Abstract: A method of measurement of arterial diastolic blood pressure includes generating first and second signals indicative, respectively, of cardiac induced pulsatile variations in tissue blood volume in a first region and a second region of the subject's body. These signals are then processed to derive values of a delay between pulses in the first signal and corresponding pulses in second signal. A baseline value of the delay is evaluated, preferably in the absence of externally applied pressure. A variable pressure is applied to a third region of the subject's body so as to affect blood flow through at least one artery in the third region, the variable pressure being varied as a function of time. The first, second and third regions of the subject's body are chosen such that the delay varies as a function of the variable pressure. The diastolic pressure is then identified as a value of the variable pressure corresponding to a predefined non-zero value of the delay measured relative to the baseline value.

Abstract: The invention relates to a sphygmomanometer capable of highly accurately judging the maximum blood pressure and minimum blood pressure, which has a cuff 10 which is attached to an appointed portion of a patient and presses the artery by supplying air therein; an optical range sensor 12 which is located opposite said cuff 10 and is able to detect the pulsation displacement of said artery; a digital processing section 14 which is able to judge the maximum and minimum blood pressure of said patient on the basis of photoelectric volumetric pulse wave signals sent out by said optical range sensor 12; and a display section 38 which is able to display the maximum and minimum blood pressure values judged by said digital data processing section 14.

Abstract: A blood pressure measuring apparatus including an inflatable cuff which is adapted to be wound around a body portion of a living subject, an air pump which supplies a pressurized air to the cuff to inflate the cuff and thereby increase an air pressure in the cuff, so that the cuff presses the body portion of the subject, an air tank which is connected to the air pump, an air restrictor which is provided between the air tank and the cuff, a deflation-control valve which is provided between the restrictor and the cuff to control an amount of discharging of the pressurized air from the cuff and thereby control deflation of the cuff, a control device which controls the air pump to supply the pressurized air to the cuff while controlling the deflation-control valve to discharge a controlled amount of the pressurized air therethrough from the cuff, so as to increase the pressure of the cuff linearly at a predetermined first rate, and a measuring device which measures at least one blood pressure value of the subject

Abstract: An apparatus for successively estimating an intraarterial blood pressure of a living subject, based on information non-invasively obtained from a circulatory organ of the subject, including: a first device for non-invasively obtaining, from the circulatory organ of the subject, first information which relates to velocity of propagation of a pulse wave which propagates through an artery of the subject; a second device for non-invasively obtaining, from the circulatory organ of the subject, at least one of second information which relates to heart rate of the subject and third information which relates to an area defined by a volume pulse wave from a peripheral portion of the subject; and a third device for estimating, according to a predetermined relationship between (A) blood pressure, and (B1) first information and (B2) at least one of (B21) second information and (B22) third information, the intraarterial blood pressure of the subject, based on the first information obtained by the first device and the at l

Abstract: An oscillometric type electronic sphygmomanometer for determining the systolic and the diastolic blood pressure on the basis of a peak formed by the variance in the pulse wave amplitude, wherein the systolic and the diastolic blood pressure are provisionally determined on the basis of the curve of the varying pulse wave amplitude which forms the first peak, when the provisionally determined diastolic blood pressure is higher than a preset value, the pulse wave amplitude continues to be detected and monitored until the cuff pressure decreases below the provisionally determined diastolic blood pressure by a predetermined pressure, and when the pulse wave amplitude detected while being monitored is equal to or higher than the said maximum pulse wave amplitude value, the pulse wave amplitude continues to be further detected so as for a new maximum pulse wave amplitude to be obtained, thereby determining at least the diastolic blood pressure on the basis of the curve of the varying pulse wave amplitude, which has

Abstract: A method and apparatus is provided for distinguishing blood pressure sounds from noise in an automatic blood pressure monitoring system using the information contained in two microphone signals. Two microphones are placed on a patient along an axis of an artery to pick up blood pressure sounds. Pressure is applied to the artery such that the artery opens and closes during each heart cycle, the opening snap of the artery producing a blood pressure sound. The two microphone signals are sampled, filtered, and multiplied together to produce a microphone signal product. The microphone signal product is wave width filtered to remove therefrom portions of the signal having a wave width which is less than a selected minimum wave width value. A blood pressure sound is indicated as being detected when an amplitude of this wave width filtered microphone signal product exceeds a noise signal threshold level.

Abstract: A blood pressure measuring system includes a transducer having first and second sensors adapted to be mounted above the artery of a patient with the second sensor more distal relative to the direction of blood flow than the first sensor. A processor digitizes the signals from the first and second sensors and determines when the second signal is phase shifted about 90 degrees relative to the first signal for determining the occurrence of the Korotkoff sound. The transducer comprises a film of a material having piezoelectric properties and at least two spaced apart electrodes on one surface of the film and a third electrode on the opposite side and opposed to the two electrodes.

Abstract: A physical information monitor system comprising: (a) physical information obtaining means for successively obtaining physical information values of a living subject; (b) moving average calculating means for continuously calculating a moving average of the physical information values successively obtained by the physical information obtaining means; (c) reference range determining means for determining a reference range on the basis of the moving average calculated by the moving average calculating means; and (d) abnormality determining means for determining whether one of the physical information values which is currently obtained by the physical information obtaining means is abnormal, the abnormality determining means generating an abnormality signal when the currently obtained physical information value is outside the reference range.

Abstract: A system and method evaluates the autonomic nervous system of a living subject based on the high frequency components present in the fluctuations of the living subject's pulse cycle and on the low frequency components present in the fluctuations of the living subject's blood pressure. The autonomic nervous system evaluation system includes an electrocardiographic waveform determiner that detects an electrocardiographic waveform of the living subject. A pulse cycle determining circuit determines a pulse cycle of the living subject based on the electrocardiographic waveform. A blood pressure estimating circuit estimates the living subject's blood pressure based on time differences between predetermined periodic points on the electrocardiographic waveform and predetermined periodic points on corresponding pulse waves.

Abstract: A blood pressure monitor kit suitable for use in emergency scenarios such as cardiopulmonary arrest situations. The kit includes a catheter for insertion in the femoral artery of the patient, a transducer arranged to receive blood pressure signals from the catheter and operative to convert the blood pressure signals into electric signals; a housing; a monitor mounted in the housing and including electric circuitry arranged to receive the electric signals from the transducer and operative to generate at least one display indicative of a condition of the patient's blood pressure; a battery positioned within the housing and operative to power the electric circuitry; a switch associated with the housing for connecting the battery into the electrical circuitry to power the circuitry; and a securement device on the housing operative to secure the housing to a patient's body at a location proximate the location of the catheter insertion.

Abstract: A data playback device which records, stores, and plays back actual patient oscillometric blood pressure data to create a more realistic NIBP simulation for testing of an NIBP monitor. The system is made up of two units, a computer and a converter. The converter has a Universal Asynchronous Receiver/Transmitter (UART) connected to the computer and 16-bit D/A and A/D converters connected to the input and output, respectively, of a blood pressure monitor. The A/D converter senses cuff pressure and sends the signal to the computer. The computer then calculates the pressure pulse data from the stored patient data and sends it to the monitor via the D/A converter, where the pressure pulse data is converted to a voltage and electronically summed with the pressure transducer signal output by the blood pressure monitor under test.

Abstract: This invention considers the problem with inflation of the units by hands, and introduces a dual action inflation unit to be used for measurement of the blood pressure cuff and similar units such as D. Devices. The prototype of this unit consists of an electrical/pedal pumps combined with a manual inflation units. This will allow the electrical/pedal pumps to be used first for inflation of most of the inflatable part and then the manual unit will be used for a lesser degree of inflation as well as the adjustment of the inflation units. This combination is to prevent straining of the hands. It will also allow quick and easy action. This unit also allows a trigger system to be used for controlling the pressure in the system to prevent from the discomfort of the rotational action; it also has safety valves to prevent the pressure from exceeding a predicted level.

Abstract: A blood pressure monitor apparatus including a blood pressure measuring device which includes a cuff and measures a blood pressure value of the subject by changing a pressing pressure of the cuff, a volume pulse wave detecting device which detects a volume pulse wave of the subject, a normalized pulse-wave area calculating device for successively calculating an area which is defined by a waveform of each of heartbeat-synchronous pulses of the volume pulse wave and is normalized based on a period and an amplitude of the each pulse of the volume pulse wave, a pulse wave area-blood pressure relationship determining device for determining a relationship between pulse-wave area and blood pressure, based on a normalized pulse-wave area value and a blood pressure value, when the blood pressure value is measured; and a monitor blood pressure determining device for successively determining a monitor blood-pressure value of the subject, based on each of normalized pulse-wave area values, according to the pulse wave are

Abstract: When it is judged by a blood-pressure-abnormality judging means that a first blood pressure value determined by a first blood pressure determining means, based on a pulse-synchronous signal produced while a pressure of a cuff is slowly increased, is abnormal, a second blood pressure value is determined by a second blood pressure determining means without needing another first blood pressure value determination. Thus, it is possible to eliminate the time necessary for decreasing and re-increasing the pressure of the cuff, thereby reducing the discomfort of the patient. Additionally, since the present blood pressure measuring apparatus can measure a second blood pressure value relatively speedily, it does not need a device for removing noise from the signal.

Abstract: A blood pressure monitoring apparatus which reduces the effects of respiration artifacts in the blood pressure samples prior to display by determining, for each heart beat detected in the blood pressure samples, the blood pressure at a median point of a line connecting a systolic, diastolic, or mean value for a current heart beat with a corresponding systolic, diastolic, or mean value for a heart beat N-1 heart beats prior to the current heart beat. The median blood pressure value for the current heart beat is then averaged with the blood pressure values of the median points of numerous previous heart beats to the current heart beat, and the resulting average is output to the display as indicative of the systolic, diastolic, or mean pressure for the current heart beat. This process is repeated for each heart beat, as desired, until the systolic, diastolic, and mean pressures are determined for each heart beat.

Abstract: Method and device for determining a proximal arterial blood pressure waveform in a person, starting from a distally measured arterial pressure waveform, by first applying age-dependent waveform filtering to the distal pressure waveform, in order to obtain the proximal pressure waveform with mutually correct systolic, diastolic and mean pressure levels, and by then shifting the filtered pressure waveform by means of calibration to the correct proximal pressure level, for example by calibration of one level of the filtered systolic, diastolic or mean pressure levels with the corresponding proximal pressure level. This can be a single noninvasively measured systolic or diastolic or mean pressure level. The age for the purpose of the age-dependent waveform filtering is derived from the distally measured pressure waveform, for example by means of a trained neural network.

Abstract: An apparatus for measuring a propagation velocity of a pulse wave which is propagated through an artery of a living subject, includes an electrocardiographic-waveform detecting device which detects an electrocardiographic waveform from the subject, a pulse-wave sensor which is adapted to be worn on the subject and which detects the pulse wave from the subject, a time-difference determining device for determining a time difference between a first periodic point relating to the detected electrocardiographic waveform and a second periodic point relating to the detected pulse wave, and a propagation-velocity determining device for determining the propagation velocity of the pulse wave based on the determined time difference.