A patient controls the delivery of therapy through volitional inputs that are detected by a biosignal within the brain. The volitional patient input may be directed towards performing a specific physical or mental activity, such as moving a muscle or performing a mathematical calculation. In one embodiment, a biosignal detection module monitors an electroencephalogram (EEG) signal from within the brain of the patient and determines whether the EEG signal includes the biosignal. In one embodiment, the biosignal detection module analyzes one or more frequency components of the EEG signal. In this manner, the patient may adjust therapy delivery by providing a volitional input that is detected by brain signals, wherein the volitional input may not require the interaction with another device, thereby eliminating the need for an external programmer to adjust therapy delivery. Example therapies include electrical stimulation, drug delivery, and delivery of sensory cues.

Patient directed therapy control

A movement state of a patient is detected based on brain signals, such as an electroencephalogram (EEG) signal. In some examples, a brain signal within a dorsal-lateral prefrontal cortex of a brain of the patient indicative of prospective movement of the patient may be sensed in order to detect the movement state. The movement state may include the brain state that indicates the patient is intending on initiating movement, initiating movement, attempting to initiate movement or is actually moving. In some examples, upon detecting the movement state, a movement disorder therapy is delivered to the patient. In some examples, the therapy delivery is deactivated upon detecting the patient is no longer in a movement state or that the patient has successfully initiated movement. In addition, in some examples, the movement state detected based on the brain signals may be confirmed based on a signal from a motion sensor.

Therapy control based on a patient movement state

The disclosure is directed to a frequency selective monitor (6) and methods for monitoring physiological signals in one or more selected frequency bands. A frequency selective monitor may utilize a heterodyning, chopper-stabilized amplifier architecture (30) to convert a selected frequency band to a baseband for analysis. The frequency selective monitor may be useful in a variety of therapeutic and/or diagnostic applications. As examples, a frequency selective signal monitor may be provided within a medical device (20) or within a sensor (14) coupled to a medical device. The physiological signal may be analyzed in one or more selected frequency bands to trigger delivery of patient therapy and/or recording of diagnostic information.

Frequency selective monitoring of physiological signals

This disclosure describes a chopper stabilized instrumentation amplifier. The amplifier is configured to achieve stable measurements at low frequency with very low power consumption. The instrumentation amplifier uses a differential architecture and a mixer amplifier to substantially eliminate noise and offset from an output signal produced by the amplifier. Dynamic limitations, i.e., glitching, that result from chopper stabilization at low power are substantially eliminated through a combination of chopping at low impedance nodes within the mixer amplifier and feedback. The signal path of the amplifier operates as a continuous time system, providing minimal aliasing of noise or external signals entering the signal pathway at the chop frequency or its harmonics. The amplifier can be used in a low power system, such as an implantable medical device, to provide a stable, low-noise output signal.

Chopper-stabilized instrumentation amplifier for impedance measurement

Chopper-stabilized instrumentation amplifier

To display radar data on the face of a cathode-ray tube or other display device, it is necessary to generate product functions of the sine and the cosine components of the antenna position angle times the radar-sweep function. Both the sine product function and the cosine product function are electronically generated in respective multipliers. Each multiplier consists of a first differential amplifier pair coupled push-pull to a second differential amplifier pair. To minimize the effect of line voltage variation on the product functions, the sweep voltage is corrected prior to multiplication with the sine and cosine components in accordance with line voltage variation.

Church Gerald C

Papers

Electronic resolved sweep signal generator