KR100929859B1 - Portable pulse measuring device using force sensor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable pulse measuring device using a force sensor, comprising a force sensor for outputting a force change applied through a contactor as a voltage signal, and the force sensor according to the pulse state transmitted from the skin surface of the user. When the change is detected, the filtering unit filters only the voltage signal of the high frequency region from the voltage signal output from the force sensor and applies it to the comparing circuit unit, and the comparing unit compares the voltage signal according to the pulse state applied by the filtering unit with the comparison voltage value. The present invention relates to a portable pulse measuring device for outputting a signal according to a current pulse state after comparison and displaying the signal through a display unit. According to the portable pulse measuring device of the present invention, the user can automatically recognize the current heart rate and pulse state so that anyone can easily grasp his or her physical state without any limitation or difficulty, such as place and time, age of use, and measuring method. There is an advantage to tell.

Portable, pulse measuring device, force sensor, high pass filter, comparator, LED

Description

Portable pulse taking device using a force sensor

The present invention relates to a pulse measuring apparatus and method, and more particularly, without any restrictions or difficulties, such as place and time, age of use, measuring method, any one's heart rate and pulse so that anyone can easily grasp their physical state quickly The present invention relates to a portable pulse measuring device and method capable of automatically informing a status.

As is known, when a person does extreme exercise without considering his or her physical condition, the body may be exposed to a dangerous state.

In other words, if you normally exercise to maintain your health, but if you exercise beyond your own physical state, such as excessive climbing or abrupt running without any consideration of the current state of the body can be a dangerous state.

In particular, it is important to understand one's physical condition during exercise because most of the physical dangers caused by excessive exercise have very fatal effects on the body. It is very important to do.

However, it is true that most people do not know their current physical state, and there is a limit to the awareness of their physical state.

Of course, at present, various methods are known for a person to understand his or her physical condition.

For example, during aerobic exercise, the heart rate (pulse rate) is an important figure indicating the state of the body.

Therefore, not only normal people but also patients with irregular heartbeats need to constantly monitor the heart rate.

Normally, heart rhythm can be easily determined by measuring the pulse rate, which means a rhythmic change in arterial pressure produced by blood being pushed into the artery as the aortic valve in the heart opens and closes. You can feel it by pressing the surface of your skin with your fingertips, and loosen the muscles around you.

Common pulses include the carotid artery in the neck, the brachial artery in the inner elbow, and the radial artery of the wrist. It is known as an important indicator of heart function.

However, the average person has a limit in finding an accurate measuring position in order to measure the pulse, and since most people do not know how to measure the pulse by themselves, not only ordinary people but also patients can measure the pulse themselves. It is almost impossible to recognize your physical condition.

Therefore, the present invention has been invented in consideration of the above points, the present heart rate and pulse so that anyone can easily grasp their physical state quickly without any restrictions or difficulties, such as place and time, age of use, measuring method, etc. It is an object of the present invention to provide a portable pulse measuring device and method that can automatically notify the user of the status.

In order to achieve the above object, the present invention, the force sensor is installed in the case so that the contactor is in contact with the skin surface to detect the force change according to the pulse state applied to the contactor on the skin surface and outputs as a voltage signal Wow; A filtering unit filtering the voltage signal output from the force sensor and applying the signal in the form of a signal usable in the comparison circuit unit; A comparison circuit unit for classifying a voltage signal applied through the filtering unit with a voltage signal as a reference and outputting a signal according to a pulse state; A display unit which displays a current pulse state by a signal applied from the comparison circuit unit; It provides a portable pulse measuring device using a force sensor, including; the case is installed, each component and the battery for the power supply.

Here, the filtering unit is characterized in that the RC high-pass filter to block the signal of the low frequency region from the voltage signal of the force sensor and to pass only the signal of the high frequency region.

In addition, the comparison circuit unit includes OP-AMPs connected in parallel to the filtering unit, and resistance values connected to the input terminals of the respective OP-AMPs are different from each other, and the display unit is connected to the output terminals of the respective OP-AMPs. Each of the OP-AMPs is configured to display LEDs connected to the output terminal by comparing the voltage signal applied from the filtering unit with the comparison voltage value applied from the battery through the corresponding connection resistor. It features.

In addition, the connection resistance is characterized in that the variable resistor so as to adjust the range of the comparison voltage value.

In addition, the case is composed of a lower body with a built-in force sensor so that the contact is exposed to the upper surface of the contact so as to be in contact with the skin surface, and the upper body is installed, the filtering unit, the comparison circuit unit, the battery and the display unit, the band member is fitted It is characterized by having a passage hole that can pass.

In addition, the lower body and the upper body is hinged at one end thereof to be able to open and close the through hole formed by the lower body and the upper body, the other end has a coupling means for coupling between the lower body and the upper body It features.

According to the portable pulse measuring apparatus and method using the force sensor of the present invention as described above, it is possible to quickly grasp their physical state without anyone having any restrictions or difficulties, such as the place and time, the age of use, the measuring method. There is an advantage that can automatically notify the user of the heart rate and pulse state.

In addition, according to the portable pulse measuring device using the force sensor of the present invention, it is possible to provide a low-cost pulse measuring device because it is manufactured in a simple configuration using low-cost components.

In addition, it is easy to use by applying a minimal interface such as LED, and the user can easily check his or her physical condition to prevent the occurrence of an accident due to excessive exercise.

In addition, it is possible to prevent the occurrence of accidents by making it easy to check the trainer's condition in the military or company training.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a block diagram showing the main components of the pulse measuring apparatus according to the present invention, as shown, the pulse measuring apparatus according to a preferred embodiment of the present invention, the contact (reference numeral 11 in Fig. 10) of the skin A force sensor (10) installed in the case (60) to be in contact with the surface and detecting a force change according to the pulse state applied to the contactor (11) on the skin surface and outputting it as an electrical signal; A filtering unit 20 for filtering an electric signal output from the force sensor 10 and applying the signal in a form of a signal usable by the comparison circuit unit 30; A comparison circuit unit 30 for outputting a signal according to a pulse state by comparing an electrical signal applied through the filtering unit 20 with a reference signal; A display unit 40 for displaying a current pulse state by a signal applied from the comparison circuit unit 30; And a case 60 in which the components and the power battery 50 are installed.

In the pulse measuring apparatus of the present invention having the above-described configuration, an analog voltage signal is obtained using the force sensor 10, and then the signal is passed through the filtering unit 20 to perform classification in the frequency domain. The voltage signal applied from 20 is compared with the comparison voltage value in the comparison circuit unit 30 to classify the magnitude of the voltage signal and then display the result through the display unit 40.

First, the sensor used to measure the pulse in the pulse measuring apparatus of the present invention is a force sensor 10, the force sensor 10 is a predetermined period corresponding to the force change applied to the contact on the surface of the skin and Outputs an electrical signal waveform of amplitude.

Pulse refers to the rhythmic change in arterial pressure produced by the flow of blood into the artery, and the rhythmic change in arterial pressure appears as a force change in the vertical direction on the skin surface at the measurement location.

In other words, on the skin surface where the pulse is transmitted, that is, on the skin surface where the heart rate can be measured, the force change in the vertical direction due to the pulse occurs. Will be shown.

Accordingly, the pulse measuring apparatus of the present invention uses a force sensor 10 that detects a force change in the vertical direction occurring on the skin surface to which the pulse is transmitted, converts it into an electrical signal, and outputs the same, and the force sensor ( When 10) is contacted with the skin surface to which the pulse is transmitted, the force sensor 10 can obtain an analog voltage signal corresponding to the force change due to the pulse.

In this way, when the contactor (reference numeral 11 in FIG. 10) of the force sensor 10 comes into contact with the skin surface to which the pulse is transmitted, the force sensor 10 causes the contact force to be changed in the vertical direction due to the pulse. 11) through the input, and converts the above-mentioned force change into an electrical signal form of the analog form, and outputs, in the end, such a force sensor 10 to measure the pulse state due to the heartbeat in the pulse measuring apparatus of the present invention It can be usefully used as a sensor.

Various types of force sensors may be used in the pulse measuring apparatus of the present invention, but when a piezo type force sensor is used, there is an advantage in that the sensor performance is excellent and the thickness is thin.

As such a force sensor, Teksan's 'FlexiForce' can be used (see Fig. 2), which can be easily purchased at a relatively low price on the market (www.sample.co.kr, sample electronics).

In view of the force sensor 10 alone, the output signal is a signal of a voltage unit proportional to the driving voltage. The signal is applied to the contactor 11 because the signal is output linearly according to the pressure applied to the contactor 11. The pressure can be input accurately in voltage units.

Figure 3 shows the linearity of the signal output according to the force applied to the contactor 11 in the force sensor 10 used, it can be seen that the linearity of the output signal is very excellent with respect to the force change applied, so the output You can estimate the force exerted on the signal.

FIG. 4 is an experimental diagram showing power signal and checking an output signal with an oscilloscope to confirm a sensor signal. The wiring state and output signal of the force sensor 10 are shown, and the pressure on the contact 11 of the force sensor 10 is shown. When the output signal is changed, the oscilloscope 1 shows the screen.

As shown, this force sensor 10 is used because it requires only minimal wiring for applying the drive voltage of the sensor from the battery 50 (also mounted in the portable pulse measuring device of the present invention) and receiving the output signal. The configuration and circuit can be very simple.

Also, the fact that the output signal is a signal in the unit of voltage means that it does not need a microprocessor to count as a signal separately, and the signal itself is a resistor type and does not require a separate Wheatstone bridge or other circuit. Therefore, it is possible to lower the product price by reducing the manufacturing cost in manufacturing the device of the present invention.

On the other hand, in the pulse measuring apparatus of the present invention requires a signal processing process for the user to easily recognize the signal output from the force sensor 10 in units of voltage, using a microprocessor, more various processing is possible, but the use is portable Considering that it is to lower the price of the product itself, etc. can be made possible with only a simple electronic device.

First, the filtering unit 20 is provided as a signal processing unit for filtering the voltage signal output from the force sensor 10, in order to apply a signal form that can be used in the comparison circuit unit 30 to be described later in the present invention, the force sensor ( A high pass filter for blocking a signal in the low frequency region and passing only a signal in the high frequency region from the voltage signal of 10) is configured.

The configuration of the high pass filter that can be used in the pulse measuring apparatus of the present invention is shown in FIG. 5, but a Butterworth primary filter having a very simple configuration can be used as shown.

FIG. 5 illustrates an analog RC high pass filter using a resistor R and a capacitor C, and shows a wiring diagram when an analog high pass filter is configured using one resistor and one capacitor.

As a general filter in an electronic system, a low pass filter is used to remove the high frequency region of the nod. However, the pulse measuring apparatus of the present invention has a difference in that a high pass filter is used to block signals in the low frequency region.

In FIG. 5, the input signal V _in becomes an output signal of the force sensor 10, and V _out represents a filtered signal.

Thus, in the present invention, the signal of the force sensor 10 is configured to pass through the high pass filter in order to make the signal of the desired form, and because only two elements used in the high pass filter is not only cheap, but also a separate Signal processing can be performed continuously rather than using a microprocessor.

FIG. 6 is a diagram illustrating board diagram characteristics of the high pass filter illustrated in FIG. 5. Referring to this, it can be seen that a signal of a low frequency region is removed and a signal of a high frequency region passes relatively well.

The high pass filter of the present invention can be configured to have a desired performance by changing the size of the device, that is, the capacity of the resistor and the capacitor, the higher frequency toward the red line (a) to the blue line (c) of Figure 6 Since only the component passes, it is necessary to determine the appropriate stop frequency.

In particular, when the resistance element is a variable resistor instead of a general resistor, it can be easily designed to have a desired stop frequency without soldering again.

FIG. 7 is a result of simulating the performance of the high pass filter shown in FIG. 5. As a result of showing a low frequency signal and a high frequency signal outputted with the same magnitude, the signal output when the high frequency signal is input. It can be seen that is larger than when passing the low frequency signal.

Therefore, when the heart rate increases due to the rapid movement when the signal output from the force sensor 10 passes through the high pass filter, a signal having a larger magnitude can be obtained, and this signal (which is a voltage signal) is later The signal is applied to the comparison circuit unit 30 to perform a signal processing process for classifying by size.

Next, the comparison circuit unit 30 is provided as a signal processing unit for classifying the voltage signal applied from the filtering unit 20 and outputting a signal for selectively driving the display unit 40 according to the pulse state. 30 compares the voltage signal applied by the filtering unit 20 with the reference voltage signal, classifies the pulse state according to the magnitude of the voltage signal, and outputs a signal according to the corresponding pulse state.

In the present invention, the comparison circuit unit 30 using elements such as the OP-AMP (31, 32) may be configured, but a signal having a magnitude proportional to the pulse state is obtained through the high pass filter, but the user can easily recognize it. An additional signal processing process is required, which is performed by the comparison circuit unit 30 and the display unit 40.

Here, the comparison circuit unit 30 is a component that applies a signal for selectively driving the display unit 40 according to the magnitude of the voltage signal applied by the filtering unit (high pass filter) 20, and the comparison circuit unit 30. Also, no microprocessor is used, but the signal range is classified into a desired group using elements such as OP-AMP (31, 32). By comparing the magnitudes, a signal for selectively driving the display unit 40 is applied.

The comparison circuit unit 30 of the present invention may be composed of a plurality of OP-AMPs 31 and 32 and connection resistors R1 and R2 connected to the respective OP-AMPs 31 and 32. FIG. FIG. 1 is a diagram illustrating an exemplary embodiment of a comparison circuit according to the present invention, in which two OP-AMPs 31 and 32 connected in parallel to a filtering unit and connection resistors R1 and R2 connected to input terminals of the respective OP-AMPs 31 and 32. ) Is a circuit diagram of the comparison circuit section 30 formed using two pieces.

Each of the OP-AMPs 31 and 32 of the comparison circuit unit 30 is operated by using the battery 50 mounted on the pulse measuring apparatus of the present invention as a power source, and the voltage of the battery 50 is connected to the connection resistance ( It is applied to the input terminal of one side through R1, R2).

Here, two connection resistors R1 and R2 having different resistance values are connected to the input terminals of the corresponding OP-AMPs 31 and 32, which are compared with the voltage values of the filtering unit according to the resistance values of the connection resistors R1 and R2. The voltage values of the OP-AMPs 31 and 32 are determined.

In addition, the other input terminal of each OP-AMP (31, 32) is connected so that a voltage signal applied from the filtering unit is applied, and the output terminal of each OP-AMP (31, 32) LED (LED1, LED2) is connected one by one.

As described above, the display unit 40 of the present invention includes, as an example, two display LEDs LED1 and LED2 connected to be turned on by voltages output from the respective OP-AMPs 31 and 32 of the comparison circuit unit 30. It can be configured, and different types of LEDs are used for the two display LEDs (LED1, LED2) to be easily distinguished by the user at the time of lighting.

Accordingly, when the voltage value of the voltage signal applied from the filtering unit 20 to the OP-AMPs 31 and 32 is compared with the comparison voltage value applied to the OP-AMPs 31 and 32 and falls within the corresponding range, LEDs (LED1, LED2) can be selectively lit.

In the comparison circuit unit 30, the resistance values of the connection resistors R1 and R2 are appropriately selected to appropriately adjust the comparison voltage values of the respective OP-AMPs 31 and 32, and the resistance values of the two connection resistors R1 and R2 are determined. When a voltage signal is applied from the filtering unit 20 in the state, the display LEDs LED1 and LED2 are selectively turned on when the voltage signal is classified according to the size and then classified into a corresponding range.

Here, the display LEDs (LED1, LED2) can be used in a variety of types of LED, the user can check the LED lighted on the two OP-AMP (31, 32) so that you can easily distinguish and recognize their own pulse state Connect LEDs (LED1, LED2) with different colors.

In this way, the pulse measuring apparatus of the present invention detects the blood flow pulse pressure on the skin surface according to the pulse state using the force sensor 10, and uses the filtering unit 20 to output a high frequency signal from the voltage signal output from the force sensor 10. Only the voltage signal of the area is filtered and applied to the comparison circuit unit 30, and the voltage signal according to the pulse state applied from the filtering unit 20 is compared with the comparison voltage value set in the comparison circuit unit 30 to display the LED of the display unit 40. (LED1, LED2) is turned on selectively.

The user recognizes the current pulse state by checking the LEDs (LED1, LED2) that are turned on the display unit 40, if the comparison voltage input to the first comparator (OP-AMP) 31 of the comparison circuit unit 30 Assuming that the value is set to 1V and the comparison voltage value input to the second comparator 32 is set to 2V, the range of the measurement signal applied through the filtering unit 20 has a maximum size of 0.5V. If it is a signal, both LEDs (LED1, LED2) of the display unit 40 will not be turned on, and if the measurement signal of 1.5V is applied from the filtering unit 20, only the green LED (LED1), green if the measurement signal of 2V or more is applied Both and red LEDs (LED1, LED2) will light up.

In the pulse measuring apparatus of the present invention as described above, the signal output from the force sensor 10 and passed through the filtering unit (high pass filter) 20 can be classified according to the size by using a comparator circuit, and the connection resistances R1 and R2. Since the classification range is determined according to the resistance value setting of the user, if the case of the pulse measuring apparatus has a control mechanism that uses a variable resistor as the connection resistors R1 and R2 and adjusts the resistance value of the variable resistors, By adjusting the resistance value and the comparative voltage value in a desired manner, it is possible to use the pulse measuring apparatus of the present invention in a more various range.

9 and 10 are perspective views showing an embodiment of a pulse measuring apparatus according to the present invention, in which each of the above-described components, that is, a force sensor 10, a filtering unit (high pass filter), and a comparison circuit unit are incorporated. And the LED (LED1, LED2) of the display unit shows the outer structure of the case 60 is installed attached to the outside, it will be described as follows.

There may be several places to measure the pulse, but in the simplest case it can be the wrist part of the user, so it can be worn on the wrist using a separate band, or can be used to fit the existing wrist strap. Configure 60.

Preferably configured to be coupled to the wristband does not require a separate band device.

9 and 10, the case 60 includes a lower body 61 in which a force sensor 10 for detecting a force change according to a user's pulse state is installed so that the contactor 11 may contact the skin surface. )Wow; The filtering unit to which the voltage signal output from the force sensor 10 is applied, the comparison circuit unit to which the output signal of the filtering unit is applied, the power battery are mounted, and the LEDs (LED1, LED2) of the display unit are installed outside and the lower body ( 61 and the upper body 63 is coupled to the hinge structure.

The lower body 61 is provided with a force sensor 10 to expose the contact 11 to the lower surface, the force transmitted from the skin surface when the lower body 61 is in close contact with the skin surface of the wrist portion of the user The force sensor 10 detects the change through the contactor 11.

In addition, the upper body 63 is formed with a groove 64 to be fitted with a band member 2, such as a wrist strap in the state coupled to the lower body 61 on the lower surface, as a whole '' 'shape Manufactured and assembled.

Accordingly, the case 60 has a passage hole through which the band member 2 can pass by the groove 64 of the upper body 63 while the upper body 63 and the lower body 61 are coupled to each other. do.

In addition, the lower body 61 and the upper body 63 is coupled to each other by the hinge structure of the one end is rotatable mutually to be opened and closed so that the through-hole to which the band member 2 is fitted, and to the coupling means of the other end The lower body 61 and the upper body 63 can be coupled to each other and fixed in the state in which the through hole is closed.

The coupling means may be a coupling structure of the groove 65 and the protrusion 62 as a means for coupling the lower body 61 and the upper body 63 to each other.

 Accordingly, the lower body 61 is brought into close contact with the measurement site so that the contactor 11 of the force sensor 10 can be in contact with the skin surface of the measurement site, and the upper body 63 is rotated downward to allow the wrist to be grooved 64. When the coupling protrusion 62 of the lower body 61 is coupled to the coupling groove 65 of the upper body 63 while the band member 2 of the portion is fitted, the body attachment of the pulse measuring apparatus is completed.

In this way, the force sensor 10 detects the force change transmitted from the skin surface after attaching the pulse measuring apparatus of the present invention to the wrist part, and in this state, the display unit that lights up according to the detected value of the force sensor 10. When the user checks the LEDs (LED1, LED2), they can easily recognize their pulse state.

1 is a block diagram showing the main components of the pulse measuring apparatus according to the present invention,

2 is a view showing an example of a force sensor that can be used in the present invention,

3 is a view showing the signal linearity of the force sensor used in the present invention,

4 is an experimental view for confirming the output signal of the force sensor in the present invention,

5 is a configuration diagram of an example of a high pass filter that can be used in the present invention,

6 is a diagram showing the board diagram characteristics of the high pass filter shown in FIG.

7 is a result of simulating the performance of the high pass filter shown in FIG.

8 is a view showing an embodiment configuration of a comparison circuit unit according to the present invention;

9 and 10 are perspective views showing an embodiment of a pulse measuring device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: force sensor 20: filtering unit

30: comparison circuit 40: display unit

50: battery 60: case

Claims (6)

The force sensor 10 installed in the case 60 to allow the contactor 11 to be in contact with the skin surface and detecting a force change according to the pulse state applied to the contactor 11 at the skin surface and outputting it as a voltage signal. Wow; A filtering unit 20 for filtering the voltage signal output from the force sensor 10 and applying the signal in the form of a signal usable by the comparison circuit unit 30; A comparison circuit unit 30 for comparing the voltage signal applied through the filtering unit 20 with the voltage signal as a reference and classifying the voltage signal and outputting a signal according to a pulse state; A display unit 40 for displaying a current pulse state by a signal applied from the comparison circuit unit 30; A case 60 in which the force sensor 10, the filtering unit 20, the comparison circuit unit 30, the display unit 40, and the power battery 50 are installed; Portable pulse measuring device using a force sensor comprising a. The method according to claim 1, The filtering unit (20) is a portable pulse measuring device using a force sensor, characterized in that the RC high-pass filter to block the signal of the low frequency region from the voltage signal of the force sensor 10 and to pass only the signal of the high frequency region. The method according to claim 1, The comparison circuit unit 30 is connected to the OP-AMPs 31 and 32 connected in parallel to the filtering unit 20 and a connection resistance having a different resistance value connected to an input terminal of each OP-AMP 31 and 32. R1, R2) The display unit 40 is composed of display LEDs (LED1, LED2) connected to the output terminal of each OP-AMP (31, 32), Each of the OP-AMPs 31 and 32 is connected to an output terminal by comparing a voltage signal applied from the filtering unit 20 with a comparison voltage value applied from the battery 50 through corresponding connection resistors R1 and R2. Portable pulse measuring device using a force sensor, characterized in that the LED (LED1, LED2) to selectively light. The method according to claim 3, Portable pulse measuring device using a force sensor, characterized in that each of the connection resistance (R1, R2) is a variable resistance to adjust the range of the comparison voltage value. The method according to claim 1, The case 60 includes a lower body 61 in which a force sensor 10 is embedded so that the contactor 11 is exposed upward when the contactor 11 is in contact with the skin surface, the filtering unit 20, and the comparison circuit unit 30. And a battery 50 and an upper body 63 on which the display unit 40 is installed, and having a passage hole through which the band member 2 is inserted, the portable pulse measuring device using a force sensor. The method according to claim 5, The lower body 61 and the upper body 63 is hinged at one end thereof so that the through hole formed by the lower body 61 and the upper body 63 can be opened and closed, and the other end thereof is the lower body ( 61) and a portable pulse measuring device using a force sensor, characterized in that it has a coupling means for coupling between the upper body (63).

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