Abstract: A method of blocking signal transmission through a nerve with reduced onset activity includes applying an HFAC to an axon of a nerve to block the transmission of signals through the axon. The method may also include applying a direct current (DC) to the axon, increasing the amplitude of the DC over time to a predetermined amplitude, applying the HFAC, and then decreasing the DC. The method may also include temporarily reducing the amplitude of the HFAC to permit the transmission of signals through the axon and subsequently increasing the amplitude to block transmission without triggering an onset response. The method may also include temporarily applying an unbalanced charge to the nerve and then balancing the charge over time.

Abstract: Systems and methods for stimulation of neurological tissue generate stimulation trains with temporal patterns of stimulation, in which the interval between electrical pulses (the inter-pulse intervals) changes or varies over time. Compared to conventional continuous, high rate pulse trains having regular (i.e., constant) inter-pulse intervals, the non-regular (i.e., not constant) pulse patterns or trains that embody features of the invention provide a lower average frequency.

Abstract: A method for treating essential tremor or restless leg syndrome using spinal cord stimulation includes implanting a lead near a spinal cord of a patient. The lead includes a plurality of electrodes disposed on a distal end of the lead and electrically coupled to at least one contact terminal disposed on a proximal end of the lead. Electrical signals are provided from a control module coupled to the lead to stimulate a portion of the spinal cord of the patient using at least one of the electrodes. The electrical signals reduce, alleviate, or eliminate at least one adverse effect of essential tremor or restless leg syndrome.

Abstract: An embodiment of the invention resides in the apparatus and technique of dynamically measuring and storing a biological condition or disposition during the time that one set of conditions are imposed on a joint or body area and applying closed-loop therapeutic action so as to re-achieve that same biological condition or disposition during a subsequent time that another different set of conditions are imposed. Furthermore, dynamic potentials surrounding said joint or body area may be created, bolstered, and/or modulated through aspects of stimulation applied which are independent of those aspects utilized to counteract force incident on the joint or body area. Other embodiments are described herein.

Abstract: Methods related to an electrical stimulation orthosis are disclosed herein. In some embodiments, a method includes disposing a connector of a stimulation electrode assembly through an opening defined by a detachable layer. The connector of the stimulation electrode assembly is reversibly coupled to a connector disposed on an inner face of a frame. The detachable layer is coupled to the inner face of the frame. The method further includes disposing the frame about a limb segment of a body such that the detachable layer is in contact with a portion of the limb segment, and an electrical stimulation electrode of the stimulation electrode assembly is in contact with at least one stimulation point on a surface of the body associated with at least one of a nerve or a muscle.

Abstract: This document provides methods and materials for modulating afferent nerve signals to treat medical conditions such as CHF, CHF respiration, dyspnea, peripheral vascular disease (e.g., peripheral arterial disease or venous insufficiency), hypertension (e.g., age-associated hypertension, resistant hypertension, or chronic refractory hypertension), COPD, sleep apnea, and chronic forms of lung disease where muscle dysfunction is a part of the disease pathophysiology. For example, methods and materials involved in using electrical and/or chemical techniques to block or reduce afferent nerve signals (e.g., nerve signals of group III and/or IV afferents coming from skeletal muscle and/or the kidneys) are provided.

Abstract: The present invention relates to a high voltage switch circuit, comprising an input port adapted to receive a pulse type input current and an output port, which can be used selectively to conduct an output current to a corresponding electrical load. The switch circuit comprises a buffer stage adapted to sense the input voltage at said input port and to provide a buffered voltage that follows said input voltage. The switch circuit comprises complementary switches electrically connected between said input port and said output port and a voltage level translator electrically connected with said switches, said buffer stage and a control terminal that provides a control signal. The voltage level translator provides suitable gate voltages at the gate terminals of said switches, so that the operation of these latter can be controlled by said control signal.

Abstract: A device and method for carrying out a dialysis of a patient and a stimulation of said patient at the same time either during dialysis sessions, or between dialysis sessions or both.

Abstract: Methods and apparatuses are disclosed for potentiating a favorable brain state that is associated with relief in symptoms of a brain condition. Techniques include monitoring one or more brain signals and detecting an episode of a favorable brain state based on the one or more brain signals, the favorable brain state associated with a decrease in one or more symptoms of a brain condition of the patient. Then, in response to the detection of the favorable brain state episode, electrical stimulation that potentiates the favorable brain state is delivered to the brain of the patient, the electrical stimulation delivered within a window of time opened for detection of each favorable brain state episode.

Abstract: An apparatus for the cardio-synchronized stimulation of skeletal or smooth muscle, but excluding the heart muscles, in a counterpulsation mode of a patient.

Abstract: A functional electrical stimulation (FES) device and system. In one embodiment, sequential bipolar pulse stimulation may be provided to an area of a living body via one or more electrode leads applied to the area via a FES device comprising a current pulse generating circuit comprising output nodes for operative coupling to the one or more electrode leads, and configured for operative coupling to a voltage supply. The current pulse generating circuit generally comprises positive and negative stimulation paths drawing from the voltage supply to respectively apply positive and negative currents through the area via the one or more electrode leads. In one example, the stimulation paths comprise respective capacitive elements, a capacitance ratio of which dictating, at least in part, an amplitude ratio of the positive and negative currents, wherein periodic alternative activation of the stimulation paths provides the sequential bipolar pulse stimulation.

Abstract: The present invention relates to a system for treating idiopathic scoliosis characterized in that it comprises a programmable subcutaneous or submuscular device (1) connected by means of wiring (5) to a plurality of sensors (2) which are configured to record electromyographic signals and a plurality of stimulators (3) which are configured to stimulate that part of the deep paraspinal muscles that is affected by the pathology, and wherein said device (1) comprises means for wireless data transmission, such that it may be programmed by means of an external console (4), and wherein muscle stimulation is controlled by control logic that comprises a feedback loop algorithm for adjustment of the stimulation based on the results obtained from the sensors (2) for recording the electromyographic signals and according to a musculoskeletal model, for the purpose of creating a suitable stimulus within a set time range.

Abstract: A wearable neuromuscular stimulation and neuroprosthetic system and device for treating spinal cord injury, stroke, and other neurological conditions; and for the management of chronic pain. This invention provides a system for transcutaneous neuromuscular stimulation and typically comprises a wearable item that further includes a flexible, non-conductive material; at least one flexible, generally flat electrode attachable to or embedded within the wearable item; and a programmable electrical stimulation device connectable to the electrode(s). Each electrode typically includes a silver-impregnated or silver-treated material.

Abstract: A system for detecting the presence of a nerve within a subject includes a stimulator configured to provide a stimulus to a portion of the subject, a sensing device configured to be placed in communication with a muscle of the subject and to generate an output signal corresponding to a monitored parameter of the muscle, the sensing device including a mechanical sensor configured to monitor a mechanical parameter of the muscle, and a receiver configured to receive the output signal from the sensing device and to determine if the output signal corresponds to the stimulus provided by the stimulator.

Abstract: By targeting on selected branches or fascicles of a vagus nerve using electrode placement and/or selection, one or more target branches of the vagus nerve are substantially activated by electrical stimulation pulses delivered to a branch without substantially activating one or more non-target branches. In one embodiment, vagus nerve stimulation is delivered through an electrode placed on a thoracic vagus nerve that is separated from a recurrent laryngeal nerve, such that the vagus nerve is stimulated without causing laryngeal muscle contractions. In another embodiment, vagus nerve stimulation is delivered through a multi-contact electrode with one or more contacts selected for delivering the electrical stimulation pulses to stimulate the vagus nerve without causing laryngeal muscle contractions.

Abstract: The invention generally relates to methods for guiding physical therapy to a subject. In certain embodiments, methods of the invention involve providing stimulation to a subject's central nervous system to modulate one or more signals sent to or from a plurality of target regions of the subject. Methods of the invention further involve assessing the response of the plurality of target regions to the stimulation to determine if there is a differential response among the target regions to the stimulation, and providing focused physical therapy to at least one of the target regions based on the assessment of the response of the plurality of peripheral target regions to the stimulation.

Abstract: A therapeutic device for treating symptoms related to restless leg syndrome comprises a remote, a pair of pads, a plurality of electrodes, and a fastener assembly. The remote comprises a power source and an interface further comprising an ON/OFF switch and a method for providing variable power to the plurality of electrodes. Each pad comprises a brace-type fitting which fits around a user's afflicted area in a comfortable but secure manner. The plurality of electrodes comprises a number of electrodes affixed to the interior of each pad. A plurality of wires connects each electrode to the power source in the remote. The fastener assembly comprises a plurality of straps permanently attached to each pad, each disposed with fasteners to allow for the secure and comfortable affixation of the pads and electrodes to a user's desired area.

Abstract: Systems, methods and devices for paired training include timing controls so that training and neural stimulation can be provided simultaneously. Paired trainings may include therapies, rehabilitation and performance enhancement training. Stimulations of nerves such as the vagus nerve that affect subcortical regions such as the nucleus basalis, locus coeruleus or amygdala induce plasticity in the brain, enhancing the effects of a variety of therapies, such as those used to treat tinnitus, stroke, traumatic brain injury and post-traumatic stress disorder.

Abstract: Systems and methods for applying signals, including contralesional electromagnetic signals, to neural populations, are disclosed. A particular method can be directed to treating a patient having a subject neural population in a first (e.g., ipsilesional) hemisphere of the brain, with the subject neural population having, or previously having, a functionality capable of being improved. The method can include directing an application of electromagnetic signals at least proximate to a target neural population at a second (e.g., contralesional) hemisphere of the brain to at least constrain a functionality of the target neural population, which has transcallosal communication with the first hemisphere.

Abstract: A neuromimetic device includes a feedforward pathway and a feedback pathway. The device operates in parallel with a suspect neural region, coupled between regions afferent and efferent to the suspect region. The device can be trained to mimic the suspect region while the region is still considered functional; and then replace the region once the region is considered dysfunctional. The device may be particularly useful in treating neuromotor issues such as Parkinson's disease.

Abstract: A device is provided for use in performing an exercise involving at least one lower extremity of a human subject. The device may include a base including at least one moveable receiver adapted for engaging the at least one lower extremity. At least one stimulator is provided for applying electrical stimulation at a first level to at least one muscle for causing movement of the at least one lower extremity. A controller is also provided for adjusting the stimulator to apply stimulation to the at least one muscle at a second level based on a volitional movement by the human subject.

Abstract: An implantable neurostimulator system for treating movement disorders includes a sensor, a detection subsystem capable of identifying episodes of a movement disorder by analyzing a signal received from the sensor, and a therapy subsystem capable of supplying therapeutic electrical stimulation to treat the movement disorder. The system treats movement disorders by detecting physiological conditions characteristic of an episode of symptoms of the movement disorder and selectively initiating therapy when such conditions are detected.

Abstract: Devices, systems and methods are disclosed for treating a variety of diseases and disorders that are primarily or at least partially driven by an imbalance in neurotransmitters in the brain, such as asthma, COPD, depression, anxiety, epilepsy, fibromyalgia, and the like. The invention involves the use of an energy source comprising magnetic and/or electrical energy that is transmitted non-invasively to, or in close proximity to, a selected nerve to temporarily stimulate, block and/or modulate the signals in the selected nerve such that neural pathways are activated to release inhibitory neurotransmitters in the patient's brain.

Abstract: A stimulation device comprises a patch body having a battery and a processing unit. An adhering surface on an underside of the patch body is provided for attaching the patch body to a patient's skin. At least one electrode is disposed on or internal to the patch body. The processing unit is configured to communicate with a remote device and send electrical signals to the at least one electrode. The remote device may comprise an application to control the processing unit and a heart rate monitor may be in communication with the application. The application may automatically control the strength and timing of the electrical signals delivered to the at least one electrode based upon a monitored heart rate detected by the heart rate monitor.

Abstract: A dynamically adjustable multiphasic pulse system and method are provided. The dynamically adjustable multiphasic pulse system may be used as pulse system for a defibrillator or cardioverter.

Abstract: The invention concerns a method for performing an electric inhibition of the facial muscles for purely aesthetic purposes, using a device comprising a support at the head of a user (1), two contact electrodes (2), an electronic circuit (3) for generating low-voltage electric pulses at said electrodes (2), a direct current electric power supply (4) and means for fixing and locking (7) said components on the head. The invention is characterized in that it includes the following steps: placing the electrodes (2) on either side of the upper part of the nose, at the glabella; passing the electric pulses via the electrodes (2) through the pyramidal muscle of the nose so as to cause said pyramidal muscle of the nose to relax and hence its antagonist muscle, the forehead muscle and the double eyebrow muscle.

Abstract: A non-invasive electrical stimulation device shapes an elongated electric field of effect that can be oriented parallel to a long nerve, such as a vagus nerve in a patient's neck, producing a desired physiological response in the patient. The stimulator comprises a source of electrical power, at least one electrode and a continuous electrically conducting medium in which the electrode(s) are in contact. The stimulation device is configured to produce a peak pulse voltage that is sufficient to produce a physiologically effective electric field in the vicinity of a target nerve, but not to substantially stimulate other nerves and muscles that lie between the vicinity of the target nerve and patient's skin. Current is passed through the electrodes in bursts of preferably five sinusoidal pulses, wherein each pulse within a burst has a duration of preferably 200 microseconds, and bursts repeat at preferably at 15-50 bursts per second.

Abstract: A method for detecting potential failures by an implantable medical lead is disclosed. The method includes sensing first, second and third signals between at least first and second combinations of electrodes, on the lead; determining whether at least one of the first, second and third signals is representative of a potential failure in the lead and identifies a failure and the electrode associated with the failure based on which of the first, second and third sensed signals is representative of the potential failure. Optionally, when the first and second sensed signals are both representative of the potential failure, the method further includes determining whether the first and second sensed signals are correlated with one another. When the first and second sensed signals are correlated, the method declares an electrode common to both of the first and second combinations to be associated with the failure.

Abstract: A neuro-stimulation system employs a includes a stimulator which may include electrode devices and/or vibration elements. A controller may be employed to drive the stimulating elements with an electrical signal. In response to the electrical signal, the stimulating elements deliver electrical and/or mechanical stimulation to the body part. The stimulation may be an aperiodic stimulation and/or may be a subthreshold stimulation. In one embodiment, the stimulator is disposable and the processor determines usage of the stimulator and ensures that the stimulator is limited to a certain amount of use. Neuro-stimulation systems may be applied to sensory cells of body parts during movement of the body parts to induce neuroplastic changes. Such movement may involve a variety of therapeutic applications, e.g. in stroke patient therapy.

Abstract: Methods and systems for neurostimulation and/or neurotelemetry of electrically-excitable biological tissue. Embodiments include implanting single or multiple semiconductor diodes and applying a high frequency electrical volume current. Neurostimulation embodiments include local rectification of the volume current by the diode, which can provide a pulsating electrical waveform capable of locally stimulating neural tissue, hi neurotelemetry embodiments, semiconductor diodes can be placed in contact with excitable tissue and a low level electrical carrier wave can be passed through the tissue and implanted diode whereby low level tissue bioelectric events intermodulate with the carrier wave and encode bioelectrical effects.

Abstract: Methods and devices for treatment to at least interfere with the function of a muscle are described herein. These methods and devices may have application in cosmetic and plastic surgery, dermatology, suppression of tension and/or migraine-type headaches, pain management, one particular application of the subject matter deals primarily with reducing wrinkles caused by ongoing muscular activation. The devices and methods described herein allow medical practitioners to effectively identify selective nerves for paralyzing muscles, without the need for injections of agents such as botulism toxin. Moreover, the devices and methods herein, may allow for artificial generation of signals in nerves that were otherwise damaged by stimulating transmission of nerve signals across damaged nerves.

Abstract: A monitoring system has biomechanical sensors, physiological sensors and a controller which receive sensory inputs from the sensors to provide output signals for the output device, and it detects from the sensory inputs risk of a syncopal event The bio-mechanical sensors include sensors arranged to allow the processor to detect a user postures and posture transitions. The processor operates a finite state machine, in which there is a state corresponding to each of a plurality of user physical postures and to each of a plurality of transitions between said postures, and the processor determines a relevant state depending on the sensory inputs. A device output may be muscle stimulation to prevent syncope, and there are stimulation permissions associated with the finite state machine states.

Abstract: Multiple designs, systems, methods and processes for control using electrical signals recorded from clinically paralyzed muscles and nerves are presented. The discomplete neural prosthesis system and method for clinically paralyzed humans utilizes a controller. The controller is adapted to receive a volitional electrical signal generated by the human that is manifest below the lesion that causes the clinical paralysis. The controller uses at least the volitional electrical signal to generate a control signal that is output back to a plant to change the state of the plant, which in one aspect is one or more of the user's paralyzed muscles to achieve a functional result or to devices in the environment around the user that are adapted to receive commands from the controller.

Abstract: Bioelectronics for controlling a skeletal muscle by means of a neuro-electrical coded signal. An actual neuro-coded signal that is naturally generated in a body and operative in control of a skeletal muscle can be collected from a nervous network and stored in a database associated with an electronic device. An implantable muscle control device having one or more electrodes can be directly attached to an appropriate nerve leading to one or more target skeletal muscles associated with a subject. The actual neuro-coded signal can be then selected from the database and broadcasted to the implantable device associated with the subject via a neuro-code transmission approach in order to activate and regulate the affected skeletal muscles.

Abstract: An apparatus for the cardio-synchronised stimulation of skeletal or smooth muscle, but excluding the heart muscles, in a counterpulsation mode of a patient.

Abstract: An electrode for continuously stimulating a facial nerve root capable of a stable holding required for an electrode that continuously stimulates a facial nerve root, and an apparatus for monitoring electromyograms of facial muscles using the electrode for continuously stimulating the facial nerve root, are provided. The electrode for continuously stimulating the facial nerve root comprises an electrode unit, a contact unit, a guard unit, an extension unit, and a wire unit. The electrode for continuously stimulating the facial nerve root is held by clamping the extension unit between the facial nerve root and the anterior inferior cerebellar artery or the small artery so that the contact unit closely contacts to the facial nerve root and is fixed.

Abstract: A method and associated stimulation device for ensuring firing of an action potential in an intended physiological target activated by a stimulus pulse generated by an electrode of a non-invasive surface based stimulation device irrespective of skin-to-electrode impedance by: (i) increasing internal impedance of the stimulation device so as to widen a Chronaxie time period thereby ensuring firing of the action potential of the intended physiological target irrespective of the skin-to-electrode impedance; and/or (ii) generating a stimulation waveform that optimizes a non-zero average current (e.g., non-zero slope of the envelope of the stimulation waveform) during preferably substantially the entire current decay of the stimulus pulse.

Abstract: A surface NMES stimulation device the device has a control processor, a voltage regulator connected to a high voltage supply, a bridge of control switches, and electrodes or electrode terminals connected in the bridge to receive drive signals via the control switches. The processor directs a drive scheme for the bridge control switches in which charge build-up on a user's skin is allowed to dissipate to ground in an inter-pulse interval. An isolation capacitor isolates the high voltage supply from the electrodes, and charging of the capacitor only occurs if a switch allows it. Sensors senses supply voltage and bridge current and the processor monitors there to determine further stimulation and faults.

Abstract: Devices, systems, and methods for automated optimization of muscle stimulation energy. In some embodiments the disclosure optimizes stimulation parameters and/or stimulation location.

Abstract: A method of assessing the effectiveness of muscle treatment is provided that includes a controller generating a control signal for transmission to an energy generator, delivering energy from the energy generator to a stimulation pad for purposes of providing muscle therapy, and measuring at least one muscle metric value reflective of the healing status of the muscle and comparing that value to a pre-established corollary between such muscle metric values and corresponding healing status for differing demographics, whereby the user may determine whether to continue muscle therapy or not.

Abstract: A brace includes a closed loop feedback system that provides electrical muscle stimulation (EMS) to a joint of a human patient in response to feedback from the joint and surrounding muscles. In one aspect, a brace for treating a human joint of a patient is provided. The brace includes one or more sensors in physical contact with the skin of the patient and configured to obtain a galvanic reading of resistance of the skin. The brace also includes brace control electronics in communication with the sensor(s) to form a closed loop system via a combination of bracing the joint and electrical muscle stimulation (EMS). The brace control electronics is configured to receive the galvanic reading of the resistance of the skin of the patient and is further configured to instruct the sensor to apply a current/voltage/power onto the skin based on the galvanic reading.

Abstract: The present invention is related to an apparatus for activating electrophysiological mechanism and the method for configuring the same, which are based on diagnostic codes comprising at least more than two codes selected from a group of code classified by hue contrast to temperature differences according to heat distribution of a body. As a prescription for the above diagnostic codes, the activation prescription codes comprising code streams are generated, and then signals corresponding to each code are sequentially extracted and outputted as stimuli, and then finally become to provide activation stimuli to a body. The apparatus according to the present invention measures the distribution of body temperature, sets potential difference within an isolated system according to the distribution, and thus forces vibrations or waves with accelerated motion to be delivered to a whole body.

Abstract: Disclosed herein is a functional electrical stimulation (FES) device and system. In one embodiment, sequential bipolar pulse stimulation may be provided to an area of a living body via one or more electrode leads applied to the area via a FES device comprising a current pulse generating circuit comprising output nodes for operative coupling to the one or more electrode leads, and configured for operative coupling to a voltage supply. The current pulse generating circuit generally comprises positive and negative stimulation paths drawing from the voltage supply to respectively apply positive and negative currents through the area via the one or more electrode leads. In one example, the stimulation paths comprise respective capacitive elements, a capacitance ratio of which dictating, at least in part, an amplitude ratio of the positive and negative currents, wherein periodic alternative activation of the stimulation paths provides the sequential bipolar pulse stimulation.

Abstract: A system for stimulating facial nerves in a subject includes an electrode having a plurality of contacts configured to be placed in a parotid region of the subject's face and a processor in communication with the electrode. The processor has program code for stimulating one or more facial nerve branches by stimulating each of the plurality of contacts separately in order to determine which nerve branch activates which facial muscle, for identifying one or more contacts from the plurality of contacts that cause the one or more nerve branches to activate a desired facial muscle, and for selecting the identified contacts to stimulate the one or more nerve branches.

Abstract: A method is provided for treating pressure ulcers by transmitting an electrical stimulus sufficient to effect contraction of a loaded muscle, wherein the method comprises the steps of providing an electrical transmission for effecting contraction of the loaded muscle, transmitting sufficient electrical stimulation to the muscle to contract it for a predetermined short period of time, and ceasing transmission of the stimulus to the muscle for a predetermined longer period of muscle relaxation, whereby the predetermined period of relaxation is sufficient to minimize muscle fatigue and cause sustained reoxygenation.

Abstract: In one example embodiment, a neuromodulation system for inducing locomotor activity in a mammal, in cooperation with a signal generator and an electrode, delivers a signal with an overlapping high frequency pulse to a mammal

Abstract: A method of electro-therapeutic stimulation uses an electrical signal with a periodic-exponential background pulse over a controllable periodic-exponential main pulse. By properly setting the signal and moving electrodes to proper locations on the body, the signal is used to electro-therapeutically return a patient to a state of neurological balance, to identify specific cellular disruption locations, to treat the identified cellular disruption locations including performing a pain associated movement, and to neurologically train from a facilitator muscle to one or more receiver muscles.

Abstract: The present invention depicts an implantable artificial pacemaker (AAP) comprising oscillatory means providing pulsating signals at a pre-selected frequency, wherein the pacemaker is pacing the aorta. The invention also describes an AAP further comprising; (i) a plurality of sensors disposed internally or externally to the aorta; and (ii) a pacing means in which the AAP stimulates the aortic media, augmenting physiological aortic elastic recoil. An AAP further comprising a processor capable of obtaining information from sensors and triggering an appropriate contraction wave in the aortic media is also introduced. A method of managing aortic rhythm comprising; (i) implanting an AAP comprising oscillatory means; and (ii) pulsating signals at a preselected frequency, so as to pace the aorta and in which the pulsating signals are provided by synchronizing and coordinating activation impulses in a portion of the aorta using electrical impulses is also taught.

Abstract: A tool for assisting in the planning or performing of electrical neuromodulation of a patient's spinal cord. The tool may have various functions and capabilities, including calculating a volume of activation, registering an electrode(s) shown in a radiologic image, constructing functional images of the patient's spinal anatomy, targeting of neuromodulation, finding a functional midline between multiple electrodes, determining the three-dimensional position of multiple electrodes, and/or accommodating for electrode migration. In certain embodiments, the tool can be embodied as computer software or a computer system.

Abstract: A system and method of stimulating a nerve of a patient is provided. A electro-therapy device is used that includes a signal generator and two electrodes. The first electrode is positioned on an epidermis of the patient over the nerve to be stimulated. The second electrode is positioned on an epidermis of the patient at a second location. A The electro-therapy device is configured to alternately deliver to a first and second electrode a summation of first and second signals which result in a therapeutic signal encompassing the nerve of the patient. The intensity of the first and second signal is adjusted over time.