Nihon Kohden Corporation

Takeshi Sohma

Yoshihiro Sugo

Rie Tanaka

Wenxi Chen

Hiromitsu Kasuya

Ryoichi Ochiai

Kohei Ono

Hidehiro Hosaka

Hiroshi Sakata

Shigeru Aso

A pacing-pulse detecting circuit,detects pacing pulses from an electrocardiogram signal led from an electrocardiogram electrode,A mode-status judging means,judges a mode status, a pacing mode or a nonpacing mode, on the basis of the pacing pulse detected. The detect result is transmitted to a CPU,The CPU,causes a display device,to display the result. An operator sees the display and operates a key,and gives an instruction to start a blood pressure measurement to the CPU,The CPU,drives a pump,and an exhaust valve,to supply and discharge air to and from a cuff,and measures a blood pressure by use of pressure data led from a pressure sensor

Patient monitoring apparatus

An apparatus for non-invasion heart monitoring includes electrocardiogram measuring means (1) for measuring electrocardiograms, pulse wave measuring means (2) for measuring pulse waves, and a CPU (30) for processing electrocardiogram signals derived from the electrocardiogram measuring means (1) and pulse wave signals derived from the pulse-wave measuring means (2). The CPU (30) detects the amplitudes of the pulse waves corresponding to the R waves of the cardiogram and the pulse wave propagation times, and computes a ratio (Nr/N) of the heart rate N and the heart rate Nr exclusive of the heart beats of wave deficits.

Non-invasive heart monitoring apparatus and method

A pacing-pulse detecting circuit 3 detects pacing pulses from an electrocardiogram signal led from an electrocardiogram electrode 1. A mode-status judging means 21 judges a mode status, a pacing mode or a nonpacing mode, on the basis of the pacing pulse detected. The detect result is transmitted to a CPU 5. The CPU 5 causes a display device 10 to display the result. An operator sees the display and operates a key 22, and gives an instruction to start a blood pressure measurement to the CPU 5. The CPU 5 drives a pump 13 and an exhaust valve 14 to supply and discharge air to and from a cuff 11, and measures a blood pressure by use of pressure data led from a pressure sensor 15.

A pulse wave propagation time is counted constantly. Not only it is judged whether or not a pulse wave propagation time change .DELTA.T exceeds a pulse wave propagation time change threshold .DELTA.Ts, but also it is judged whether or not cardiovascular dynamic changes .DELTA.HR, r.sub.1, r.sub.2 exceed thresholds thereof .DELTA.HRs, r.sub.1 s, r.sub.2 s, whereby a sudden turn for the worse in the blood pressure fluctuation of a subject is monitored. If any one of the changes exceeds the threshold thereof, a blood pressure measurement using a cuff 2 is made on the subject.

Blood pressure monitoring apparatus

A pacing-pulse detecting circuit 3 detects pacing pulses from an electrocardiogram signal led from an electrocardiogram electrode 1. A mode-status judging means 21 judges a mode status, a pacing mode or a nonpacing mode, on the basis of the pacing pulse detected. The detect result is transmitted to a CPU 5. The CPU causes a display device 10 to display the result. An operator sees the display and operates a key 22, and gives an instruction to start a blood pressure measurement to the CPU 5. The CPU 5 drives a pump 13 and an exhaust valve 14 to supply and discharge air to and from a cuff 11, and measures a blood pressure by use of pressure data led from a pressure sensor 15.

An electrocardiogram signal derived from electrocardiogram measuring means 1 and a pulse signal derived from pulse-wave measuring means 2 are applied to a CPU 30. The CPU 30 processes the cardiogram signal to detect a QRS wave signal, and processes the pulse signal to detect the amplitude of the pulse signal. The CPU 30 judges whether or not the QRS wave is caused by a ventricular premature contraction. If two QRS waves, not caused by ventricular premature contraction, occurs successively, and the CPU 30 judges if A0.times.k&gt;A1. The CPU 30 judges that a supraventricular extrasystole is occurred. Here, A0 is an amplitude of the first QSR wave; A1 is an amplitude of the second QSR wave; and k is a preset value, 0&lt;k&lt;1.

During a noninvasive blood pressure measurement using a cuff 2, a pulse wave propagation time T1 from the appearance of the peak value of an R wave in an electrocardiogram (ECG) waveform to the appearance of the bottom value of a pulse wave is counted, and a blood pressure value BP1 is calculated from a count result T1 and parameters .alpha., .beta. specific to a subject obtained during a pulse wave propagation time calibration. Then, the absolute value of a difference between the blood pressure value BP1 and a blood pressure value NIBP1 obtained by the noninvasive blood pressure measurement using the cuff 2 is calculated, and it is indeed whether or not the calculated absolute value is within a predetermined threshold.sub.-- BP. If the absolute value is judged to exceed the threshold.sub.-- BP, then blood pressure is measured again noninvasively using the cuff 2, and a blood pressure value NIBP1'obtained from such repeated measurement is displayed on a display 22.

After an initial blood pressure measurement using a cuff 2 has been made, not only a pulse wave propagation time Tt is counted consecutively, but also a pulse wave propagation time change .DELTA.T is calculated every time the pulse wave propagation time Tt is counted and compared with a pulse wave propagation change threshold .DELTA.Ts. When the pulse wave propagation time change .DELTA.T exceeds the pulse wave propagation time change threshold .DELTA.Ts, not only a blood pressure value BPt is measured with the cuff 2, but also a pulse wave propagation time Tt.sub.1 is counted. If there are at least two sets of data, each set of data consisting of a blood pressure value BPt and a pulse wave propagation time Tt.sub.1, coefficients .alpha., .beta. specific to a subject are calculated from such two sets of data by a least-squares method. Then, the pulse wave propagation time change threshold .DELTA.Ts is calculated from the coefficient .alpha., and the current pulse wave propagation time change threshold .DELTA.Ts is updated.

A blood pressure measuring device includes: a memory for storing a standard constant .alpha.; an input means for inputting a correcting blood pressure value; a time interval reference point detection section for detecting a time interval detection reference point in a pulse wave on the side of aortae; a pulse wave detection section for detecting a pulse wave on the side of peripheral blood vessels appearing with a time lag with respect to the pulse wave on the side of aortae; a pulse wave propagation time measurement section for measuring a pulse wave propagation time based on respective detected outputs from the time interval detection reference point detection means and the pulse wave detection means; an operation means for determining a constant .beta. using the blood pressure value for calibration, pulse wave propagation time, and standard constant .alpha. inputted for calibration; an operation means for calculating the blood pressure value from the pulse wave propagation time measured at a predetermined time interval for measuring a circadian blood pressure fluctuation, and the standard constants .alpha., .beta.; a memory for consecutively storing the measured pulse wave propagation time and the blood pressure value calculated from the pulse wave propagation time; and an external output connector for outputting at least the blood pressure value and pulse wave propagation time data as a result of the circadian blood pressure fluctuation measurement.

Blood pressure measuring apparatus

A pulse-wave propagation time basis blood pressure monitor includes a memory for storing an equation describing the relationship between the pulse wave propagation time and the parameter .alpha., input means for entering the blood pressure value for calibration, a time-interval detect reference point detecting means for detecting a reference point for detecting the time interval of a pulse wave in the aorta of a subject; pulse wave detecting means for detecting a pulse wave which appears in the peripheral blood vessel after it appears in the aorta; pulse-wave propagation time measuring section for measuring a pulse wave propagation time from the output signals of the time-interval detect reference point detecting means and the pulse wave detecting means, first computing means for determining the parameter .alpha. proper to the subject on the basis of the general equation stored in the memory by using the pulse wave propagation time for calibration gathered from the subject, second computing means for determining the parameter .beta. to be added in computing a blood pressure value by using the pulse wave propagation time, by using the blood pressure value inputted for calibration, the pulse wave propagation time measured for calibration, and the parameter .alpha. determined by the first computing means, third computing means for computing a blood pressure value by using the measured pulse wave propagation time, and the parameters .alpha. and .beta., and measured data output means for outputting data of the computed blood pressure value.

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Tokyo, Japan

Takeshi Sohma