Abstract: Methods and apparatus for constructing optically stabilized, shutterless infrared capnographs are disclosed. The capnographs of the present invention provide the absolute concentration of the constituents of the respiratory airstream of a patient, without the thermal drift problems normally associated with thermopile detectors, thereby providing a device with a high degree of accuracy. The present invention eliminates the need for a mechanical shutter to modulate the incident infrared beam and the need for a modulated source, thereby increasing the reliability and response time of the devices disclosed. Capnographs which are substantially unaffected by changes in the ambient temperature at which they operate are provided by connecting pairs of optically filtered thermopiles in series and processing the resulting differential pair. In addition, techniques are provided for selecting overlapping optical filters for use with thermopiles with a minimum level of cross-talk.

Abstract: A fiberoptic based sensor for patient care use. The sensor includes a catheter placed transcutaneously into a blood vessel which is connected to an external measuring head. A sensing tip of the catheter includes a pressure sensing element and an oxygen saturation measuring element. Features of the invention include novel tip designs, measuring head features, and approaches for enhancing measurement though correlation of the saturation and pressure readings.

Abstract: An apparatus and method for regulating tissue growth in vivo are provided. The apparatus includes a magnetic field generator and a magnetic field detector for producing a controlled, fluctuating, directionally oriented magnetic field parallel to a predetermined axis projecting through the target tissue. The field detector samples the magnetic flux density along the predetermined access and provides a signal to a microprocessor which determines the average value of the flux density. The applied magnetic field is oscillated at predetermined frequencies to maintain a preselected ratio of frequency to average flux density. This ratio is maintained by adjusting the frequency of the fluctuating magnetic field and/or by adjusting the intensity of the applied magnetic field as the composite magnetic flux density changes in response to changes in the local magnetic field to which the target tissue is subjected.

Abstract: A pulse oximeter of the present invention is to provide a greatly simplified in construction and a simplified procedure for performing arithmetic operations.

Abstract: The blood flow measuring apparatus comprises at least three electrodes, namely, a measuring electrode, reference electrode and an active neutral electrode, which are implanted at a predetermined tissue region. The signals of the measuring electrode and the reference electrode are delivered by input lines to a current and voltage isolated differential amplifier, the output of which is connected with a central unit controlling further instruments. What is important for the measuring accuracy of the blood flow measuring apparatus is an opposite feedback of external spurious fields which couple-in spurious potentials into the tissue and the shields of the input lines of the measuring electrode, reference electrode and neutral electrode. Further probes can be provided as an aid for the central unit.

Abstract: A method and apparatus for acquiring a magnetic resonance image representing a surface anatomy of an object, the method comprising the steps of setting a surface coil near the head of a subject, executing a predetermined pulse sequence for selecting magnetic resonance signals from protons inside the head, thereby applying a static magnetic field, gradient magnetic field, and a radio frequency pulse, detecting the magnetic resonance signals from protons by using the surface coil in accordance with the predetermined pulse sequence, reconstructing an image representing the brain surface anatomy of the subject utilizing the detected magnetic resonance signals, and displaying the image in gray scale so that the distribution of the protons is displayed in black level in proportion to the density thereof.

Abstract: A sensor placement and retention mechanism for use with fetal sensor sites beyond the user's reach are disclosed. The preferred embodiment of this invention is a fetal pulse oximetry sensor having an active face through which a light source and a light detector operate. The sensor includes a handle that facilitates placement of the active face at a sensor site in a preferred region beyond the transcervical region and beyond the reach of the user. A pair of electrodes--one disposed against the fetus' skin and one exposed to the amniotic fluid--are used to confirm that the sensor is firmly in place on the fetus. In an optional sensor retention feature, a self-inflating bladder presses the active face of the sensor against the fetus' skin to optically couple the sensor with the tissue at the sensor site.

Abstract: Devices are described which can be used to study the physiological function of the intestinal wall. These devices include an ultrasonic transducer that can be attached to a region of the intestinal wall. The transducer interrogates the wall and echoes are obtained from the different wall layers. The echoes are processed to produce an M-mode display of the wall. This allows monitoring how the wall changes with time. For example, as the wall contracts the muscle layer thickens and this action may be observed with the device. Other sensors and electrodes can be combined with this probe to correlate various physiological action. Finally, several such probes can be combined into a common introducible probe but which will monitor several regions along the intestinal wall. The major advantage of the disclosed device is that it provides a measurement of intestinal motility previously unattainable and it is introducible by endoscopy. This makes it a suitable tool for studying patient disease.

Abstract: A noise insensitive pulse transmittance oximeter (11) is disclosed. Two LEDs (21 and 23) are included in the pulse transmittance oximeter. The LEDs alternately emit a red light pulse and an infrared light pulse. A detector (13) detects corresponding red transmittance pulses and infrared transmittance pulses that are indicative of the amount of light transmitted through tissue having blood flowing therein. A microprocesser (29) determines the peak and valley values of the red transmittance pulses and infrared transmittance pulses over a cycle. The difference between the peak and valley values for the red transmittance pulses and infrared transmittance pulses are calculated by the microprocessor. The microprocessor generates control signals that vary the intensity of the LEDs until the differences between the peak and valley values of the red transmittance pulses and infrared transmittance pulses are substantially equal.

Abstract: Stimulated Raman spectroscopy is used to non-invasively measure the concentration of an Raman active molecule, preferably D-glucose in the ocular aqueous humor of living being. The apparatus and method make use of two monochromatic laser beams, a pump laser beam and a probe laser beam. The output power of the pump laser beam is amplitude modulated, combined with the probe laser beam and directed into the ocular aqueous humor. The introduction of the laser beams into the ocular aqueous humor induces scattered Raman radiation, which causes a portion of the energy at the pump frequency to shift over to the probe frequency. The pump and probe laser beams are then detected as they exit the ocular aqueous humor. The probe laser beam is filtered, converted into an electrical signal and amplified. It is then compared to the modulation signal to generate an electrical signal representative of the concentration of D-glucose in the ocular aqueous humor.

Abstract: An ultrasonic imaging and diagnosing device comprises a section to be inserted into the body cavity, an ultrasonic wave transmitting and receiving section located at the front end of the inserting section, a conductive hollow shaft arranged in the inserting section and connected to the ultrasonic wave transmitting and receiving section, a scanning device for scanning the body cavity while changing the direction of ultrasonic wave transmitted from the ultrasonic wave transmitting and receiving section, a circuit for receiving electric signals applied from the ultrasonic wave transmitting and receiving section, and a signal cable passed through the hollow shaft to connect the ultrasonic wave transmitting and receiving section to the signal receiving circuit. Both of an outer conductive line of the signal cable and the hollow shaft are connected to the common of the signal receiving circuit to prevent noises from entering into the signal cable.

Abstract: Apparatus for Measuring Stroke Volume/Cardiac Output includes a transducer for measuring arterial blood pressure waveform, a digitizer for digitizing the analog signal generated by the transducer and a digital signal processor for determining ejection time and heart rate. Processor circuitry determines cardiac output using the ejection time, heart rate, the body surface area and age of the patient, with the cardiac output measure being displayed by the meter.

Abstract: A method of detecting and recording action-potential-related fluorescent changes from a remote tissue situs which has been treated with a voltage-sensitivity dye. The method utilizes a single optical fiber to both direct excitation light to the remote tissue situs and receive emitted fluorescence from the remote tissue situs. The emitted fluorescence from the remote tissue situs is directed to a photomultiplier or photodiode which produces a resulting fluorescence-related signal which is analyzed. The method and related apparatus eliminates signal noise and allows accurate recording and analysis of action-potential-related fluorescent changes.

Abstract: An apparatus for imaging and displaying a blood stream state of an eye to be tested. A laser beam is first irradiated onto an eye to be tested. And light reflected from an irradiated area on the eye is detected and information about the reflected light is stored. And second, the bloodstream state of the eye are calculated on the basis of the information, the imaged results are displayed on a display means of the apparatus. At the same time, a pulse wave of a person to be tested is detected by a pulse wave detecting means, the wave shaped of the pulse wave is displayed by a display controlling means, which controls to display the measuring time and portion of the bloodstream state compositely on the present wave shape.

Abstract: In a process for continuous measurement of blood pressure, the mean blood essure is derived from the measured pulse wave duration. The other blood pressure parameters are obtained by combination with an optoelectrical determination of blood volume density in a typical manner at the ear lobes. An initial individual basic calibration of the blood pressure values is carried out by a conventional method. In addition, a continuous automatic optoelectronic post-calibration is carried out. The measuring sensors are preferably a pair of ear clips and ECG electrodes or a photoelectric sensor. The method can be used to particular advantage in prevention and diagnosis.

Abstract: Disclosed is an integrated lead frame pulse oximetry sensor which includes a thin metal lead frame to which is connected light emitting diodes and a photodiode chip for the purpose of emitting light and detecting light respectively. The thin metal frame is deformable to attach to perfused tissue. The lead frame has a very low mass which diminishes its acceptability to motion induced artifact.

Abstract: Neurological testing apparatus by which the sense receptor's of a person can be tested. The apparatus is of a configuration to be held in the hand and includes a body having a front surface opposed to a rear surface to provide ample space for supporting a plurality of spaced apart covered substances thereon. The substances are each different from the other and each substance test one of a person's sense receptors. One of the members include a sweet tasting substance, another member includes a sour tasting substance, and another member includes a substance fragrant to a person's smell. Other substances include color and indicia. A protective cover is removably placed on the substance for testing the smell and taste. The testing apparatus further includes a sharp end opposed to a disk end for testing a person'sense of feel and peripheral vision.

Abstract: A method for accentuating the differences in blood perfusion between normal and tumorous tissue is provided which comprises the steps of measuring the blood perfusion in a local area of the body, heating the local area, then measuring the blood perfusion for variations or inhomogenieties in blood perfusion after the local area has been subjected to heating. As a result of heating normal tissue will generally exhibit increased blood perfusion compared with its preheated condition and as compared with blood perfusion in tumorous tissue, rendering the tumorous tissue more susceptible to detection by techniques such as ultrasonic Doppler blood flow measurement. Apparatus for performing the inventive method is described, including an ultrasonic scanhead which includes a high intensity transducer for heating tissue to be scanned, and an array transducer for performing Doppler measurements of the tissue before and after it has been heated.

Abstract: A lithotripter (13), and a device for the localization of calculi (11), are mounted on radially moving slides attached to the supporting ring (10). In this manner, their longitudinal axes lie in the same diametric vertical plane, and pass through the center of the supporting ring. The angular distance between the longitudinal axes of the two devices is fixed, as determined by their mounting on the ring. An echograph, with its illustrated free floating probe (19), is interfaced with a computer. The origin of the echograph coordinate system corresponds to both the center of the rotating ring, and to the calculus (16), in the patient's body (14).

Abstract: An intrauterine pulse oximetry apparatus and method are provided to measure fetal blood oxygen saturation at sites in a preferred region on the fetus. The sensor of the apparatus is attached to a stiff cable which can be inserted into the uterus past the presenting part and transcervical region of the fetus. The cable may have visual and tactile markings by which the user, without seeing or feeling the sensor, can guide it to an appropriate site on the fetus.