CN210843013U - Blood leakage detection circuit for puncture needle head - Google Patents

Abstract

The utility model relates to a detection circuit, which comprises two Y-shaped optical fiber sensors, a monochromatic light emitting diode arranged at the light source end of the Y-shaped optical fiber sensor, and a color sensor arranged at the detection end of the Y-shaped optical fiber sensor; the output end of the color sensor is connected with a homophase voltage amplifier, the homophase voltage amplifier is connected with a voltage comparator, the output end of the voltage comparator is connected with the signal input end of the singlechip, and the control output end of the singlechip is connected with an alarm circuit; the Y-shaped optical fiber sensor comprises two optical fibers, wherein one ends of the two optical fibers are bundled to form an optical fiber detection end, and the other ends of the two optical fibers respectively lead out a light source end and a detection end; the optical fiber detection end is fixed above the puncture part through the band-aid, and the front end part of the optical fiber detection end is arranged on the gauze of the band-aid. The utility model discloses a to the effective detection of little blood leakage in the puncture of dialysis, it is high to detect the precision, operation convenient to use and safe and reliable.

Description

Blood leakage detection circuit for puncture needle head

Technical Field

The utility model relates to a sensor and medical instrument field, specific puncture needle head blood leakage detection circuitry that says so.

Background

Hemodialysis is one of kidney replacement treatment modes for patients with renal failure, and belongs to a blood purification technology. At present, about 200 thousands of patients in China need to be subjected to hemodialysis to maintain life, and the patients need to be subjected to hemodialysis 2-3 times per week for 4-5 hours each time. Clinically, the internal venous and arterial fistula of a patient remains an ideal vascular access for maintaining hemodialysis. However, after the arteriovenous internal fistula is constructed, the venous pressure of a dialysis part is increased, the elasticity of the venous blood vessel can be reduced due to factors such as long-term fixed-point puncture and use of an anticoagulant in dialysis, blood leakage of a puncture needle hole of the internal fistula is caused, in addition, the blood leakage of a patient is caused by falling off of a puncture needle head due to body movement in a long-time dialysis process, the blood leakage is dangerous during dialysis, and the life safety of the patient can be endangered if measures are not taken in time.

The blood leakage detection methods used in clinic include the following methods: 1) manual patrolling, which increases the workload and psychological stress of medical staff; 2) a pressure detection method, wherein when the blood inlet needle head and the blood outlet needle head are simultaneously separated in the dialysis process, the dialysis machine cannot detect the pressure difference change and cannot trigger the dialysis machine to alarm; 3) the impedance detection method realizes blood leakage detection by using impedance change of an electrode caused by blood, and has the problems that false alarm is easily caused when a patient sweats, potential safety hazard is brought to the patient by the contact of the electrode and the skin, and the reliability and the safety are lower; 4) in the image detection method, in order to acquire the blood leakage information, an image sensor system needs to cover the puncture needle head, which is not beneficial to the patrol of medical staff. The blood leakage detection methods all have certain disadvantages and shortcomings, and innovative detection methods are required.

The occurrence of blood leakage in the dialysis process is a serious medical liability accident, and therefore, the blood leakage detection method should meet the following requirements: 1) puncture parts cannot be shielded, blood leakage detection cannot influence patrol of medical care personnel, and any detection equipment cannot completely replace manual patrol; 2) the blood leakage detection equipment is simple to operate, and cannot bring extra workload while relieving the psychological pressure of medical staff; 3) the blood leakage detection technology is safe and reliable, and avoids bringing additional potential safety hazards to patients; 4) the blood leakage detection equipment needs high comfort level and can not bring uncomfortable pain to patients.

In view of the above requirements, the applicant of the present application has developed a blood leakage detection circuit for a dialysis puncture needle based on an optical fiber sensor, which can effectively detect trace blood leakage of a puncture needle hole, improve the sensitivity of a detection device, and has the advantages of safety and reliability. The detection device adopting the technical method has a blood leakage alarm function, can effectively overcome the problems of false alarm and missed alarm, and reduces the safety risk in the dialysis process.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a puncture needle head blood leakage detection circuitry based on optical fiber sensor, this circuit structure can effectively detect the trace blood leakage of puncture needle hole, and detectivity is high, convenient operation, use safe and reliable.

In order to solve the technical problem, the detection circuit of the utility model comprises two Y-shaped optical fiber sensors, a monochromatic light emitting diode arranged at the light source end of the Y-shaped optical fiber sensor, and a color sensor arranged at the detection end of the Y-shaped optical fiber sensor; the output end of the color sensor is connected with a homophase voltage amplifier, the homophase voltage amplifier is connected with a voltage comparator, the output end of the voltage comparator is connected with the signal input end of the singlechip, and the control output end of the singlechip is connected with an alarm circuit; the Y-shaped optical fiber sensor comprises two optical fibers, wherein one ends of the two optical fibers are bundled to form an optical fiber detection end, and the other ends of the two optical fibers respectively lead out a light source end and a detection end; the optical fiber detection end is fixed above the puncture part through the band-aid, and the front end part of the optical fiber detection end is arranged on the gauze of the band-aid.

By adopting the circuit structure, in the dialysis puncture, the puncture needle is fixed by the band-aid, the gauze of the band-aid directly covers the puncture part, if blood leakage occurs, the blood firstly dyes the gauze red, therefore, the optical fiber detection end is arranged on the gauze of the band-aid, the gauze of the band-aid is white, the intensity of reflected light is highest when no blood leakage occurs, and when the gauze is dyed red, the intensity of the reflected light is weakened, therefore, whether blood leakage occurs can be intuitively judged by detecting the intensity of the emitted light. The light intensity is reflected to be the height of a voltage value by the color sensor, a threshold voltage value is set, the detection voltage is compared with the threshold voltage by the voltage comparator, when the detection voltage is smaller than the preset threshold voltage, the light intensity is weakened, gauze is dyed red, the blood leakage phenomenon is caused, and at the moment, the single chip microcomputer controls the alarm circuit to send out an alarm signal to inform medical staff of timely treatment, so that accidents are avoided.

The optical fiber detection end is sleeved with a blood leading cap made of non-woven fabric or absorbent cotton. The blood-leading cap is arranged to lead the leaked blood to the blood-leading cap, so that the aim of vertically irradiating the detection position by the probe can be fulfilled, the blood-leading range can be expanded, and the detection precision is improved.

One input end of the voltage comparator is connected with the output end of the in-phase voltage amplifier, the other input end of the voltage comparator is connected with a reference voltage source through a slide rheostat, and the slide rheostat forms a voltage division circuit. The voltage division is adjusted through the sliding rheostat, so that the threshold voltage entering the voltage comparator can be flexibly adjusted.

The alarm circuit comprises a horn, a triode switch is connected in series with a power supply loop of the horn, and the control end of the triode switch is electrically connected with the singlechip; the power supply loop of the horn is also connected with a function starting key and a reset key. In the alarm circuit, two keys which can be operated by a user are arranged, when the function opening key is pressed down, the blood leakage detection alarm system starts to operate, the blood leakage state of the puncture needle head part is detected in real time, and the alarm system is immediately triggered once blood leakage occurs to remind medical staff of timely treatment. After the treatment is finished, a reset key is pressed down, the alarm is eliminated, and the normal detection working state is returned.

The monochromatic light emitting diode is a blue light emitting diode, and the color sensor is a blue photosensitive diode. According to the detection principle of the scheme, the preferred color of the incident light is as follows: when the incident light source irradiates red gauze with different colors, the larger the change amplitude of the reflected light intensity is, the better the voltage change quantity is when the voltage reflecting the detection electric signal is. Experiments prove that the effect of the blue light source is best, so that the blue light source can ensure higher detection sensitivity.

To sum up, the utility model discloses a method and detection circuitry have realized the effective detection to little blood leakage in the dialysis puncture, and it is high to detect the precision, operation convenient to use and safe and reliable.

Drawings

The invention will be described in further detail with reference to the following drawings and embodiments:

fig. 1 is a schematic diagram of a circuit for signal acquisition and amplification in the detection circuit of the present invention;

FIG. 2 is a schematic circuit diagram of a signal processing circuit and an alarm circuit in the detection circuit of the present invention;

FIG. 3 is a graph showing the output characteristics of the voltage of the detection electrical signal of the incident light of three colors, red, green and blue;

fig. 4 is a schematic structural diagram of a specific placement mode of the optical fiber probe of the present invention.

Detailed Description

Referring to the drawings, the detection circuit of the utility model comprises two Y-shaped optical fiber sensors SY1, SY2, single-color light emitting diodes L1, L2 arranged at the light source end of the Y-shaped optical fiber sensor, and color sensors D1, D2 arranged at the detection end of the Y-shaped optical fiber sensor; the output ends of the color sensors D1 and D2 are connected with a same-phase voltage amplifier U1A and U1B, the same-phase voltage amplifier U1A and U1B are connected with a voltage comparator U1C and U1D, the output ends of the voltage comparator U1C and U1D are connected with the signal input end of the singlechip U2, and the control output end of the singlechip U2 is connected with an alarm circuit; the Y-shaped optical fiber sensors SY1 and SY2 comprise two optical fibers, one end of each of the two optical fibers is bundled to form an optical fiber detection end 1, and the other ends of the two optical fibers respectively lead out a light source end and a detection end; the optical fiber detection end 1 is fixed above the puncture position through the band-aid 2, and the front end part of the optical fiber detection end 1 is arranged on the gauze 20 of the band-aid.

In the dialysis puncture, the puncture needle is fixed by the band-aid 2, the gauze of the band-aid 2 directly covers the puncture part, if blood leakage occurs, the blood firstly dyes the gauze 20 red, therefore, the optical fiber detection end 1 is arranged on the gauze 20 of the band-aid 1, the gauze of the band-aid 1 is white, the intensity of reflected light is highest when no blood leakage occurs, and when the gauze is dyed red, the intensity of the reflected light is weakened, therefore, whether blood leakage occurs can be intuitively judged by detecting the intensity of the emitted light. The light intensity is reflected to be the height of a voltage value by the color sensor, a threshold voltage value is set, the detection voltage is compared with the threshold voltage by the voltage comparator, when the detection voltage is smaller than the preset threshold voltage, the light intensity is weakened, gauze is dyed red, the blood leakage phenomenon is caused, and at the moment, the single chip microcomputer controls the alarm circuit to send out an alarm signal to inform medical staff of timely treatment, so that accidents are avoided.

One input end of each of the voltage comparators U1C and U1D is connected with the output end of the non-inverting voltage amplifier, the other input end of each of the voltage comparators U1C and U1D is connected with a reference voltage source Vref through a slide rheostat W1 and a slide rheostat W2, and the slide rheostats W1 and W2 form a voltage division circuit.

The alarm circuit comprises a horn SPK, a power supply loop of the horn SPK is connected with a triode switch T1 in series, and the control end of a triode switch T1 is electrically connected with the single chip microcomputer U2; the power supply loop of the horn SPK is also connected with a function starting key K1 and a reset key K2.

Because the blood leakage states of the blood inlet needle hole and the blood outlet needle hole need to be monitored simultaneously in the actual dialysis puncture, the signal acquisition and processing circuits in the attached drawings are provided with two identical sets, and the two sets of circuits share one single chip microcomputer circuit and an alarm circuit. The specific circuit configuration is described in detail below.

Fig. 1 is a schematic diagram of a circuit for signal acquisition and amplification, which is composed of a Y-type optical fiber and a voltage amplifier. The puncture vein forms the circulation route of blood during the dialysis, need monitor the hourglass blood state of bleeding pinhole and advancing blood pinhole simultaneously, so should set up two sets of optical fiber sensor and carry out real-time detection to the dialysis syringe needle. In this design, monochromatic emitting diode L1, L2 send the light of three kinds of colours red, green, blue respectively as the light source, light source end through Y type optic fibre SY1, SY2 jets into, and the probe end shines test sample center perpendicularly, and the light source shines on the check point from the probe end, and when blood oozes, the sense terminal of optic fibre will derive the light signal of different intensity, is received by color sensor D1, D2 and converts the signal of telecommunication into, and wherein, color sensor is the photosensitive diode sensitive to specific wavelength. U1A and U1B constitute two sets of cophase voltage amplification circuits, and its magnification is about ten times, are used for amplifying the electrical signal of optical fiber sensor output, realize the signal acquisition of blood leakage detection.

Fig. 2 is a schematic circuit diagram of a signal processing circuit and an alarm circuit, which mainly comprises three parts, namely two voltage comparators, a singlechip system and the alarm circuit. Voltage signals output by two groups of optical fiber sensorsU1、U2And comparing the voltage signals with the threshold values set by the voltage comparator U1C and the UID corresponding to the voltage comparators, outputting a blood leakage signal by the comparator when any group of input voltage signals are smaller than the threshold voltage, and outputting an alarm signal after the signals are confirmed by an STC15F104E singlechip U2 system to drive an alarm circuit to give out an audible and visual alarm. The blood leakage alarm system is provided with two user operable buttons which, when pressed, are activated₁When the puncture needle is in operation, the blood leakage detection alarm system starts to operate, the blood leakage state of the puncture needle head part is detected in real time, the alarm system is triggered immediately once blood leakage occurs, medical workers are reminded to process the puncture needle in time, and K is pressed down after the processing is finished₂And the system eliminates the alarm and returns to the normal detection working state.

As shown in FIG. 4, a blood-drawing cap 3 made of non-woven fabric or absorbent cotton is sleeved on the optical fiber detection end 1. When the detection device is used specifically, the optical fiber detection end is hidden under the woundplast gauze 20, so that the angle and the distance of the probe are difficult to keep consistent, and the detection precision can be ensured only by normalizing the measurement condition. Therefore, preferably, the blood-leading cap 3 made of non-woven fabric or absorbent cotton is sleeved on the optical fiber detection end, and the leaked blood is directly led to the blood-leading cap 3, so that the aim of vertically irradiating the detection position by the detection end can be fulfilled, the blood-leading range can be expanded, and the detection precision can be improved.

The preferred monochromatic light source is a blue light source, and the photoelectric conversion element is a blue light color sensor; the preset threshold voltage is selected according to the amplification factor set by the amplifier and the sensitivity of the photoelectric conversion element. According to the detection principle of the scheme, in order to achieve higher detection sensitivity, the preferred colors of the incident light are as follows: when the incident light source irradiates red gauze with different colors, the larger the change amplitude of the reflected light intensity is, the better the voltage reflected by the detection electric signal is, the larger the change quantity of the voltage is, the better the voltage is. Experiments prove that the effect of the blue light source is best, so that the blue light source can ensure higher detection sensitivity. Correspondingly, the photoelectric conversion element, i.e., the color sensor, is a blue color sensor.

The method for determining the color of the optical fiber sensor and the experimental process will be briefly described below.

The method for determining the color of the optical fiber sensor comprises the following steps: 3.1) preparing multiple groups of blood solutions with the concentration of 0-100% for the rabbit venous whole blood by using physiological saline, and dripping an equivalent blood solution into non-woven fabrics with the same thickness and area size to prepare a blood experiment sample in each group, wherein the sample with the concentration of 0% only needs to be dripped into the non-woven fabrics with the equivalent physiological saline; 3.2) in a dark environment, respectively using the light of three colors of red, green and blue as a monochromatic light source to irradiate the experimental sample through the light guide fiber of the Y-shaped optical fiber; 3.3) converting the detected optical signal into a detection electric signal at the detection end by using a photoelectric conversion element, and outputting a signal voltage after the detection electric signal is amplified by an amplifying circuit; and 3.4) drawing an output characteristic curve between the blood solution concentration and the detection signal voltage, judging the change amplitude of the signal voltage, and taking the monochromatic light source with the maximum change amplitude as the optimal light source.

The specific experimental process is as follows: the method selects common red, green and blue light irradiation detection samples to perform a simulated blood leakage experiment, and is used for optimizing the optical fiber sensor with higher sensitivity. In order to simulate the amount of blood leakage of a puncture needle head in the dialysis process, 12 groups of blood solutions with the concentration of 0% -100% are prepared from rabbit venous whole blood by using 0.9% physiological saline, an equal amount of blood solution is taken from each group and is dripped on non-woven fabrics with the same thickness and area size to prepare blood experimental samples, wherein the sample with the concentration of 0% only needs to be dripped on the non-woven fabrics with an equal amount of physiological saline.

Optical fiber sensors respectively adopting red, green and blue light in experiments are used for measuring concentrationCThe rabbit blood is detected in 0-100%, and the dialysis needle and the optical fiber detection end are embedded below the band-aid, so that the interference of ambient light on detection is avoided in order to simulate the detection environment, and the simulation experiment is performed under the dark condition. The output voltages of the red, green and blue optical fiber sensors are Ur, Ug and Ub respectively, and the experimental data are shown in Table 1.

Fig. 3 is a graph of the output characteristics of the optical fiber sensor for three colors, plotted according to the experimental data of table 1, in which,Uis the output voltage of the optical fiber sensor,Cthe concentration of the blood sample is shown as Ur, Ug and Ub, respectively, and the output characteristic curve of the red light optical fiber sensor, the output characteristic curve of the green light optical fiber sensor and the output characteristic curve of the blue light optical fiber sensor are shown as Ub. The characteristic curves of Ur, Ug and Ub are contrastively analyzed, so that the red optical fiber sensor is least sensitive to the change of the sample concentration and has the least sensitivity; the green light optical fiber sensor is sensitive when detecting the micro-change of the sample, and the sensitivity is high; the voltage variation of the blue light optical fiber sensor is far larger than that of the green light optical fiber sensor, which shows that the sensitivity of the blue light optical fiber sensor is the highest, so the blue light optical fiber sensor is preferably used as an optical fiber sensor for blood leakage detection.

The experimental process and the method for determining the color of the monochromatic light source are also used for further proving why the blue optical fiber sensor is used in the present application, and the specific experimental process and method steps are not the core of the present application. The core of the scheme is a circuit structure.

In addition, the setting and comparison of the threshold voltage related to the scheme are realized through a circuit structure, the signal output to the singlechip by the voltage comparator is a simple high-level signal and a simple low-level signal, the singlechip controls the alarm circuit to be switched on and off through the high-level signal and the low-level signal, and the function of the scheme can be realized by simply setting the singlechip on the basis of the circuit structure provided by the scheme by a person skilled in the art without a complex computer program.

To sum up, the present invention is not limited to the above-mentioned specific embodiments. The technical personnel in this field can do a plurality of changes or modifications without departing from the technical proposal of the utility model, and the changes or modifications all fall into the protection scope of the utility model.

Claims (5)

1. A blood leakage detection circuit for a puncture needle head is characterized by comprising two Y-shaped optical fiber sensors (SY 1 and SY 2), single-color light emitting diodes (L1 and L2) arranged at the light source ends of the Y-shaped optical fiber sensors, and color sensors (D1 and D2) arranged at the detection ends of the Y-shaped optical fiber sensors; the output ends of the color sensors (D1, D2) are connected with homophase voltage amplifiers (U1A, U1B), the homophase voltage amplifiers (U1A, U1B) are connected with voltage comparators (U1C, U1D), the output ends of the voltage comparators (U1C, U1D) are connected with the signal input end of the singlechip (U2), and the control output end of the singlechip (U2) is connected with an alarm circuit; the Y-shaped optical fiber sensors (SY 1, SY 2) comprise two optical fibers, one end of each of the two optical fibers is bundled to form an optical fiber detection end (1), and the other ends of the two optical fibers respectively lead out a light source end and a detection end; the optical fiber detection end (1) is fixed above the puncture position through the band-aid (2) and the front end part of the optical fiber detection end (1) is arranged on the gauze (20) of the band-aid.

2. The blood leakage detection circuit of the puncture needle head according to claim 1, wherein the blood-leading cap (3) made of non-woven fabric or absorbent cotton is sleeved on the optical fiber detection end (1).

3. The blood leakage detection circuit of the puncture needle head as claimed in claim 1, wherein one input terminal of the voltage comparator (U1C, U1D) is connected to the output terminal of the non-inverting voltage amplifier, the other input terminal of the voltage comparator (U1C, U1D) is connected to the reference voltage source (Vref) through the slide rheostat (W1, W2), and the slide rheostat (W1, W2) forms a voltage divider circuit.

4. The blood leakage detection circuit of the puncture needle head as claimed in claim 1, wherein the alarm circuit comprises a horn (SPK), a triode switch (T1) is connected in series with a power supply loop of the horn (SPK), and a control end of the triode switch (T1) is electrically connected with the single chip microcomputer (U2); the power supply loop of the loudspeaker (SPK) is also connected with a function starting key (K1) and a reset key (K2).

5. The blood leakage detection circuit according to claim 1, wherein the single-color light emitting diodes (L1, L2) are blue light emitting diodes, and the color sensors (D1, D2) are blue light sensitive diodes.

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