CN1307937C - Signal peak point search device and method and its application in blood pressure measurement - Google Patents

Abstract

The invention discloses a signal top end point searching device which comprises a plurality of operational amplifiers, a plurality of capacitors, resistors, variable resistors, diodes and transistors. It can be used to measure the apical points of the Electrocardiograph (ECG) or photoplethysmography (PPG) signals delivered by the body, which can be used for the measurement of the body's blood pressure. In addition, the invention also discloses a signal top end point searching method and application thereof in blood pressure measurement. The device of the present invention can be applied to, but not limited to, a lossless, continuous and wristband-less air bag type sphygmomanometer, and aims to simplify the later signal processing, such as a signal top end point searching procedure. Therefore, some signal processors with slower operation speed can be selected for signal analysis. Compared with the common signal processor, the cost is lower and the electricity is saved, and the time for developing the processor is relatively reduced due to simplified procedures, thereby greatly increasing the cost benefit.

Description

Signal peak point search device and method and its application in blood pressure measurement

technical field

The present invention generally relates to signal measurement technology, and in particular to a device and method for searching the apex point of a signal such as an electrocardiogram signal (ECG) or a photoplethysmography signal (PPG) issued by a human body in blood pressure measurement and its application in blood pressure measurement. Application in blood pressure measurement.

Background technique

Today's sphygmomanometers can be divided into two categories: damaged sphygmomanometers and non-destructive sphygmomanometers. Because the damaged sphygmomanometer needs to damage the patient's skin during the measurement period, it is easy to cause bacterial infection and blood flow. Therefore, for the sake of safety, comfort and convenience, general medical staff and citizens are willing to use non-destructive sphygmomanometers as blood pressure measurement tools.

Today's non-destructive sphygmomanometers mainly include Tonometer, Sphygmomanometer and Photoplethysmographic meter.

Tone measuring sphygmomanometers use a set of pressure sensors to measure the patient's blood pressure signal waveform, but because the sensors used in this method are expensive and easily interfered by the measurement location, they are not popular in the market.

There are two measurement methods of the pulse sphygmomanometer, namely the auscultatory method and the vibration method (Oscillometric method). The principle of auscultation is to collect what are called Korotkoff sounds. Vibration Law requires the help of wristband airbags to collect pressure vibration signals. Its disadvantage is that repeated use of the pulse sphygmomanometer will cause the patient's blood vessels to be compressed, which will reduce its accuracy and is not conducive to continuous blood pressure measurement.

There are two main types of photovolume change sphygmomanometers. The first type of photovolume change sphygmomanometer determines the change of blood volume in blood vessels through the change of light, and thus finds out the relative blood pressure change. This approach assumes that changes in blood volume and blood pressure are similar, but this assumption has not been proven experimentally. The second type of photovolume change sphygmomanometer utilizes the relationship between blood pressure and pulse wave velocity. When blood pressure rises, blood vessels harden due to dilation of blood vessels, thereby increasing pulse wave velocity. Therefore, as long as the relationship between pulse wave velocity and blood pressure is found, the patient's blood pressure can be measured.

Pulse wave velocity can be determined by pulse transit time (Pulse Transit Time). The pulse transit time can be determined by measuring the time difference between the ECG signal and the photoplethysmography signal. When using the time difference between the electrocardiogram signal and the photoplethysmography signal to measure the pulse transit time, the usual practice is to use the top point of the R-wave signal in the electrocardiogram signal and the top point of the photoplethysmography signal as the measurement base points respectively , and calculate the time difference between these two base points to determine the pulse transit time.

There are already some instruments in the prior art that can use the above method to measure the pulse transit time. However, the shortcoming of these existing measuring instruments is that the work that they are used to perform the signal top point search is generally completed by a complex software program such as the top point search program, and the complex software program has higher requirements on the signal processor. This increases the development cost of the whole instrument, and its development time is also longer.

Contents of the invention

Therefore, the present invention is produced in view of the above-mentioned shortcomings in the prior art, and its purpose is to provide a signal top point search device and method and its application in blood pressure measurement, which can make the signal top point in the blood pressure measurement process The point search process is simplified, and at the same time, the accurate time at which the top point of the signal as the measurement base point appears can be effectively measured, and then the time gap between the measurement base points is used as a reference index for measuring blood pressure.

In order to achieve the above object, according to the first aspect of the present invention, it provides a signal top point search device, which includes: an input terminal, used to input the signal to be tested; a current steering detection circuit, used to The input current direction of the measured signal and output the corresponding signal; the top point detection circuit is used to detect the top point of the signal to be tested, so that the amplitude of the output signal can be kept near the top point as much as possible, and the output signal can be close to a certain amplitude The DC signal; the amplitude adjustment circuit, used to adjust the amplitude of its input signal; the amplitude comparison circuit, used to compare the amplitude of its input signal, and output the corresponding signal according to the comparison result; the switch circuit, used in the control signal The signal passing through under the control is turned on or cut off; and the output terminal is used to output the signal to the outside,

Wherein, the signal to be measured is input to one end of the amplitude comparison circuit through the input end, the top point detection circuit and the amplitude adjustment circuit, and the signal to be measured is also directly connected to the amplitude comparison circuit through the input end. The other end of the comparison circuit, the amplitude comparison circuit compares the amplitudes of the two input signals, and outputs the comparison result signal to the control end of the switch circuit as its control signal, and the switch circuit according to the control The signal control is to output the signal from the input terminal through the current steering detection circuit to the outside through the output terminal, or cut off the connection between the current steering detection circuit and the output terminal.

In the signal top point search device according to the first aspect of the present invention, the signal output from the current steering detection circuit to the output terminal through the switch circuit is a square pulse signal, and the square pulse signal is the same as The top points of the signal to be tested have a corresponding relationship.

In an embodiment of the present invention, the falling edge of the square pulse signal corresponds to the top point of the signal to be tested.

In the device for searching for a top point of a signal according to the present invention, the signal to be tested is a signal capable of reflecting physiological characteristics of a human body.

The human physiological characteristic signal may be an electrocardiogram signal. In this case, the input terminal is connected to the sensor of the electrocardiogram signal, and the signal apex point measured by the device at this time may be the apex point of the R-wave signal in the electrocardiogram signal.

The human physiological characteristic signal may also be a photoplethysmography signal. In this case, the input is connected to the sensor of the photoplethysmographic signal, and the top point of the signal measured by the device at this time is the top point of the photoplethysmographic signal.

In an embodiment of the present invention, the top point detection circuit includes a first operational amplifier, a second operational amplifier, a diode and a capacitor,

Wherein, the non-inverting input terminal of the first operational amplifier is connected with the input terminal of the device, and its inverting input terminal is connected with the inverting input terminal and the output terminal of the second operational amplifier, and the first operational amplifier The output terminal of the amplifier is connected to the non-inverting input terminal of the second operational amplifier through the diode, and the non-inverting input terminal of the second operational amplifier is grounded through the capacitor.

In addition, in the embodiment of the present invention, the output end of the device may be connected to an external signal processor for processing the output signal of the device.

According to the second aspect of the present invention, it provides a method for searching the top point of a signal using the above-mentioned device, the method comprising the following steps: 1) inputting the signal to be tested through the input terminal of the device; 2. ) using the current steering detection circuit to detect the current steering of the signal to be tested, and output a corresponding signal; and 3) selecting a signal related to the top point of the signal to be tested from the signals output by the current steering detection circuit and outputting the signal.

The method further includes the following steps: 3-1) using the top point detection circuit of the device to detect the top point of the signal to be measured, so that the amplitude of its output signal is maintained near the top point as much as possible, and its output signal is close to the top point. It is a DC signal with a certain amplitude; 3-2) using the amplitude adjustment circuit of the device to adjust the amplitude of the output signal of the top point detection circuit; 3-3) using the amplitude comparison of the device The circuit compares the magnitude of the signal to be measured input through the input terminal with the magnitude of the output signal of the top point detection circuit, and generates a comparison result signal; and 3-4) using the comparison result signal as a control signal to The switch circuit is controlled to turn on or cut off the signal output by the current steering detection circuit to the output terminal of the device.

In the signal top point search method according to the second aspect of the present invention, the signal output from the current steering detection circuit to the output terminal through the switch circuit is a square-shaped pulse signal, and the square-shaped pulse signal is the same as The top points of the signal to be tested have a corresponding relationship.

In an embodiment of the present invention, the falling edge of the square pulse signal corresponds to the top point of the signal to be tested.

In the signal top point search method according to the present invention, the signal to be tested is a signal that can reflect the physiological characteristics of a human body.

The human physiological characteristic signal may be an electrocardiogram signal. In this case, the input terminal is connected to the sensor of the electrocardiogram signal, and the signal apex point measured by the device at this time may be the apex point of the R-wave signal in the electrocardiogram signal.

The signal to be measured may also be a photoplethysmography signal. In this case, the input is connected to the sensor of the photoplethysmographic signal, and the top point of the signal measured by the device at this time is the top point of the photoplethysmographic signal.

In addition, in an embodiment of the present invention, the method further includes the step of processing the output signal of the device by using an external signal processor connected to the output terminal of the device.

According to the third aspect of the present invention, it provides a device for blood pressure measurement using the above-mentioned device, the device includes: a first signal apex point search device, used to search for the apex point of the first human body biometric signal search; the second signal apex point search device is used to search the apex point of the second human biometric signal; the signal processor is used to record the apex point search device and the second signal from the first signal respectively. The top point searching device searches for the time base point of the result signal, calculates the time gap between the two time base points, and calculates the blood pressure according to the time gap.

In the device according to the third aspect of the present invention, the first human body biometric signal may be an electrocardiogram signal, and in this case, the apex point is the apex of an R-shaped wave signal in the electrocardiogram signal point. The second human body biometric signal is a photoplethysmography signal.

The device may further include a display for displaying blood pressure measurements.

The device also includes a memory for storing parameters and formulas required for calculating blood pressure.

The device may also include keyboard input means for inputting parameters required for calculating blood pressure.

According to the fourth aspect of the present invention, it provides a method for measuring blood pressure using the above-mentioned device, the method comprising the following steps: 1) using the first signal apex point search device to search for the apex point in the electrocardiogram signal 2) use the second signal apex point search device to search for the apex point of the photoplethysmography signal; 3) use the signal processor to record the apex point search device and the apex point from the first signal respectively 4) calculating the blood pressure by the signal processor according to the time gap between the two time base points.

In the method according to the fourth aspect of the present invention, the first human body biometric signal may be an electrocardiogram signal, and in this case, the top point is the top of the R-shaped wave signal in the electrocardiogram signal point. The second human body biometric signal is a photoplethysmography signal.

The above step 4) further includes a step of calculating blood pressure according to parameters and formulas stored in a memory.

The method may further include the step of displaying the calculated blood pressure.

The method may further comprise the step of inputting parameters required for calculating blood pressure.

The present invention is applicable to but not limited to non-destructive, continuous and non-wristband balloon blood pressure monitors, since it simplifies post signal processing using procedures such as signal tip search, so it is less demanding on the signal processor. Compared with the prior art, the present invention not only has lower cost and saves electricity, but also, because the program is simplified, the development time is relatively reduced, thereby greatly increasing the cost-effectiveness.

Description of drawings

Through the following detailed description and with reference to the accompanying drawings, the above-mentioned purpose, features and advantages of the present invention will become more clear, in the following drawings:

FIG. 1 is a circuit structure diagram of a signal top point search device according to an embodiment of the present invention;

FIG. 2 is a flowchart of a method for searching a top point of a signal according to an embodiment of the present invention;

Fig. 3 is a signal waveform diagram in an embodiment of the present invention;

Fig. 4 is a structural block diagram of a blood pressure measuring device according to an embodiment of the present invention;

Fig. 5 is a flowchart of a method for measuring blood pressure according to an embodiment of the present invention.

Description of the preferred embodiment

Various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Firstly, referring to FIG. 1 and FIG. 3 , the device for searching a top point of a signal according to an embodiment of the present invention will be described.

FIG. 1 is a circuit structure diagram of a signal top point search device according to an embodiment of the present invention. Fig. 3 is a signal waveform diagram in an embodiment of the present invention. As shown in Figure 1, the device includes: an input terminal 110 for receiving an input signal, the input signal can be from an electrocardiogram signal or a photoplethysmography signal, and its typical signal waveform is shown as 310 in Figure 3; The current steering detection circuit 120 connected to the terminal 110 includes an operational amplifier U1, a resistor R1 and a capacitor C1. This circuit is used to sense the steering of the input current, thereby outputting a square pulse signal. The typical signal waveform of the square pulse signal output As shown at 340 in FIG. 3, since the current turning detection circuit 120 will output a square pulse signal every time the current turns, it cannot represent the position of the top point of the input signal (from 310 and 340 in FIG. 3 Correspondence can be seen), so additional circuit is needed to search for the top point; the top point detection circuit 130 connected with the input terminal 110 includes two operational amplifiers U2 and U3, diode D1 and capacitor C2, this circuit is used for Detect the top point of the input signal and keep the amplitude of the output signal near the top point as much as possible, so that the output signal is close to a DC signal with a certain amplitude. Its typical output signal waveform is shown as 320 in Figure 3; The amplitude adjustment circuit 140 connected to the output terminal of the point detection circuit 130 is provided with a variable resistor VR1 to adjust the amplitude of the top point signal, so as to output a DC signal with an adjusted amplitude. The typical signal waveform is as shown in 330 The amplitude comparison circuit 150 is provided with an operational amplifier U4, and the two input terminals of the operational amplifier U4 are respectively connected with the output terminal of the amplitude adjustment circuit 140 and the input terminal 110, and the circuit 150 is used to compare the amplitude-adjusted DC signal with the The amplitude of the input signal is compared, if the amplitude of the input signal is greater than the amplitude-adjusted DC signal, it will output a square pulse signal, otherwise, it will ground its output (that is, keep the output low); The switch circuit 160 is provided with a transistor Q1, a bipolar vacuum tube D2 and a resistor R2, the base of the transistor Q1 is connected to the output terminal of the amplitude comparison circuit 140 through the resistor R2 as the control terminal of the switch circuit 160, and its gate It is connected to the output terminal of the circuit steering detection circuit 120, and its emitter is connected to the output terminal 170 through the diode D2. If the signal output by the amplitude comparison circuit 150 is a square pulse signal (high level), the switch circuit 160 will turn on the current Turning to the detection circuit 120 and the output terminal 170, if the output terminal of the amplitude comparison circuit 150 is grounded (low level), then the switch circuit 160 will cut off the current to turn to the connection of the detection circuit 120 and the output terminal 170, like this, through the processing of the switch circuit 160 , those square-shaped pulses that have nothing to do with the top point in the waveform 340 shown in Figure 3 can be filtered out, thereby forming a typical waveform as shown in 350; Send to an external device (such as a signal processor) for further processing.

The inventor draws attention to the fact that although the embodiments of the present invention have been described in the form of specific circuit structures in the above description, these descriptions should not be regarded as limiting the present invention. For those of ordinary skill in the art, there may be various known implementation methods for each of the above circuits. For example, in Willis J. Tompkins and John G. Webster, EDS, "Signal Processing-Hardware versus Software", inDesign of Microcomputer-Based Medical Instrumentation, London, Prentice-Hall International, Inc., 1981 ; Sergio Franco, "Nonlinear Circuits", in Design with Operational Amplifiers and AnalogIntegrated Circuits-2 ^nd edition, New York, The McGraw-Hill Companies, 1997 and MJ Burke, "Low-power ECG amplifier/detector fordry- Electrode heart rate monitoring" (low-power ECG amplifier/detector for dry electrode heart rate monitoring), Medical & Biological Engineering & Computing, vol.32, pp.678-83, 1994 and other references have recorded the above circuits Some concrete implementation examples.

Next, the method for searching for a top point of a signal according to an embodiment of the present invention will be described with reference to FIG. 1 , FIG. 2 and FIG. 3 .

FIG. 2 is a flowchart of a method for searching a top point of a signal according to an embodiment of the present invention. As shown in FIG. 2 , firstly, in step 210 , the signal to be tested is input, and the input signal to be tested can be from an electrocardiogram signal or a photoplethysmography signal, and its typical signal waveform is shown as 310 in FIG. 3 . Then, in step 220, the signal to be tested is input into the circuit turning detection circuit 120 (see FIG. 1 ), and is subjected to current turning detection in step 230. As the current produces a turning like waveform 310, the turning detection circuit 120 will respond accordingly The ground outputs a square pulse signal to the switch circuit 160 , and its typical waveform is shown at 340 . Since the circuit steering detection circuit 120 will output a square pulse signal every time the current turns, these signals cannot represent the position of the top point of the input signal, so these signals need to be further filtered to filter out those signals that are different from the top point. Unrelated square pulse signal. At the same time, the signal to be tested is also input to the top point detection circuit 130 , and in step 240 , the top point detection circuit 130 detects the top point of the signal to be tested and outputs a top point signal. Then, in step 250 , the amplitude of the apex point signal output by the apex point detection circuit 130 is adjusted by the amplitude adjustment circuit 140 and output to the amplitude comparison circuit 150 . In step 260, the amplitude comparison circuit 150 compares the amplitude of the signal to be measured with the output signal of the amplitude adjustment circuit, and outputs a control signal according to the comparison result. The circuit steering detection circuit 120 and the output terminal 170 will be connected or cut off accordingly under the control of the control signal. Specifically, if the amplitude of the signal to be tested is greater than the amplitude of the output signal of the amplitude adjustment circuit, the switch circuit 160 is turned on. , and then turn on the circuit to turn to the output of the detection circuit (step 270), otherwise, the switch circuit is closed, and then turn off the circuit to turn to the output of the detection circuit (step 280). Finally, the measurement result signal (having a signal waveform such as shown at 350 ) is output through the output terminal 170 to an external device such as a signal processor (step 290 ).

The purpose of the above-mentioned steps 240 to 260 is to filter out those signals irrelevant to the top point from the square pulse signal output by the current steering detection circuit. However, those of ordinary skill in the art should understand that the technical means for filtering non-apex point signals are not limited to the above-mentioned specific methods. For example, low-pass and high-pass filters can also be used for filtering. Since the electrocardiogram signal and the photoplethysmography signal are only inspected at the top point in the present invention, the effective frequency spectrum used therein is approximately between 0.5 Hz and 30 Hz. The noise spectrum is mostly around DC or 50 Hz, so low-pass and high-pass filters can be used to filter out non-signal noise. The design of low-pass and high-pass filters can refer to the following literature, for example: Sergio Franco, "ActiveFilters: Part I" (active filter: Chapter 1), in Design with Operational Amplifiers and Analog Integrated Circuits-2 ^nd edition, New York, The McGraw-Hill Companies, 1997.

The application of the device of the present invention in blood pressure measurement will be described below with reference to FIG. 4 and FIG. 5 .

Fig. 4 is a schematic block diagram of a blood pressure measuring device according to an embodiment of the present invention. As shown in FIG. 4 , a blood pressure measuring device according to the present invention is mainly composed of two apex point measuring devices 430 and 440 according to the present invention and a signal processor 450 . The device 430 can be used to measure the apex point of the ECG signal collected by the electrocardiogram signal sensor 410, and output the accurate time of the apex point to the signal processor 450 as a reference index for blood pressure measurement. When determining the exact time of the top point, the top point of the R-shaped wave signal in the electrocardiogram signal can be used as the base point. The circuit 440 of the present invention can be used to measure the top point of the photoplethysmography signal collected by the photoplethysmography signal sensor 420, and output the accurate time of the top point to the signal processor 450 as another item of blood pressure measurement reference indicator. When determining the exact time of the apex point, the apex point of the photoplethysmography signal can be used as the base point. In addition, when the above-mentioned top point is used as the base point for measuring blood pressure, the falling edge (see 360 in FIG. 3 ) of the square pulse signal output by the device of the present invention can be used as the time position of the top point of the input signal. The signal processor 450 uses the accurate time of the top points of the signals collected by the devices 430 and 440 as the base points respectively, calculates the time difference between the two time base points, and uses the corresponding correlation relationship between the blood pressure and the pulse transmission time (that is, the above-mentioned time difference) Calculate blood pressure. The blood pressure measurement device according to this embodiment may also include, for example: an input keyboard 470 for manually inputting parameters required for blood pressure measurement to the signal processor 450; memory 460 for storing parameters required for blood pressure measurement and calculation formulas; and a display 480 for reporting the results of blood pressure measurement to users or medical personnel, and the like. Since these components are well known to those skilled in the art, they will not be described in detail here.

Fig. 5 is a flowchart of a method for measuring blood pressure according to an embodiment of the present invention. As shown in FIG. 5, when using the device of the present invention as shown in FIG. 4 to measure blood pressure, in step 510, firstly execute the apex detection algorithm, that is, use the signal processor 450 to detect the The peak pulse 290 of the output electrocardiogram signal and the peak pulse of the photoplethysmography signal are calculated to calculate the time position of the peak point of the electrocardiogram signal and the photoplethysmography signal. Then, in step 520, the signal processor 450 determines the value of the pulse transit time according to the time difference between the ECG signal and the photoplethysmography signal. Next, in step 530, the signal processor 450 makes a judgment on whether the total number of pulse transit times reaches a default value (for example, 10). Using a single pulse transmission time to determine blood pressure will have many unstable factors, which will increase the error of blood pressure detection. In the present invention it is based on the average of 10 pulse transit times. Step 530 needs to be repeated until 10 pulse transit times are detected. Next, in step 540, the signal processor 450 calculates systolic pressure, mean pressure and diastolic pressure according to the equations loaded in memory 460 and using the average pulse transit time calculated in step 530. After the systolic, mean and diastolic pressures are determined, the values are passed to step 550 . In step 550 , if the blood pressure value is not within the normal range (for example, the systolic blood pressure is greater than 240 mmHg), the processor 450 will issue an error message in step 560 . The calculated systolic pressure, mean pressure and diastolic pressure can be displayed on the display 480, and can also be transmitted to the remote end through a communication device such as a wireless transmission device for further processing. Step 570 will repeat steps 510, 520, 530, 540, 550 and 560 if additional blood pressure measurements are required.

Claims (27)

1. signal top point search device comprises:

Input is used to import measured signal;

The electric current steering detection circuit is used for exporting corresponding signal according to the input current direction of measured signal;

Point testing circuit in top is used to detect the top point of measured signal, the amplitude of its output signal is maintained near the point of top as far as possible, and make its output signal be close to the direct current signal of certain amplitude;

Amplitude regulating circuit, the amplitude that is used to regulate its input signal;

The amplitude comparison circuit is used for the amplitude of its input signal is compared, and exports corresponding signal according to comparative result;

On-off circuit is used for making under the control of control signal its signal that passes through to be switched on or to cut off; And

Outfan is used for exporting signal to outside,

Wherein, measured signal is by described input, described top point testing circuit and described amplitude regulating circuit are input to an end of described amplitude comparison circuit, measured signal also is connected directly to the other end of described amplitude comparison circuit by described input, described amplitude comparison circuit compares the amplitude of two described input signals, and the control end that compare result signal is exported to described on-off circuit is with as its control signal, described on-off circuit is according to the control of this control signal, to export the outside to by described outfan from described input and via the signal of described electric current steering detection circuit input, perhaps cut off being connected of described electric current steering detection circuit and described outfan.

2. device according to claim 1, it is characterized in that, is the square pulse signal by described electric current steering detection circuit by the signal that described on-off circuit exports described outfan to, and described square pulse signal has corresponding relation with the top point of described measured signal.

3. device according to claim 2, it is characterized in that, when the ratio of the amplitude of the pairing described measured signal extreme point of the trailing edge of described square pulse signal and the amplitude of described measured signal top point equaled or exceeded predetermined ratio, the extreme point of this trailing edge correspondence of described square pulse signal was considered as the top point of described measured signal.

4. device according to claim 1 is characterized in that, described measured signal is for reflecting the signal of human body physiological characteristics.

5. device according to claim 4 is characterized in that, described human body physiological characteristics signal is an ECG signal.

6. device according to claim 5 is characterized in that described input is connected to the induction apparatus of ECG signal, and the signal top point of described measurement device is the top point of the R type ripple signal in the ECG signal at this moment.

7. device according to claim 4 is characterized in that, described human body physiological characteristics signal is a light change in volume trace signal.

8. device according to claim 7 is characterized in that described input is connected to the induction apparatus of light change in volume trace signal, and the signal top point of described measurement device is the top point of light change in volume trace signal at this moment.

9. device according to claim 1 is characterized in that, described top point testing circuit comprises first operational amplifier, second operational amplifier, diode and electric capacity,

Wherein, the in-phase input end of described first operational amplifier links to each other with the described input of described device, its inverting input links to each other with the inverting input and the outfan of described second operational amplifier, the outfan of described first operational amplifier is connected to the in-phase input end of described second operational amplifier by described diode, and the in-phase input end of described second operational amplifier is by described capacity earth.

10. device according to claim 1 is characterized in that, the described outfan of described device is connected to a signal processor, and this signal processor is used for the output signal of described device is handled.

11. one kind is utilized the described device of claim 1 to carry out the method that signal top point is searched, may further comprise the steps:

1) imports measured signal by the described input of described device;

2) utilize described electric current steering detection circuit to carry out electric current to measured signal and turn to detection, and export corresponding signal; And

3) from the signal of described electric current steering detection circuit output, select with the signal of the top spot correlation of measured signal and export this signal.

12. method according to claim 11 is characterized in that described step 3) further may further comprise the steps:

3-1) utilize the described top point testing circuit of described device to detect the top point of measured signal, the amplitude of its output signal is maintained near the point of top as far as possible, and make its output signal be close to the direct current signal of certain amplitude;

3-2) utilize the described amplitude regulating circuit of described device that the amplitude of the output signal of described top point testing circuit is regulated;

3-3) the described amplitude comparison circuit that utilizes described device compares the amplitude of the measured signal by the described input input amplitude with the output signal of described top point testing circuit, and the generation compare result signal; And

3-4) utilize described compare result signal described on-off circuit to be controlled, with conducting or cut off the signal of described electric current steering detection circuit to the described outfan output of described device as control signal.

13. method according to claim 12, it is characterized in that, is the square pulse signal by described electric current steering detection circuit by the signal that described on-off circuit exports described outfan to, and described square pulse signal has corresponding relation with the top point of described measured signal.

14. method according to claim 13, it is characterized in that, when the ratio of the amplitude of the pairing described measured signal extreme point of the trailing edge of described square pulse signal and the amplitude of described measured signal top point equaled or exceeded predetermined ratio, the extreme point of this trailing edge correspondence of described square pulse signal was considered as the top point of described measured signal.

15. method according to claim 11 is characterized in that, described measured signal is for reflecting the signal of human body physiological characteristics.

16. method according to claim 15 is characterized in that, described human body physiological characteristics signal is an ECG signal.

17. method according to claim 16 is characterized in that, described input is connected to the induction apparatus of ECG signal, and the signal top point of described measurement device is the top point of the R type ripple signal in the ECG signal at this moment.

18. method according to claim 15 is characterized in that, described measured signal is a light change in volume trace signal.

19. method according to claim 18 is characterized in that, described input is connected to the induction apparatus of light change in volume trace signal, and the signal top point of described measurement device is the top point of light change in volume trace signal at this moment.

20. method according to claim 11 is characterized in that the step that external signal processor that described method comprises that further utilization links to each other with the described outfan of described device is handled the output signal of described device.

21. an equipment that utilizes the described device of claim 1 to carry out blood pressure measurement comprises:

The first signal top point search device is used for the top point of the first human body biological characteristics signal is searched;

Secondary signal top point search device is used for the top point of the second human body biological characteristics signal is searched; And

Signal processor, be used to write down respectively time origin from the top point search result signal of described first signal top point search device and described secondary signal top point search device, calculate the lead time between two time origins, and calculate blood pressure according to described lead time.

22. equipment according to claim 21 is characterized in that, the described first human body biological characteristics signal is an ECG signal.

23. equipment according to claim 22 is characterized in that, described top point is the top point of the R type ripple signal in the described ECG signal.

24. equipment according to claim 21 is characterized in that, the described second human body biological characteristics signal is a light change in volume trace signal.

25. equipment according to claim 21 is characterized in that, described equipment also comprises a display that is connected with described signal processor, is used to show the measurement result to blood pressure.

26. equipment according to claim 21 is characterized in that, described equipment also includes memory body, is used to preserve required parameter of calculating blood pressure and formula.

27. equipment according to claim 21 is characterized in that, described equipment also comprises finger-impu system, is used to import the required parameter of calculating blood pressure.

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