for heat generation, and a control section which performs pattern control on the power source for heat generation on the basis of the power decrease pattern acquired from the storage section.

Abstract: Tunable matching circuits for power amplifiers are described. In an exemplary design, an apparatus may include a power amplifier and a tunable matching circuit. The power amplifier may amplify an input RF signal and provide an amplified RF signal. The tunable matching circuit may provide output impedance matching for the power amplifier, may receive the amplified RF signal and provide an output RF signal, and may be tunable based on at least one parameter effecting the operation of the power amplifier. The parameter(s) may include an envelope signal for the amplified RF signal, an average output power level of the output RF signal, a power supply voltage for the power amplifier, IC process variations, etc. The tunable matching circuit may include a series variable capacitor and/or a shunt variable capacitor. Each variable capacitor may be tunable based on a control generated based on the parameter(s).

Abstract: A system and method for performing electrosurgical procedures are disclosed. The system includes an electrosurgical generator adapted to supply electrosurgical energy to tissue in form of one or more electrosurgical waveforms having a crest factor and a duty cycle. The system also includes sensor circuitry adapted to measure impedance and to obtain one or more measured impedance signals. The sensor circuitry is further adapted to generate one or more arc detection signals upon detecting an arcing condition§. The system further includes a controller adapted to generate one or more target control signals as a function of the measured impedance signals and to adjust output of the electrosurgical generator based on the arc detection signal. An electrosurgical instrument is also included having one or more active electrodes adapted to apply electrosurgical energy to tissue.

Abstract: An electrosurgery system includes a catheter including one or more active electrodes adapted to be positioned adjacent biological tissue at an in vivo treatment site in a patient and to deliver electrical energy to the biological tissue. The electrosurgery system further includes a dispersive electrode assembly including a conductive element having a first end and a second end. The dispersive electrode assembly is configured to surround a waist of the patient such that a first surface of the conductive element is in contact with the waist and the first end of the conductive element is adjacent the second end of the conductive element.

Abstract: A surgical instrument includes an end effector including first and second jaw members movable relative to one another between a first, spaced-apart position and a second position proximate tissue. In the second position, the jaw members cooperate to grasp tissue therebetween. A first optical fiber is disposed within the first jaw member and is configured to provide a first signal, and a second optical fiber is disposed within the first jaw member and is configured to provide a second signal. A controller is coupled to the first and second fibers and is configured to determine the temperature and the strain of the first jaw member as a function of the first and second signals, respectively.

Abstract: A medical device system and associated method for guiding ablation therapy sense cardiac signals using implantable electrodes and detect spontaneous cardiac events from the sensed cardiac signals. Pacing pulses are delivered in response to detecting a spontaneous cardiac event and a return cycle length is measured. The spontaneous cardiac event is clustered with a previously detected cardiac event in response to the measured return cycle length. Data corresponding to the clustered cardiac events is displayed to guide an ablation therapy.

Abstract: Volumetrically oscillating plasma flows, the volume of which controllably expands and contracts with time, are disclosed. Volumetrically oscillating plasma flows are generated by providing an energy with a power density that changes with time to the plasma-generating gas to form a plasma flow. The changes in the energy power density result in plasma flow volumetric oscillations. Volumetric oscillations with a frequency of above 20,000 Hz results in ultrasonic acoustic waves, which are known to be beneficial for various medical applications. System for providing volumetrically oscillating plasma flows and a variety of surgical non-surgical applications of such flows are also disclosed.

Abstract: Provided is a combinable electrode needle base structure in which a base to which electrode needles are coupled can be used in a combined or separated state to use the electrode needles according to the size and location of a lesion. In the combinable electrode needle structure, electrode needles are connected to the front side of an electrode needle base, and receive RF waves from RF (radio frequency) generator. The electrode needle base is divided into dividable bases to which the electrode needles are respectively coupled. When a lesion to be cauterized is large or cauterization should be concentrated, the dividable bases are combined and then used, and when a lesion is small or lesions are scattered, the dividable bases may be separated and then used.

Abstract: An electrosurgical system includes at least a first unit and a second unit, the second unit being detachably connectible to the first unit and including an electrode assembly. The first unit includes a power supply, an RF oscillator circuit for generating a radio frequency output, and an output stage adapted to supply an RE output to the electrode assembly. The second unit includes an identification circuit presenting, in an alternating manner, a parameter with a first finite non-zero value for a first time period, and a parameter with a second finite value for a second time period. The first unit includes a sensing circuit and a controller adapted to detect a characteristic of the identification circuit and provide an output signal, the controller connected to the sensing circuit and receiving the output signal, adjusts the RF output so as to suit the particular electrode assembly.

Abstract: An ablating device has a cover which holds an interface material such as a gel. The cover contains the interface material during initial placement of the device. The ablating device may also have a removable tip or a membrane filled with fluid. In still another aspect, the ablating device may be submerged in liquid during operation.

Abstract: Single-use electrical leads for a nerve stimulator are disclosed. The nerve stimulator has a “test mode” that determines a current value for treatment, and a “therapy mode” that administers treatment with the chosen current value. Preferably the fuse is electrically isolated from the leads that contact the patient.

Abstract: A system for delivering electrosurgical energy is provided. The system includes an electrosurgical instrument comprising at least one electrode and an electrosurgical generator coupled to the electrosurgical instrument. The electrosurgical generator includes an output stage configured to generate electrosurgical energy; and a controller coupled to the output stage, the controller configured to control the output stage to output electrosurgical energy at a predetermined power level to generate an arc between the at least one electrode and tissue and to output electrosurgical energy at a predetermined current level once the arc is generated to sustain the arc.

Abstract: An energy-delivery device suitable for delivery of energy to tissue includes an antenna assembly, a chamber defined about the antenna assembly, and a cable having a proximal end suitable for connection to an electrosurgical energy source. The energy-delivery device also includes a flexible, fluid-cooled shaft coupled in fluid communication with the chamber. The flexible, fluid-cooled shaft is configured to contain a length of the cable therein and adapted to remove heat along the length of the cable during delivery of energy to the antenna assembly.

Abstract: In accordance with various embodiments, methods for controlling electrical power provided to tissue via a surgical device may comprise providing a drive signal to a surgical device; receiving an indication of an impedance of the tissue; calculating a rate of increase of the impedance of the tissue; and modulating the drive signal to hold the rate of increase of the impedance greater than or equal to a predetermined constant.

Abstract: A method of assessing lesion quality of an ablated tissue region comprising ablating at least a portion of the tissue region. The reactance of the ablated tissue region is measured at a plurality of frequencies. The lesion quality of the ablated tissue region is determined based on the measured reactance. For example, an untreated tissue reactance value and a predetermined thermally treated tissue region reactance threshold may be determined. The measured reactance at each of the plurality of frequencies is compared to the threshold to determine the lesion quality of the thermally treated tissue region. The thermal treatment of the tissue may be modified based on the lesion quality determination.

Abstract: 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.

Abstract: Ablation devices and methods for determining a degree of contact between an electrode and a target tissue are disclosed. An example ablation device for treating body tissue may include a catheter having a proximal end region and a distal end region. An electrode may be disposed adjacent to the distal end region of the catheter. The device may also include a processing unit having a memory. The processing unit may be in electrical communication with the electrode. The processing unit may be capable of determining a degree of contact between the electrode and a target tissue.

Abstract: Headache treatment methods are described and include providing an energy delivery device; locating a secondary or higher-order branch of a postganglionic nerve that provides innervation for a patient's head, by identifying a target region of the patient's head that includes the nerve branch; positioning, within the target region, a portion of the energy delivery device; and applying, from the positioned portion of the energy delivery device to the target region, an amount of energy effective to result in a stimulation activity of the nerve branch; and, after observing the stimulated nerve branch activity, delivering, from the energy delivery device to the nerve branch, energy in an amount effective to reduce a headache severity in the patient.

Abstract: An electrosurgical energy delivery apparatus includes an energy delivery circuit, a control circuit and an energy-harvesting system with a plurality of energy-harvesting circuits and a voltage regulator that provides a regulated DC voltage to the energy delivery circuit and/or the control circuit. The energy delivery circuit receives an electrosurgical energy signal having a primary frequency and selectively provides the electrosurgical energy signal to an energy delivery element. The control circuit connects to the energy delivery circuit and selectively enables the flow of electrosurgical energy to the energy delivery element. The plurality of energy-harvesting circuits each include an energy-harvesting antenna tuned to a particular frequency, a matched circuit configured to receive an RF signal from the energy-harvesting antenna, rectify the RF signal and generate a DC signal, and an energy storage device that connects to the voltage regulator to receive and store the DC signal.