Abstract: Arrangements are disclosed for producing images based upon diffusional wave theory and frequency domain analysis. A medium to be imaged is illuminated with amplitude modulated radiation, and diffusional radiation transmitted or reflected by the medium is detected at a plurality of detection locations, as by a television camera. The phase and also the amplitude demodulation of the amplitude modulated diffusional radiation is detected at each detection location. A relative phase image and also a demodulation amplitude image of the medium are then generated from respectively the detected relative phase values and the detected demodulation amplitudes of the diffusional radiation at the plurality of locations. The present invention is particularly suited for medical applications for generating images of internal anatomical details of the body by using a near infrared amplitude modulated source for illumination of the body.

Abstract: An apparatus for use in measuring the chemical constituents of a patient's breath, such as CO.sub.2, O.sub.2 or the like in the form of an airway adapter having opposed circular ends for installation in a patient's ventilation tubing, the adapter having an intermediate portion, a window formed in the intermediate portion of the type, such as of sapphire, to permit light of the required frequency to pass therethrough, and a mirror within the adapter immediate portion opposite of the window and arranged so that at least a portion of the patient's ventilation gases pass between the mirror and the window so that light may be directed through the window and received back therefrom as reflected from the mirror to permit an analysis of the absorption of light by the patient's breath for determination of the constituents of the patient's breath.

Abstract: A technique is disclosed for the detection of cancer using nuclear magnetic resonance (NMR). Specifically, NMR parameters for protons of lipid methyl and/or methylene groups are determined and compared against a corresponding value for healthy patients. In the preferred embodiments, an NMR spectrometer is employed in conjunction with a Fourier transformer to provide a spectrum for non-water components of blood, blood serum or blood plasma and the width of the methyl and/or methylene groups is measured at half-height as a determination of spin-spin relaxation time (T.sub.2) which is the parameter used for purposes of comparison with healthy controls. Suppression of the water proton signal is employed where necessary in order to obtain a suitable spectrum for the non-water component protons.

Abstract: An ultrasound examination system, including an ultrasound probe detachably connected at its proximal end to a probe operating unit and having an ultrasound transducer rotatably mounted on the tip end of a flexible insert member and a rotation transmitting means passed through the insert member to rotate the ultrasound transducer. The probe operating unit is provided with a linear operating means for displacing the ultrasound transducer linearly for a linear scan, and a radial operating unit for rotating the ultrasound transducer for a radial scan, in combination with a mode selector means for switching the operation of the ultrasound transducer between linear scan mode in which the transducer is displaced linearly during transmission and reception of ultrasound signals and a radial scan mode in which the transducer is rotated during transmission and reception of ultrasound signals.

Abstract: A method of and apparatus for controlling one or more parameters of an electrical stimulation generator in response to measured results of the stimulation. In the preferred mode, this technique is employed in a system for the treatment of obstructive sleep apnea. Sensors are used to determine the effectiveness of the stimulation. Amplitude and pulse width are modified in response to the measurements from the sensors.

Abstract: Disclosed is a system and a method for computer-supported analysis of arrhythmic potentials in ECG signals, particularly those of late potentials. Interference discrimination advantages of frequency domain analysis are combined with temporal localization advantages of time domain analysis to determine the accurate location of arrhythmic potentials. Several small signal segments are selected in an ECG waveform. A determination is made of parameters corresponding to extended signals which closely match fluctuations of each respective small signal, allowing more information is discerned about the small signals than is possible with more conventional techniques. A comparison is made with respect to extended signals rather than small signals. Two autoregressive models are used, the maximum entropy method and adaptive filter determination. Area integrals of the frequency characteristics of small signal segments are recorded successively with respect to the frequency range of the arrhythmic potentials analyzed.

Abstract: An implantable atrial defibrillator provides cardioverting electrical energy to the atria of a human heart in need of cardioversion. The atrial defibrillator includes a first detector for detecting ventricular activations of the heart, a second detector for detecting atrial activity of the heart, and an atrial fibrillation detector responsive to the second detector for determining when the atria of the heart are in need of cardioversion. The atrial defibrillator also includes a cardioverting stage for applying the cardioverting electrical energy to the atria of the heart when the atria of the heart are in need of cardioversion and when the time between immediately successive ventricular activations is greater than a preselected minimum time interval.

Abstract: An ultrasonic transesophageal scanhead is provided which enables a physician to easily and quickly change the orientation of the image plane during a scanning procedure. Means are provided on either the scanhead or the ultrasound system for selecting the imaging plane. As the imaging plane selector is actuated, an indication of the orientation of the selected plane appears concurrently on the monitor of the system along with a display of ultrasonic information of the selected plane. In a preferred embodiment the indication of the selected plane is displayed both graphically and numerically. A recording of the displayed information will thus capture both the ultrasonic information as well as the image plane orientation. A physician reviewing the recording will thereby know the exact orientation of the image being viewed, leading to a better informed and more precise diagnosis of medical conditions of the body.

Abstract: A multipurpose medical stimulating electrode is described for use in external cardiac pacing, Transcutaneous Electrical Nerve Stimulation and neuromuscular stimulation which includes a protective cover layer at the top extending over and bonded to the upper surface of an electrically conductive layer, e.g. carbon filled silicone rubber having a resistivity of about 100 ohm centimeters on the lower surface of which is coated a selfsupporting skin contacting hydrogel layer comprising a matrix having a sticky surface adapted to make a good electrical contact with the skin and having a resistivity of greater than 1,000 and less than 10,000 ohm centimeters. The matrix is composed of natural or synthetic hydrocolloid, e.g. polyacrylamide, and/or natural gum such as karaya gum, water and a humectant comprising a polyhydric alcohol and optionally with Mg(OAc).sub.2 as a gelation inhibitor and electrolyte.

Abstract: In conjunction with a medical device for stimulating the vagus nerve of a patient to modulate the electrical activity thereof as part of a prescribed therapy, apparatus is provided to selectively suppress the stimulation while the patient is speaking, to avoid undesirable modulation of the voice. The suppression apparatus includes a speech sensor and discriminator, to detect speech by the patient while avoiding false detection attributable to sounds other than speech. The suppression of nerve stimulation is ceased after a preset time interval regardless of continued detection of speech, to assure that beneficial therapy is not unduly inhibited in favor of mere cosmetic considerations or in the presence of prolonged false detections.

Abstract: An implantable cardioverter capable of delivering pacing and cardioversion level therapies. The device distinguishes between stable and unstable ventricular tachyarrhythmias by monitoring the progression of atrial cycle lengths during the detected ventricular tachyarrhythmia. A detected increase in atrial cycle lengths during the early stages of the detected ventricular tachycardia is taken as an indication of hemodynamically unstable ventricular tachycardia.

Abstract: A subcutaneous data port which may be surgically implanted beneath the skin of a subject and electrically connected to implanted leads, sensors or an implanted medica device. The data port provides electrical connections through conductive rubber access ports. The access ports can be penetrated by a coated needle, establishing an electrical connection. An indifferent plate electrode provides a replicable ground or body reference electrode.

Abstract: An optimized dose delivery system using computer graphics simulation techniques and computerized numerical optimization. A volume, such as a tumor volume, is graphically simulated and meshed with node points. The dose delivery is calculated depending upon input variables, deriving an objective function related to dose efficacy. A numerical optimization algorithm optimizes the input variables based upon such objective function.

Abstract: Implantable electrodes for defibrillation are formed of pluralities of electrode segments. Each of the segments is relatively long and narrow. The electrode segments can be parallel and spaced apart from one another a distance at least ten times the nominal width, with one end of each segment mounted to a transverse distal portion of an electrically conductive lead coupling the electrode to a defibrillation pulse generator. Alternatively, segments can branch or radiate outwardly from a common junction. In yet another arrangement, electrode segments are portions of a single conductive path at the distal end of a lead from a pulse generator, arranged in either a spiral configuration or a serpentine configuration which can align electrode segments side by side, parallel and spaced apart.

Abstract: A method for preventing restenosis after angioplasty comprises internally radiating the treated portion of the lumen to prevent restenosis of the enlarged lumen portion. A device useful for radiating the treated portion comprises an elongated flexible catheter with radioactive means located in a distal section of the carrier. Stiffening elements are located along the length of the catheter to enable the catheter to be pushed through the tortuous segments of coronary or peripheral vasculature without crimping.

Abstract: A method and apparatus for stimulating the right and/or left carotid sinus nerves or the right stellate ganglion or the epidural space at about T.sub.2 with continuous and/or phasic electrical pulses in response to detected myocardial ischemia to decrease cardiac workload as a method to protect the myocardium. The automatic detection of the need for such stimulation is responsive to a change in ST segment variation different from a predetermined or programmed threshold suggesting acute myocardial ischemia and/or other criteria or indicators of myocardial ischemia, including changes if pH and/or oxygen saturation (SO.sub.2) detected from a sensor located in the heart, preferably the coronary sinus.

Abstract: Tympanic temperature measurements are obtained from the output of a thermopile mounted in an extension from a housing. The housing has a temperature display thereon and supports the electronics for responding to sensed radiation. The thermopile is mounted in a highly conductive can which includes a radiation guide and thermal mass. The guide provides a narrow field of view due to a fairly high emissivity. Electronics determine the target temperature as a function of the temperature of the hot junction of the thermopile determined from the cold junction temperature and a thermopile coefficient. The tympanic temperature is adjusted to provide an indication of core temperature.

Abstract: An esophageal-stomach displacement electrode comprises a flexible tubular member designed to be inserted through the esophagus into the stomach. An electrode is carried by the tube in the region of its distal end. The tube is hinged near the distal end which enables that end of the tube to displace angularly in the stomach and displace the stomach wall. The stomach wall displacement may occur by angularly displacing the distal end or by otherwise pulling the tube partially out of the esophagus after its distal end partially displaced toward the stomach wall. A displacement mechanism is disposed in the tube in the region of the hinge and is controlled from a point externally of the body for causing the distal end of the tube to displace angularly, and to be positioned to engage and displace the stomach.

Abstract: There is provided a system and method for enhancing collateral blood flow to the heart of a patient having angina with otherwise normal cardiac function. Skeletal muscle from the patient is attachd to the left ventricle, and stimulated with both chronic and acute stimulation to provide chronic long-term collateral blood flow and increased acute collateral blood flow during periods of exercise or times when angina is at greater risk. The stimulation system includes a sensor for determining cardiac demand and/or for sensing natural heartbeats, and processing circuitry for acutely increasing stimulation of the skeletal muscle in response to the sensor or natural rate. The system is further provided with internal clock means for causing cessation of delivery of stimulus pulses during periods of low activity, and external programming means for programming changes in either chronic or acute stimulation.

Abstract: A thin layer of a drug in a liquid form in a carrier is applied to the skin. Thereafter, 15-30 milliamps of a D.C. current is applied to the skin and drug by an iontophoresis device capable of being hand held and activated by thumb contact with a positive electrode and scalp skin contact with a negative electrode. The device has a two component housing enclosing an electrical circuit connecting the two electrodes. The circuit utilizes a 9 V battery, two load regulators, two capacitors, a momentary switch and a 2V-40V output range DC/DC converter. Alternatively, negative electrodes of varying structure can be plugged into the device to provide multi-purpose application to the scalp and the positive electrode can be separately plugged to the device to free the hand of the treating technician.