公开(公告)号：JPH02172443A

公开(公告)日：1990-07-04

申请号：JP32703788

申请日：1988-12-23

Applicant: MINOLTA CAMERA KK

Inventor： MAJIMA YUTAKA ,  SAKAI TAKAO ,  ARIIZUMI MASAHIRO

IPC: A61B5/0245 ,  A61B5/145 ,  A61B5/1455

Abstract: PURPOSE:To improve precision of a measuring value itself, to stabilize the display value of oxygen saturation, and to improve reliability by a method wherein a noise component contained in a photoelectric pulse wave signal before the degree of oxygen saturation of arterial blood is reduced. CONSTITUTION:With the source switch of an oxymeter turned ON, initialization is effected. A number of pulses detecting part 5 detects the number pulses from a pulse wave signal outputted from a logarithm converting part 4, and outputs it to a control part 6. Reliability of the number of pulses determined by the number of pulses detecting part 5 is evaluated by the control part 6, the selection frequency of a B.P.F. part 7 is decided and controlled by means of the number of pulses, and only the main frequency component of a pulse wave signal outputted from the logarithm converting part 4 passes the B.P.F. part 7, and noise of other frequency region is removed by the B.P.F. part 7. From reliability of number of pulses data, the width of the pass-band of the B.P.F. part 7 is decided. A signal on which filtering process is applied by the B.P.F. part 7 is inputted to a computing part 8 to compute an SaO2 value of the degree of oxygen saturation. A computing result is outputted to a display part 9 for display.

公开(公告)号：JPH0386152A

公开(公告)日：1991-04-11

申请号：JP22644689

申请日：1989-08-31

Applicant: MINOLTA CAMERA KK

Inventor： SAKAI TAKAO ,  MAJIMA YUTAKA ,  YAMAMOTO SHINJI

IPC: G01N33/49 ,  A61B5/145 ,  A61B5/1455

Abstract: PURPOSE:To heighten measuring accuracy by finding the change quantity of a pulse wave signal from a signal in which only a fluctuation component is taken out and amplified from the pulse wave signal. CONSTITUTION:The measurement of the saturation of oxygen in an arterial blood is performed by irradiating a measured part with light of two wavelength R and IR, and measuring the light transmitting or reflected on the measured part at a time phi1 and a time phi2 a little later, and finding the change quantity between the time of a measured value at every wavelength, and computing the saturation of the oxygen from the change quantity or the measured value at the time phi1. Therefore, the change quantity per hour of the pulse wave signal can be found from the signal from which a DC signal component is eliminated, and since only the required component of the signal can be amplified by eliminating a DC component even without increasing the dynamic range of a circuit unnecessarily, amplification can be performed sufficiently, and the S/N of the circuit to find a difference can be improved, and also, by finding the change quantity of the pulse wave signal from that of an amplified AC component, the number of digits of the change quantity used in computation can be expanded, which improves the S/N of the measured value as the whole of computation.

公开(公告)号：JPH03242558A

公开(公告)日：1991-10-29

申请号：JP4037790

申请日：1990-02-20

Applicant: MINOLTA CAMERA KK

Inventor： SAKAI TAKAO ,  YAMANISHI AKIO ,  MAJIMA YUTAKA

IPC: G01R15/08 ,  A61B5/0245 ,  G01R13/22

Abstract: PURPOSE:To permit simultaneous observation of changes in amplitude and in a shape by changing an amplifying magnification so that a product of pulse wave signal intensity and the magnification monotonously increases along with the pulse wave signal intensity. CONSTITUTION:A pulse wave signal detected by a sensor 1 is amplified, filtered, etc. in a pulse wave processing unit, and then the signal is input to a control arithmetic unit 3 where oxygen saturation in artery blood, the number of pulses, etc. are calculated. A display control unit 5 determines a display magnification of the pulse wave signal to be displayed on a display unit 6, wherein such a magnification is used for calculation that a product of a wave height value of the pulse wave signal and the magnification monotonously increases.

公开(公告)号：JPH02237544A

公开(公告)日：1990-09-20

申请号：JP5813689

申请日：1989-03-10

Applicant: MINOLTA CAMERA KK

Inventor： MAJIMA YUTAKA ,  KAMEZAWA HITOSHI ,  SAKAI TAKAO

IPC: G01N21/27 ,  A61B5/145 ,  A61B5/1455

Abstract: PURPOSE:To extend the life of a light source by reducing the consumption of a battery and to alleviate the pain of an examinee by stopping light emitting operation for a predetermined time when it is detected that the saturation degree of oxygen in arterial blood is unstable timewise. CONSTITUTION:When a light emitting part 2 starts light emission at predetermined frequency by the light emitting order of an operation part 7, the saturation degree of oxygen in arterial blood and a pulse rate are calculated from the signal outputted from a signal processing part 6 on the basis of the operation of a light detecting part 3 and that of a photoelectric conversion part 4 and the stabilities thereof are investigated. Next, it is judged whether the calculated saturation degree of oxygen in arterial blood and pulse rate are within set ranges and, when the measured values are within an alarm range, measurement is continued. When the measured values are judged to be stable and also judged to be not within the alarm range, an operation part 7 issues a light putting-out order to a light emission control part 5 to stop the light emission of the light emitting part 2. After a predetermined time is elapsed, the light emission of the light emitting part 2 is reopened and the same operation is repeated in the same way.

公开(公告)号：JPS5145488A

公开(公告)日：1976-04-17

申请号：JP11854374

申请日：1974-10-14

Applicant: MINOLTA CAMERA KK

Inventor： KONISHI MASAICHIRO ,  KISA TSURAYUKI ,  YAMANISHI AKIO ,  MAJIMA YUTAKA

IPC: A61B5/145 ,  A61B5/00 ,  A61B5/1455 ,  G01N21/31 ,  G01N33/49

Abstract: An optical non-invasive oximeter for measuring oxygen saturation in arterial blood utilizes a light source capable of giving off light having different wavelengths, such as light in the infrared and red region, and a pair of photoelectric devices, one responding to one wavelength and the other to the other wavelength, for detecting the amount of such light transmitted through living tissue. Each photoelectric device is connected to a computing circuit which generates a signal that represents the logarithm of the quotient of the signal received from the photoelectric device divided by its direct current component. The signals from each of the computing circuits are differentiated and then divided, one by the other, to provide an indication of oxygen saturation in the blood.