Abstract: A long term analyte sensor for measuring at least one analyte in the body of a user and which includes a housing, a plurality of analyte contacting sensor elements and at least one structure for relaying information away from the sensor. This plurality of analyte contacting sensor elements are typically disposed in an array. The analyte sensor further includes at least one sensor protection membrane that is controllable in a manner such that sensor elements may be activated (e.g. exposed to the external environment) at different times so as to extend the useful life of the sensor. In illustrative analyte sensors, the analyte is glucose.

Abstract: A long term analyte sensor for measuring at least one analyte in the body of a user and which includes a housing, a plurality of analyte contacting sensor elements and at least one structure for relaying information away from the sensor. This plurality of analyte contacting sensor elements are typically disposed in an array. The analyte sensor further includes at least one sensor protection membrane that is controllable in a manner such that sensor elements may be activated (e.g. exposed to the external environment) at different times so as to extend the useful life of the sensor. In illustrative analyte sensors, the analyte is glucose.

Abstract: A long term analyte sensor for measuring at least one analyte in the body of a user and which includes a housing, a plurality of analyte contacting sensor elements and at least one structure for relaying information away from the sensor. This plurality of analyte contacting sensor elements are typically disposed in an array. The analyte sensor further includes at least one sensor protection membrane that is controllable in a manner such that sensor elements may be activated (e.g. exposed to the external environment) at different times so as to extend the useful life of the sensor. In illustrative analyte sensors, the analyte is glucose.

Abstract: A long term analyte sensor for measuring at least one analyte in the body of a user and which includes a housing, a plurality of analyte contacting sensor elements and at least one structure for relaying information away from the sensor. This plurality of analyte contacting sensor elements are typically disposed in an array. The analyte sensor further includes at least one sensor protection membrane that is controllable in a manner such that sensor elements may be activated (e.g. exposed to the external environment) at different times so as to extend the useful life of the sensor. In illustrative analyte sensors, the analyte is glucose.

Abstract: An implantable coronary perfusion assist system to divert blood from large arteries, such as the aorta, to small arteries, such as the coronary arteries where additional blood flow is needed. The assist system includes a shunt graft which is connected to the aorta or another convenient source of oxygenated blood at one end, and to the coronary artery or the atrium at its other end. A pump, preferably of the type employing a trained muscle wrapped around a fluid chamber is connected by a conduit to a bladder disposed in line with the graft, to assist in pumping of blood from the aorta to the coronary artery. The pump action is synchronized to the dastolic phase of the patient's cardiac cycle, and the coronary perfusion is accomplished without increasing the concentration of oxygen in the patient's body.

Abstract: Apparatus for monitoring and storing heart activity signals is disclosed as including a data processor illustratively in the form of a digital microprocessor. The monitoring and storing apparatus comprises a memory comprising first and second pluralities of storage locations, a circuit operating in a real time frame for sampling at a regular rate the patient's heart activity and for storing such sample signals in corresponding locations of said first plurality, an the data processor for processing the signals stored in the first plurality and for storing the processed signals in selected locations of said second plurality. The storage of the signals in the second plurality is performed in a second computer time frame and at a rate faster than the real time sampling rate. A sampling clock provides a sampling clock signal to the sampling circuit whereby the samples of the patient's heart activity are taken.

Abstract: Apparatus is disclosed for monitoring and storing electrical signals in a manner to detect the intervals between heartbeats and to provide a manifestation of whether the corresponding heart signals have a regular heart rhythm or not. Such apparatus comprises a memory having at least first and second areas, a circuit for receiving and sampling the heart signals, and a circuit for temporarily storing the heart sample signals in the first area. Further, there is included a circuit for processing or evaluating the heart signals stored in the first area to determine the occurrences of the patient's heartbeat and for determining the intervals between adjacent heartbeats. The determined intervals are stored in the second area and are evaluated to determine whether the patient's heart activity occurs with a regular rhythm. The monitoring and storing apparatus is operative over a monitoring period comprised of a plurality of trend sample intervals.

Abstract: Heart monitoring and storing apparatus is disclosed for evaluating heart activity signals to determine if valid, for identifying a characteristic of the valid heart activity signal, and for storing the signal into a corresponding location of a memory depending upon the characteristic of the heart activity signal. Such apparatus comprises the memory including a first area and a second area, and a circuit for sampling the heart activity signals and for storing the heart signal samples into corresponding locations of such first area. There is further included an evaluation circuit for determining whether the sampled heart activity signals as stored within the first area are valid and particularly if they indicate the occurrence of a heartbeat. An addressing circuit is provided for determining the various characteristics of a valid heart signal and for selectively addressing a location within said second area to store the valid heart signal of the corresponding characteristic.

Abstract: Cardiac monitoring and pacing apparatus comprising a first external unit for transmitting electromagnetic energy within the patient's body to be received by a second, surgically implanted unit within the patient's body and adapted to be solely powered by the transmitted electromagnetic energy. The first external unit transmits electromagnetic energy within the patient's body which is sensed and used to power the implanted unit, which stimulates, via pacing electrodes, the patient's heart. The internal unit also includes a monitoring circuit connected to the same pacing electrodes coupled to the patient's heart, for providing atrial and ventrical signals to be pulse-width modulated for transmission to the external unit. The external unit decodes the transmitted signals to provide diagnostic quality signals indicative of the patient's EKG.

Abstract: Apparatus for stimulating body tissue and in particular the heart, is disclosed as including a device or circuit responsive to the initiation of stimulation and/or to the failure or pending failure of a component of the stimulating apparatus to provide the patient with a perceivable stimulation to a second, different portion of body tissue. There is disclosed an impedance level detector for sensing the impedance presented between the outputs of the stimulation apparatus to provide a warning signal indicating that the output impedance falls outside a predetermined range. In particular, the impedance level detector output is sensed by a stimulation control logic to apply a first train of pulses at a first rate to an auxiliary electrode for stimulating the second portion of tissue.

Abstract: A demand pacemaker having different standby and pacing rates and circuitry for selectively rendering the standby and pacing rates substantially identical. First and second capacitors control the standby and pacing rates, respectively, one capacitor being responsive to either a natural heartbeat or a pacemaker output pulse to alter the rate established by the other. In a preferred embodiment, the second capacitor is charged during a pacemaker output pulse and discharges through the first capacitor to decrease its charging time, the charging time of the first capacitor controlling the pacemaker output pulse frequency. Circuitry responsive to externally generated signals causes the second capacitor to charge during both a natural heartbeat or a pacemaker output pulse to render the pacemaker standby and pacing rates substantially identical.