KR100391790B1 - Apparatus for detecting release gas using piezoelectric element - Google Patents

Abstract

The present invention relates to an emission gas detector using a piezoelectric element, in particular, a device which can be installed in the thigh of the human body to detect the fart emitted from the anus.

A piezoelectric sensor unit having one or more piezoelectric elements for generating a piezoelectric current (voltage voltage) according to the pressure variation of the applied gas, a signal amplifier for amplifying an output signal of the piezoelectric element, and a signal amplified by the signal amplifier The sensing control unit for detecting whether the gas is discharged by using, an output unit for outputting the gas detection results by the detection control unit, and a power supply unit for supplying power.

By using the apparatus and the gas detection algorithm according to the present invention, it is possible to easily detect the discharge gas by using a simple piezoelectric element, and in particular, it is possible to accurately detect whether a fart is released by a surgical patient or the like to determine the recovery time of the patient.

Description

Emission gas detector using piezoelectric element {Apparatus for detecting release gas using piezoelectric element}

The present invention relates to an emission gas detection apparatus using a piezoelectric element, and more particularly, to an apparatus capable of detecting a fart emitted from the anus installed in the thigh of the human body.

Adults produce an average of 700 ml of farts on an average of 14 times, and individual differences are large. Fart is a normal physiological phenomenon caused by fermentation of foods that are not absorbed mainly in the small intestine, but in certain cases, whether or not fart is important information about human health. In other words, farts eat poorly digested food, or enteric bacteria increase in the intestinal gas increases often appears. In addition, if the intestines are stuck after surgery, or if you have diabetes, a lot of pain medications when the bowel function comes out a lot.

The release of a fart by a patient after a surgical open surgery such as general intestinal surgery means that the disordered intestine has found its place and is an important measure of the success of the operation and the patient's postoperative prognosis. After the patient's first fart after the operation, a light meal can be started, and then the patient's recovery is accelerated.

However, according to statistics, about 75% of patients postoperative their first fart, while about 25% of patients are unable to realize their first fart due to sleep or unconsciousness. Therefore, although the recovery can be promoted by awaking the fart and starting a meal thereafter, the patient who misses the fart will miss the period and the recovery will be delayed. In such a case, the success of the operation or the availability of the meal depends entirely on the judgment of the doctor. If the first meal is delayed after surgery, the patient sometimes has a risk of intestinal obstruction.

Therefore, there is a need for a device that automatically detects the fart of the patient. However, few devices have been developed for detecting a fart of a patient, and in the case of the proposed device, it is generally in the form of a gas detector.

That is, a pipe for collecting gas is installed in the thigh of the patient (around the anal), and the air that enters through the pipe is sent to the measuring device, and the measuring device measures the concentration of hydrogen gas or methane gas contained in the air. It is a way to detect whether it emits. Devices for detecting farts in this way are already commercialized, but they are not widely used because they are relatively expensive because of gas detection systems and the configuration of the devices is relatively complicated.

As another example, Korean Patent Application No. 2000-039418 proposes a fecal detection device using a micro gas detector capable of detecting ammonia gas and / or hydrogen sulfide generated from human feces. Because of the use of gas, there are disadvantages similar to those of the conventional method.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide an apparatus for detecting an emission gas of a simple structure, particularly a fart gas, by using a piezoelectric element that generates a piezoelectric current in response to a pressure change.

An object of the present invention is to provide a low-cost emission gas detection device of a simple structure using a piezoelectric element.

Another object of the present invention is to provide a small discharge gas detection device operable at a low power source by using a piezoelectric current generated by pressure variation of a ferroelectric.

It is another object of the present invention to provide a device mounted around the anus of a subject to detect a fart.

1 is an overall configuration diagram of a fart detecting apparatus using a conventional gas sensor.

2 is a block diagram showing the overall configuration of a discharge (fart) gas detecting device using a piezoelectric element according to the present invention.

3 shows the configuration of the piezoelectric sensor portion used in this embodiment.

Figure 4 shows the configuration of the detection control unit according to the present invention for each module.

Fig. 5 shows in detail the entire configuration of the emission gas detecting apparatus using the piezoelectric element according to the present invention.

6 shows the overall flow of the gas (fart) detection method according to the present invention.

7 to 10 show patterns of piezoelectric element outputs and differential amplification signals in various cases used in the gas (fart) detection algorithm according to the present invention.

7 is when gas (fart) is released;

8 is a case in which the subject equipped with the gas detection apparatus according to the present invention is turned over or the detection apparatus is pressed by a futon or the like;

9 is a case where a sudden shock is applied to the sensing device;

10 illustrates a case where a gradual pressure is applied to the sensing device.

** Description of the symbols for the main parts of the drawings **

100: piezoelectric sensor unit 110: piezoelectric element

120: (printed) substrate 130: circuit of the piezoelectric element

200: signal amplifier 300: detection control unit

310: differential amplifier 320: multiplexer

330: microprocessor 400: output unit

500: power supply

In order to achieve the above object, the emission gas detection apparatus according to the present invention has the following configuration.

A piezoelectric sensor unit having one or more piezoelectric elements for generating a piezoelectric current (pies voltage) according to the pressure variation of the applied gas, a signal amplifier for amplifying the output signal of the piezoelectric element, and amplified by the signal amplifier And a detection control unit for detecting whether the gas is discharged using the received signal, an output unit for outputting a gas detection result by the detection control unit, and a power supply unit for supplying power to the respective parts.

In addition, the discharge gas detector may be packaged by a thin thin film outer casing made of a material such as aluminum, iron, and SUS so that a minute pressure difference of the gas can be easily detected.

The piezoelectric element (piezoelectric element) may be a device of any type according to the prior art, it is preferably made of a ferroelectric such as _{LiTiO 3, TGS (triglycine sulphate)} , PZT, PbTiO 3, SBN.

In addition, the piezoelectric elements may be disposed in an array form on and under the substrate, and the amplifying means and the sensing control unit may exist on the substrate.

The sensing control unit, for all piezoelectric elements, a differential amplifier for differentially amplifying the amplified signal from one piezoelectric element and another piezoelectric element on the same surface, and a multiplexer for selectively transferring the differentially amplified signal to the microprocessor. And a microprocessor for determining whether the gas is discharged based on the pattern of the differential amplified signal transmitted from the multiplexer.

In addition, the emission gas detector according to the present invention may further include a fixing means to be fixed to the object requiring the detection of the gas, the fixing means includes a band, an adhesive band and the like connected to the emission gas detector body, It is not limited to this.

In addition, the emission gas detection method according to the present invention using the above-described device is composed of the following steps.

The sensing control unit receives the (amplification) output signals of all the piezoelectric elements, and amplifies the differential amplification difference between the output signals from one element eA _i and the other element eA _j on the same plane. Calculating (Si);

Determining that the gas is sensed only when at least one of the differential amplification values input from the side at which the gas is applied has a value equal to or greater than a predetermined threshold V _th ;

And outputting a corresponding signal through the output unit when detecting a gas.

In addition, the above-described step may further include the step of digitally converting the analog differential amplification value (Si) by using the ADC of the sensing control unit, and the differential amplification value equal to or greater than a predetermined threshold (V _th ) which is the basis of the gas detection. It is preferable that the number of (peak) is 1-5.

The emission gas detector according to the present invention is mainly used to detect the release of farts by being mounted around the anus of a patient or a human body, but can also be used for detection of other emission gases.

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

1 is an overall configuration diagram of a fart detection apparatus using a conventional gas detection sensor.

When exposed to methane, ammonia or hydrogen sulfide gas, the gas sensor unit 11 for generating an electrical signal, and the signal processing unit 12 for generating an output signal by amplifying or digitizing the electrical signal generated from the gas sensor unit And an output section 13 for generating a predetermined output in accordance with the output signal from the signal processing section, and a power supply section 14 for supplying power to each component.

Such conventional equipment is expensive using a gas detection sensor as described above, and the components of the fart, which is the physiological gas emitted from the human body, are varied, so only gas sensing can accurately detect whether the fart is released. There is a disadvantage.

Fig. 2 is a block diagram showing the overall configuration of a discharge gas (fart) detecting device using the piezoelectric element according to the present invention.

The gas (fart) detecting device according to the present invention includes a piezoelectric sensor unit 100, a signal amplifier 200, a detection control unit 300, an output unit 400, and a power supply unit 500.

As described with reference to FIG. 3, the piezoelectric sensor unit 100 preferably has one or more piezoelectric elements 110 disposed to face both sides of a printed board. In FIG. 3, a total of 32 piezoelectric elements are arranged in an array ( array). The spacing of the piezoelectric elements is not limited, and may be variously modified according to the size of the field or device used. For example, in the case of a device for detecting a fart of a human body, the size and placement interval of the piezoelectric element may be determined accordingly because it is large enough to be mounted around the anus. However, as the number of piezoelectric elements increases, the sensing sensitivity will increase.

The piezoelectric element used in this embodiment is preferably made of a ferroelectric. The ferroelectric material is a kind of dielectric that is electrically insulated, and has a special physical property such as a pyroelectric effect and a piezoelectric effect. Ferroelectrics have spontaneous polarization which is spontaneously arranged in a certain direction due to the interaction of electric dipoles present in the crystal even without external electric field, and polarization reversal when external electric field Will be Since ferroelectrics having such properties consist of polarized crystals, they all exhibit piezoelectricity. Piezoelectricity means the conversion between mechanical energy and electrical energy. When pressure is applied to a polarized crystal to cause mechanical deformation, an electric field is formed to induce a voltage. On the contrary, when a voltage is applied to the polarized crystal, mechanical deformation is caused. It means the nature of being. Therefore, the piezoelectricity of such ferroelectrics is applied to manufacture igniters of lighters, vibrators and pressure sensors of electronic watches.

The material constituting the piezoelectric element used in this embodiment include, but are limited, it is preferably made of a ferroelectric such as _{LiTiO 3, TGS (triglycine sulphate)} , PZT, PbTiO 3, SBN.

3 shows the configuration of the piezoelectric sensor unit 100 used in this embodiment. As shown, 16 square ferroelectric piezoelectric elements 110 are uniformly distributed on one surface of the substrate 120 such as eA ₁ to eA ₁₆ (FIG. 3A), and the other side of the substrate opposes the aforementioned 16 elements. 16 piezoelectric elements of eB ₁ to eB ₁₅ are arranged at the position (Fig. 3B). There is no limit to the number and spacing of the piezoelectric elements, but as the size and the number of the elements become smaller, the sensitivity of the sensing may be increased.

Each piezoelectric element also has a field-effect transistor (FET), a resistor (Rg), for generating a piezoelectric voltage output from a piezoelectric current (or piezoelectric charge) generated by an applied pressure, as will be described with reference to FIG. A circuit 130 consisting of R) and capacitor C is provided. The output voltage signal from the circuit 130 of each piezoelectric element 110 enters the input terminal of the signal amplifier 200 along the print lead of the substrate.

The signal amplifier 200 according to the present invention is used to amplify a weak piezoelectric current (voltage) output from the piezoelectric element 110 or the circuit 130 to a processable size, and corresponds to each piezoelectric element circuit 130. It consists of an amplifier circuit 210. Since the amplification unit can be implemented using a general signal amplification circuit, a detailed description thereof will be omitted. In practice, the piezoelectric current (voltage) generated in a typical piezoelectric element is a very small value, and to be processed, it must be amplified to a certain magnitude, and to remove (white) noise included in a signal, for example, a low frequency band. A predetermined filter such as a low-pass filter may be further provided.

FIG. 4 shows the configuration of the sensing controller 300 by modules, and includes one or more differential amplifiers 310, a multiplexer 320 for selectively transferring signals from the differential amplifiers to a microprocessor, and a multiplexer. The microprocessor 330 is configured to detect whether the fart is released or not according to the fart detection algorithm in which the signal is received. Although not shown, an analog-to-digital converter (ADC) may be further provided to digitize electrical signals from a multiplexer or differential amplifier for processing by a microprocessor.

5 shows in detail the overall configuration of the emission gas detector using the piezoelectric element according to the present invention.

As described above, each piezoelectric element 110 is provided with a circuit 130 for converting the piezoelectric charge (piezoelectric current) into a piezoelectric voltage (hereinafter referred to as "circuit of the piezoelectric element eA _i or eB _i "). Display). The circuit 130 of the piezoelectric element converts the piezoelectric charge (piezoelectric current) generated in the piezoelectric element (eA _i or eB _i ) by the external pressure into a voltage by the resistor Rg and converts the impedance into a field effect transistor (FET) and a resistor R by an external pressure. One voltage is output, and this signal is amplified by each amplifying circuit 210 constituting the signal amplifier 200.

In the same way, all the piezoelectric elements eA ₁ to eB _n are output and amplified, followed by differential amplification. The differential amplifier 310 differentially amplifies the amplified signal from another piezoelectric element eA _j or eB _{j in the} same plane as the amplified signal from one piezoelectric element eA _i or eB _i to differential amplification signal S _i ) and input it to the multiplexer 320. A device that differentially amplifies a signal with respect to one device is preferably an adjacent device, but in some cases, may be a device that is slightly separated in the same plane. In the present embodiment, however, for the sake of clarity, the difference between the immediately adjacent elements will be described as an example.

For example, when a total of 32 piezoelectric elements are provided as shown in FIG. 3, the differential amplification signal between eA ₁ and eA ₂ is called S ₁ , and the differential amplification signal between eA ₃ and eA ₄ is referred to as S ₂ . and the process proceeds in the same manner is referred to as a differential signal between ₁₅ and eB eB ₁₆ S _16.

The differential amplification signal S _i generated in this way is input to the multiplexer 320, and is digitally converted through the ADC 340 in order from S _i to S _n by the data selection signal of the microprocessor 330, and then the microprocessor. 330 is entered.

The microprocessor determines whether the emission gas (flatulence) by recognizing the pattern of the differential amplification signal (S _i) are sequentially input by using the same algorithm as will be described in Figures 6 to 10.

The gas (fart) detection result is output to the outside through the output unit 400, may provide an output in the form of a simple alarm, it may also provide an output having a wireless (such as RF) transmitter and receiver. However, the shape of the output unit is not limited, and any means capable of displaying the gas detection result to the outside may be used.

6 shows the overall flow of the gas (fart) detection method according to the present invention.

First, an output (voltage or current) of one piezoelectric element and its adjacent piezoelectric elements is amplified (S61, S62), and a differential amplification signal of the two element signals is calculated (S63). The calculated differential amplification signal is input to the multiplexer (S64), and is sequentially digitally converted by the data selection signal to the microprocessor (S64, S65). This series of procedures is performed sequentially for all piezoelectric elements (S67), and when all the differential amplification signals are input, the microprocessor recognizes the pattern of the differential amplification signal (S68), and the differential amplification input from the side to which the gas is applied. When it is determined that the gas (fart) has been released only when one or more predetermined threshold values (V _th ) of the signals are exceeded (S69), the result is output (S70).

However, after receiving all the differential amplification signals, a pattern may be recognized immediately after the gas emission condition is satisfied by recognizing the pattern for each of the input differential amplification signals.

7 to 10 show patterns of piezoelectric element outputs and differential amplification signals in various cases that are the basis of judgment in the gas (fart) detection algorithm according to the present invention.

FIG. 7 illustrates a case in which gas (fart) is released. When the fart is released as shown in FIG. 7A, pressure is applied only to the piezoelectric element of the center or part of one side of the detector. In FIG. 7, it is assumed that the fart pressure is applied only to eA ₆ and eA ₁₀ (the area in which the ellipse portion of FIG. 7A is fart is applied).

As a result, the output signal from each piezoelectric element has a large value only for eA ₆ and eA ₁₀ as shown in FIG. 7B and a very small value for the remaining piezoelectric elements. Therefore, the pattern of the differential amplification signal peaks only at the values of S ₃ , which are the differential signals between eA ₆ and eA ₇ , and S ₅ , the differential signals of eA ₁₀ and eA ₁₁ , as shown in FIG. 7C, and the remaining differential signal values are below the threshold. Has the value Of course, the piezoelectric element disposed on the rear side has a small output value because it is hardly influenced by the emitted gas (fart), and the differential signal values S ₉ to S ₁₆ also have a threshold value or less.

8 corresponds to a case in which the subject equipped with the gas detection device according to the present invention is turned over or the detection device is pressed by a futon or the like. In this case, similar pressure is applied to all the piezoelectric elements as a whole, and as a result, an output signal shown in FIG. 8A is shown. Therefore, in this case, the differential signal pattern has a smooth curved shape as shown in FIG. 8B and no peak that exceeds the threshold occurs.

FIG. 9 illustrates a case where a sudden shock is applied to the sensing device, for example, a person wearing the apparatus may fall down or hit somewhere.

In this case, pressure is intensively applied to one side, and as a result, it may have a signal distribution as shown in FIG. 9A. Even in this case, a peak exceeding a threshold is unlikely to occur in the differential amplifier signal as shown in FIG. 9B.

10 illustrates a case where gradual pressure is applied, such as when the subject is standing up or sitting down.

In FIG. 10, it is assumed that a patient equipped with the device according to the present invention is standing and sitting around the anus, and a gradual pressure is applied to the peripheral portion of the piezoelectric elements arranged on both sides as shown in FIG. 10A. As a result, it has a piezoelectric element signal distribution as shown in FIG. 10B, and the pattern of the differential amplification signal has a smooth curved shape as shown in FIG. 10C and no peak as shown in FIG. 7A.

Of course, a case where the differential amplification signal value exceeds the threshold V _th may occur due to a sudden pressure change in addition to the emission of (fart) gas (for example, in FIG. 10C, the maximum value ΔV _max of the differential amplification signal may be a threshold value. In such a case, the same result is shown on both sides, as in the case of exceeding V _th , and peaks are not shown only on the output signal of either side as in the case of the emission of the (fart) gas in FIG. 7. Therefore, in addition to comparing the differential amplification signal value and the threshold, a procedure for comparing the signal patterns on both sides is also required.

Therefore, the microprocessor recognizes the pattern of the output signal by comparing the value of the differential amplification signal with a predetermined threshold value, and finally detects the emission of gas (fart) by determining which of the above cases is applicable. Done.

By using the emission gas detector according to the present invention, it is possible to simply detect the emission gas by using a simple piezoelectric element without using a conventional complicated and expensive gas sensor.

By using the apparatus and the gas detection algorithm described above, detection of the emitted gas can be made accurate and simple. In particular, the device according to the present invention can detect the fart release of the surgical patient accurately and can quickly and accurately determine the recovery time of the patient.

Claims (7)

A piezoelectric sensor unit having one or more piezoelectric elements for generating a piezoelectric current (voltage voltage) according to a pressure variation of an applied gas; A signal amplifier for amplifying the output signal of the piezoelectric element; A detection control unit detecting whether gas is discharged using the signal amplified by the signal amplifier; An output unit for outputting a gas detection result by the detection control unit; Emission gas detection apparatus using a piezoelectric element, characterized in that consisting of; a power supply unit for supplying power to each of the parts. The method of claim 1, The piezoelectric sensor unit includes one or more piezoelectric elements disposed opposite to both sides of the substrate, The piezoelectric element (piezoelectric element) emits a gas detection apparatus using a piezoelectric element, characterized in that consisting of at least one of _{LiTiO 3, TGS (triglycine sulphate)} , PZT, PbTiO 3, SBN ferroelectric. The method of claim 2, The sensing control unit includes: a differential amplifier for differentially amplifying an amplified signal from one piezoelectric element and another piezoelectric element on the same surface for all the piezoelectric elements; A multiplexer section for selectively transmitting differentially amplified signals to a microprocessor; It consists of a microprocessor to determine whether the gas is discharged based on the pattern of the differential amplified signal transmitted from the multiplexer unit, And the microprocessor determines that the gas is discharged only when at least one of the differential amplification signals from one surface of the piezoelectric sensor portion exceeds a predetermined threshold (V _th ). The method according to any one of claims 1 to 3, The emission gas detection device is packaged by a thin thin film outer casing made of at least one material of aluminum, iron, and SUS so as to easily detect a minute pressure difference of the gas. Emission gas detector. The method according to any one of claims 1 to 3, The emission gas detection device further includes a fixing means for fixing the device to the object requiring the detection of gas, The fixing means is an emission gas detection device using a piezoelectric element, characterized in that at least one of the band, the adhesive band is connected to the emission gas detection device. A piezoelectric sensor unit having one or more piezoelectric elements for generating a piezoelectric current (pies voltage) according to the pressure variation of the applied gas, a signal amplifier for amplifying the output signal of the piezoelectric element, and amplified by the signal amplifier An emission gas detection method using a device comprising a detection control unit for detecting whether the gas is discharged using the received signal, an output unit for outputting the gas detection result by the detection control unit, and a power supply unit for supplying power to the respective parts, The sensing control unit receives the (amplification) output signals of all the piezoelectric elements, and amplifies the differential amplification difference between the output signals from one element eA _i and the other element eA _j on the same plane. Calculating (Si); Determining that the gas is sensed only when at least one of the differential amplification values input from the side at which the gas is applied has a value equal to or greater than a predetermined threshold V _th ; And outputting a corresponding signal through the output unit when detecting the emitted gas. The method of claim 6, 2. The method of detecting emitted gas using a piezoelectric element, wherein the number of differential amplification values (peaks) equal to or more than a predetermined threshold (V _th ) serving as a basis for gas detection is 1 to 5.