Abstract: A wireless system for brain monitoring/mapping of neurological-disorder patients includes a plurality of electrodes each configured for surface abutment of brain tissue and main circuitry for placement outside a body of a patient and configured to transmit power at radio frequencies and send and receive data using infrared energy. Remote circuitry is provided for subcutaneous implantation in a head of the patient. The remote circuitry is connected to the plurality of electrodes and includes a multiplexer sampling signals from the plurality of electrodes. The multiplexer outputs electrode signals to an amplifier and A/D converter for transmission to the main circuitry. The remote circuitry is configured to (a) receive transmitted power at radio frequencies from the main circuitry, (b) capture and digitize full-bandwidth EEG signals from each of the electrodes, and (c) send data to and receive data from the main circuitry using infrared energy.

Abstract: A wireless system for brain monitoring/mapping of neurological-disorder patients includes a plurality of electrodes each configured for surface abutment of brain tissue and main circuitry for placement outside a body of a patient and configured to transmit power at radio frequencies and send and receive data using infrared energy. Remote circuitry is provided for subcutaneous implantation in a head of the patient. The remote circuitry is connected to the plurality of electrodes and includes a multiplexer sampling signals from the plurality of electrodes. The multiplexer outputs electrode signals to an amplifier and A/D converter for transmission to the main circuitry. The remote circuitry is configured to (a) receive transmitted power at radio frequencies from the main circuitry, (b) capture and digitize full-bandwidth EEG signals from each of the electrodes, and (c) send data to and receive data from the main circuitry using infrared energy.

Abstract: A wireless system for brain monitoring/mapping of neurological-disorder patients includes a plurality of electrodes each configured for surface abutment of brain tissue and main circuitry for placement outside a body of a patient and configured to transmit power at radio frequencies and send and receive data using infrared energy. Remote circuitry is provided for subcutaneous implantation in a head of the patient. The remote circuitry is connected to the plurality of electrodes and includes a multiplexer sampling signals from the plurality of electrodes. The multiplexer outputs electrode signals to an amplifier and A/D converter for transmission to the main circuitry. The remote circuitry is configured to (a) receive transmitted power at radio frequencies from the main circuitry, (b) capture and digitize full-bandwidth EEG signals from each of the electrodes, and (c) send data to and receive data from the main circuitry using infrared energy.

Abstract: A wireless system for monitoring a patient's brain tissue including (1) a plurality of electrodes abutting brain tissue, (2) main circuitry outside the patient's body to transmit power at radio frequencies and send/receive data using infrared energy, and (3) subcutaneously-implanted remote circuitry connected to the electrodes and configured to (a) receive transmitted RF power, (b) capture and digitize EEG signals from the electrodes, and (c) send/receive data to/from the main circuitry using IR energy, including sending digitized EEG signals from each electrode to capture the full bandwidth of each EEG signal. The system preferably includes circuitry to measure the electrical impedance of each electrode for real-time monitoring of the condition of the electrode/tissue interfaces to enhance interpretation of captured EEG signals.

Abstract: A wireless system for monitoring a patient's brain tissue including (1) a plurality of electrodes abutting brain tissue, (2) main circuitry outside the patient's body to transmit power at radio frequencies and send/receive data using infrared energy, and (3) subcutaneously-implanted remote circuitry connected to the electrodes and configured to (a) receive transmitted RF power, (b) capture and digitize EEG signals from the electrodes, and (c) send/receive data to/from the main circuitry using IR energy, including sending digitized EEG signals from each electrode to capture the full bandwidth of each EEG signal. The system preferably includes circuitry to measure the electrical impedance of each electrode for real-time monitoring of the condition of the electrode/tissue interfaces to enhance interpretation of captured EEG signals.

Abstract: Continuous, non-invasive method and apparatus for measuring blood pressure parameters and the like are disclosed. One disclosed apparatus includes an earpiece for sealing an individual's ear canal so that arterial blood pressure changes adjacent the sealed ear canal produce air pressure changes in the sealed ear canal. The apparatus further includes pressure sensing means for measuring the air pressure changes in the sealed ear canal and producing a signal related to the measured air pressure changes. In addition, the apparatus preferably includes processing means for processing the signal to measure blood pressure parameters, as well as means for displaying and/or recording the processed signal. The method may be used to determine heart rate, blood pressure, cardiac output, stroke volume, cardiac function, circulatory function, and other parameters. To obtain absolute pressure readings, two sensors, one in each ear, may be used to monitor pulse time transit delay.

Abstract: A leadless implantable cardiac arrhythmia alarm is disclosed which continuously assesses a patient's heart function to discriminate between normal and abnormal heart functioning and, upon detecting an abnormal condition, generates a patient-warning signal. The alarm is capable of sensing impedance measurements of heart, respiratory and patient motion and, from these measurements, generating an alarm signal when the measurements indicate the occurrence of a cardiac arrhythmia. Because it requires no external leads or feedthrough connectors, the hermetically-sealed patient alarm is minimally invasive and results in reduced trauma to a patient.

Abstract: A time domain reflectometry (TDR) impedance sensor is provided for measuring body impedance along a lead or catheter implanted in a patient's cardiovascular system. The TDR sensor applies an electrical stimulus to the lead and measures reflections echoed from impedance variations along and distal to the lead, which are superimposed on the applied stimulus. The measured signals may be analyzed with respect to time-of-flight and distance along the lead to detect a plurality of physiologically meaningful signals.

Abstract: A rate-responsive pacemaker employing a rate control parameter of respiratory minute volume, derived over a unipolar lead. The pacemaker performs the minute volume measurement by periodically applying a measuring current between the lead and a reference point on the pacemaker case. This measuring current has frequency components in a range from approximately 10 kilohertz to 1000 megahertz. Application of this measuring current allows the pacemaker to detect the voltage which arises from the applied current and, from the detected voltage, to measure the patient's spatial impedance. Spatial impedance and minute volume vary as a function of the patient's pleural pressure. The pacemaker derives minute volume and rate-responsive pacing rate from the spatial impedance measurement.

Abstract: A metabolic demand rate-responsive cardiac stimulation apparatus and method are disclosed which employ multiple physiological rate control parameters, such as respiratory minute volume, patient motion and cardiac stroke volume. The parameters are derived using a single standard pacing lead or transducer. The apparatus and method perform each physiological measurement by periodically applying a measuring current between two points within the apparatus. This measuring current has frequency components in a range of from approximately 10 kilohertz to 1000 megahertz. Application of this measuring current allows the apparatus to detect the voltage which arises from the applied current and, from the detected voltage, to measure the patient's spatial impedance. For a particular measurement, the apparatus controls which physiological parameter is sensed by regulating the frequency content of the measuring current.

Abstract: A radiosonde has a novel and improved measuring circuitry for measuring atmospheric conditions, such as, temperature, humidity and pressure through the direct conversion of resistance and capacitance values into binary numbers. The binary numbers are transmitted in digital form along with calibration coefficients to a remote ground station. The measuring circuitry can be mounted on the same substrate with the pressure transducer, and the electrical connections between the pressure transducer and measuring circuitry are simplified by utilization of an offset diaphragm, pressure cell arrangement.