KR20200023121A - A sensor interface electric circuit for health monitoring and wearable health monitoring system thereof - Google Patents

Abstract

The present invention relates to a sensor interface circuit and, more particularly, to a sensor interface circuit for health monitoring and a wearable health monitoring system using the same. The sensor interface circuit comprises: a sensor unit sensing body signals in close contact with an infected area of a patient; an interface chip receiving values of the body signals sensed by the sensor unit, sequentially processing the values, and transmitting the processed signals to a microcontroller; an AC power supply supplying power required for the interface chip; a low loss-type linear regulator (low dropout) operated at a low potential difference corresponding to a power value required by the interface chip to supply power; and a wireless communication unit transmitting the signals transmitted to the microcontroller to an external device, and wirelessly receiving power from the outside to wirelessly supply power to the low loss-type linear regulator. Therefore, the sensor interface circuit can achieve low power and improvement in efficiency by sequentially processing sensors having various electrical signal outputs with a single circuit.

Description

Sensor interface circuit for health monitoring and wearable health monitoring system using same {A SENSOR INTERFACE ELECTRIC CIRCUIT FOR HEALTH MONITORING AND WEARABLE HEALTH MONITORING SYSTEM THEREOF}

The present invention relates to a sensor interface circuit, and more particularly, a sensor interface circuit for health monitoring that can achieve low power and efficiency improvement by sequentially processing sensors having various electrical signal outputs using a single circuit and the same. It relates to a wearable health monitoring system used.

Currently, the paradigm of medical care is directed from the center of treatment by doctors to the consumer's health check and prevention in advance, and the demand for monitoring vital signs is rapidly increasing due to this demand.

Because the body's biological signals vary not only pH, but also temperature and humidity, it is possible to diagnose the patient's condition more accurately when sensing these various indicators, and similarly, the types of sensors that detect them and the types of output signals of the sensors also vary. Do.

However, in the conventional method for diagnosing a wound state of a patient, a limited process using only an electrical parameter sensor measuring voltage is generally not possible, and thus a sensor such as a resistor or a capacitor cannot be utilized.

In particular, in the case of Korea Patent Publication No. 10-2016-0120396, it is a patch type thermometer which is attached to the user's body with little foreign object feeling when used, and the user can easily check the body temperature data through wireless communication, and by supplying power through wireless power transmission for a long time Or a device and method for continuously monitoring the temperature is disclosed, the patch-type thermometer for implementing this feature, the sensor unit attached to the user's body to measure the temperature; A transmitter electrically connected to the sensor unit and wirelessly transmitting the measured temperature; And a wireless power generator electrically connected to the transmitter and wirelessly powered from an external source, wherein the wireless power generator converts an RF signal into a DC signal to supply power to the transmitter. .

In addition, in the case of Korean Patent Laid-Open Publication No. 10-2017-0113930, it receives a wireless power from an external device to measure the pH of the wound and measures the pH to transmit the information generated back to the external device. The present invention relates to a dressing and a related system, and has disclosed a smart dressing comprising a pH sensing unit for measuring a pH of the dressing unit and a wound site to generate a measurement signal.

However, in the circuit for processing a conventional sensor, the sensor is processed through a separate circuit according to the output signal of the sensor. That is, in a system that needs to simultaneously monitor various bio signals output according to voltage, resistance, or capacitor, each circuit must use a separate circuit. Therefore, it requires a lot of space and consumes a lot of power. I had.

In order to solve this problem, a circuit for simultaneously processing various sensors using a structure of a charge amplifier has been used. However, the disadvantage of this simultaneous processing circuit is that when processing a capacitor-type sensor, not only a capacitor corresponding to the initial value of the capacitor sensor is required separately, but also a capacitor corresponding to the change value of the sensor must be embedded in the chip. In addition, there is a problem in that the area of a chip is greatly increased to process a commercial capacitor sensor corresponding to several hundred pF.

Korean Patent Publication No. 10-2016-0120396 Korean Patent Publication No. 10-2017-0113930

An object of the present invention for solving the above problems, by using a switch controlled by a digital signal in the existing dual-slope integrator circuit, by changing the operation mode of the circuit suitable for each voltage, resistance, capacitor sensor, It is to provide a sensor interface circuit for health monitoring that can process voltage, capacitor, and resistance sensors sequentially with a single circuit, and a wearable health monitoring system using the same.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned above may be clearly understood by those skilled in the art from the following description. There will be.

The configuration of the sensor interface circuit for health monitoring of the present invention for achieving the above object, the sensor unit for detecting a body signal in close contact with the infected area of the patient; An interface chip which receives the body signal value detected by the sensor unit and processes the received signal sequentially and delivers the processed signal to a microcontroller; An AC power supply for supplying power required for the interface chip; A low loss type linear regulator (Low Dropout) for supplying power by operating at a low potential difference corresponding to the power value required by the interface chip; And a wireless communication unit for transmitting the signal transmitted to the micro controller to an external device, and wirelessly supplying power to the low loss type linear regulator from the outside. Characterized in that it comprises a.

The sensor unit may be configured to detect the body signal by any one of a voltage, a resistance, and a capacitor type.

In addition, the interface chip, an analog-to-time converter (ATC) that receives the analog signal sensed by the sensor unit and converts it into a time value, and transmits the time value converted by the analog signal time converter. It is preferable to include a time-to-digital converter (TDC) for receiving and converting to a digital value.

Among these, the analog-time converter may output a dual-slope integrator and a dual-slope integrator that derive an output voltage by calculating voltages corresponding to various signals sensed by the sensor unit. It is preferable to include a comparator for converting the voltage into a time value.

In addition, the time-to-digital converter is preferably configured to add output values of the plurality of counters after receiving different time values converted by the analog-time converters from a plurality of counters.

In addition, the body signal detected by the sensor unit is made to detect any one of the voltage, resistance and capacitor type of the sensor, and the value detected by the sensor of the voltage, resistance and capacitor type by the analog-time converter The step of converting the value into a digital value by the time-to-digital converter by converting the time value converted by the analog signal time converter is characterized in that it is made to sequentially process as a circuit using a time division multiplexing scheme.

The analog-time converter may include a charging switch unit configured to process voltage values having different magnitudes in one supply circuit in order to sequentially process values sensed by the voltage, resistance, and capacitor type sensors into one circuit; It is preferable to include a discharge switch part.

The charging switch unit, a voltage charging switch unit (T _VC ) for configuring a circuit to convert the value detected by the sensor of the voltage type to a time value, the process of converting the value detected by the sensor of the resistance type to a time value Resistor charge switch unit (T _RC ) for configuring the circuit to be configured, and a capacitor charge switch unit (T _CC ) for configuring the circuit to convert the value detected by the capacitor-type sensor to a time value,

The discharge switch unit, a voltage discharge switch unit (T _VD ) for configuring a circuit to convert the value detected by the sensor of the voltage type to a time value, the process of converting the value detected by the sensor of the resistance type to a time value Resistive discharge switch unit (T _RD ) for configuring the circuit so that it is preferable to include a capacitor discharge switch unit (T _CD ) for configuring the circuit to convert the value detected by the capacitor-type sensor to a time value.

In addition, it is preferable to further include a digital clock generator for receiving a counter output value summed from the time-to-digital converter and sequentially processing the output values so as not to overlap the output clock to generate a digital clock.

The effect of the present invention according to the above configuration is to reduce the area and power consumption of the chip by sequentially processing a voltage, resistance, capacitor type sensor into a single circuit using a time division multiplexing scheme, It has the advantage that it can be applied to wearable health monitoring system that emphasizes miniaturization and low power.

In addition, by using a single structure, different voltages, resistors, and capacitor sensors are sequentially read and digitalized in the time domain to reduce chip size and power. Therefore, this has the advantage that it can be a circuit suitable for wearable applications that require monitoring of various biological signals.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a schematic diagram showing the overall configuration of the present invention, the sensor interface circuit for health monitoring.
2 is a schematic diagram showing the configuration of an interface chip used in the present invention.
3 is a schematic diagram showing a charging process in a dual slope integrator used in the present invention.
4 is a schematic diagram showing a discharge process in a dual slope integrator used in the present invention.
5 is a schematic diagram illustrating a process of converting a voltage signal to time using a dual slope integrator in the analog-to-time converter used in the present invention.
6 is a schematic diagram illustrating a process of converting a resistance signal to time using a dual slope integrator in the analog-to-time converter used in the present invention.
7 is a schematic diagram illustrating a process of converting a capacitor signal to time using a dual slope integrator in the analog-to-time converter used in the present invention.
8 is a graph showing the voltage and signal values output after the dual slope integrator in the analog-time converter used in the present invention.
FIG. 9 is a graph showing experimental results of measuring an output value according to a voltage, a resistance, and a capacitor biosignal detected by an oscilloscope according to the present invention.
10 is a graph showing a clock and a signal value output after passing through the digital clock generator used in the present invention.
11 and 12 are prototype photographs of the present inventors implemented a sensor interface circuit for health monitoring.
13 and 14 are a perspective view and an exploded perspective view of the smart dressing for wound infection monitoring equipped with a liquid induction pad to which the present inventors sensor interface circuit for health monitoring is applied.
Figure 15 is a plan view of the PH sensor and the gauze connected by the discharge member of the smart dressing for wound infection monitoring equipped with a liquid guide pad to which the present invention is applied.
Figure 16 is an exploded cross-sectional view of the smart dressing for wound infection monitoring equipped with a liquid induction pad to which the present invention is applied.
17 is a perspective view and a partially enlarged view of another liquid induction pad of the smart dressing for monitoring wound infection with a liquid induction pad to which the present invention is applied.

Hereinafter, with reference to the accompanying drawings will be described the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, coupled) with another part, it is not only" directly connected "but also" indirectly connected "with another member in between. "Includes the case. In addition, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

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

In order to determine the state of a conventional wound site, the present invention provides a sensor interface circuit for health monitoring in order to determine in real time whether a wound site such as an image or a wound is additionally infected and to take a prompt action accordingly. This is to solve the problem that the wound could not be judged by removing the dressing and identifying it with eyes or taking a sample.

In other words, a dressing equipped with a pH sensor is used to monitor a wound of a patient, and when the pH sensor is applied to a body, the health of the body can be basically understood, and in particular, a wound part of the body If the pH sensor is in contact with the pH sensor, the pH sensor outputs different pH values depending on the degree of healing of the wound or the degree of infection of the wound, and thus monitoring is possible.

However, in order to perform such real-time monitoring, the PHS sensor to be used must be more accurate, faster, and more compact and have low power.

Accordingly, in the present invention, by using a switch that is controlled by a digital signal in the existing dual-slope integrator circuit, by changing the operation mode of the circuit suitable for each voltage / resistance / capacitor sensor, having one circuit, voltage, capacitor, It is configured to process resistance sensors sequentially.

That is, by attaching a comparator behind the dual-slope integrator circuit, the output of the circuit was changed to time rather than voltage. Therefore, analog-to-digital converters (ADCs), which are analogous power consuming analog blocks, can be replaced by time-to-digital converters (TDCs) operating with digital logic, which can greatly reduce the power of the entire system. Has an advantage.

As shown in Figure 1 and 2, the configuration of the sensor interface circuit for the health monitoring of the present invention, the sensor unit 10 for detecting a body signal in close contact with the infected area of the patient; An interface chip 20 which receives the body signal values sensed by the sensor unit 10 and sequentially processes them, and transmits the processed signals to the microcontroller 50; An AC power supply 30 for supplying power required for the interface chip 20; A low loss type linear regulator 40 (Low Dropout) for supplying power by operating at a low potential difference corresponding to the power value required by the interface chip 20; And a wireless communication unit 60 for transmitting a signal transmitted to the microcontroller 50 to an external device and wirelessly supplying power to the low loss type linear regulator 40 by receiving power from the outside wirelessly. Characterized in that it comprises a.

In addition, the sensor unit 10 is preferably configured to detect the body signal by any one of a voltage, a resistor, and a capacitor type.

In addition, the interface chip 20 receives an analog signal sensed by the sensor unit 10 and converts the analog signal into a time value (ATC, Analog sensor signal to Time Converter) and the analog signal. It is preferable to include a time-to-digital converter (TDC) 26 which receives the time value converted by the time converter and converts it into a digital value.

The analog-time converter 21 may include a dual-slope integrator 22 that calculates a voltage corresponding to various signals sensed by the sensor unit 10 and derives an output voltage. It is preferable to include a comparator 23 for converting the output voltage derived from the dual-slope integrator 22 into a time value.

Further, the time-to-digital converter 26 is preferably configured to add the output values of the plurality of counters after receiving different time values converted by the analog-time converter 21 from a plurality of counters.

That is, the time-to-digital converter 26 uses 8 MHz as a reference clock, uses a 10-bit solution, and can measure up to 128 microseconds.

In addition, the wireless communication unit 60 is made of a wireless power transmission and reception structure that can perform energy harvesting while simultaneously transmitting and receiving a signal wirelessly with an external device, preferably 13.56 MHz RFID method. (NT3H1101 (NXP) 13.56 MHz RFID, 5 mA @ 2V including AFE, MCU, RFID, Clock)

In order to solve the problems of the prior arts described above, the present invention uses a circuit based on the dual-slope integrator 22. The output voltage equation of the dual-slope integrator 22 is as follows.

As shown in the dual-slope integrator 22 output voltage equation, since the voltage, resistance, and capacitor values are included, the output voltage corresponding to each sensor can be obtained by selecting the resistance and capacitor sensors using various switches. The capacitor value is inversely proportional to the output voltage, making it suitable for handling large capacitors.

 In order to digitize the value obtained through the sensor processing circuit (interface chip) through the dual-slope integrator 22, the voltage is converted into time by attaching a comparator 23 after the dual-slope integrator 22 circuit, The converted time was converted into a digital value using a time-to-digital converter (TDC) 26.

In general, time-to-digital conversion circuits consume less power than analog-to-digital conversion circuits that digitize conventional voltages, making them suitable for low-power systems.

Charging and discharging processes in the dual-slope integrator 22 are shown in FIGS. 3 and 4.

The circuit description used in the present invention is as follows. When all sensor inputs are received, the voltage applied to the feedback capacitor is fixed to Vref and then operated. In addition, the time interval for reading the signal of the sensor is defined as the charging phase, and through the known value, the interval for changing the sensor signal to the time is defined as the discharging phase.

That is, as shown in FIG. 3, the charging process in the dual-slope integrator 22 satisfies the following equation.

In addition, as shown in FIG. 4, the discharge process in the dual-slope integrator 22 satisfies the following equations.

Furthermore, the body signal sensed by the sensor unit 10 used in the present invention is configured to detect any one of a voltage, a resistance, and a capacitor type, and the value detected by the sensor of the voltage, resistance, and capacitor type. The process of converting the time value converted by the analog-to-time converter 21 to the digital value by the time-to-digital converter 26 is performed using a time division multiplexing method. Characterized in that it is made to process sequentially in one circuit.

That is, in the case of the voltage sensor, as shown in FIG. 5 (a), a current proportional to the input voltage charges the feedback capacitor for a predetermined time during a charging phase. The equation is as follows.

On the contrary, in the discharging phase, a known voltage is connected in a direction opposite to the slope of the voltage increase in the charging phase to discharge the charge charged in the feedback capacitor.

At this time, when the voltage of the dual-slope integrator 22 falls below the voltage Vref value of the initial reset period in the discharging phase, the output voltage of the comparator 23 is changed, and the voltage sensor is measured by measuring this time. You can see the value of. The following equation represents the equation of the dual-slope integrator 22 in the discharging phase, and the voltage of each sensor can be estimated by the following equation.

In the case of the voltage sensor, since the direction in which the dual-slope integrator 22 increases in accordance with the magnitude of the input voltage is different, according to the state of the comparator 23 when the charging process is completed using the D-flip-flop. The voltage for each situation was connected.

In the case of using the sensor for detecting the resistance value in the present invention, as shown in Figure 6, the same principle as in the case of the voltage sensor.

The difference is that the digital-to-analog converter (DAC) and charging time (charging time) can be adjusted according to the range of each sensor in order to operate the circuit even with a resistance sensor lower than the feedback resistance (Rf). It was made adjustable.

More specifically, the V _INT values can be collected constantly (Rf: 1.66 MW), and 8-bit DACs can be used within the range of 0 to 0.9 V to adjust the charging current. In addition, with adjustable time, T _RC can be changed to 0.25 / 0.5 / 0.75 / 1T _RC, with a maximum value of T _RC of 128 μs.

This function regulates the amount and time of charge charged to the feedback capacitor, allowing a wide range of resistive sensors to operate within the supply voltage. The value of the resistance sensor using the above principle can be expressed as follows.

-Charging process

-Discharge process

Additionally, the process of processing the capacitor sensor is shown in FIG.

The difference from the previous process of the voltage sensor is that during charging, the capacitor sensor and the feedback capacitor are charged simultaneously, and the voltage values are the same because the two capacitors are connected in parallel.

Therefore, even if only the charge charged in the feedback capacitor during the discharge process, the sensor value can be known. To increase the processing range of the capacitor sensor, digital-to-analog conversion circuits (DACs) were used to regulate the current during the discharge process.

The value of such a capacitor sensor can be known through the following equation.

-Charging process

-Discharge process

As described above, in the present invention, the voltage, resistance, and capacitor type sensors are sequentially processed into a single circuit using a time division multiplexing method, thereby reducing chip area and power consumption, thereby miniaturizing and minimizing power consumption. There is an advantage that can be applied to the wearable health monitoring system.

That is, the analog-to-time converter 21 used in the present invention sequentially processes the values sensed by the voltage, resistance, and capacitor type sensors in one circuit. It is preferable to include a charge switch section 24 and a discharge switch section 25 for processing in the supply circuit.

Further, the charge switch unit 24, the voltage charge switch unit (T _VC ) for configuring the circuit to convert the value detected by the sensor of the voltage type to a time value, the value detected by the sensor of the resistance type Resistance switch unit T _RC for configuring a circuit to convert the signal into a time value, and capacitor charge switch unit T _CC for configuring the circuit to convert the value detected by the capacitor-type sensor into a time value. Including;

The discharge switch unit 25 is a voltage discharge switch unit (T _VD ) for configuring a circuit to convert the value detected by the sensor of the voltage type to a time value, the time detected by the sensor of the resistance type A resistive discharge switch unit T _RD for configuring a circuit to convert the value into a value, and a capacitor discharge switch unit T _CD for configuring the circuit to convert the value detected by the capacitor type sensor into a time value. Good to do.

According to the operation of the various switches such as shown in Figures 5, 6 and 7, it is possible to configure each independent circuit according to the voltage, resistance, and capacitor sensor, each using a single circuit structure By reading the voltage, resistance, and capacitor sensors sequentially and digitizing them in the time domain, the chip size and power can be reduced, which makes it a suitable circuit for wearable applications requiring monitoring of various biological signals. There is this.

When sequentially processing the sensors of each of such voltages, resistors, and capacitors, a graph of the voltages of the duode-slope integrator and the converted time values according to the input signals of the sensors is shown in FIG. 8. The measurement results are shown in FIG.

The time value converted from each sensor is digitized and stored using one or more counters of the time-to-digital converter 26 (TDC). Since the frequency of the biosignal is low, it does not need to be processed at high speed, so that a counter used in the present invention may be a general counter.

A digital clock generator 70 capable of adjusting circuits in the analog sensor signal to time converter (ATC) and the time to digital converter (TDC) 26 (Digital) Clock Generator) is shown in FIG.

That is, the present invention preferably further includes a digital clock generator 70 which receives the counter output values summed from the time-to-digital converter 26 and sequentially processes the output values so that the output values do not overlap to generate a digital clock. .

In order to reduce power consumption, the digital clock generator 70 used in the present invention lowers the frequency of the signal, such as the reference clock of the counter, through the divider, and then generates each of the 32 delayed time signals using the Johnson counter. Then, the AND gate and the OR gate were combined to generate a digital clock control signal.

The result is shown in FIG.

That is, as described above, in the charging phase of the resistance sensor, time can be adjusted through a digital code.

11 and 12 illustrate an experimental environment for measuring a circuit according to an embodiment of the present invention, and in order to connect and measure various sensors, a microcontroller 50 (MCU, micro control) for controlling a circuit unit), a clock generation chip, and a voltage buffer that will generate a reference voltage V _REF in the circuit are attached to the printed circuit board (PCB).

Using this, the measured signal waveforms are as shown in FIGS. 9 and 10 above, and each current consumption when using a 1.8 V power supply is shown in the following table.

Components Current (μA) Buffer 4.43 LDO One Chip oscillator 447.57 Micro control unit 668 Proposed chip 1060 Total 2180

Therefore, the power consumption of the proposed circuit has a value of 1.9 mW, which is lower than that of other conventional technologies for processing resistors or capacitor sensors.

As various applications using the present inventors' health monitoring sensor interface circuit as described above, smart dressing and wearable health monitoring system for wound infection monitoring may be considered.

An embodiment of the smart dressing for monitoring wound infection to which the present inventors' health monitoring sensor interface circuit is applied as shown in FIGS. 13 to 16 is as follows.

That is, the surface where the PH sensor and the fluid channel are shown is a portion facing the wound portion, and the fixing portion is the outermost portion of the smart dressing for monitoring the wound infection provided with a liquid induction pad attached to the wound portion.

Accordingly, in the present invention, the wound is placed down and the smart dressing for monitoring the wound infection with the liquid induction pad is attached. The lower surface is the wound area, and the upper surface is the smart dressing for monitoring the wound infection with the liquid induction pad. It means.

13 to 16, the wound dressing monitoring smart dressing 100 with a liquid guide pad according to the present invention is disposed to face the wound, the fluid channel 121 to guide the exudates generated in the wound site ) Is formed in the plate-shaped liquid induction pad 120, the PH sensor 110, the PH sensor 110 disposed on the upper surface of the liquid induction pad 120 to measure the acidity from the exudates guided from the liquid induction pad Gauze unit 130, the PH sensor 110 and the liquid induction pad 120 and the gauze unit 130 disposed on the upper surface of the PH sensor 110 and the liquid induction pad 120 to absorb the exudates measured acidity through It is arranged to surround the gauze portion 130 to provide a fixing portion 140 made of a material having an adhesive to fix from the wound.

More specifically, the PH sensor 110 is a sensor for measuring the pH of a fluid, an antimony electrode using a change in the ionization equilibrium of hydroxide by the pH of the liquid, and a neutron carrier organic sensitizer having a polyvinyl chloride matrix. And a liquid film electrode using the same, a pH FET sensor having an inorganic insulating film such as Al2O3 or Ta2O5 attached to the metal gate portion of the MOSFET, and a glass electrode using a pH sensitive silicate glass thin film containing Li2O2.

In addition, the liquid induction pad 120 is disposed on the lower surface of the PA sensor 110 in a plate shape, and a groove-shaped fluid channel 121 is formed to guide the exudates to the PA sensor 110.

Thus, the exudate flows to the PA sensor 110 along the groove of the fluid channel 121.

In addition, the gauze unit 130 is disposed on the upper surface of the PA sensor 110 and the liquid induction pad 120 in the shape of a plate, the exudates generated in the wound portion is passed through the PA sensor 110, the gauze ( Absorbed from the gauze portion 130 when absorbed by the 130 or the generation of excessive exudate.

In addition, the PA sensor 110, the liquid induction pad 120 and the gauze portion 130 is fixed to the wound portion is provided with a fixing portion 140 having an adhesive to maintain a constant position.

Accordingly, the fixing part 140 maintains a constant position of the PH sensor 110, the liquid induction pad 120, and the gauze part 130, thereby protecting the wound and preventing contamination from the outside. The sensor 110 allows to stably measure the acidity of the wound.

In addition, the fluid channel 121 is formed as a tapered groove having a narrow width from the edge of one surface of the liquid guide pad 120 facing the wound to the center, and a pressure difference is generated in the tapered shape so that the exudates It may be provided to guide from the edge of the liquid induction pad 120 toward the center side.

In more detail, the liquid induction pad 120 is provided with a fluid channel 121 formed of a tapered groove narrowing from the edge to the center portion to guide the exudates along the tapered groove. The acidity of the exudates guided through the PH sensor 110 is measured.

That is, the fluid channel 121 has a width narrowed from the edge to the center side, so that the pressure increases during the movement of the fluid, so that the fluid moves in the narrow width, so that the exudates generated on one side of the tapered groove The PSI sensor 110 flows to the PSI sensor 110 located at the other side of the tapered groove of the fluid channel 121, and the PSI sensor 110 may measure the acidity of the exuded fluid.

In addition, the PA sensor 110 may be disposed at the center of the liquid induction pad 120, and the exudant may be guided to the PA sensor 110 through the fluid channel 121.

More specifically, the PH sensor 110 is disposed at the center of the liquid induction pad 120, and the fluid channel 121 is formed to have a width narrowing from the edge to the center, so that the exudate is the liquid induction pad. The PH sensor 110 is moved from the edge of the 120 to the center, and the PH sensor 110 is disposed at the center, so that the exudates generated apart from the PH sensor 110 are guided through the fluid channel 121 to provide the PH sensor ( 110) may be flowed to the side.

Therefore, the PH sensor 110 may determine the state of infection and inflammation in front of the wound site by measuring the acidity of the exudate generated apart from this.

In addition, a through hole 123 is provided at the center of the liquid induction pad 120, and the through hole 123 serves as a passage through which the exudates guided through the fluid channel 121 flow into the PH sensor 110. It may be provided to.

In more detail, a through hole 123 is provided at the center of the liquid induction pad 120, and the PHS sensor 110 is positioned in the through hole 123. Therefore, since the exudates guided through the fluid channel 121 flow into the through hole 123 and finally flow to the P sensor 110, the acidity of the exudates can be easily measured.

That is, the exudates are guided to the central side of the liquid induction pad 120 by the fluid channel 121, and the through-holes 123 are moved to the PH sensor 110 disposed at the center of the liquid induction pad 120. This will act as a passage.

Meanwhile, a plurality of fluid channels 121 may be formed radially around the PA sensor 110 on one surface of the liquid induction pad 120 so that the PA sensor 110 may measure acidity uniformly throughout the wound. have.

More specifically, the liquid induction pad 120 is centered on the PH sensor 110 on one surface of the liquid induction pad 120 to guide unspecified exudates from the wound to the PH sensor 110. The fluid channel 121 is formed radially.

Therefore, the fluid channel 121 is formed over the entire surface of the wound to uniformly guide the unspecified exudates.

In addition, the PH sensor and the gauze portion 130 may be provided with a discharge member 150 so that the exudates are discharged to the gauze portion 130.

More specifically, the exudates guided to the PH sensor 110 by the fluid channel 121 are absorbed into the gauze unit 130 after the pH is measured, and the new exudates are guided to measure the new pH. Accordingly, the pH sensor and the gauze portion 130 are discharged by the discharge member 150 so that the pH of the exudates is continuously measured so that the absorption of the exudate proceeds quickly to the gauze portion 130 so as to grasp the state of the wound site. Connected.

The discharge member 150 is formed in the shape of a rod having a predetermined length to directly connect the P sensor and the gauze portion 130, and is made of a cotton fabric of the same plain fabric as the gauze portion 130 so as to easily absorb the fluid. It may be constructed or formed of a porous polyurethane component.

In addition, since the discharge member 150 is formed in various lengths, the discharge member 150 having a short length is absorbed by the gauze portion 130 adjacent to the PH sensor, and the discharge member 150 having a long length is discharged at a short length. Since it is absorbed by the gauze portion 130 of a relatively longer distance than the member 150, the absorption force of the gauze portion 130 can be kept constant.

In addition, the liquid induction pad 120 may be in close contact with the skin so that the protrusion 124 may be formed along the outer surface so that the exudate is not lost to the outside.

More specifically, the protrusion 124 is formed to protrude along the outer surface of the liquid induction pad 120 facing the wound, wound portion dressing 100 with a liquid induction pad according to the invention When attached to the can act to be in close contact with the skin so that exudates from the wound are not lost to the outside.

Therefore, since the protrusion 124 is in close contact with the skin, the exudates do not leak to the outside, and the new exudates are continuously flowed to the PH sensor 110 to monitor the state of the wound site by measuring acidity.

In addition, the PH sensor 110 may be provided to determine the state of infection and inflammation by measuring the acidity of the exudate.

In more detail, the PH sensor 110 may measure the acidity of the exudate and grasp the infection and inflammation of the wound site according to the acidity.

That is, the pH index of normal wounds ranges from 5.5 to 6.5, but infected wounds have a pH index greater than 6.5. Therefore, the acidity of the exudate can be measured to determine the infection and inflammation of the wound. It can prevent and prevent the condition from worsening.

In addition, the PH sensor 110 is coupled to a temperature sensor (not shown), the temperature sensor may determine the inflammatory state by measuring the temperature of the wound.

More specifically, the PH sensor 110 is coupled to a temperature sensor, the temperature sensor may measure the temperature of the wound or exudates. In general, the temperature of the wound is changed according to the inflammatory state, and the temperature sensor can measure the temperature of the wound and the exudate to determine the inflammatory state, and can prevent and prevent the deterioration of the wound.

In addition, the gauze portion 130 may be composed of a plain weave cotton fabric so that the exudates are absorbed, or may be composed of a porous polyurethane component.

More specifically, the gauze portion 130 may be easily absorbed, composed of a plain weave cotton fabric or porous polyurethane components to maintain the wet environment to help the wound healing environment.

In addition, a power unit (not shown) electrically connected to the PA sensor 110 may be provided to supply power to the PA sensor 110.

In more detail, the power supply unit may be provided at one side of the PA sensor 110 to be coupled to the PA sensor 110 to supply power, and the PA sensor 110 may be electrically connected to the outside having the power unit. Can be connected and powered.

Accordingly, the PH sensor 110 may be supplied with power through a power supply unit to measure the acidity of the wound and exudate in real time.

In addition, the dressing with the liquid induction pad 120 may be provided with a real-time monitoring dressing to monitor the wound site in real time through a wireless communication device.

In more detail, the real-time monitoring dressing can monitor the wound site in real time by grasping the state of the wound site through a pH measured in real time by the dressing equipped with the wireless communication device, and transmitting and receiving it to the wireless communication device. .

17 is a perspective view and a partially enlarged view of a liquid induction pad of the smart dressing for wound infection monitoring equipped with a liquid induction pad according to an embodiment of the present invention.

Referring to FIGS. 13 and 17, the fluid channel 321 is formed in the shape of a straight groove, and an auxiliary groove 322 is formed on the side of the straight groove, and the auxiliary groove 322 is unspecified at the wound site. A plurality of exudates generated may be formed on the side of the straight groove so as to uniformly supply the PH sensor 310.

In more detail, the fluid induction pad 320 is uniformly formed with a fluid channel 321, the side of the groove of the fluid channel 321 is further formed with an auxiliary groove 322 to exudate the wound site Can be guided uniformly.

That is, the auxiliary groove 322 formed at the side of the slot groove of the fluid channel 321 increases the cross-sectional area that can be in contact with the exudate, thereby uniformly guiding the exudate to the PA sensor 310.

The above description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is represented by the following claims, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present invention.

10: sensor
20: interface chip
21: Analog sensor signal to Time Converter (ATC)
22: Dual Slope Integrator
23: Comparator
24: charge switch unit
25: discharge switch
26: Time to Digital Converter (TDC)
30: AC power
40: Low Loss Type Linear Regulator (LDO, Low Dropout)
50: Micro Control Unit (MCU)
60: wireless communication unit
70: Digital Clock Generator
100, 200: Smart dressing for wound infection monitoring with liquid induction pad
110, 210: P sensor
120, 220: liquid induction pad
121, 221: fluid channel
123: through hole
124: protrusion
130: gauze
131: storage groove
140: fixed part
150: discharge member
222: auxiliary groove

Claims (12)

A sensor unit which detects a body signal in close contact with an infected part of the patient;
An interface chip which receives the body signal value detected by the sensor unit and processes the received signal sequentially and delivers the processed signal to a microcontroller;
An AC power supply for supplying power required for the interface chip;
A low loss type linear regulator (Low Dropout) for supplying power by operating at a low potential difference corresponding to the power value required by the interface chip; And
A wireless communication unit which transmits a signal transmitted to the micro controller to an external device, and wirelessly supplies power to the low loss type linear regulator by receiving power wirelessly from the outside; Sensor interface circuit for health monitoring comprising a.
The method of claim 1, wherein the sensor unit,
And the body signal is sensed by any one of a voltage, a resistance, and a capacitor type sensor.
The method of claim 1, wherein the interface chip,
An analog-to-time converter (ATC) that receives the analog signal sensed by the sensor unit and converts it into a time value, and a time that receives the converted time value from the analog signal time converter and converts it into a digital value A sensor interface circuit for health monitoring, comprising a time to digital converter (TDC).
The method of claim 3, wherein the analog-to-time converter,
Dual-Slope Integrator that calculates a voltage corresponding to various signals sensed by the sensor unit and derives an output voltage and a Comparator that converts the output voltage derived from the Dual-Slope Integrator into a time value. Sensor interface circuit for health monitoring comprising a).
The method of claim 3, wherein the time-to-digital converter,
And after receiving different time values converted by the analog-time converter from a plurality of counters, summing output values of the plurality of counters.
The method of claim 3,
The body signal detected by the sensor unit is made to detect by any one of the voltage, resistance and capacitor type,
Converting the value detected by the sensor of the voltage, resistance and capacitor type into a time value by the analog-time converter, and converting the time value converted by the analog signal time converter into a digital value by the time-digital converter. The process of the health monitoring sensor interface circuit, characterized in that the process is made to sequentially process as one circuit using a time division multiplexing scheme.
The method of claim 6, wherein the analog-to-time converter,
In processing the values sensed by the voltage, resistance, and capacitor type sensors in one circuit, a charging switch unit and discharging for processing voltage values of different magnitudes in one supply circuit. Health monitoring sensor interface circuit comprising a switch unit.
The method of claim 7, wherein the charging switch unit,
A voltage charging switch unit (T _VC ) for configuring a circuit to convert the value detected by the sensor of the voltage type to a time value, and configuring the circuit to convert the value detected by the sensor of the resistance type to a time value A resistance charging switch unit (T _RC ) for the health monitoring sensor, characterized in that it comprises a capacitor charging switch unit (T _CC ) for configuring a circuit to convert the value detected by the capacitor-type sensor to a time value Interface circuit.
The method of claim 7, wherein the discharge switch unit,
A voltage discharge switch unit (T _VD ) for configuring a circuit to convert the value detected by the sensor of the voltage type to a time value, and to configure the circuit to convert the value detected by the sensor of the resistance type to a time value Resistive discharge switch (T _RD ) for the health monitoring sensor, characterized in that it comprises a capacitor discharge switch (T _CD ) for configuring a circuit to convert the value detected by the capacitor-type sensor to a time value Interface circuit.
The method of claim 5,
And a digital clock generator configured to receive a counter output value summed from the time-to-digital converter and sequentially process the output values so that the output values do not overlap, thereby generating a digital clock.
Smart dressing for wound infection monitoring to which the health interface sensor interface circuit of any one of claims 1 to 10 is applied.
A wearable health monitoring system to which the sensor interface circuit for health monitoring according to any one of claims 1 to 10 is applied.

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