Abstract: An automatic blood pressure measuring system employs an oscillometric method, a cuff applying pressure to an arterial vessel and then gradually reducing the pressure. On a distal side of the cuff, as seen from the heart of the subject, a pulse wave sensor presses against a distal section of the vessel. If the pulse wave sensor detects a pulse wave from the distal section of the vessel after the force applied by the cuff reaches a first target value, indicating that the initial pressure was insufficiently low, the force is increased to a second target value. After determining a relationship between the blood pressure and the magnitude of the pulse wave detected by the pulse wave sensor, blood pressure can be monitored by the pulse wave sensor.

Abstract: A non-invasive aortic blood flow sensor is disclosed. The sensor determines the blood flow in the aorta of a patient based on the pressure difference between the right and left subclavian arteries. The pressure of the subclavian arteries is non-invasively measured by determining the blood pressures in the arteries of the patient's right and left arms by means of tonometric blood pressure sensors. The signals from the tonometric sensors are first equalized to account for any pressure waveform distortion due to propagation of the pulse from the aorta to the sensor locations. Next, a correction is made for DC offset. The modified pressure signals are then compared, and the pressure difference determined. The blood flow is determined from the pressure difference by known pressure/flow relationships.

Abstract: A blood pressure monitor system, including a pulse wave detecting device detecting a pulse wave produced from an artery of a living subject, a blood pressure measuring device including a pressing device, for measuring a blood pressure of the subject by pressing a body portion of the subject with the pressing device, a relationship determining device determining a relationship between blood pressure and pulse wave magnitude, based on a pulse wave magnitude detected by the pulse wave detecting device and a blood pressure value measured by the blood pressure measuring device, a blood pressure monitor device continuously determining, according to the relationship, blood pressure values of the subject based on magnitudes of the pulse wave detected by the pulse wave detecting device, the relationship determining device updating the relationship at intervals of time, based on blood pressure values measured by the blood pressure measuring device, a blood pressure variation determining device determining a variation o

Abstract: An improved pressure sensor element and pressure sensor array is formed by a cathode layer, a cathode tip attached to the cathode layer, and an anode layer opposing the cathode layer. The magnitude of the electron current flowing between the cathode tip and the anode layer is dependant on the field strength at the cathode tip, which is dependant on the separation between the cathode tip and the anode layer. As a deflectable anode layer is deflected towards the cathode tip, the field strength increases, causing a corresponding change in the magnitude of the flow of electrons. The cathode tip is separated from the anode layer such that electron current is produced at relatively low voltages by tunneling or field emission. The exact method of current production is selected by controlling the initial separation between the anode layer and the cathode tip.

Abstract: A method and apparatus for arrhythmia detection comprise steps and means for acquiring at least one continuous analog signal produced by an ECG system, producing at least one digital signal based on the analog signal, producing a plurality of scalar signals from the at least one digital signal, extracting features from the scalar signal, and plotting the extracted features in a feature space having a number of dimensions equal to the number of extracted features. A normal QRS complex is identified based on the population of QRS complexes located within clusters of QRS features within the feature space. Subsequent QRS complexes acquired after identification of the normal QRS complex are labeled based on a plurality of rules and the location of each subsequent QRS complex with respect to both prior and subsequent normal QRS complexes.

Abstract: A pressure pulse wave transmitting sheet for being interposed between a skin surface of a living subject such as a patient and a pressure pulse wave sensor set on the skin surface in pressed contact therewith, the sensor having a press surface in which at least one pressure sensing element is provided and which is pressed against the skin surface so that the at least one pressure sensing element detects a pressure pulse wave transmitted from an artery of the subject underlying the skin surface, to the press surface via the sheet, the sheet being formed of an elastic material having a hardness substantially equal to a hardness of human being's skin.

Abstract: An oscillometric-type automatic blood pressure measuring apparatus, including a pressure device such as a cuff, an oscillometric-type blood pressure measuring device for (a) occluding an artery of a patient by increasing the cuff pressure, (b) detecting a first pulse wave transmitted from the artery to the cuff by reducing the increased cuff pressure, and (c) determining a first systolic blood pressure of the patient based on variation in amplitude of successive pulses of the first pulse wave, a display for indicating the determined first systolic blood pressure, a detecting device disposed downstream of the cuff, for detecting a second pulse wave produced from a portion of the artery located downstream of the cuff, a first determining device for determining, as an initial-pulse detection pressure, a cuff pressure at the time of detection of an initial pulse of the second pulse wave after the commencement of reduction of the cuff pressure in each of periodic measurement cycles, a second determining device for

Abstract: A blood pressure monitor system for monitoring blood pressure of a living subject, including a pulse wave detecting device detecting a first pulse wave produced from an artery of the subject via a body surface of the subject over the artery, an inflatable cuff pressing a body portion of the subject, a blood pressure measuring device measuring a systolic and a mean blood pressure of the subject, based on variation in amplitude of pulses of a second pulse wave transmitted to the cuff by changing a pressure in the cuff, and a blood pressure determining device determining a relationship between blood pressure and pulse wave magnitude, based on the systolic and mean blood pressure values measured by the blood pressure measuring device and an upper-peak magnitude and a mean magnitude of the first pulse wave detected by the pulse wave detecting device, and continuously determining, according to the relationship, blood pressure values of the subject based on magnitudes of the first pulse wave detected by the pulse wa

Abstract: A blood pressure monitor system including a pressing device for pressing a body portion of a subject, a measuring device for increasing the pressing force of the pressing device to a predetermined level, subsequently varying the pressing force, and measuring a blood pressure of the subject during the variation of the pressing force, the measuring device repeating the blood pressure measurement, a setting device for setting a frequency at which the measuring device repeats the blood pressure measurement, and a changing device for changing a rate of increase of the pressing force depending upon the measurement frequency set by the setting device.

Abstract: A pulse rate sensor system is packaged in a wristwatch sized assembly and is worn by the user to provide an accurate determination of pulse rate. A tonometer sensor is provided to detect heartbeat pressure waves produced by a superficial artery. A microcomputer manipulates the unprocessed tonometer sensor element signals using multiple algorithms to determine an accurate pulse rate.

Abstract: A blood pressure measure system for iteratively measuring a blood pressure of a living subject at predetermined intervals of time, the monitor system including a pressing device pressing a body portion of the subject; a regulating device regulating the pressing force of the pressing device; a blood pressure measuring device iteratively measuring at least a systolic blood pressure of the subject at the intervals of time, each of the iterative blood pressure measurements being effected when the pressing force of the pressing device is decreased at a predetermined rate by the regulating device; a pulse rate measuring device measuring, as a pulse rate, a pulse number per unit time of the subject; a first determining device determining, by utilizing the pulse rate, a pressing force increase amount such that as the pulse rate is increased the increase amount is decreased; and a second determining device determining a target pressing force to be greater by the increase amount than a systolic blood pressure measured

Abstract: An apparatus for detecting a pressure pulse wave produced from an artery of a living subject, including a first press member having a first press surface, a pressure sensing device supported by the first press surface, a second press member having a second press surface surrounding the first press surface, a pressing device pressing the first and second press members toward a body surface of the subject so that the first press surface is pressed against the artery via the body surface, the pressure sensing device generating an electric signal representing the pressure pulse wave produced from the artery and transmitted thereto via the body surface, the first and second press members being displaceable relative to each other in a direction in which the first and second press members are pressed by the pressing device, an actuating device displacing the first press member relative to the second press member so that the first press surface is advanced outward from the second press surface, and a determining devi

Abstract: A probe protector for protecting a heartbeat-synchronous pulse wave detecting probe set on a limb of a living subject, from contacting a medical staff attending to the subject on the side of the limb, the limb being supported on a support member having a side surface, the protector including (a) a flat portion adapted to be inserted between the support member, and a part of the limb on which part the detecting probe is set, the flat portion having a pair of opposite ends, (b) a protect portion extending from one of the opposite ends of the flat portion in a direction away from the flat portion, the protect portion protecting the detecting probe from contacting the medical staff, and (c) a stop portion extending from the one end of the flat portion in a direction opposite to the direction in which the protect portion extends, the stop portion being adapted to engage the side surface of the support member when the medical staff contacts the protect portion, so that the probe protector is prevented from being di

Abstract: A probe for a reflection-type oxymeter which measures a blood oxygen saturation of a subject, the probe including a light emit device emitting at least two lights having different wavelengths toward a body portion of the subject, a light detect device detecting the lights reflected by the body portion of the subject, a housing supporting the light emit and detect devices, and an elastic member secured to the housing, the elastic member including an adhesive portion, the adhesive portion being spaced from the body portion of the subject with the housing contacting the body portion, the adhesive portion being elastically deformed and adhered to the body portion so that the housing is pressed against the body portion with a pressing force within a predetermined range due to an elastic return force of the deformed adhesive portion.

Abstract: A noninvasive optical oximeter measures oxygen saturation of arterial blood. A patient's arterial blood is illuminated with light at two different wavelengths and the intensity of the reflected light is sensed by a photodetector and an output signal is created in response thereto. The output signal is processed to form a ratio representing the AC component of the reflected light at each wavelength over the DC component. The oxygen saturation of the blood is calculated by correlating the quotient of these ratios with an oxygen reference curve uniquely representative of the blood oxygen characteristics of a particular patient. The pulse amplitude signals for the AC component at each wavelength are compensated for the effects of upward or downward trends and, therefore, the accuracy of the blood oxygen saturation calculation is significantly increased.

Abstract: A noninvasive oximeter sensor for controlling and optimizing the minimum detection depth in the tissue of a patient is disclosed. In general, a minimum detection depth of 0.35 mm in the skin is considered optimum. The reflectance oximeter sensor component configuration of the present invention achieves the minimum detection depth. The present invention offers a more accurate indication of blood oxygen saturation in a patient's arterial blood than was available from previous reflectance oximeter sensors.

Abstract: An apparatus for detecting a state of peripheral blood circulation of a subject, including a transmission type blood oxygen saturation measuring device emitting a plurality of lights having different wavelengths toward a subject, producing a photoelectric pulse wave signal indicative of intensity of each of the lights transmitted through the subject, and determining a first blood oxygen saturation by using the pulse wave signals corresponding to the transmitted lights; a reflection type blood oxygen saturation measuring device emitting a plurality of lights having different wavelengths toward the subject, producing a photoelectric pulse wave signal indicative of intensity of each of the lights reflected from the subject, and determining a second blood oxygen saturation by using the pulse wave signals corresponding to the reflected lights; and a determining device determining a state of peripheral blood circulation of the subject by utilizing a difference between the first and second blood oxygen saturations.

Abstract: A pulse wave sensor for detecting a pressure pulse wave produced from an arterial vessel of a living subject in synchronism with heartbeat of the subject, the sensor having a press surface adapted to be pressed on a body surface of the subject over the arterial vessel, the sensor including (a) a protruding portion protruding from the press surface, the protruding portion having a top surface adapted to be pressed on the body surface of the subject, (b) a sensing device provided in the top surface of the protruding portion, for detecting the pressure pulse wave from the arterial vessel via the body surface, and (c) a sheet spring provided around the protruding portion and having a height generally equal to, or greater than, a height of the protruding portion as measured from the press surface, the sheet spring being deflectable in a direction in which the top surface of the protruding portion is pressed on the body surface.