JPS62500843A - Optical pulse detection method and device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Optical pulse detection method and device This invention is an improvement in non-invasive pulse oximetry, particularly in the photoelectric measurement of blood components. Concerning a good method and apparatus.

Technical background of the invention A method for measuring oxygen concentration using non-invasive photoelectric pulses is described in U.S. Patent No. 4,407.290. No. 1 No. 4,266.554, No. 4,086,915, No. 3.9913 ．． 550 No. 3,704.706, published on March 13, 1984 State Patent Application No. 102.816, European Patent Application No. 10, published April 4, 1984 4.772 and European Patent Application No. 104,77 published on April 4, 1984. Each is described in Publication No. 1.

The pulse oximeter is manufactured by Nelcar, Hayward, California, USA. For example, the pulse oximeter model J It is known as l-100.

A pulse oximeter typically measures blood oxygen and hemoglobin in a patient's arterial blood. It is not limited only to the feeling of saturation, but also corresponds to the amount of blood pulse supplied to the flesh tissue and each heartbeat. It measures and displays many blood flow characteristics, including blood pulse velocity. oxygen The densitometer measures the tissues perfused with white fluid, such as fingers, ears, nasal septum or! llI Light is transmitted through human cells such as skin or animal tissues, and the amount of light absorbed by the tissue is measured by photoelectric sense it emotionally. The amount of light absorbed is used to calculate the amount of blood component measured be done.

The light that passes through the tissue is selected to have one or more wavelengths. indicates the blood components 9 that are absorbed by the blood and present in the blood. Penetrates throughout the tissue The amount of light emitted varies depending on changes in blood components q in the tissue and the associated light absorption rate. For example, Nelcar N-100 type pulse r! I element 1 degree measuring meter is a hemoglobin The oxygen saturation of the bottle is measured using two light emitting diodes, one of which Light emitting diodes have a single frequency of about 660 nm in the red light range, unlike other light emitting diodes. The ord has a single frequency in the infrared range of about 925 nm. The two light emitting gui Auto is illuminated alternately by a 4-state clock, which allows the incident light to The detection light, that is, the transmitted light, is detected by a single photodetector. Black lights from other light sources using high strobe rates, e.g. 2000 cycles per second. Be easily identifiable. The photodetector current is 2-channel synchronous detection separated by a container. In this case, one chamfer processes the red light waveform and the other The channel is Red Sun! Processing the waveform The 0 separated signal is filtered and strobed frequency, electrical noise and ambient) noise, then analog-to-digital Converter rAIl)C4 counts. The above-mentioned jIA, incident light or transmitted light Transillumination is the light produced by a photodiode or other light source and is Distinguished from external light.

Adjust the intensity of the light source to adjust the patient's skin color, thickness, hair, and blood.

It is possible to respond to changes in other changing factors. Therefore, the transmitted light is a variable element, In particular, it is modulated by @pulse blood pulses or pulsatile components and collated as an optical signal2. Ru. The count representation of the optical signal is collated as a digital optical signal. succumb to the pulsating component The portion of the digital optical signal that is used is labeled into the optical pulse.

The digital optical signal is transmitted from the microproducer of a Nelker Ntoo type pulse oxygen 9m meter. processed by a processor to identify individual light pulses and displayed by infrared light wavelengths. Maximum and minimum pulse level when expressed by red light wavelength compared to pulse Calculate the rlil hook state from the ratio.

Several other methods of processing and translating optical signal information are described in the patent publications and publications cited above. and the application publication.

A problem with non-invasive pulse oximeters is that optically dedicated pulse oximeters The number may become an irregularly changing element and interfere with the detection of blood flow characteristics, including motion artifacts. That is. Motion artifact tM is the movement of the patient's muscles near the sensing part of the oximeter. movement, for example, the patient's finger to which the sensing part of the oximeter is attached.

Similar to the pulses produced by the ear or other body parts and caused by arterial blood flow generates a false pulse. These false pulses are then sent to an oximeter. Energize to process artifact waveforms and provide false information. This problem is particularly important for infants and important for infants or patients who do not remain still during monitoring.

Yet another problem occurs under conditions where the patient is debilitated and the pulse strength is very low. light When processing information continuously, the true pulsatile component is separated from artificial pulses and noise. It is difficult to distinguish between them due to the low signal to noise ratio. light signal beat Due to the lack of reliability in detecting blood components, the information needed to calculate blood components is not available. Missing.

Electric heart? Erections occur simultaneously with heartbeats and can be monitored externally: 1. S It is also known that it can be characterized as an electrocardiogram waveform. The electrocardiogram waveform can be determined by a person skilled in the art. As is known from Consists of.

The QR3 component is related to ventricular contraction. The R waveform part of the QR3 component is generally the highest Gradient waveform, with maximum amplitude and slope, indicating the onset of heart defect motion used to do. Arterial blood pulses are mechanically flowing and flowing at neglected locations in the body. The pulses generated are continuous to the R waveform of the electrical heartbeat by a configurable time. For example, "Obstetrics F4 and Gynecology" by Gutudrin Bu, Vol. 39, No. 2, 1972. According to "Fetal and Neonatal Contraction Time" published in February 2017, the fetal scalp pulse is It has been announced that there will be a delay of 0.03 to 0.04 from the R waveform in the figure, and similar The facts are described in US Pat. No. 3,734,086.

Therefore, the purpose of this invention is to detect the pulse component of the optical signal and calculate the amount of blood components and the number of pulses. The purpose of the present invention is to provide an improved method and apparatus for measuring the Oxygenate the patient's heartbeat, preferably electrically detected in the form of an electrocardiogram waveform. Low signal to artifact and noise rate by incorporating into meter operation In addition to solving the problems caused by Ru.

Another object of the present invention is to detect a digital optical signal generated within a scheduled acquisition time of an optical pulse. An oxidant that analyzes only the blood and calculates the amount of blood components using information from the signal part. Provide data. This allows the oximeter to detect light containing the pulse component of arterial blood. This increases the possibility that only the optical waveform is processed and the false pulses are not processed.

Another purpose in the history of this invention was to use a pulse oximeter to treat patients with irregular heartbeats. Used for monitoring, when an arterial pulse is generated using electrocardiogram information, especially the R waveform component. The digital optical signal waveform is further processed within this time to perform the desired measurement. The goal is to do the following.

Another object of the invention is to determine Il+ by an oximeter from a digital optical signal. The purpose of the present invention is to correlate the pulse number information obtained with the number of cardiac pulses measured by an electrocardiogram.

This correlation allows the measurement of the time relationship between the electrocardiogram and the light pulse, This is particularly important when the optical signal is weak and the fetal heart pulse rate is important and is usually monitored. Advantageous in the birthing room, which is a sign.

Furthermore, another object of the present invention is to provide redundant measurement of the number of cardiac pulses from both optical signals and electrocardiograms. This allows continuous patient monitoring even if one of the signals is lost. It's about doing.

Also, is the other purpose of this invention the polarity used for electrocardiogram measurement? ili (X circuit The polarity of the electrocardiogram waveform can be made uniform from top to bottom without the need to adjust the lead wires. It's about doing.

Summary of the invention This invention is useful for pulses used in surgical procedures, life-threatening medical situations, and childbirth. The goal is to increase the accuracy and reliability of oximeters and to The goal is to measure the patient's heartbeat and correlate this with the patient's blood flow, allowing for more accurate calculations. and measure vital information including oxygen saturation and pulse rate.

In one embodiment, the correlation operation is performed using automatic correlation techniques to Enhances the temporal information contained in shapes and measures the temporal relationship between one waveform and another waveform do.

In a preferred embodiment, the method includes measuring an electrocardiogram signal to determine the occurrence of cardiac defective behavior. By correlating with the 1ff11 constant of the arterial pulse, Detect the occurrence, measure the time delay in which the optical pulse follows the R waveform, and measure the time delay in which the optical pulse follows the R waveform. The measured time delay between the optical blood pulse and the true m Arterial blood flow is divided by +11 only when the 11-night pulse occurs. This method is even more Based on electrographic signals, optical pulses or both? ,? Hand measuring f heart pulse rate Including steps.

In a preferred embodiment, the method and apparatus of the invention are located in California, USA. Model N-100 manufactured and sold by Furukar Inkobore Itenoto, located in -Features the use of a type pulse oximeter. According to the improved method , the oximeter uses the patient's digital optical signal waveform in conjunction with other parameters to make it more effective. This allows for effective analysis. The device according to the invention includes a heartbeat detection device and a Pulse oximeter function and oximeter of Kerr N-100 type pulse oximeter Rough 1-Uni 1 and memory are combined to control and process the data and 6 heartbeat information. It consists of a combination of an integrated microprocessor device. Another input signal Multi-channel and digital status of data, input signals in addition to input signals is received from the heartbeat detection electronics. Furthermore, the improved oximeter , the detected heartbeat waveform is processed simultaneously and independently with the optical signal, and both waveforms are digitalized. The signal is converted to a digital signal and processed by the signal processing component of the N-100 oximeter. Understand.

Heart beat parameters can be generated by conventional methods and by novel methods, Dark artery pulse including electrogram signals, ultrasound, ballistocardiogram, accelerometer, nuclear magnetic resonance meter , the heartbeat can be measured independently from electrical impedance techniques, etc. heartbeat The fundamental requirements for dynamic parameters and associated electrical circuitry are Symmeter signal processing is used to ensure identity in response to each heartbeat. The objective is to obtain a signal that can be detected and detected.

In a preferred embodiment, the heartbeat parameters (electronic heart pulse) are transferred to the Kanayama electrical circuitry. instrumentation that detects the ECG signal in the form of an electrocardiogram and electrically separates it from the oximeter. passed through an amplifier and further derived from the electrocardiogram signal by system electronics. This creates a large number of waveforms. The amplifier differentially amplifies and inverts the original ECG information. and then returns the common mode signal to the patient to strike the patient's common mode voltage. quench, amplify, and combine AC 2a into the signal to remove the DC (off-cent) voltage component. , filter the signal to remove unnecessary frequencies, e.g. frequencies below 0.051-1z. remove, buffer, and then couple the electrocardiogram signal to system electronics. child The coupling of the amplitude of the signal transmitted through a transformer with suitable electrical circuitry, e.g. modulation or by optically coupled isolation circuit breakers.

The system electronics demodulates the concatenated signal and amplifies the signal if necessary. is supplied to an automatic gain control (AGC) amplifier to keep the ECG signal output within a predetermined range. Hold. In this case, the actual ECG signal strength will vary depending on the patient and lead configuration. It may change depending on the location.

In a preferred embodiment, the output of the AGC amplifier is applied via a polarity compensation circuit. , the polarity of the waveform is changed to obtain a preselected rising or falling polarity. child There is no need to switch leads or handle the patient. This is life's Useful in critical situations. Lid and in such cases improperly connect the ECG leads. The connection precludes proper detection of heart pulse rate and correlation with light pulses, which may result in fetal harm. This is because, in some cases, the use and reuse of the gland is undesirable.

The signal derived as a diagnostic electrocardiogram is displayed as an analog of approximately 8 electrical beats and is Analog DevicesCan be displayed on analog devices such as cathode ray tubes and chart recorders. Wear. The diagnostic ECG signal is filtered and selected as the R wave of the ECG waveform and together to remove the DC component. The resulting signal is a filtered electrocardiogram signal.

In the case of R-wave generation by processing the filtered ECG signal, this generates a digital pulse. It then sends a filtered ECG signal to the oximeter, which generates an R wave. Display what has been done.

The functions of the oximeter generally remain unchanged except as explained in this section. My The microprocessor has a bipolar drive current of 2 f! ! In addition to light emitting diode 1, this The positive current pulse drives the infrared light emitting diode, and the negative current pulse drives the red light emitting diode. Drive the ord. The magnitude of the current is adjusted by the microprocessor to Assists in calculating changes in somatic cells. The light emitted by the light emitting diode is detected by a single photodetector. Preferably, the photodiode detects the detected transmitted light. Generates a current proportional to the amount. The photocurrent can be amplified by a current-to-voltage converter. I can do it. The resulting voltage is then transferred to the system elect under the control of the microprocessor. Analyzes and detects the arterial pulse which is processed by Ronics and history regarding the number of pulse periods , elicit the pulse shape as well as the oxygen saturation state. The oximeter detects the detected pulse The detected pulse corresponds to an arterial pulse by comparing the pulse history with the pulse history. determine whether it is acceptable as such. To be accepted, the detected pulse must be The device must meet certain criteria according to the desired degree of reliability. Next, blood components Measurements are taken based on the accepted pulses.

According to the improved method and apparatus according to the present invention, 1. For example, electronic heart pulse detection voltage The cardiac signal from the heart circuit is transferred to an analog-to-digital converter and an N-10 The heart is processed using the Type 0 pulse oximeter's digital processing electronics. Measures the polarity, rhythm and magnitude of electrogram signals. For this measurement, microb Digital electrocardiograms can be used to convert diagnostic electrocardiograms, filtered electrocardiogram signals, or both. Analyze the digital electrocardiogram signal by converting it into an electrocardiogram signal and adjust the automatic gain control amplifier and polarity compensation circuit.

In a preferred embodiment of the invention, the microprocessor operates in an integrated manner to Deriving and comparing information from electrographic waveforms and optical pulse signals. Microp The processor first independently measures a time period during which the optical pulse becomes an R-wave. This is then averaged with multiple pulses, and then independently calculated for each waveform. Calculate the number of pulses and compare the number of light pulses and the number of electrocardiogram pulses. This allows electricity to The reliability of the analysis of approximately 6 pulses and arterial blood flow waveforms is ensured.

A preset criterion for an optical pulse signal may be, for example, when a pulse is expected to occur. The expected magnitude of the pulse and the red and infrared light pulses detected This preset criteria, including the expected ratio, is used to create a pulse history. can be preselected or set depending on the Pulse history shows some of the latest pulses For example, it consists of four pulses in a last-in, first-out stack memory; The memory automatically stores the data for the last 41[1] accepted detection optical pulses. to be memorized.

The improved oximeter uses a measured time delay between the R-wave and the optical pulse. Using this, we can detect the optical pulse that corresponds to the true arterial pulse following the generation of the R wave. The 0-time window, which measures the time window when there is a high probability of and accept or reject the detected pulse as an optical pulse. detected Pulses that do not fall within the time window are rejected and used to calculate blood component amounts. (similarly, these cannon pulses usually form part of the pulse history) However, if the pulse is received within a time window for a pulse period of approximately 31[1] If none are acceptable, pulses within the time window that would normally be rejected are accepted. child This is achieved by changing the preset optical pulse criteria, as explained later. can.

Optical signals are easily detected with high quality by adjusting the microprocessor In some cases, a relatively high correlation between the detected pulse and the pulse history can be required; The resulting detected pulse is accepted as an optical pulse. This ensures high reliability. This enables accurate measurements. In contrast, if the optical signal is of poor quality, the need for correlation performance is reduced and measurements are less reliable. This element of reliability depends on the frequency of the optical signal. It can be articulated according to dynamic changes or the relative strength of the light pulse signal.

acceptable within a time window of a period specified by inferior criteria, e.g. within 10 seconds; If the optical pulse cannot be detected, the microprocessor will ijf to reset the relationship between the electrocardiogram R wave and an acceptable optical pulse.

In an integrated manner, the improved oximeter measures blood component levels within a set time window. can only be calculated from the amount of digital optical signal detected. Thus , the time window reduces the processing of any spurious pulses caused by artifacts or noise It can be used to. This allows the integration of ECG information to provide reliable oxygen Ensure that saturation measurements are taken.

The advantage of integrated measurement of heartbeat and optical signals is that the oximeter uses optical pulses to generate The goal is to anticipate and detect. One advantage of using ECG signals The purpose of this is to define the relationship between the R wave and the arterial pulse, thereby regulating the heartbeat. Regularity or irregularity can be checked and, for example, oxygen saturation can be measured. The determination is made reliably and accurately based on the pulse component of blood flow.

Additionally, another advantage is that if either the ECG signal or the optical signal is missing, , the oximeter can revert to a non-integrated mode, which allows the ECG signal and light can be processed independently from the scientific signal. Non-missing signals continuously flood information about life. It is especially important that the lack of a signal can lead to defects in the patient's bodily functions, such as cardiac arrest. This is to indicate that it is not caused by. Oki improved in this way The simeter performs redundant measurements of the patient's heart pulse rate to measure electrocardiogram or optical signals. indicates that one of the devices is not operating properly.

Once the missing signal is restored, the integration operation is restarted as previously described.

Yet another advantage of the improved method and apparatus of this invention is that The goal is to be able to reliably monitor patients who do not have a normal heartbeat. An improved version of this invention The ximeter improves the possibility of treating arrhythmia, and the optical pulse follows the R wave. In addition, it is possible to detect and analyze the time interval by setting a retroactive time window. Furthermore, continuous Uses a time window set by including R1, which occurs irregularly when R waves occur. This allows the oximeter to count the digital optical signals detected within the time window. The optical pulse history is extracted and the amount of blood present is calculated. No Patients with regular heartbeats can also be monitored, and furthermore, blood component amounts can be compared to the actual Measured based on blood pulses.

Detailed description of the invention Figure 1 shows an electrocardiogram (hereinafter referred to as EKG) detection and output means 100 and a pulse oximeter. This is a specific example of the present invention consisting of data. EKC: Detection means 100 is (+) fallen lead wire 102. (-) It has a fi11 lead wire 104 and a reference lead wire 106, Each is electrically connected to a patient 108. Typically, (+NII+lead 10 2 is connected to the right hand, the (-) side lead wire 104 is connected to the left hand, and the reference lead wire 104 is connected to the left hand. is connected to the right leg. If the patient is a fetus, the (+) side lead wire 102 is connected to the fetus. Connected, (-)i! The I11 lead wire 104 is connected to the mother's vaginal canal and is The lead wire 106 is connected to the mother's right leg. Other optical detection means and KG inspection An oximeter means during childbirth consisting of a combination with a delivery means is disclosed in European Patent Application No. 135 No. 840. This is by Nelcar Incorporated. , hereby incorporated by reference into this application as disclosed herein.

The EKC and detection means 100 further include an amplifier 12o, a coupling circuit 138. automatic Gain control (hereinafter referred to as AGC) amplifier 140, polarity switch 160. band fill 17o, a DC frequency detector 180, and an R wave detector 190. during operation In this case, the EKGJQ output means 100 outputs an EKG diagnostic waveform DEKG filtered. It generates three outputs: an EKG waveform FEKG and an R wave pinched waveform DRW. is shown in FIG.

EKG front end printed circuit board work as shown in Figure 2A and Figure 2B A preamplifier 'rr120 is installed on the board 64 (board 164), and this front amplifier printed circuit boards are used to process and analyze EKG and optical signal waveforms. The patient 108 is electrically isolated to protect the patient 108 from strong electrical signals. Previous rI ! The amplifier 120 consists of an instrumentation amplifier 122, and as this instrumentation amplifier 122, [1urr-Brown's lNA104HP ultra-high precision instrument amplifier etc. are preferred. Yes. Furthermore, this instrument amplifier 122 has a high reverse withstand voltage due to the diode 124. and its insulation voltage is ±Viso. This instrument amplifier 122 is designed to have a gain factor of approximately 100.

The signal generated on the (-) measuring single lead wire 104 is of the interface strip J3. The signal input to bin 2 for the input into bin 1 for strip J3, then the signal is input to amplifier 122 are supplied to the respective output terminals. The common mode signal CMS is based on the standard code Sho 62-5 (1 (1843(6) It is returned to the patient via lead wire 10G. As a result, the zero common mode voltage is reduced. As it decreases, the rejection of common mode signals increases. This technique applies to other bottles. 5# in the technical field! As is known to those skilled in the art, as shown in Figures 2A and 2B, connected to the sea urchin. For ease of understanding and identification, the input terminals of the main semiconductor devices are As mentioned above, the electronic circuit diagram includes the elements "A100~". 16'', which indicates element person 101 for bin 16.

The output of instrumentation amplifier 122 is transmitted to isolation amplifier 500, which Isolation amplifier 500 is analog.

Model 286 J manufactured by Devices (!: It is preferable to The amplifier 500 connects the isolated preamplifier 120 to the system electronics. Provides transformer coupling of the EKG waveform. In addition, the isolation increaser 500 is provides insulation power to the mechanical amplifier 122. The oscillation circuit 510 is a Hechsschmitt inverter 511. Resistor 512. Capacitor 5] 3 and variable resistor 514 etc. It consists of This circuit ensures that the isolation booster 500 operates properly. Provides a 100KHz signal.

The EKC signal is coupled to the system electronics and transmitted to two different circuits. Ru. The first circuit is the LD OF detection circuit 134. The LDOF circuit 134 is Indicates when the power line is disconnected or disabled, and this LD OF circuit 134 is a parallel connected comparator arranged in a window comparator configuration. 135a and 135b, and the output of the isolated preamplifier 120 is ±3. ．． When the voltage is within 8V, the potential of the contact 136 increases to 115V due to the action of the boost resistor 137. so that it becomes The comparator 135a is connected to the inverting input terminal side. 1134a, 1134; b, a capacitor 1134d, to which a reference voltage of ÷15■ is supplied.

This voltage is divided into +3.8■ and supplied to the inverting input terminal via resistor 1134c. be provided. Similarly, the comparator 135b is connected to the non-inverting input terminal side. It has a voltage dividing resistor circuit including a filter capacitor, which is connected to resistors 1135a and 113. 5b and a capacitor 1135d, to which a reference voltage of -15V is supplied. It will be done. This base/$ lightning voltage is divided into -3,8 cm and connected via resistor 1135c. It is supplied to the non-inverting input terminal of amplifier lake 135b. Comparator 135a is It has a feedback resistor 1135e that connects the output side and the non-inverting input terminal. , this gives hysteresis.

The output of isolated preamplifier 120 is connected to filter capacitor 1131 and The inverting terminal of comparator 135b and comparator 13 are connected through resistor 12130. 5a to both non-inverting terminals. +7- wires 102 and 104 properly , the voltage at contact 136 is +5v when connected to patient 108. lead If either wire 1'02 or 104 is non-conducting and is not operating, disconnect it. The voltage at point 136 is OV. This is supplied to status launch 9 (, -13 This is a digital QVFLC.

The EKG signal is also supplied to a second circuit, a bandpass filter circuit 330. . This bandpass filter circuit 330 includes buffer amplifiers 331 . Resistor 332-33 3 and capacitors 334-336, and the frequency is approximately 0.05Hz or less. It is designed to selectively filter out wavelengths above Hz.

The signal then passes through a notch filter 380, e.g. Certain components such as This notch filter 380 is mainly used for Designed to eliminate all disturbances such as noise. This notch filter 3 80 is an amplifier 381 and 382 . Resistance FS=383a-383f.

Consisting of capacitors 384a and 3B4b and variable resistors 385a and b. Adjust the filter to 60Hz. The output of notch filter 380 is substantially It has the same waveform as the output of the instrumentation amplifier 122.

The output of the notch filter 380, ie, the electrocardiogram signal, is sent to the bandwidth-limited inverting amplifier 14. 2 and is input to the AGC amplifier 140. This AGC amplifier 14 0 converts the bandwidth-limited signal into a digital-to-analog converter (DAC) 144. is received at the bin 15 and analog input end of the . Note that DAC144 is an inverting amplifier. 143 feedback loop. Also, the DAC 144 has latch 1 It also receives digital input from 45. The digits supplied to this DAC144 The word is entered into lunch 145 by the oximeter's microprocessor 16. It will be done. The diode supplied to the latch 145 according to the amplitude of the diagnostic EKG signal DEKC; By changing the zikuru word, the microprosensor 16 can perform the AGC amplification 51. 44--The gain of DACI 44 can be adjusted, and these are Used as a variable resistor in the loop.

Amplifier 147 provides a second stage of gain to the signal, which is connected to the polarity switch. 160. The polarity switch 160 is made by Sirconi or Kusu? i! J A PG201 analog switch is preferred, which connects the inverting input terminal of amplifier 162 or The EKG signal can be controlled by appropriately gate controlling either the The EKG signal is designed to maintain a constant polarity. micro Processor 16 processes the filtered EKG waveform, detects polarity, and For example, a voltage signal of F5v is generated. Also, this +5■ voltage signal is an inverter. 161 to a second voltage signal (e.g., 0, OV), these voltages The signals together form a logical word (positive, negative). Polarity determined by logic word voltage signal Inochi 160 gates the IEKG signal and increases this IEKG signal. Processing is performed so that proper human power of the width scaler 162 is defeated. The output of amplifier 162 is diagnostic E The KG signal is DEKG, and this signal goes up to the microblossom...→G16. In addition to being buffered by 168 additional units and 14 units, pulse oxidation and metering are also available. is transmitted to an analog-to-digital converter (ADC).

The output of the corner filter 162 is amplified by the amplifier 166 and further passed through the bandpass filter. 170, resulting in a center frequency of approximately 15-40Hz with a center frequency of approximately 20H2 frequencies are selectively transmitted. The filtered signal connects capacitor 176 to The DC voltage component generated during the previous amplification is removed, and the DC voltage component is further removed. input to the shifter 180. The DC shield cover 180 is connected to the non-inverting input terminal. Offset voltage Voff (preferably Voff -1-5V) @supplied amplifier 1ii1': 5182, and the above-mentioned filter is connected to the inverting input terminal of this amplifier 182. A filtered signal is provided. Voff is when the output of amplifier 182 is pulsed off. It is adjusted to be within the detectable range of the ximeter's ADC and is set to 6 priority mode. The ADC of the pulse oximeter cannot detect the positive voltage U7, so the DC voltage is Requires health softer 180. A/D/C of pulse oximeter is positive/negative voltage If it is possible to detect a bipolar signal consisting of Probably not.

The output C3 of amplifier 182 is a filtered 13KG signal FEKG, This signal is buffered by amplifier 186S and pulsed to analyze the waveform. It is transmitted to the oximeter's ADC. In addition, the output FEKG is sent to the R wave detector 190. This R1 skin detector 190 is supplied with a Koni/Parator 192. L, loud (direct voltage V th (preferably +5.5 V), and the pressure V (1 2 (6N or 75V pulla gummy pressure). filtered The amplitude of the EKG signal FEKG is input to the inverting input terminal of the comparator 192. ] When the threshold voltage Vth 1 (direct) is obtained, the comparator 192 outputs the logic (t ti indicates "1'" and generates a digital pulse as an output. The amplitude of the voltage is equal to VCL2, for example +5v.

In all other cases, the output of comparator 192 is a logical value "O", e.g. ■ Become. vth can be adjusted by the ministry of drying the pulse oximeter. If no R-wave pulse occurs, set the threshold voltage (and confidence level) to R The wave can be lowered until a pulse occurs. R wave pulse is not detected L D　OF　If the F signal indicates that an R-wave pulse should be present, the vth can be adjusted by the croprocessor. The output signal of the R wave detector [90 is It is a detection R wave DI machine, and as shown in Figure 3, each pulse (+5V) is the patient's E 1- (logical value “1”) indicates the occurrence of an R wave in the KG waveform.

Next, as shown in FIGS. 4A and 4B, the detected R wave DRW is is supplied to input terminal 280-2 of pull-up 280. The flip-flop 280 is DR The rising edge of the R wave pulse is detected as the W voltage signal rises from 0 to VCl2. At this time, the appearing logic state at the output terminal 280-1 is changed from the logic value "0" to the logic state. Change the value to “1” by 1. The Furi 7 Pfronop 280 is a microprocessor. A logic “1” until cleared by the processor 16 via the input terminal 280-3. Maintain output. Then, when the flip-flop 280 is cleared, Furi, Bufu The knob 280 has a logic value of "0" at the output terminal 280-1. Furi The output of flip-flop 280 is supplied to status latch 9G-19, which Accumulated as a logical value “1” indicating the R wave flag in the status human power Lanochi 9G-+9. be done. In this way, the instantaneous R-wave signal voltage DRW returns to the logic value "0". The presence of R waves continues to be indicated.

Because the microprocessor 16 has information regarding the signals that perform sequence control, Periodically check the status of each input terminal of the status manual latch 9G. 6th A As shown in Figure 6C, the presence of the R wave flag causes the macro processor 16 to perform the following make something happen. (Resets the output terminal 280-1 of the flip-flop 280. to set the output to logic value “O”, thereby setting the status manual latch 9G-1. 9 l? The el flag is reset to l-L, and the flip-flop 280 then detects the R wave. When issued, the output returns to the logic (IN"1°). (2) Unconquered EK c , start analyzing the waveform, and set the R wave number and regularity by +1) to distinguish between the wave and the optical pulse. Establish a delay time between (see Figure 7) or an optical pulse wave during the established time period We begin to search for the shape of anti-coalescence, and then 1 oxygen saturation, pulsating flow 8, and the number of fractions, etc. are related to life. Analyze the second signal.

As shown in Figure 3, the diagnostic EKG waveforms DE and KG are F' and Q.

It consists of an analog wave having signal components of p, S and T with different signs. QI? The S part shows 6 contractions of the heart, and 6 contractions occur due to this ('L). In this case, the occurrence of fJ in each heart becomes the P Q RS T pattern of the same Lit. Ma In addition, the filtered EKG waveform FEKG contains only the R portion of the diagnostic waveform. It becomes an analog signal with other components blocked. The R part is different from other parts and is large. Set slope and amplitude to 4. Filter-passed EKG waveform FEKG R wave is diagnostic EKG It matches the R wave part of waveform DEKG. In addition, the detected R wave DRW is a step, that is, Contains digital small R pulse waveform, which is the R wave part of diagnostic E, K G waveform DEKG Match minutes.

The arterial pulse detection circuit is manufactured and sold by Nelcar Incorporated. -Identical to that found in the 100 pulse oxometer.

As shown in Fig. 1, Fig. 4A, Fig. tB, and Fig. 8, pulse oximetry is as follows. The 5° clock 70 achieved as below is φ1. φ2. φ3. 4 consecutive φ4 This clock 70 is connected to the microprocessor 16. .

Segment φ1 turns on LED 30 and segment φ2 turns on LED 30. turn off, φ3 turns on i,, E D 32, and segment φ 4 turns off LF, D32. Each LED is strobed sequentially , only one LED becomes conductive at one time. Each LED is turned off The photoelectric detector returns to a stationary state and determines the surrounding environmental light level by 1111+7. Do it like this. While the clock 70 is operating according to its operating cycle, the patient 10 The light passed through tissue 7 at 8 is detected by light emitter 38. clock 70 has three output signals A, B and P. Outputs A and B are -IIn6 It is input to the pulse width modulation circuit, and the pulse frequency of System Stimnyrev I Ronix is input to the board. 164 and the appropriate 1. of LEDs 30 and 32. , set E D brightness. Set. The reference brightness is set by the 71′ filter sensor 16, and this microphone Lobrose, Nosa 16 generates brightness voltage VLI for infrared LE D 30 However, a brightness voltage VY is generated for the red LED 32. These groups P and voltage are different. and forms the output portion of hold circuit 200.

Referring to FIGS. 1, 5A, and 5B, parallel pulse width modulation circuit 220 and and 230 are shown. The circuit 220 has as inputs A, A, → -15V, - 15V and V47. Matching amplifier 3ε has the same resistor and gate. Using a connection circuit of a capacitor and a capacitor, as shown in Fig. 1/- the waveform shown as °RAMP'' in FIG. supply. When input A is a logic value "1", gate 2E opens the circuit and -1 5V power is supplied. Otherwise, it is connected and the inverting input terminal 3E-6 is inverted. 1 resistors R5, R7 and by shorting gate 2E-9. A feedback loop consisting of capacitor C25 and ClO3 is made conductive. . This conduction causes the First, increase the output of the amplifier from 0 to 15V. The input must be a logical value '0''. That is, when the voltage is approximately 0■, the gate 2E-16 is closed, and the voltage of -15■ becomes 3E-16. The signal is input to the amplifier 3E via. And the feedback loop resistor 5R7 is Opened by gate 2E-9, output 3E-7 becomes approximately OV and maintains this. be done. During the period when the input A is at the logical value "O", the signal B is at the logical value "O". Pal Modulation circuit 230 operates similarly to circuit 220. Therefore, signal B is approximately QV ramping output 3 except when it increases from E-1 becomes approximately 0■.

Outputs 3E-7 and 3E-1 are connected to comparators 4F-6 and 4I?, respectively. ~ 2 is input. Brightness voltage input Vl-1 and VL2 are each comparator where inputs 4F-5 and 4F~2 are supplied and ramping 1 pressure is present. are compared with the brightness voltage, respectively. In this way, the ramp at 3F>7 1 voltage is 1 transform VEVL (= during the period when the upstream is low, the comparator output 4F-7 is In response to a logic “1” condition, its output is a pull-up voltage across resistor 72. Therefore, it becomes approximately +5■. When the ramping voltage is larger than ■Ll, the output 4F-7 is Emit a pulse that changes to a logical value of “0” and has a pulse width that easily responds to the brightness level. arise. Similarly, the comparator output 4F-1 is the lamp voltage 3E-1 becomes the logic value “1” during the period when the brightness voltage is lower than the brightness voltage “LL”, and the output voltage at this time becomes the resistance The pull-up voltage of the resistor 73 results in approximately +5V. As a result, output 4F-7 and and 4F~1 are ■Ll and ■L?, respectively. A parameter indicating the required voltage strength corresponding to It has a ruth width.

Comparator outputs 4F-7 and 4F-1 are NAND gate input terminals 3F-1 3 and 3F-1, respectively. Signal A is NAND gate input terminal 3N -12, and the 6th signal FiifB is manually input to the NAND gate input terminal 3F-2. be done.

NAND gate output terminals 3F-11 and 3F-3 are NAND gate output terminals 3F-11 and 3F-3, respectively. It is input to input terminals 3F-5 and 31''-4, where each fδ signal is effectively connected. The output 3F-6 is a digital waveform 5LOPE ( 1m-1).

In addition, the output 3F-6 is the input terminal 2F-1 and 2F-2 of the NAND gate 2F. input to both, and the output 2F-3 enters the NAND gate manual I filler 2F-4. Powered.

Signal LED"2 is input to NAND game 1-input terminal 2F-5, output 2F-6 is the digital waveform ZEl? shown in FIG. It will look like O (zero).

Signal '5LOPE' (M oblique), 'ZERO' (zero) and 'PH ASE” (phase) becomes as shown in Figure 8, and the signal “PI(ASg”) (phase ) is generated by Kukotoku 70. Each of these signals is then connected to an optical coupler. coupled to the substrate 164 via U4, U5 and U6 (ffi9A diagram and (See Figure 9B). These signals are input to the receiving circuit 800, and this receiving port 180 0 is the signal 5 LOPE (slope), ZERO (zero), PHASE (position demodulates information based on the pulse width of phase). And also infrared L　E　D　30 and generates a voltage to operate the red LED 32 according to a certain operation opening/opening. .

As can be seen from Figures 8, 9A and 9B, the signal ZERO is Switching gate [U8-16 is controlled, and this switching gate U3-16 is Change the gain of amplifier tJ11. Signal 5LOPE (slope) is game) U8- 1, the conogate U3-1 controls the integrating amplifier Ull and the coupling capacitor CG Control the presence or absence of human power. The size of the output Ull-1 is the signal 5LOPE (M@ : Determined by the pulse width of l). The larger the pulse width, the longer U3-1 will short-circuit. Ru. This determines how long amplifier Ull and capacitor C6 hold the input signal. It is directly correlated with the integration value, that is, it is correlated with the peak value of the output Ul 1-1. Ma In addition, this causes the predetermined LE D to have a predetermined luminance brightness in the amplifier circuit 804. It is related to the proportional current for

The signal ZERO turns off the gain of amplifier Ull at predetermined intervals. The voltage of the amplifier tJ11 attenuates to approximately 0, and the current of the amplifier circuit 804 also decreases to approximately 0. Attenuates to 0. As a result, any LEDs that are on will turn off and remain stationary. Return to state. In addition, the signal qZElio (zero) is the inch grater amplifier IJ 11 and prevents leakage currents that would cause a gradual error in coupling capacitor C6. Signal PH A5ε (phase) charges gates U3-8 and U3-9, and this game) 08- 8 and U3-9 supply either -15V or +15V to gate U3-2. Select whether to input pressure. As a result, these voltages are Inch grater amplifier Ul when shorted by 5LOPE ('4 diagonal) Since it is input to gate U3-2, it is input to gate U3-2.

In this way, the signal at the amplifier output terminal Ul 1-1 becomes as shown in FIG. A waveform is provided to control LEDs 30 and 32. LED30 and and 32 are connected in parallel to the output ports J2-9 and 32 of the amplifier circuit 804, respectively. Contact U2-7 from the anode to the cathode and from the cathode to the anode. Continued. The amplifier circuit 804 uses the amplifier circuit UIO and the current detection resistor R25. The output voltage Ull-1 is transferred to the consumption current of the LED. As a result, the output IJ II-1 changes from positive to negative and is converted into a current by circuit 804 when the boat J The positive current in l-9 turns on LED 30 while keeping LED 32 off. This bias current causes an open circuit. In addition, negative current beam, E Turn on D 32 and open LED 30. Signal between positive and negative current Due to the effect of ZERO, the operating current of the LED is turned off and the LED 30 and 32 are turned off.

The light emitted by LEDs 30 and 32 illuminates patient 108. pass. This is preferably the finger's navy blue (5).A more preferable tissue position 1 is the ear. bu, the inner wall of the nose, the forehead where there is no reflected light, and other desired parts. Anti-light is used In the position where the LE is used, the LE Preferably, an optical barrier (not shown) is installed between D and the photodetector. stomach.

Referring to FIG. 1, photodetector 38 receives all light passing through the tissue of patient 108. Shine. Therefore, photodetector 38 detects an infrared pulse during clock output state φ1. Ambient light and noise and ambient light and noise during clock output state φ2 , the red light pulse and the ambient light and noise during the clock output state φ3, and the clock Ambient light and noise during output state φ4 are received. This signal “DLS” is The photodetection current is passed through an amplifier 40, which increases the photodetection current at a rate of approximately 1 volt per 1 μA. Pressure is converted. This signal further passes through capacitor 41 and into transformer 39. is coupled to the system electronics from the electrically insulating substrate 164. This The stem electronics is itself electrically isolated and the signals are connected to this system element. A parallel electrical circuit for separating the red and infrared signals after coupling to the processed by the road mechanism. As a result, it is necessary to process red and infrared signals. Different desired gains are set. The output φ1-φ4 of the clock 70 is Controls the synchronization of the detector gate and combines the integrated signal DLS with the infrared signal component I RLS and red The signals IRLS and RLS are separated into signal components RLS, and these signals IRLS and RLS are sent to a parallel synchronization detector 4. 3 and 44. Also, the parallel synchronous detectors 43 and 44 are pure frequency The ambient light and noise signals are reversed using a delayed time constant filter and and noise signals to the adjacent LED light pulse signal, thereby eliminating ambient light and noise signals. and noise signal components. These filtered signals are 45 and 46 to remove switching frequency and noise. Out The force signals Va and vb are transmitted to the oximeter's ADC for digitization. Ru. It is also transmitted to parallel offset amplifiers 47 and 48, to which Therefore, the DC bias component is removed and the residual voltage signal is amplified. Offse Cut amplifiers 47 and 48 increase the resolution of the alternating voltage signal components for digital input. make it big The outputs Va' and Vb' are further converted into oxygen for analog-to-digital conversion. It is transmitted to the meter's ADC.

Referring to FIGS. 5A and 5B, a system error for processing signal DLS is shown. Lectronics is shown in more detail. Signal DLS is passed through transformer 39 Bin 1 of connecting strip J1 is coupled to front end printed circuit board 164. 0 to the system electronics. The signal DLS is the photodetector 38 consists of a continuous response to an infrared LED 30 and a red LED 32, which is Timing diagram [Figure 8 “PH0TOCURRENT” (photocurrent) Reference]. The signal DLS is input by one of the two amplifiers IK. amplified.

The output of amplifier IK is connected to four analog switches, and these analog switches The switch forms the switching element 2H of the parallel two-channel synchronous detector 43.44. to be accomplished. The synchronous detectors 43 and 44 detect the red light detected by the photodetector 38. Separates outside line and red light pulses, and eliminates low frequency noise and DC offset current. Remove pressure. As the clock 70 repeats its operation cycle, the state φ1 is At first, analog switch 2H-10 is closed, and detector channel 43 and amplification The coupled preamplified signal DLS passing -1 to the resistor R33 and R 44 has a gain of about -1.

During state φ2, first switch 2H-10 opens, then switch 2H-7 opens. closed, resulting in a gain of -1 to amplifier 2 of approximately +1; 1 is a resistor R forming a feedback loop with a substantially open resistor R34. It operates together with 33 as a voltage follower. In states φ3 and φ4, red Snake D32 turns on and turns off, and a similar switching action It occurs at -7 in the second detector channel 44 and intensifier 2. More detectors The outputs 2 to -1 and 2 to -7 of the width transducer are thus energized at 50% operating cycle. , half the period is inverted and the other half is non-inverted. Direct current or low frequency voltage has opposite polarity removed by two adjacent pulses with On the other hand, the photodetection signal DLS is , only exists in one of the two time states and is effective with a gain of about 0.25. effectively amplified.

Amplifier 2-1 and 2-1) outputs, signals rRLs and RLS are are supplied to matched low-pass filters 45 and 46, respectively, for frequencies below about 10 Hz. The details are transmitted. The matched low-pass filters 45 and 46 are connected to the amplifier 3 at -1,4. -7 at -1°3, -7 at 4, and approximately 4 at signals IRLS and RLS, respectively. Grant a gain. These filters have a switching component of about 2KHz and a total Remove all high frequency noise.

The signal processing means for processing the EKG signal and the optical signal is, for example, Intel 8 It includes a programmed microprocessor such as a 085A. Therefore, the equipment Explain basic functions so that they can be understood. At the same time, this invention The following is a detailed explanation of the improvements made.

Referring to FIG. 1, the signal processing means includes a microprocessor 16 and a data bus 17. ．． RAMI 9. ROMI 8. Latch 23° comparator 52. analog Multiplexer 50. Hold circuit 200. Gate 24. Latch select 21. consisting of latch digits 22 and display 20, each connected to bus 17. connected and thereby placed under the control of microprocessor 16. data bus 17 switches digital information going in and out of the microprocessor 16 and each component. I can do it. Uh, Chi Select 21. The latch deshift 22 and display 20 are Displays all measured blood component amounts (e.g. optical pulse rate and oxygen concentration) and a suitable numerical display for indicating.

The function of the signal processing means is to use an optical signal detector and an EKG detector for continuous waveform analysis. It converts each analog signal from the output device into a digital signal independently. Ru. Waveform analysis is performed by microprocessor 16. By ROM18 and RAM19 controlled.

Figures 6A to 6C relate to optical signal and EKG signal detection systems. be. The oximeter's microprocessor makes a determination of the optical signal and determines the Determine oxygen saturation and pulse rate by the method.

A preferred embodiment of the present invention processes the EKG signal and displays the calculated EKG pulse rate. using the same analog-to-digital conversion circuitry that processes the optical signals. to generate the diagnostic EKG signal DEKG and the filtered EKG signal FEKG. A means for converting into a digital EKG signal may be incorporated into the microprocessor 16. That is. As shown in FIGS. 5A and 5B, an analog multiplexer 50 is the input terminal of the ADC of the pulse oximeter, and this analog multiplexer 5 0 consists of two analog multiplexers 5G and 6G. light pulse Signals V a', V b', V a and vb are each sent to multiplexer 5G. is connected to pins 13, 14, 15 and 12 of. Improved equipment allows diagnosis ! ! The frEKG signal DEKG is connected to pin 15 of multiplexer 6G and The EKG signal FEKG that has passed through the filter is sent to pin 12 of multiplexer 6G. Connecting.

A microprocessor 16 is used to convert all analog inputs into digital signals. connects the clear channels of either 5G or 6G multiplexer. Must dress. This sends a 3-bit word to both ports via bus I7. This is achieved by inputting to pins 9, 10 and 11 of the multiplexer 5G, 6G. It will be done. The microprocessor program generates signals Va, Vb, Va' and vb ’ plus conversion of EKG signals DEKG and FEKG from analog to digital Furthermore, these digital signals are stored in the RAM 19 as appropriate. It will be done.

As shown in Figures 4A, 4B, 5A and 5B, the microprocessor The sensor 16 converts the analog signal by selecting which input is converted. Convert to digital signal and load digital word into latches 8H and 9K .

Latches 8H and 9 are connected to the DigiCrew Analog Converter (DAC) 8K. Stores the digital words provided.

This digital-to-analog converter (DAC) 8 converts digital signals into analog convert the signal into a DAC. Signal DAC is fed to pin 2 of comparator 5H . The other input to comparator 5H at pin 3 is Microbrosse, 2s16. In Anacok No. 18 by multiplexer 5o to convert selected by be. To DAC3! , :The analog signal supplied by Therefore, is it supplied? When the analog fault value is exceeded, the output DAC of comparator 51 MP becomes logic value "1'. Digital word is converted to analog voltage by DAC8K. This analog voltage is supplied by multiplexer 50. It is lower than the log pressure, and the output DACMP of the comparator 5H changes to the logical value “O”. picture·':,). As shown in Figure 4B, the output DACMP is a status latch 9G. -17 is input. Then, this output D A CM P +, :j: Microphone The data is sampled by the l processor 16 at a period of 57 cycles/sec.

When the microprocessor detects the logical value "0", the latch 8 shown in FIG. The words stored in H and 9K indicate the physcial value of the analog signal and its This word is stored in RAM 19 by microprocessor 16 for later processing. -1).

Regarding EKG signal processing, Microbe I] CEF 41□16 uses appropriate software. Software control allows stored digital words to be analyzed as LEKG waveforms. Calculate the amplitude 2, - amplitude is calculated from the digital source 1 supplied to the DAC 144. By changing ', the AGC amplifier 140 is not restricted and is used for S.

As a result, the output D E K G and t? εK G controls p concave circle 2 Must be within the voltage range limits of the electronic circuitry used for signal processing and reliable. It is compatible with not at all spoiling the important emotion within the issue. Standing-Nika In other words, in the non-integrated state, independent and continuous pulse signal processing is performed. , calculates and displays oxygen concentration and pulse rate. And 2, at the same time, EKG wave Shape D E K G, F E K Gtri J’, Bi D RW! =Y, Tsuite Continuous processing is also carried out, and when the predetermined state is reached -7, the status enters Karanochi 9. A flag is generated inside the microprocessor 16 and the microprocessor 16, and the next is executed.

As shown in Figures 4A, 4B, 5A and 5B, the microprocessor The sensor 16 periodically sends a status input signal at a period of about 57 cycles/sec. Search for Chi9G. According to the invention, the output DRW is also provided by the flip-flop 280 The status is input to Karanochi 9G via . In this way, the detected R wave D When RW is logic (^“1’), macroblock sensor detects 1 status. , select the next action based on this status. The action occurs subsequently It can be one of the events. In the initial stage of R-wave detection, micro Processor 16 clears output 280-1 of flip-flop 280 to a logical value. "O" and the step at input terminal 9G-19 regarding EKG output DRW. Clear Karanochi with Tatas. At this initial stage, the microprocessor 16 uses the clock 70 to detect the R-wave pulse DRW and then input the status. Start measuring the time interval until the next logical value “1°” is generated in latch 9G. Based on the time interval measured by Show numbers. Establish a regular EKG pulse rate by calculating the average of several time intervals. After that, the microprocessor 16 moves to the second processing stage.

R/ll! ! With the detection of the pulse, the microbrona, S16, detects the time of the light pulse. Start calculating the amount. This light pulse is separately processed by the microprocessor 16. This is determined by analyzing the digital optical signal. Note that this optical pulse is A time window that follows the outgoing R-wave pulse and is the period during which an optical pulse can be generated. is confirmed. During the second phase, the pulse oximeter continues to detect The pulse time period, that is, the pulse period, is calculated and displayed.

The third processing step begins after the time window has been established. With the detection of R-wave pulse Then, Mike "] Processor 1G activates the time window. As a result, the R-wave pulse Only Hikarigo issues that follow the occurrence and are detected within this time window will be accepted. D (If 11' is divided by 1 constant, this is the oxygen concentration, H'l1ii:) - 111 is used for calculating and displaying fixed values related to life such as blood pressure and pulse rate. , , , the determination of the detected pulse is determined by a preselected reliable '7! ! elemental spirit This element is achieved by a 9,1-containing optical signal. The quality of Hikari No. 13 The higher the value, the better the correlation between the recorded pulse course and the 1Hi7 output pulse. Reliability becomes 9 stone. This reliability is automatically determined by the microprocessor. Ru. This reliability is due to the improved 4th make operation ftL. It will be adjusted.

Microprocessor 16 eliminates all detected pulses that occur outside the time window 17 [Sui], What is the specific time window for performing fingertip oximeter testing on adult males? R wave occurs (approximately 50 m s e c from 2,7 .

Also, the oximeter detects a tumor for which one pulse has been detected, if the time window has not yet expired. Eliminate all pulses detected within the same time: α, even if not.

If no pulse is detected while the time window is in Lobrocenosa 16 has been lowered! to search for light pulses. this is , performed during a time window of 4 or several (e.g. 3) consecutive detections of the R-wave DRW. , then the microprocessor 16 performs a search with the lowered criteria for a predetermined period of time ( If no light pulse is detected after a period of 10 seconds (for example, 10 seconds), the microb U SENO''++16 is an independent or non-integrated processing process of optical signals and EKG signals. and the pulse oximeter returns to its initial state. Therefore, oximeter can establish or maintain a reliable correlation between the R-wave and the optical pulse. If not, each waveform is processed independently. Oxometer is EKG and A display that shows that the optical signal data is integrated and the amount of blood components is calculated. It is suitable if it is installed. After achieving the third processing stage, the EKG or optical signal If any deviation is lost, an alarm will be activated and the program will return to its initial state.

Although all the operations have been explained, this can be explained using the calculation software shown in Figures 6A to 6C. The software will be illustrated and explained by a flowchart. In FIG. 6A, R The wave determination routine receives electrical signals from the E and KG leads at 600. The period from the detection of the previous R wave to the arrival of the next R wave is determined in 601. Calculate the time RRPER. Average time from previous R wave to current R wave HI 5TORY is calculated at 602 and at 603 the time RRPE determined at 601 R is compared to the average time HISTORY. RRPER is HI at 604 If it does not match 5TORY, the routine jumps to 613 where the flip The R wave (or EKC flag) on Pflo knob 280 is reset and the routine I was forced to wait for another R wave. 604, RRPER is HI 5TORY If the timer is activated at 605 and an R-wave pulse is generated, the light is emitted. Measure the time until the pulse occurs. At 606, the output HRCEKG heart beat rate) is calculated based on continuous R waves. At 6o7, the system Inquires whether the R-R cycles of are synchronized (EKG synchronized). If not synced , the system compares the output F(R at 609 with a preset heart rate). The system checks the alarm and generates an i-report if the output HR is too low.

At 608, the EKG is synchronized and the flow from light pulse to light pulse is not synchronized. If not, the output HR is transmitted to the display at 609 and the output HR is transmitted at 610 to the display. Alarm checks are performed. If the optical pulses are synchronized at 608, , the system further checks for alarms at 610 . EKG is synchronized And only when the optical pulses are not synchronized, and the R wave is compared with HrSTORY. If the R-wave is different in 611, HI5TORY uses the new R-wave. will be updated. After updating HI5TORY, the system itself will be updated at 612. is updated (timed out). EK if timeout is not updated for 5 seconds G synchronization is lost and a new HI5TORY must be created.

Figure 6B shows digital light for propagating optical pulses in the third stage (see Figure 6C). 3 is a flowchart showing a system routine for pulse information processing. The system is 6 Starting with continuous evaluation of the data of the detected digital optical signal at 44 do. This data is first determined at 645 for suitability for signal processing.

If this data exceeds the voltage range of the electrical circuitry and becomes electrically overvalued or undervalued, If so, the system exits the routine at 646 and sets the LED brightness to the electrical value. Therefore it is adjusted correctly. If the data fits, this data is then The number will be evaluated. At 651, the relative maximum value is determined and saved.

The next value is then compared with the saved maximum value, and if a new maximum value occurs, It is saved instead at 651. If the value found is not the new maximum value , 650, the max flag is sent. Then the next received data and again at 653, bypassing the maximum section 648-652. Detect the maximum slope by successive comparisons of . When the maximum slope value is detected, 65 Saved at 8 and raised slope flag at 656. after that, The following data is evaluated to 659-662, bypassing the maximum and slope calculations: Detect the minimum value corresponding to the end of the pulse. When the lowest minimum value is detected , its value is saved at 661 and the slope value saved at 658 is 6 63, the slope value is compared with a predetermined minimum threshold value, and this slope value is It is determined whether it is large enough to become a space. If this slope value is large enough If not, the pulse is rejected at 664 and 659 and 656 at 665 The flag generated at 644 is reset and the routine returns to the next valid pattern at 644. Start the process of russ. If the slope is large enough, the maximum value of each parameter of the pulse , the minimum value and the slope are saved in memory at 667, which is used to determine the correct pulse used in the third stage of evaluation. Then, the appropriate pulse from the R wave The delay time will be calculated. The data flag is then set at 669. This data flag indicates that there is a valid pulse that can be evaluated for the third stage. Instruct. And Max and slope flags are recessed at 670. After that, the routine begins processing the next data and generates a new update corresponding to the correct pulse. Search for large values.

Referring to Figure 6C, the software for the third stage of the component [1 constant calculation] is shown. ing. The system detects a potential optical signal at 615 after the data flag is generated. Wake up by typing. Then, EKG synchronization is performed and regular EKG cycles are performed. Ask if the period is fixed. If no data flag occurs The system exits the routine at 617. If EKG synchronization is not performed In this case, the microprocessor processes the optical pulse signal independently of the EKG. this This tends to occur with Nelcar N-100 oximeters that do not have EKG capability. be. The question at 616 as to whether an R wave is present is then bypassed.

If F, KC synchronization has been performed but no R wave has occurred, the system will The routine is exited at , and the pulse is not processed. As EKG synchronization is performed If an R-wave occurs, the microprocessor processes the pulse as described below. Ru.

It is determined at 618 whether the LED brightness requires adjustment.

Reset system gain based on minimum required LED strength for proper signal strength , is checked if the g clause is required.

The course of the light pulse is calculated at 620, which is based on the historical average pulse width, amplitude and It is done on a periodic basis. The system then checks the EKG device at 621. Ask if it is working properly. If operating properly, at 622 , the average time from the R wave to the next optical pulse is calculated for the four most recent pulses. and the time window is calculated. Then, at 623, the pulse waveform is analyzed and the current Observe whether Shigenobu's notch is present rather than an actual light pulse. Shigenobu The descent of the notch (ψ oblique or other artifacts can be mistaken for a light pulse. However, this The amplitude of these pulses is 1/2 of the actual pulse amplitude, 625 if the pulse is determined to be an artifact or an artificial structure. The system then determines from the routine and processes the next pulse supplied.

If it is determined that it is not Notsuchi, 626! The pulse is analyzed at , :, FJ is determined.

Assuming the EKG is synchronized, does the system meet two criteria? 1 set. The first group 7 is that the time delay falls within the pre-calculated time window. It depends on whether or not there are.

If this is not met, the microprocessor rejects the pulse. Second The test criterion is whether the cycle is within an acceptable range. Pulse is both reference If it satisfies the above, the pulse is accepted and saturation calculation is performed.

If the EKG is not synchronized, the comparison at 627 determines (1) pulse time, ( Two of the three coefficients must be provided: 2) amplitude, and (3) period. child Preferably, this is a pulse that is transmitted as an accepted pulse. these pairs For example, the combination may be pulse, time, 2 hours, and amplitude, pulse and amplitude, or all three. . Once the pulse is received, the oxygen concentration is calculated at 628.

After the system is powered up, or a timeout alarm ( If no proper light pulse is detected for a period of 10 seconds), the #element concentration is A series of constituent pulses are used to generate a course of light pulses before being transmitted to the play. must be detected. As a result, the optical pulses are synchronized at 629. If not, the oxygen concentration will not be displayed at 630, and all accepted A light pulse that is rejected or not accepted is a pulse that is removed as an artifact. 631-643 are entered into the calculation routine.

If the EKG signals are not synchronized, the optical heart rate (OHR) is calculated at 632. To perform the calculation, the time from pulse to pulse and the width of one line, or period, One of these must exist L5. EKG':, two or optical normals and 'r) force) is executed at iTh% 632 when [kawamei] is 11. Ul-IR The calculation of is displayed in 634), and if the same JJ is like total < f, OHR2, Please display, Noiyu 635-6434 Kooi ζ-1・Nislam (j: Pulse! 1 1 fixed 1 phantom cup has been reached, and the time window has opened. Judging whether it is Aotsu or not, ′:J. fFK G synchronization is performed and the preferred pulse is I ★If issued, Saturday 7:: (; Time $ 5 iI1 period has finished 9,), time window The next Y wave is (extrusion I”i); ll　：After March, 1 prick leaked and blood was formed. 1. ’l, f,: Patient’s blood acid The elementary saturation is Z + 6 oxygen saturation (the old calculation is; h, color), detected at 2 -, Comparing the pulse detected by the first ray of red light and the pulse detected by the first ray of red light, we obtain 7. ) is executed based on the coefficient, and the relationship between 5 and 2 is shown by the following equation. Zu'5 aRR2-R (BRI> Oxygen saturation--1~--1--1--1--1------- -----X100″! Stone R (801-BRI) +B172-802 Here, 1301 is light wavelength 1 (red evening (line) (,)!/Jte] oxidized S]': globin extinction coefficient for BO2 is the extinction coefficient for 1 bottle of oxidized hemoglobin at light wavelength 2 (red) BRI is the extinction coefficient for reduction/nee globin at light wavelength 1 BR2 is the extinction coefficient for reduced cobin at light wavelength 2 Optical wavelength technology uses red and F-ray light. Light wavelength 2 is red light And R is a coefficient of light intensity of wavelength 2 with respect to wavelength 1, and is calculated as follows.

Jn ([max2/lm1n2] R=□～-1-□ In(Imaxl/lm1nl) here, l max 2 is the maximum transmitted light I min 2 at light a length 2 is 8 orders of magnitude at light wavelength 2. The minimum transmitted light I max 1 is the maximum transmitted light lm1nl at the light wavelength 1, which is the light wavelength As is known to those who have worked in this technical field, the minimum transmitted light at Various extinction coefficients can be determined by experimental studies. For convenience of calculation, the coefficients are The natural logarithm of the ratio is calculated using the Taylor expansion series for natural logarithms.

As another example, the microprocessor can be programmed to determine the duration of the first pulse. Utilizes the correlation between detected R-wave DRW pulses and optical pulses without the need for can be adapted to do so. In this embodiment, a microprocessor 16 searches for the status person Karanochi 9G, and the detected R wave D RW is logical value “1”. At some point, the microprocessor 16 detects the R-wave pulse frequency 6! Detection regardless of i number R wave D F? Analyze the optical signal that follows the W pulse. Follows numerous R-wave pulses By comparing the optical signals that Extraction of pulses shown in , detection R wave D R', detection pulse that follows V pulse Calculate the correlation with time.

Referring to Figures 2A and 2B, the EKG front end printed circuit board The board wiring diagram shows the breathing monitor section. used. The respiration monitor uses a pressure-sensitive detector to detect respiration at 2-, l-2; It is designed to detect the floating of the wall of the dog part by the 7i11 constant of pressure change. pressure The force detector is Grasby Dynamis! Gas type sensors such as gas pressure capsule senna or with a silicone rubber tube filled with liquid water. 5. By tightening f1i[71+, it can be operated as a variable resistance. gas According to the type sensor, no matter how it is designed, it will not occur during breathing. The movement is caused by a pressure transformer (for example, Spnsym type LX 0503 A bridge pressure converter) and converted into a voltage signal11. bridge output signal or other The voltage signal is connected to a differential amplifier lA having a nominal gain IJ of IO2 or more -L. difference Is the output of dynamic amplifier IA AC? 7i is combined and frequencies below approximately 0.07Hz are removed. The signal is +11, and the signal is 1-Natsuyama by the amplifier IB. This signal is IA It is transmitted through a low-pass filter interposed between and IB. This low pass filter is approximately 5 It has a nominal cut-off frequency of H2. The output of the low-pass filter is further amplified, and AC coupled to the first buffer amplifier ID. At this point, the signal is transferred to the second amplifier ID is input to the respiratory voltage Vre! ip is generated. This V resp is chest This is an analog waveform showing the fluctuation of . Also, the output signal of the first amplifier ID is at the threshold The respiratory waveform and the reference threshold value set pass through the value detector 1E, and the threshold value detector 1E) IT: ,,! ,, without comparing). This reference threshold voltage is be set or adjusted by If the amplitude of the respiratory waveform is larger than the reference threshold, In this case, the detector output increases to approximately +5■. , 2+5vO'y electric 1 piece; yo invar Data 2AS is converted 7, digital pulse F? SPTRGM formation n, this RS　P　T　RG of 　P　T　RG corresponds to the respiration nosaku -4''.This RS　P　T　n　G , from the status latch qc-z] 7. τ).

Monitoring of respiratory movements is helpful. For example, many infants and children You may have difficulty breathing, which may cause your breathing to stop during sleep. Fi1 wall call Check for such interruptions and cessation of breathing by monitoring the inhalations. I can do it. In a preferred embodiment, the microprocessor creates and regulates the respiratory history. Establish a regular breathing pattern. After that, breathing occurs within a predetermined period (for example, 15 seconds). If not, the alarm will be activated. Respiratory movement model correlated with EKG-enhanced oximetry If the patient's blood flow characteristics decrease during sleep due to monitoring, this decrease may be abnormal. Whether due to normal breathing, respiratory arrest, or other causes It is possible to determine whether the

call como rijiri Brief description of the drawing FIG. 1 is a block diagram illustrating the improved method and apparatus of the present invention; FIG. 2A and FIG. FIG. 2B shows the electrocardiogram detection electrical circuitry and system electronics of the present invention. Circuit wiring diagram, Figure 3 is an explanatory diagram of the output waveform in Figure 2, Figure 4A and Figure 4Br f! J is a detailed circuit wiring diagram of the microprocessor status input in Figure 1; Figures 5A and 5B show the analog multiprocessor of the microprocessor in Figure 1. Detailed wiring diagram of plexer and digital analog converter, Figure 6A, Figure 6B Figures 6C and 6C show the electrocardiogram and optical pulse microprocessor of the present invention. Fig. 7 is an explanatory diagram of the output waveform in Fig. 1, Fig. 8 is a flowchart showing the operation of the Figures are illustrations of oximeter timing diagrams, Figures 9A and 9B. is a detailed wiring diagram of the isolated front-end printed circuit board in FIG. .

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I Continued phase■ Positive 1 bottom (method) ■Death January 30, 1962

Claims (19)

[Claims] 1. Blood flow, including arterial pulses and artifacts, detected in the patient's body tissues By optical detection using a device that calculates the amount of blood components from blood flow, A method of measuring optical pulses in a patient that detects the occurrence of a patient's heartbeat. Correlate the optical pulse with the detection of the optical pulse by the oximeter and set the correlation value. The optically detected pulse using the detected heartbeat and the measured arterial pulse. Improved patient optical pulse measurement featuring determining whether Method. 2. In the method according to claim 1, the means for detecting the occurrence of a heartbeat comprises: An improved patient characterized by detecting the occurrence of a selected portion of a patient's electrocardiogram waveform. optical pulse measurement method. 3. In the method according to claim 2, the selected portion of the patient's electrocardiogram waveform is An improved method for measuring an optical pulse of a patient, characterized in that it is an R waveform portion. 4. In the method according to claim 2, generation of a selected portion of an electrocardiogram waveform is performed. The means for correlating the detection of optical pulses detects the arterial pattern after the occurrence of selected portions of the electrocardiogram waveform. In addition, the optical pulse determines the time to detect the electrocardiogram waveform as much as possible. The optical pulse can be treated as an arterial pulse when measured for a predetermined period of time after its occurrence. Predetermining the optical pulse as the first pulse or after the occurrence of a selected portion of the ECG waveform Is it a second pulse that cannot be treated as an arterial pulse when detected outside the period? An improved method for measuring optical pulses of a patient, characterized in that: 5. In the method according to claim 4, the amount of blood components is further increased within a predetermined time. Improved patient blood flow measurement characterized by optically measured blood flow at Optical pulse measurement method. 6. Means for optically detecting blood flow in body tissue, including arterial pulses and artifacts means for detecting a patient's heartbeat in an apparatus for detecting optical pulses of a patient comprising: and a means for correlating optically detected arterial pulses with the occurrence of heartbeats, and further testing. A means of determining whether the output pulse is an arterial blood pulse and is optically detected. and a discriminating means responsive to the detected arterial pulse and the detected heartbeat. An improved Fool's optical pulse detection device. 7. In the device according to claim 6, the heartbeat detection means further comprises: Means for detecting electrical heartbeats in the form of an electrocardiogram waveform and filtering of the electrocardiogram waveform to produce an electrocardiogram By detecting selected components of the waveform, the occurrence of said detected components indicates the occurrence of a heartbeat. What is claimed is: 1. An improved patient optical pulse detection device comprising: 8. In the device according to claim 7, the selected component of the electrocardiogram waveform is an R waveform. An improved patient optical pulse detection device characterized in that: 9. In the device according to claim 7, the predetermined time is set by the correlation means. the optically detected arterial blood pulse at this time as a selected component of the electrocardiogram waveform. The pulse detected by the discriminating means is substantially subsequent to the occurrence of the pulse, and the pulse detected by the discriminating means is within the predetermined time. It is determined that the detected pulse can be used as an arterial pulse. An improved patient optical pulse measuring device characterized by: 10. In the apparatus according to claim 9, further optical inspection is performed at a predetermined time. The method is characterized in that it includes means for measuring the amount of blood components and heart rate in response to the emitted blood flow. An improved patient optical pulse measurement device with the following features: 11. The amount of blood components is determined using a method that transmits light from the patient's bloodstream into the patient's body tissues. This method uses a photoelectric method to measure the transmitted light and detects the amount of light transmitted through the artery. Converts analog blood flow signals, including pulses and artifacts, to digital signals. The arterial pulse is detected by digitally processing the digital signal, and the arterial pulse number and movement are In a method for measuring the amount of one or more blood components present in pulsating blood , detects the patient's heartbeat as an electrocardiogram waveform with selected components corresponding to the heartbeat. The electrogram waveform is converted into digital heart pulses corresponding to each occurrence of selected components of the EKG waveform. convert it into a digital electrocardiogram waveform with The digital electrocardiogram waveform and digital heart pulse rate are compared with the arterial pulse rate to determine a predetermined value. Set the time so that the selected portion will fire when an arterial pulse is assumed to be detected. After birth, the arterial pulse follows the occurrence of selected portions of the electrocardiogram waveform at intervals of time, and Next, the digital signals detected within the set time are digitally processed and the arterial pattern is calculated. measuring the number of lupus and the amount of one or more blood components present in the blood An improved patient optical pulse measurement device featuring: 12. The apparatus of claim 11, wherein the selected number of heartbeats is A digital heart pulse is detected within the time it should have occurred based on the heart rate of Improved feature of restarting processing of all digital signals if not present Patient optical pulse measurement device. 13. 13. The apparatus of claim 12, wherein the apparatus operates within a selected number of times. Special feature that restarts processing of all digital signals if no pulse pulse is detected. An improved patient optical pulse measurement device with the following features: 14. Any one of claims 1 to 5 and 11 to 13 In the method described in , the method for measuring the amount of blood components further includes measuring hemolysis in arterial blood. An improved patient characterized in that it consists of measuring the oxygen saturation status of globin. optical pulse measurement device. 15. Optically detects blood flow including arterial blood pulses and artifacts as digital signals. Equipped with a microprocessor, it measures the amount of blood components in the patient's body. Electrocardiogram leads electrically connected to the patient in an improved non-invasive device that detects the patient's electrical heartbeat waveform and generates selected portions of the electrical heartbeat waveform. A hand that generates a digital waveform with a series of digital heart pulses corresponding to the an electrocardiogram circuit means electrically connected to the electrocardiogram lead, and an electrocardiogram waveform; means for indicating that a selected portion of the The electrocardiogram circuit means that each digital signal is A cardiac pulse energizes the status input device to generate the selected portion of the ECG waveform. status input means to display the ECG pulse number and respond to the ECG circuit device. electrocardiogram signal processing means that calculates the digital signal and digital heart pulse waveform. and over multiple digital heart pulses, and set a base time that allows The arterial blood pulse follows selected portions of the electrocardiogram waveform and is measured as a timed period. A digital display that displays the arterial blood pulse after the occurrence of a digital heart pulse within this period. Microprocessor and electrocardiogram signal processing an analysis means coupled to the device and a microprocessor for generating digital heart pulses; To prevent analysis of signals other than digital signals measured within a specified time period after birth. means that responds to the set time period and the digital waveform, thereby determining the heart rate. A program that calculates blood components based on each component of blood flow detected within a predetermined time period. an improved patient optical pulse measurement device comprising: gram interrupting means; Place. 16. In the device according to claim 15, the first reset means is a microphone. a selected number of digital cores by coupling to and energizing a microprocessor; Separates all digital optical signals when no optical pulse is detected after the pulse has occurred. An improved patient optical pulse measuring device characterized by: 17. In the device according to claim 15, the second reset device is a microphone. Digital heart pulses are detected by connecting to and energizing the heart processor. after the selected number of heartbeats should occur based on the given heart rate. Improved patient optical pulses featuring analysis of all digital signals measuring device. 18. In the device according to claim 15, the electrocardiogram circuit means further comprises: Includes variable resistor means in the feedback loop that can control the electrical heartbeat an automatic gain control amplifier that amplifies the waveform and adjusts the gain of the automatic gain control amplifier; The electrical heartbeat waveform is non-inverted or inverted for the human-powered switching means. polarity switching means for maintaining uniform polarity of the signal output from the electrical heartbeat waveform; selectively passing the frequency between 15 and 40 Hz, thereby selecting the electrocardiogram waveform. A bandpass filter that passes only the relevant frequencies of the detected components and a digital signal output. forming an electrocardiogram circuit means for carrying out an electrocardiogram for processing by a microprocessor means; An improved patient light comprising: an analog-to-digital conversion means; Medical pulse measuring device. 19. In the device according to claim 15, the electrocardiogram circuit means further comprises: It has an adjustable reference signal and an electrical heartbeat waveform as an output, as well as a digital heartbeat waveform as an output. has a digital heart pulse waveform and compares the electrical heart beat waveform to a selected reference signal. comprising comparison means so that the selected portion of the electrical heartbeat waveform corresponds to the reference signal; a comparator for generating a digital heart pulse and the output of this comparator means; bistable circuit means connected to the side and having a first condition, a second condition and a reset operation; The first condition occurs when a digital heart pulse occurs and the status input is display the occurrence of selected portions of the electrocardiogram waveform by energizing the force device; The second condition occurs when the bistable circuit is reset without the selected part occurring. , and the reset operation also causes the display of the portion selected by the microprocessor to remain unchanged. output of the bistable circuit means from the first condition to the second condition. An improved optical pulse measurement device for a patient, characterized in that the optical pulse measurement device is characterized in that: