Abstract: A one-piece needle guide for use with a medical ultrasonic scanning apparatus to guide a needle. The needle guide includes a body which is adapted to be releasably secured to the scanning apparatus. A tubular channel extends the length of the body on its upper surface. The channel is for engaging and guiding the needle in proper alignment with the scanning apparatus. A pair of flexible lips form the shape of the channel and are adapted to secure the needle in a slidable manner. The flexibility of the lips allow the needle to be removed from the body.

Abstract: A multi-axis, multi-purpose sensor for use with implantable medical devices, and for simultaneously detecting the patient's posture and activity level. The sensor includes a hermetically sealed, fluid-tight, bio-compatible housing. The housing is formed of a plurality of adjacently secured sides, and a plurality of side electrodes coupled to the sides. A central electrode is disposed at the geometric center of symmetry of the housing, to allow measurement of voltage changes between the central electrode and the side electrodes. A non-toxic electrically conductive electrolyte fills about half the housing, and immerses part of the central electrode and the side electrodes. The sensor further includes a low frequency bandpass filter for passing low frequency signals indicative of the patient's posture, and a high frequency bandpass filter for passing high frequency signals indicative of the patient's activity.

Abstract: An apparatus for and method of preoperative and intraoperative screening of obstructive sleep apnea patients. The screening device employs a plurality of stimulation channels which may be individually controlled to terminate or prevent an apnea event. The apparatus also contains a plurality of sensor processing channels to permit selection of the optimal sensor configuration and the sensing parameters. The preoperative procedure determines the suitability of a patient for therapy using an automatic implantable system. The type and placement of sensors and stimulation electrodes is also determined. During the intraoperative procedure, the initial screening determinations are verified and the various sensing and stimulation parameters are optimized.

Abstract: A medical patient's compliance with a prescribed regimen of treatment is monitored through elapsed time of equipment operation. A treatment device used by the patient applies a stimulation signal to the patient through an electrode and counts a first clock signal which produces a first count indicative of the length of time which the stimulation signal is applied. When the patient revisits the doctor, a compliance monitor readout device is connected to the treatment device to facilitate the compliance monitoring. The treatment device then counts, in response to second clock signal generated by the compliance monitor, from the first count to a second predetermined count. The compliance monitor readout device also counts the second clock signal and produces a third count. The compliance monitor readout device then displays an output as a function of the third count.

Abstract: Apparatus for promoting waste-free primary flow in a patient monitoring device is disclosed and includes a waste trap with a body defining a waste chamber with the body including an entry port for communication with a primary channel of the device, and an exit port for communication with a secondary channel of the device. The exit port has a first cross-sectional area. The exit port is defined by a porous, gas-permeable, waste-blocking member that extends into the chamber to promote waste-free primary flow in any orientation of the trap. The member has a total-pore area exceeding the first cross-sectional area. Operatively connected between the ports is means for monitoring the differential pressure therebetween and for sending signals representative of such pressure to associated control circuitry of the device for determining the volume of waste in said body based on signals received from the monitoring means.

Abstract: In a coiled wire medical lead structure, such as a transvenous, endocardial cardiac pacemaker and/or cardioverter/defibrillator lead, an improved mechanical structure for strengthening the lead to enable its intact removal by traction after a period of chronic implant, one or more normally relaxed, nonextensible filaments loosely contained within the insulating sheath and having proximal and distal ends mechanically coupled to the connector and electrode shank, respectively, of the lead operate as means for restraining the stretching of the lead body to a stretched length exceeding the relaxed, predetermined length by an amount sufficient to allow the lead to be stretched without breaking in its normal usage and during removal by traction. In certain embodiments, the filament may take the form of a loosely woven fabric sheath formed in a tubular shape and fitted in the space between the lead body outer sheath and one or more coiled wire conductors.

Abstract: Method and apparatus are described for treating and controlling diabetes and other systemic pancreatic endocrine disorders attributable to abnormal levels of secretion of endogenous insulin. An electrical stimulator implanted into or worn external to the patient's body is adapted, when activated, to generate a programmable electrical waveform for application to electrodes implanted on the vagus nerve of the patient. The electrical waveform is programmed using parameter values selected to stimulate or inhibit the vagus nerve to modulate the electrical activity thereof to increase or decrease secretion of natural insulin by the patient's pancreas. The stimulator is selectively activated manually by the patient in response to direct measurement of blood glucose or symptoms, or is activated automatically by programming the activation to occur at predetermined times and for predetermined intervals during the circadian cycle of the patient.

Abstract: A cardiac pacemaker and related pacing method. The cardiac pacemaker includes atrial and ventricular sense amplifiers for generating atrial and ventricular sense signals. An activity control circuit measures the activity level and initiates an activity interval. A control circuit responds to the atrial sense signals, the ventricular sense signals, and the activity control circuit, for controlling the atrial and ventricular stimuli generation, by matching the activity interval with the depolarization of the atrial tissue, in order to differentiate true exercise induced sinus tachycardia from atrial arrhythmias and retrograde atrial events, and to permit a selective ventricular rate control. The control circuit initiates a 2 to 1 ventricular to atrial response when the activity interval is greater than a VV interval, which is the sum of the interval between the last sensed or paced ventricular event and the atrial intrinsic depolarization (VA.sub.

Abstract: A pacemaker capable of automatically adjusting the activity threshold setting of its activity sensor signal processing circuitry to its optimal value is disclosed. In one embodiment, the pacemaker maintains a running average of zero activity time and a cumulative summation of zero activity time over a predetermined history period. Periodically, the pacemaker computes a time difference between the running average of zero activity time and the cumulative summation of zero activity time, and adjusts the activity threshold of the activity sensor signal processing circuitry according to this computation. By basing the adjustment of activity threshold on a long-term average of zero activity time, the effects of cycle-to-cycle variation in sensed zero activity time are minimized. In another embodiment, the pacemaker periodically computes a time difference between a preprogrammed margin value and the cumulative summation of zero activity time.

Abstract: An intra-aortic balloon pump of this invention comprises a catheter (4) which introduces a pumping media, a wrapped membrane (5) which is mounted on one end of the catheter (4), a protection sleeve (1) which accommodates the membrane (5), a sealing cap (3) which is mounted on the catheter (4) and is movable along the catheter (4), and, an intermediate member (2) which is located between the membrane (5) and the sealing cap (3) and is movable along the catheter (4) together with the membrane (5) so as to prevent the membrane (5) from unwrapping. After the intermediate member (2) is moved to the membrane (5) so that the intermediate member (2) overlaps the membrane (5), the intermediate member (2) prevents the membrane (5) from unwrapping. Therefore, the sleeve (1) can be removed from the membrane (5) without unwrapping the membrane (5). After the membrane (5) is inserted in a femoral artery through a sheath (9), the membrane (5) ascends in the descending abdominal aorta toward the failing heart.

Abstract: The evoked potential processing system includes, in one embodiment, a spectral averaging method. Time based, digital pre-stimulus and post-stimulus electroencephalographic (EEG) signal streams are obtained and are converted into frequency spectrum signals. A differential spectrum is obtained. The differential spectrums from a plurality of sweeps are summed. The summed differential spectrum is then converted into a time based signal stream which contains the evoked potential (EP) signal therein. The EP signal can also be obtained utilizing a two-dimensional filter. Pre- and post-stimulus EEG signal streams for a sub-group of stimuli, wherein each stimulus in a group has the same intensity or frequency, are filtered by conventional averaging or spectral differential averaging. The time based, filtered, post-stimulus EEG signal streams are placed in an array and the array is then filtered by a two-dimensional Fast Fourier Transform (FFT) filter.

Abstract: A portable apparatus having electronic circuitry for selectively monitoring and recording a user's ECG signals, wherein a first conductive electrode is disposed on a first surface of the apparatus casing for contact with an ECG lead position on the user's body and second and third electrodes are disposed on at least one other surface of the casing for ease of contact by a thumb and finger, respectively, of the user's hand. One of the second and third electrodes provides a ground signal source for the electronic circuitry. A wristband is provided for securing the apparatus to the user's wrist and a microprocessor controls the electronic circuitry such that the user's ECG signal is monitored/recorded only when the user grasps the second and third electrodes. A separate modem device is attachable to the apparatus for effecting burst mode transmission of data to an external receiver.

Abstract: A pacemaker system includes a dual sensor implantable pacemaker and an external programmer for automatically and simultaneously optimizing and initializing a plurality of pacing parameters. The pacemaker includes means for automatically initializing a sensitivity threshold, pacing pulse width, pacing pulse amplitude, activity threshold, and pressure rate response gain setting.

Abstract: A patient monitoring system is provided which includes a monitor and a transmitter which can optically communicate with each other. The monitor receives analog physiological data from a patient and converts the analog data to a digital optical signal which is sent to the transmitter optically. The transmitter includes a memory for storing the digital signal thereby allowing separation of the monitor from the transmitter prior to subsequent transmission. Additionally, the transmitter is capable of converting the digital signal to a modulated tone for transmission via standard phone lines. In this manner, the transmitter is able to send the converted signal to a central processing system via phone lines. This converted signal can then be monitored at the central processing system or it can be further communicated to one or more remote receiving stations.

Abstract: A pacemaker with a variable, asynchronous minimum heart rate and a second variable, synchronous heart rate. The second, variable heart rate has an absolute minimum, lower than the asynchronous minimum heart rate, which is preselected by the attending physician. The minimum heart rates can vary, conditioned upon sensed physiologic need. The cardiac pacemaker attempts to reestablish synchrony in every cycle, even if the intrinsic or natural atrial heart rate is below the asynchronous minimum heart rate in that cycle and can maintain cardiac synchrony at lower rates, thereby increasing cardiac efficiency and minimizing strain on the heart.

Abstract: A doppler guide wire having an inflatable balloon thereon which is inflatable with a balloon inflation medium. An elongate flexible member having proximal and distal extremities. An ultrasonic transducer is secured to the distal extremity of the elongate flexible member. An inflatable balloon mounted on the distal extremity of the elongate flexible member proximal of the ultrasonic transducer. A balloon inflation lumen opens into the interior of the balloon and extends along the length of the elongate flexible member. Conductors are connected to the ultrasonic transducer and extend along the length of the elongate flexible member.

Abstract: A device (10) and method for cutaneously marking the venous anatomy with an ink. The method comprises selectively locating a portion of the venous anatomy to be marked and coating the skin (20) corresponding to the venous anatomy to be marked with a transmission gel (22). The transmission gel (22) permits a technician utilizing an ultrasound transducer to pinpoint the portion of the venous anatomy to be marked. Device (10) simultaneously clears the transmission gel from the skin (20) corresponding to the portion of the venous anatomy to be marked and marks the open space (24) on the skin (20) with the ink.

Abstract: A method and apparatus for adaptively enhancing a scanned ultrasound image of a body portion having both areas of tissue and areas of blood pool. Clutter which appears in the blood pool areas is removed by processing the image signal to generate a mask signal, which signal is substantially present in areas of tissue to pass such areas and is substantially not present in areas of blood pool to block such areas. The image signal is modulasted with the mask signal, preferably on a pixel-by-pixel basis, to substantially remove the clutter.

Abstract: A system for monitoring the application and removal of physical restraints such as straps that may be used to restrain a patient in an institution or other medical facility, and recording data relating to the application and removal of such restraints. The system includes one or more portable monitoring units, each of which can be used for any one patient at a time, with the system including as many monitoring units as are necessary for the facility that uses such physical restraints. The monitoring units provide an accurate record of the times and dates during which each application and removal of such restraints are carried out.

Abstract: A computer controls a video display having a display screen for displaying ECG heartbeats superimposed over one another. The ECG data is collected during Holter monitoring and stored in a memory. The Holter monitor preliminarily classifies each beat to a morphology. A representative sample of each morphology is presented in a display window. Each sample can be overlaid with any other selected sample, in different colors, in a compare window having an enlarged scale from the display windows. After comparison, different morphologies can be merged and a selected beat classification can be reclassified to another morphology.