Intelligent temperature control system for laparoscope lens based on PTC thermoelectric effect

Abstract

The invention provides a laparoscope lens intelligent temperature control system based on the PTC thermoelectric effect, and relates to the technical field of medical instruments.The laparoscope lens intelligent temperature control system based on the PTC thermoelectric effect is characterized in that a temperature sensor obtains a temperature signal of a laparoscope in real time and transmits the temperature signal to a single chip microcomputer; according to the system, the lens of the laparoscope is heated in real time through the thermoelectric effect, the temperature sensing module and the intelligent control module are additionally arranged in the lens, accurate temperature control is achieved, tissue damage in the operation process is reduced, the amount of bleeding in the operation is reduced, and therefore the operation efficiency is improved. Different from the characteristics that a lens is coated with an antifogging agent, the price is high and the cost is high, heat radiation is low in price and can be repeatedly utilized, and compared with the mode that a laparoscope is soaked in warm normal saline for two minutes or more, the laparoscope intelligent temperature control system can shorten the time for the operation preparation process.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to an intelligent temperature control system for a laparoscope lens based on the PTC thermoelectric effect. Background Art

[0002] A laparoscope is a precision medical device with an integrated miniature camera. Its operating principle is that the doctor inserts the laparoscope and accompanying instruments into the patient's abdominal cavity. The laparoscope lens captures images of the abdominal cavity and transmits them to an external monitor. The doctor then performs the surgical operation by observing the display. During laparoscopic surgery, the laparoscope lens is prone to fogging due to the temperature difference between the operating room and the human abdominal cavity. Lens fogging is a common problem that affects surgical performance. The root cause lies in the principles of thermodynamics: when a laparoscope lens at room temperature enters the warm and humid abdominal cavity, the lens surface temperature is lower than the dew point temperature of the abdominal gas. The significant thermodynamic gradient causes water vapor in the abdominal cavity to condense into small water droplets on the lens surface, forming fog.

[0003] This phenomenon is more common in certain scenarios. In winter, the temperature difference between indoors and outdoors is significant, and the sudden change in temperature after the lens enters the abdominal cavity significantly increases the chance of fogging. During prolonged surgeries, moisture accumulates in the abdominal cavity, further exacerbating the possibility of lens fogging. If the patient has a lung infection or increased respiratory secretions before surgery, the increased moisture content in the exhaled air will increase the humidity in the abdominal cavity, which can also easily cause lens fogging.

[0004] The existing anti-fogging measures include: (1) hot salt water immersion method: a quick treatment for lens fogging before or during surgery, using high-concentration (0.9% NaCl) warm salt water (60-70°C) to soak the lens. By increasing the mirror surface temperature (close to the body cavity temperature), the temperature difference is reduced. At the same time, the salt forms a hydrophilic layer to inhibit water vapor condensation; (2) iodine tissue wiping method: suitable for emergency defogging or primary medical institutions that lack special anti-fogging consumables, use 0.5% povidone iodine solution to soak sterile gauze and wipe the mirror surface in one direction. The surfactant in the iodine tincture forms a polar molecular layer, which changes the wettability of the mirror surface and reduces the water contact angle to below 30°; (3) anti-fog oil anti-fog method: a routine configuration in high-end minimally invasive surgery centers, especially suitable for precision optical systems such as 3D laparoscopes. The main component is polydimethylsiloxane (PDMS) or perfluoropolyether (PFPE) based anti-fog coating. It forms a hydrophobic barrier by reducing the surface energy (<20mN / m), and the nano-scale microstructure increases light scattering to inhibit droplet aggregation.

[0005] However, current anti-fogging measures have many limitations. Traditional methods, such as soaking the lens in hot saline, can reduce the risk of fogging to a certain extent. However, NaCl solution (conductivity 15mS / cm) acts as an electrolyte, forming micro-batteries at the metal joints of the lens (such as stainless steel screws and aluminum housings), and the anode reaction (Fe→Fe2+ +2e - ) accelerates corrosion, and the average annual corrosion depth can reach 0.02-0.05mm. The hydrophilic layer formed by salt (contact angle θ<30°) inhibits droplets, but the residual Na + (Concentration > 0.1 mol / L) may interfere with peritoneal mesothelial cell ion channels (such as ENaC channels), inducing local edema (incidence 0.1-0.3%). Commercially available anti-fogging agents for laparoscopic lenses not only carry the risk of irritating tissue and triggering allergic reactions in patients, but their high price also imposes an additional financial burden on hospitals and patients. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect to solve the technical problems that the anti-fog measures used in the prior art are subject to corrosion, and the use of special laparoscopic lens anti-fog agents adds additional economic burden.

[0007] In order to achieve the above-mentioned objectives, the present invention provides a laparoscope lens intelligent temperature control system based on the PTC thermoelectric effect, comprising a temperature sensor for detecting the temperature of the laparoscope, a single-chip microcomputer and a PTC heating element for heating the laparoscope, the temperature sensor being electrically connected to the single-chip microcomputer, the single-chip microcomputer being electrically connected to the PTC heating element, the PTC heating element being arranged close to the laparoscope, the temperature sensor obtaining the temperature signal of the laparoscope in real time and transmitting the temperature signal to the single-chip microcomputer, and the single-chip microcomputer controlling the start and stop of the PTC heating element after processing the temperature signal.

[0008] Optionally, the temperature sensor is a DS18B20 temperature sensor, the probe of the DS18B20 temperature sensor extends to the lens surface of the laparoscope through a metal heat pipe, and its data pin is directly connected to the P3.7 pin of the microcontroller through a shielded DS18B20 data transmission line. The communication protocol adopts a single bus mode, the sampling interval is 500ms, and the temperature resolution is 0.0625°C.

[0009] Optionally, a DS18B20 data transmission line is provided between the single-chip microcomputer and the temperature sensor. The DS18B20 data transmission line adopts a twisted pair structure, is wrapped with a Teflon insulation layer on the outside, and is connected to an RC filtering circuit between the single-chip microcomputer digital ground to suppress high-frequency interference and ensure that the temperature data error is ≤±0.1°C.

[0010] Optionally, the single chip microcomputer is a 51 single chip microcomputer, and the 51 single chip microcomputer has a built-in PID control algorithm, which reads the lens surface temperature collected by the DS18B20 temperature sensor in real time and performs a difference operation with a preset target value.

[0011] Optionally, when the temperature is lower than 36°C, the single chip microcomputer outputs a low level to trigger the relay to close, and the PTC heating element is energized for heating; when the temperature reaches 36.5°C, the single chip microcomputer outputs a high level to disconnect the relay, automatically switching to the PWM constant temperature maintenance mode and stopping heating.

[0012] Optionally, the P0 port of the single chip microcomputer is connected to the data pin of the digital tube through a digital tube data line, and a dynamic scanning drive method is adopted to refresh the display content every 100ms. The digital tube is used to display the current temperature of the laparoscope lens in real time.

[0013] Optionally, the device housing includes a housing body, a single-chip microcomputer module integrated base plate and an aluminum alloy heat-conducting frame for fixing the laparoscope are provided in the housing body, the PTC heating element is embedded in the bottom of the aluminum alloy heat-conducting frame, and the single-chip microcomputer is welded to the single-chip microcomputer module integrated base plate.

[0014] Optionally, the PTC heating element includes a ceramic substrate, and a portion of the ceramic substrate and the lens of the laparoscope form a directional heat conduction channel through the aluminum alloy heat-conducting frame, directly heating the lens portion of the laparoscope, and the remaining portion of the ceramic substrate transfers heat to the lens of the laparoscope through thermal radiation.

[0015] Optionally, a power management unit is further provided on the integrated base plate of the single-chip microcomputer module. The input end of the power management unit is connected to an external 5V / 2A DC power supply, and the output end is divided into two paths: one path is stabilized to 3V by LDO to power the single-chip microcomputer and the temperature sensor, and the other path is provided with a driving power supply for the PTC heating element through a switching power supply and a relay.

[0016] Optionally, the device housing further includes a top protective cover and an anti-slip base, wherein the top protective cover is located above the housing body and is locked to the housing body via a stainless steel buckle, and the anti-slip base is located below the housing body and is a ring-shaped silicone pad.

[0017] The PTC thermoelectric effect-based intelligent temperature control system for laparoscopic lenses provided by the present invention has at least the following technical effects:

[0018] This laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect has a temperature sensor that obtains the temperature signal of the laparoscope in real time and transmits the temperature signal to the single-chip microcomputer. The single-chip microcomputer controls the start and stop of the PTC heating element after processing the temperature signal. The present invention heats the laparoscope lens in real time through the thermoelectric effect, and adds a temperature sensing module and an intelligent control module inside the lens to achieve precise temperature control. This allows the abdominal cavity temperature to be kept stable, the field of view to be clear, tissue damage to be reduced during surgery, and intraoperative bleeding to be reduced, thereby improving the efficiency of the surgery. Unlike the expensive and high-cost anti-fog agent applied to the lens, the thermal radiation of the present invention is low-priced and reusable. Compared with soaking the laparoscope in warm saline for more than two minutes, the laparoscopic intelligent temperature control system of the present invention can also reduce the time of the surgical preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a structural diagram of a preferred embodiment of the laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect of the present invention;

[0021] Figure 2 yes Figure 1 Diagram of the internal structure of the laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect.

[0022] in, Figure 1-Figure 2 :

[0023] 101. Device housing; 102. Top cover; 103. Non-slip base; 104. Laparoscope; 105. 51 single-chip microcomputer; 106. DS18B20 temperature sensor; 107. PTC heating element; 108. MCU module integrated baseboard; 109. DS18B20 data transmission cable; 110. Aluminum alloy thermal frame; 111. Metal heat pipe.

[0024] 201. Data connection line; 202. Relay; 203. Switching power supply; 204. Digital tube; 205. Buzzer; 206. Central control screen; 207. Button; 208. Switching power supply live wire; 209. PTC drive current control line; 210. Switching power supply neutral wire; 211. Digital tube data line; 212. Relay live wire; 213. Relay control line. DETAILED DESCRIPTION

[0025] To make the objectives, technical solutions, and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other implementations obtained by those of ordinary skill in the art without inventive effort are within the scope of protection of the present invention.

[0026] Based on the defects recorded in the background technology, the following Figure 1-2 The intelligent temperature control system for the laparoscope 104 lens of the present invention is described in detail.

[0027] like Figure 1 and Figure 2 As shown, this is a structural schematic diagram of an intelligent temperature control system for a laparoscope 104 lens based on the PTC thermoelectric effect. The intelligent temperature control system for a laparoscope 104 lens includes a temperature sensor, a single-chip microcomputer and a PTC heating element 107. The temperature sensor is used to detect the temperature of the laparoscope 104, and the PTC heating element 107 is used to heat the laparoscope 104. The temperature sensor is electrically connected to the single-chip microcomputer, and the single-chip microcomputer is electrically connected to the PTC heating element 107. The PTC heating element 107 is arranged adjacent to the laparoscope 104. The temperature sensor obtains the temperature signal of the laparoscope 104 in real time and transmits the temperature signal to the single-chip microcomputer. The single-chip microcomputer controls the start and stop of the PTC heating element 107 after processing the temperature signal.

[0028] The temperature sensor is preferably a DS18B20 temperature sensor 106. The probe of DS18B20 temperature sensor 106 extends to the lens surface of laparoscope 104 via a metal heat pipe 111. Its data pin is directly connected to the P3.7 pin of the microcontroller via a shielded DS18B20 data transmission line 109. The communication protocol adopts a single bus mode, with a sampling interval of 500ms and a temperature resolution of 0.0625°C. A DS18B20 data transmission line 109 is provided between the microcontroller and the temperature sensor. DS18B20 data transmission line 109 uses a twisted pair structure with a Teflon insulation layer. An RC filter circuit is connected to the digital ground of the microcontroller to suppress high-frequency interference and ensure that the temperature data error is ≤±0.1°C.

[0029] The microcontroller is preferably a 51 microcontroller 105, which has a built-in PID control algorithm. It reads the lens surface temperature, as measured by the DS18B20 temperature sensor 106, in real time and calculates the difference between the value and the preset target value. When the temperature falls below 36°C, the microcontroller outputs a low level, triggering the closure of relay 202 and energizing the PTC heating element 107. When the temperature reaches 36.5°C, the microcontroller outputs a high level, disconnecting relay 202 and automatically switching to PWM constant temperature maintenance mode, stopping heating.

[0030] The P0 port of the single chip microcomputer is connected to the data pin of the digital tube 204 through the digital tube data line 211. The dynamic scanning drive mode is adopted to refresh the display content every 100ms. The digital tube 204 is used to display the current temperature of the laparoscope 104 lens in real time.

[0031] Working principle: Use DS18B20 temperature sensor 106 to collect lens temperature data in real time and transmit it to the microcontroller through a single bus. The microcontroller preprocesses the data, including sign bit judgment and precision conversion, and compares the processed temperature value with the preset target value. If the temperature is lower than 36°C, the microcontroller outputs a low level to trigger the relay 202 to close, and the PTC heating element 107 is energized for heating; if the temperature reaches 36.5°C, the microcontroller outputs a high level to disconnect the relay 202, automatically switching to the PWM (pulse width modulation) constant temperature maintenance mode and stopping heating.

[0032] As a preferred embodiment, Figure 1 As shown, the device also includes a housing 101, which includes a housing body, a top protective cover 102 and a non-slip base 103. The housing body is provided with a single-chip microcomputer module integrated base plate 108 and an aluminum alloy heat-conducting frame 110 for fixing the laparoscope 104. The PTC heating element 107 is embedded in the bottom of the aluminum alloy heat-conducting frame 110, and the single-chip microcomputer is welded to the single-chip microcomputer module integrated base plate 108.

[0033] The top protective cover 102 is disposed above the housing body and is locked with the housing body via a stainless steel buckle. The anti-slip base 103 is disposed below the housing body and is a ring-shaped silicone pad.

[0034] The PTC heating element 107 includes a ceramic substrate. Part of the ceramic substrate and the lens of the laparoscope 104 form a directional heat conduction channel through the aluminum alloy heat conductive frame 110, which directly heats the lens part of the laparoscope 104, and the rest of the ceramic substrate transfers heat to the lens of the laparoscope 104 through thermal radiation.

[0035] A power management unit is also provided on the integrated base plate 108 of the single-chip microcomputer module. The input end of the power management unit is connected to an external 5V / 2A DC power supply, and the output end is divided into two paths: one path is stabilized to 3V by LDO to power the single-chip microcomputer and temperature sensor, and the other path is provided through the switching power supply 203 and the relay 202 to provide driving power for the PTC heating element 107.

[0036] The laparoscope 104 lens intelligent temperature control system of the present invention has the following technical effects:

[0037] (1) Anti-fog performance

[0038] Existing technologies (such as anti-fog agents) reduce surface tension through chemical coatings or temporarily increase lens temperature through external heating (such as soaking in warm saline), but these methods lack real-time temperature control. The self-heating device of the present invention maintains the lens temperature at a temperature close to that of the human abdominal cavity through a built-in temperature control system, fundamentally preventing water vapor condensation caused by the temperature difference between the lens and the body. This provides continuous and active anti-fog protection, eliminating the need for frequent wiping or re-application of anti-fog agent, and reducing intraoperative visual field interruptions.

[0039] (2) Timeliness

[0040] The effective time of anti-fog agents is usually only a few minutes to more than ten minutes, and they may become ineffective due to intra-abdominal fluid flushing and instrument contact; the self-heating device of the present invention can maintain a stable temperature throughout the entire surgical process, which is particularly suitable for long-term operations (such as radical gastrointestinal resection and complex gynecological surgery), avoiding the tedious operation of repeatedly handling the lens during the operation.

[0041] (3) Surgical efficiency and safety

[0042] The PTC thermoelectric effect-based intelligent temperature control system for the laparoscope 104 lens eliminates the need for interrupted operation, allowing surgeons to focus on the procedure. The continuous, clear field of view reduces the risk of misoperation, especially during delicate procedures. The self-heating device utilizes physical anti-fog technology, leaving no chemical residue and offering increased safety. It also minimizes lens damage, extending the life of the device.

[0043] (4) Cost

[0044] The laparoscopic 104 lens intelligent temperature control system is a one-time investment (or reusable), with low cost per operation, and reduces the use of wiping consumables such as cotton balls and gauze. It can also prevent lens wear and tear caused by lens scratches caused by wiping the lens with cotton balls.

[0045] (5) Convenience and low operational complexity

[0046] The laparoscopic 104 lens intelligent temperature control system can be started with one button, saving preoperative preparation time and reducing training costs.

[0047] (6) Anti-fouling ability

[0048] When the lens temperature is close to body temperature, the adhesion of body fluids such as blood and tissue fluid to the lens surface is reduced, reducing the frequency of blood stains during surgery (although it is not a direct anti-contamination measure, the warm surface can reduce liquid condensation and adhesion).

[0049] The following is a detailed description of the intelligent temperature control system for the laparoscope 104 lens based on the PTC thermoelectric effect of the present invention in conjunction with specific embodiments 1-2.

[0050] Example 1:

[0051] refer to Figure 1 , is a schematic diagram of the structure of an intelligent temperature control system for a laparoscope 104 lens in this embodiment. Its purpose is to solve the fogging problem caused by lens surface temperature fluctuations in the prior art, as well as the shortcomings of traditional heating devices such as slow response speed and insufficient temperature control accuracy, thereby ensuring a continuous clear field of view during laparoscopic surgery 104. The core technical solution of this embodiment is described in detail below:

[0052] Specifically, the laparoscope 104 lens constant temperature device is composed of an equipment housing 101, a top protective cover 102, a non-slip base 103, a laparoscope 104, a 51 single-chip microcomputer 105, a DS18B20 temperature sensor 106, a PTC heating element 107, a single-chip microcomputer module integrated base plate 108, a DS18B20 data transmission line 109, an aluminum alloy heat-conducting frame 110, and a metal heat-conducting pipe 111.

[0053] The device housing 101 adopts a split structure. The top protective cover 102 is locked to the housing body by four sets of stainless steel clips. Its inner cavity is equipped with an aluminum alloy heat-conducting frame 110 for fixing the laparoscope 104, and its bottom is embedded with a PTC heating element 107. Part of the ceramic substrate of the PTC heating element 107 and the metal surface of the lens form a directional heat conduction channel through the aluminum alloy heat-conducting frame 110 to directly heat the lens part. The remaining ceramic part basically participates in heat transfer through thermal radiation, effectively improving the heating efficiency per unit time and reducing the equipment preparation time during surgery. The anti-slip base 103 of the device is a bottom annular silicone pad with anti-slip texture on its surface. It is fixed to the bottom surface of the housing by bolts to ensure the stability of the device on the operating table.

[0054] The microcontroller module integrated baseboard 108 is a four-layer PCB, onto which is soldered a 51 microcontroller 105, signal conditioning circuitry, and a power management unit. The probe of the DS18B20 temperature sensor 106 extends through a metal heat pipe 111 to the surface of the laparoscope 104 lens. The data pin is directly connected to the P3.7 pin of the microcontroller via a shielded DS18B20 data transmission cable 109. The communication protocol uses a single bus mode, with a sampling interval of 500ms and a temperature resolution of 0.0625°C. The electrodes of the PTC heating element 107 are connected to the power output terminal of the integrated baseboard via high-temperature resistant silver-plated wires. Its drive circuit consists of a MOSFET, a freewheeling diode, a switching power supply 203, and a relay 202X. The maximum drive output current is 3A, and the response time is ≤10ms.

[0055] The temperature control logic is implemented by the built-in PID control algorithm of the 51 single-chip microcomputer 105, which reads the lens surface temperature collected by the DS18B20 in real time and performs a difference operation with the preset target value (36.5±0.5℃); when the temperature is lower than 36℃, the single-chip microcomputer drives the relay 202X to turn on through the PWM signal, so that the PTC heating element 107 heats at the rated power; when the temperature enters the 36-37℃ range, the PID algorithm dynamically adjusts the PWM duty cycle to achieve linear attenuation of the heating power; if the temperature reaches 36.5℃, the PWM output is turned off and the temperature maintenance mode is started to compensate for the ambient heat loss through intermittent heating.

[0056] The power management unit includes an overvoltage protection module and a resettable fuse. Its input end is connected to an external 5V / 2A DC power supply, and the output end is divided into two paths: one path is stabilized to 3V by an LDO to power the microcontroller and DS18B20, and the other path is provided with a driving power supply for the PTC heating element 107 through a switching power supply 203 and a relay 202X; the DS18B20 data transmission line 109 adopts a twisted pair structure, wrapped with a Teflon insulation layer on the outside, and an RC filtering circuit is connected between it and the digital ground of the microcontroller to suppress high-frequency interference and ensure that the temperature data error is ≤±0.1℃.

[0057] All joints of the equipment are filled with medical silicone sealing strips. The thermal conductivity of the inner cavity heat conduction frame is ≥200W / m·K. The thermal resistance of the contact surface between the PTC heating element 107, the aluminum alloy heat conduction frame 110 and the laparoscope 104 is ≤0.03℃ / W, and the surface temperature uniformity deviation of the heating element is <±0.3℃. The signal trace impedance of the microcontroller module integrated baseboard 108 is matched to 50Ω±5%, and the PWM signal rise time is ≤50ns.

[0058] This system complies with the electromagnetic compatibility requirements of YY 0505-2012 medical electrical equipment, is suitable for anti-fog and constant temperature control of lenses during laparoscopic 104 surgery, and has clinical practical value.

[0059] Example 2

[0060] refer to Figure 2 This embodiment provides an intelligent temperature control system for the laparoscope 104 lens, the purpose of which is to solve the fogging problem caused by the large difference between the lens surface temperature and the ambient temperature due to insufficient temperature control accuracy (±2°C) of the heating device and slow response in the prior art, as well as the defect that the traditional solution lacks multiple safety protection mechanisms. Through the closed-loop temperature control system and modular circuit design of this system, the surface temperature of the laparoscope 104 lens is quickly stabilized (target value 36.5±0.5°C), and safe and reliable operation is ensured in the surgical environment. The specific structure and technical solution of this embodiment are elaborated in detail below.

[0061] Specifically, the interior includes a 51 single-chip microcomputer 105, a DS18B20 temperature sensor 106, a PTC heating element 107, a DS18B20 data transmission line 109, a data connection line 201, a relay 202, a switching power supply 203, a digital tube 204, a buzzer 205, a central control screen 206, a button 207, a switching power supply live wire 208, a PTC drive current control line 209, a switching power supply neutral wire 210, a digital tube data line 211, a relay live wire 212, and a relay control line 213.

[0062] In this embodiment, when the temperature is detected to be below 36°C, the microcontroller outputs a PWM signal through pin P3.7. After being amplified by the transistor drive circuit, it is transmitted to the coil end of relay 202 via relay control line 213, driving its internal normally open contacts to close. The contact end of relay 202 is connected in series between the relay live wire 212 (5V DC, current carrying capacity 3A) and the PTC drive current control line 209. When the contacts are closed, the current flows through the live wire 208 → the switching power supply 203 → the relay live wire 212 → the relay 202 contact → the PTC drive current control line 209 → the PTC heating element 107, forming a closed loop. When the contacts are open, the loop is disconnected, and heating ends.

[0063] Furthermore, the nickel alloy electrodes of the PTC heating element 107 are welded to the drive current control wire via high-temperature-resistant silver-plated wires. The metal stent of the laparoscope 104 forms zero-gap contact with the surface of the PTC ceramic substrate via nano-thermal adhesive. The surface heating rate is ≥2°C / s, and the self-limiting temperature ensures the temperature does not exceed 80°C. The input of the switching power supply 203 is connected to the power management unit via the live wire 208 and the neutral wire 210, providing 5V / 3A DC power.

[0064] The data pin of the digital tube 204 is connected to the P0 port of the single-chip microcomputer through the digital tube data line 211 (4-core cable, line spacing 2.54mm), and adopts a dynamic scanning drive mode. The display content is refreshed every 100ms to display the current temperature in real time. The data connection line 201 is responsible for powering the equipment when needed and transmitting information with the computer. The control screen communicates with the single-chip microcomputer interface, and the user can set the target temperature, view the historical temperature curve, or stop heating in an emergency through the button 207. The positive pole of the buzzer 205 is connected to the P3.7 pin of the single-chip microcomputer, and the negative pole is grounded. When the temperature exceeds the set range for 5 seconds, the single-chip microcomputer outputs a high-level signal to drive the buzzer 205 to sound, and the central control screen 206 displays a red alarm mark and automatically stops heating.

[0065] The working process of the intelligent temperature control system for the laparoscope 104 lens based on the PTC thermoelectric effect in this embodiment is as follows:

[0066] refer to Figure 1-Figure 2First, the PTC heating element 107 is attached to the aluminum alloy heat-conducting frame 110 via a nano-thermal silicone layer. When the laparoscope 104 is placed on top, a directional heat conduction path is formed. The remaining PTC heating elements 107 also participate in heat transfer through thermal radiation. The metal probe of the DS18B20 temperature sensor 106 is in close contact with the contact surface of the scope. Its data pin is directly connected to the P3.7 pin of the 51 single-chip microcomputer 105 via a shielded data transmission cable, forming a closed-loop temperature monitoring link.

[0067] Subsequently, the target temperature (default value: 36.5±0.5°C) is set on the central control screen 206 via button 207. The PID algorithm embedded in the 51 single-chip microcomputer 105 receives the digitized temperature signal from the DS18B20 in real time and performs Kalman filtering to eliminate ambient noise. When the temperature is detected to be below 36°C, the single-chip microcomputer outputs a PWM signal through the P3.7 pin. This signal, which drives the coil end of the relay 202 through the transistor amplifier circuit, closes its normally open contact. The current then flows through the hot wire 208, the switching power supply 203, the hot wire 212 of the relay, the contact of the relay 202, the PTC drive current control wire 209, and the PTC heating element 107, forming a closed loop and initiating full-power heating with a heating rate of ≥2°C / s.

[0068] When the temperature reaches the 36-37°C range, the PID algorithm dynamically adjusts the PWM, achieving linear attenuation of the heating power by controlling the on-off frequency of relay 202. If the temperature reaches 36.5°C, the microcontroller turns off the PWM output and switches to maintenance mode, switching on only as needed to compensate for ambient heat loss, ensuring steady-state temperature fluctuations of ≤±0.3°C.

[0069] The monitoring and safety control process is as follows:

[0070] (1) Real-time temperature display: The digital tube 204 displays the current temperature and status mark through dynamic scanning;

[0071] (2) Abnormal alarm mechanism: When the temperature exceeds the limit (>37°C for 5 seconds), the buzzer 205 triggers a 75dB sound and light alarm, and the central control screen 206 displays a red warning sign;

[0072] Technical verification stage: In a simulated surgical environment (humidity ≥ 80%, ambient temperature 25°C), the device only takes 15 seconds to heat up from the initial temperature of 25°C to 36°C, and the temperature fluctuation range in the steady-state stage is ≤±0.3°C, verifying its reliability and safety in complex environments.

[0073] In the description of the present invention, it should be noted that, unless otherwise specified, "plurality" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed, or operate in a specific direction, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0074] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; and direct or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. An intelligent temperature control system for laparoscopic lens based on PTC thermoelectric effect, characterized in that: It includes a temperature sensor for detecting the temperature of the laparoscope, a single-chip microcomputer and a PTC heating element for heating the laparoscope. The temperature sensor is electrically connected to the single-chip microcomputer, and the single-chip microcomputer is electrically connected to the PTC heating element. The PTC heating element is arranged close to the laparoscope. The temperature sensor obtains the temperature signal of the laparoscope in real time and transmits the temperature signal to the single-chip microcomputer. The single-chip microcomputer controls the start and stop of the PTC heating element after processing the temperature signal.

2. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 1 is characterized in that: The temperature sensor is a DS18B20 temperature sensor. The probe of the DS18B20 temperature sensor extends to the lens surface of the laparoscope through a metal heat pipe. Its data pin is directly connected to the P3.7 pin of the microcontroller through a shielded DS18B20 data transmission line. The communication protocol adopts a single bus mode, the sampling interval is 500ms, and the temperature resolution is 0.0625°C.

3. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 2 is characterized in that: A DS18B20 data transmission line is provided between the single-chip microcomputer and the temperature sensor. The DS18B20 data transmission line adopts a twisted pair structure, is wrapped with a Teflon insulation layer on the outside, and is connected to an RC filtering circuit between the single-chip microcomputer digital ground to suppress high-frequency interference and ensure that the temperature data error is ≤±0.1°C.

4. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 2 is characterized in that: The single chip microcomputer is a 51 single chip microcomputer, and the 51 single chip microcomputer has a built-in PID control algorithm, which reads the lens surface temperature collected by the DS18B20 temperature sensor in real time and performs a difference operation with a preset target value.

5. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 4 is characterized in that: When the temperature is lower than 36°C, the single chip microcomputer outputs a low level to trigger the relay to close, and the PTC heating element is energized for heating; when the temperature reaches 36.5°C, the single chip microcomputer outputs a high level to disconnect the relay, automatically switching to the PWM constant temperature maintenance mode and stopping heating.

6. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 1 is characterized in that: The P0 port of the single chip microcomputer is connected to the data pin of the digital tube through a digital tube data line, and a dynamic scanning drive mode is adopted to refresh the display content every 100ms. The digital tube is used to display the current temperature of the laparoscope lens in real time.

7. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to any one of claims 1 to 6, characterized in that: It also includes a device housing, which includes a housing body, in which a single-chip microcomputer module integrated base plate and an aluminum alloy heat-conducting frame for fixing the laparoscope are provided, the PTC heating element is embedded in the bottom of the aluminum alloy heat-conducting frame, and the single-chip microcomputer is welded to the single-chip microcomputer module integrated base plate.

8. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 7 is characterized in that: The PTC heating element includes a ceramic substrate, and a portion of the ceramic substrate and the laparoscope lens form a directional heat conduction channel through the aluminum alloy heat-conducting frame, directly heating the laparoscope lens portion, and the remaining portion of the ceramic substrate transfers heat to the laparoscope lens through thermal radiation.

9. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 7, characterized in that: A power management unit is also provided on the integrated baseboard of the single-chip microcomputer module. The input end of the power management unit is connected to an external 5V / 2A DC power supply, and the output end is divided into two paths: one path is stabilized to 3V by LDO to power the single-chip microcomputer and the temperature sensor, and the other path is used to provide driving power for the PTC heating element through a switching power supply and a relay.

10. The laparoscopic lens intelligent temperature control system based on the PTC thermoelectric effect according to claim 7, characterized in that: The device housing also includes a top protective cover and an anti-slip base. The top protective cover is arranged above the housing body and is locked with the housing body through a stainless steel buckle. The anti-slip base is arranged below the housing body and is an annular silicone pad.

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