279 results about "Evoked potential" patented technology

Induced movement in a patient is detected and correlated with a TMS stimulating pulse so as to determine the patient's motor threshold stimulation level. Direct visual or audible feedback is provided to the operator indicating that a valid stimulation has occurred so that the operator may adjust the stimulation accordingly. A search algorithm may be used to direct a convergence to the motor threshold stimulation level with or without operator intervention. A motion detector is used or, alternatively, the motion detector is replaced with a direct motor evoked potential (MEP) measurement device that measures induced neurological voltage and correlates the measured neurological change to the TMS stimulus. Other signals indicative of motor threshold may be detected and correlated to the TMS stimulus pulses. For example, left / right asymmetry changes in a narrow subset of EEG leads placed on the forehead of the patient or fast autonomic responses, such as skin conductivity, modulation of respiration, reflex responses, and the like, may be detected. The appropriate stimulation level for TMS studies are also determined using techniques other than motor cortex motor threshold methods. For example, a localized ultrasound probe may be used to determine the depth of cortical tissue at the treatment site. When considered along with neuronal excitability, the stimulation level for treatment may be determined. Alternatively, a localized impedance probe or coil and detection circuit whose Q factor changes with tissue loading may be used to detect cortical depth.

A method for identifying and treating a neural pathway associated with chronic pain via nerve stimulation and brain wave monitoring of a mammalian brain includes positioning a probe to stimulate a target nerve, wherein the target nerve is suspected of being a source of chronic pain; delivering a first nerve stimulation from the probe to the target nerve, wherein the first nerve stimulation is sufficient to elicit a chronic pain response in the brain; and monitoring for evoked potential activity in the brain as a result of the first nerve stimulation. The method can also include delivering second and third nerve stimulations to confirm the correct identification of the neural pathway and to treat the chronic pain, respectively. A system and apparatus for performing a procedure to identify and treat a nerve that is the source of chronic pain are also described.

A method and apparatus for processing a composite signal generated by a transient signal generation mechanism to extract a repetitive low SNR transient signal, such as an evoked potential (EP) appearing in an electroencephalogram (EEG) generated in response to sensory stimulation, by: (a) dynamically identifying, via a learning process, the major transient signal types in the composite signal; (b) decomposing the identified major transient signal types into their respective constituent components; (c) synthesizing a parametric model emulating the transient signal generation mechanism; and (d) utilizing the model and the constituent components to identify and extract the low SNR transient signal from the composite signal.

New and useful neurostimulation systems are provided that include an implantable pulse generator dimensioned and configured for implantation in the skull of a patient. The implantable pulse generator has an electrode operatively associated with a distal end portion thereof and can be provided with adjustment means, such as an adjustable biasing member or spring arranged between the electrode to the distal end portion of the pulse generator. Also provided are systems involving networked neurostimulators that are configured and adapted to work jointly in accordance with prescribed treatment protocol to effect a desired recovery from brain injury. Such networked neurostimulation systems are particularly advantageous for effecting relatively large and / or relatively distant regions of the brain. Additionally, systems and methods for motor-evoked potential (MEP)-based neuromodulation are provided. Further, AC and / or DC stimulation can be utilized, depending on the precise implementation.

Systems and methods for closed loop spinal cord stimulation are provided. The systems and methods position a first electrode proximate to a dorsal column. The first electrode is electrically coupled to an implantable pulse generator (IPG). The systems and methods further program the IPG to deliver excitation pulses to the first electrode based on a stimulation level. The excitation pulses are emitted from the first electrode. The systems and methods further position a second electrode proximate to a dorsal root. The second electrode is electrically coupled to the IPG. The systems and methods further measure at the second electrode a first evoked potential waveforms resulting from the excitation pulses.

Amplification of an evoked potential signal is carried out utilizing a high pass filter implemented as an integrator in a feedback loop which drives the DC offset voltage to zero. As a result, the feed-forward amplifier circuit has almost zero volts at its output since the only voltage remaining is the offset voltage of the operational amplifier, which is selected so as to maintain this parameter as low as possible. Because the voltage impressed across the feed-forward amplifier section is close to zero, the gain of this section can be set to zero during the time that the electrical stimulus pulse is present without introducing any additional artifacts and subsequent amplifier stages are not driven into saturation. When the electrical stimulus potential is no longer present or is significantly reduced in amplitude and before the time of receipt of the response signal, the feed-forward amplifier is brought back into the circuit to provide the high gain required to amplify the response signal, which can be measured without interference from saturation of any of the amplifier stages as they recover to baseline.

A portable EEG (electroencephalograph) instrument, especially for use in emergencies and brain assessments in physicians' offices, detects and amplifies brain waves and converts them into digital data for analysis by comparison with data from normal groups. In one embodiment, the EEG electrodes are in a headband which broadcasts the data, by radio or cellular phone, to a local receiver for re-transmission and / or analysis. In another embodiment, the subject is stimulated in two modes, i.e., aural and sensory, at two different frequencies to provide the subject's EPs (Evoked Potentials), assessing transmission through the brainstem and thalamus.

A dermatomol somatosensory evoked potential (DSSEP) diagnositic apparatus for evaluating nerve root functions in a mammalian subject is presented. The DSSEP apparatus includes an electrical stimulator, a stimulus site selector switchbox, a connection box, a plurality of stimulating electrodes, a plurality of recording electrodes, a computer system, and a software package. The stimulating electrodes are configured to receive and to apply an electrical stimulus onto a dermal stimulation site of the mammalian subject. The recording electrodes are configured to receive an evoked potential induced by the applied electrical stimulus such that the evoked potential response passes through nerves from the dermal stimulation site to the dermal recording site. The computer system and software package process the results.