Pressure detection device and sheath, perfusion suction system having the same

Abstract

The present application provides a kind of pressure detection device and including its sheath and perfusion suction system, the pressure detection device includes shell and pressure detection component, the shell has pressure measuring cavity and installation cavity, the pressure measuring cavity has for with sheath pressure measuring interface communication air inlet and for with ambient communication vent, the vent is provided with switch;The pressure detection component is arranged in installation cavity, and the pressure detection component includes gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit and conversion circuit, the gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit and conversion circuit are electrically connected, the gauge pressure sensor in the pressure signal in pressure measuring cavity is converted into voltage signal.

Description

Technical Field

[0001] This invention relates to the field of sheaths, and more specifically to a pressure-measuring sheath device and a micro-pressure sensor for sheaths. Background Technology

[0002] In conventional ureteroscopic lithotripsy, stone powder and hematuria in the renal pelvis can obscure the field of vision, necessitating irrigation to maintain a clear view. However, this rapid irrigation and poor reflux can significantly increase intrarenal pelvic pressure, allowing infected urine, bacteria, and endotoxins to enter the bloodstream and lymphatic system. This can lead to postoperative fever, systemic inflammatory response syndrome, and even fatal urosepsis. To prevent serious infections caused by excessively high renal pelvic pressure during flexible ureteroscopy, it is crucial to control the intrarenal pelvic pressure within a safe range. Furthermore, it is necessary to adjust the irrigation rate and / or negative pressure suction value based on the intraoperative renal pelvic pressure feedback. The ability of the pressure measurement method to accurately and in real-time measure renal pelvic pressure is fundamental to ensuring the performance of the pressure measurement and control system and the safety of the surgical procedure.

[0003] There are three traditional methods for measuring renal pressure: 1. The first method measures pressure by installing a pressure sensor on the perfusion tubing. The saline solution is monitored via a silicone membrane. However, this method only provides feedback on the perfusion pressure and is not the most direct way to monitor intrarenal pressure. 2. The second method directly monitors intrarenal pressure using a sensor installed in the main control unit and connected to the guide sheath via tubing. This method monitors and provides feedback based on the fluid level difference in the long tubing. However, the sensor's range is too large compared to the intrarenal pressure, resulting in relatively low accuracy. 3. The third method also monitors intrarenal pressure using an external sensor with a small measurement range. It connects to a guide sheath via a tubing filled with fluid. Pressure monitoring and feedback are achieved through perfusion or aspiration of the fluid. However, this method also faces challenges due to the excessive length of the tubing, and the fluid level affecting pressure accuracy. All three methods suffer from excessively long tubing leading to the sensor (i.e., the pressure measuring chamber), causing significant measurement errors. Most importantly, the perfusion / aspiration systems are large and have numerous cables. Doctors must simultaneously operate the endoscope, the main unit, aspiration, and perfusion, inevitably leading to accidental collisions with the pressure measuring tubing. These collisions can cause sudden pressure changes, further increasing measurement errors. Therefore, placing the sensor in the perfusion tubing, the perfusion unit, or externally all present these technical problems.

[0004] Currently, there are also methods that directly embed the sensor at the distal end of the endoscope or sheath. This allows for direct pressure monitoring after the endoscope or sheath enters the body cavity. This installation method directly locates the renal pelvis and reduces detection errors. However, in actual operation, the perfusion and suction system is used for laser lithotripsy. The high temperature generated during laser lithotripsy can damage tissue, so perfusion and suction circulation is needed to reduce the temperature in the body cavity and maintain constant temperature and pressure. However, laser lithotripsy can cause instantaneous high pressure, which cannot reflect the true pressure in the cavity. Currently, it generally takes 2-5 seconds for the sensor to collect and display the pressure value. By the time the instantaneous high pressure is displayed, the pressure in the cavity has already stabilized. The pressure output value at this time cannot accurately reflect the true pressure in the cavity and may miscontrol the perfusion and suction device. Therefore, placing the sensor inside the cavity has more disadvantages than advantages. Summary of the Invention

[0005] In a first aspect, the present invention provides a sheath tube with a pressure measuring function. The sheath tube includes a sheath tube body, the sheath tube body having a main channel extending from a proximal end to a distal end and a pressure measuring channel inside the sheath tube body. The proximal end of the pressure measuring channel is provided with an interface. The sheath tube further includes a pressure detection device, the pressure detection device comprising:

[0006] The housing has a pressure measuring chamber and a mounting chamber. The pressure measuring chamber has an air inlet for communicating with the pressure measuring interface of the sheath and a vent for communicating with the outside. A switch is provided at the vent.

[0007] A pressure detection assembly is disposed in the mounting cavity, and the pressure detection assembly includes a gauge pressure sensor, a voltage adjustment circuit, an operational amplifier circuit, and a conversion circuit. The gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit, and conversion circuit are electrically connected. The gauge pressure sensor converts the pressure signal in the pressure measuring cavity into a voltage signal.

[0008] The voltage adjustment circuit is used to increase the voltage difference of the voltage signal, and the operational amplifier circuit amplifies the increased voltage difference by a factor of two; the conversion circuit is used to convert the amplified voltage signal into a pressure value.

[0009] Aerogel insulation is encapsulated on the surface of a pressure sensing component to transmit pressure.

[0010] In some embodiments, the gauge pressure sensor has an input voltage positive terminal (+vin), an input voltage negative terminal GND (-vin), an analog signal output voltage positive terminal (+out), and an analog signal output voltage negative terminal (-out); the voltage adjustment circuit includes at least a first resistor (R1) and a second resistor (R3), the first resistor (R1) being connected in parallel between the input voltage positive terminal (+vin) and the analog signal output voltage positive terminal (+out), and the first resistor (R3) being connected in parallel between the input voltage negative terminal GND (-vin) and the analog signal output voltage negative terminal (-out).

[0011] In some embodiments, the operational amplifier circuit is a GS8332 precision operational amplifier chip, which amplifies the voltage difference by 100 times.

[0012] In some embodiments, the resistance values ​​of the first resistor (R1) and the second resistor (R3) are 100K.

[0013] In some embodiments, the conversion circuit is a single-chip microcontroller STM32F103C8T6.

[0014] In some embodiments, the housing includes:

[0015] The base is provided with a pressure measuring tube for forming a pressure measuring chamber. One end of the pressure measuring tube is provided with an air inlet, and the other end forms a vent hole. The pressure measuring tube has an outlet for the gas inside the pressure measuring tube to flow out.

[0016] The upper cover is disposed above the base;

[0017] The PCB board is located inside the base and fixed on the top cover. The PCB board integrates a pressure detection component and a control circuit. The pressure detection component is positioned directly over the outlet and is sealed by an aerogel insulator.

[0018] The control buttons are mounted on the housing and are communicatively connected to the control circuit.

[0019] A connecting cable is provided, which is connected to a conversion circuit to output a pressure test value.

[0020] Secondly, the present invention provides a method for detecting the aforementioned sheath device, the method comprising the following steps:

[0021] Step 1) Conversion stage: The gauge pressure sensor converts the pressure signal into a voltage in the μV range;

[0022] Step 2) Increase voltage difference stage: By connecting the first resistor (R1) in parallel between the positive terminal of the input voltage (+vin) and the positive terminal of the analog signal output voltage (+out), and connecting the second resistor (R3) in parallel between the negative terminal of the input voltage GND (-vin) and the negative terminal of the analog signal output voltage (-out), the voltage difference is increased to reach the mV level to meet the minimum voltage difference requirement of the op amp circuit.

[0023] Step 3) Operational Amplifier Stage: The voltage difference is amplified 100 times through the operational amplifier circuit, reaching the V (volt) level; range (0.5-3.0V).

[0024] Step 4) In the conversion stage, the voltage difference from step 3) is converted into a pressure value output through a conversion circuit;

[0025] Step 5) Acquisition stage: The gauge pressure sensor acquires data multiple times, and the microcontroller removes extreme values, calculates the average, and converts it into a pressure value output.

[0026] Thirdly, the present invention provides a pressure detection device, which employs the aforementioned pressure detection device.

[0027] Fourthly, the present invention provides an intelligent constant-pressure regulated perfusion and suction system, the system comprising:

[0028] The aforementioned sheath also has an suction channel within its body;

[0029] An endoscope, wherein the endoscope is inserted into a sheath and a fluid delivery channel is formed inside the endoscope;

[0030] An infusion device, wherein the infusion device is connected to a delivery channel for injecting infusion fluid into a body cavity;

[0031] A suction device, wherein the suction device is connected to a suction channel for extracting fluid from a human cavity, and an infusion device cooperates with the suction device to maintain a suitable pressure within the cavity;

[0032] The main controller is communicatively connected to the conversion circuit, the infusion device, and the suction device. The main controller controls the flow rate and pressure of the infusion device and the suction device based on the pressure value output by the conversion circuit.

[0033] In some embodiments, the pressure detection component further includes a control circuit connected to a main controller to control the infusion device and the suction device.

[0034] Fifthly, the present invention provides a method for intelligent constant pressure control of an infusion suction system, the method comprising the following steps:

[0035] Step 1) Preset the maximum warning pressure value, minimum warning pressure value, pressure control value, and injection flow rate level;

[0036] Step 2) The main control unit controls the infusion fluid delivery of the infusion device and the suction device for extraction, and collects the intracavitary pressure and negative pressure suction pressure:

[0037] Step 3) The pressure detection device collects the pressure in the cavity and transmits it to the main control unit. The main control unit dynamically adjusts the infusion and suction states according to the real-time monitored pressure value and the pressure value data change trend, so that the current pressure in the cavity is balanced at the pressure control value, and the infusion and suction are balanced. The infusion parameters include the infusion flow rate level, and the suction parameters include the opening of the pressure relief valve and the suction pressure threshold.

[0038] The main control unit's pressure regulation modes include coarse adjustment mode, fine adjustment mode, and hybrid adjustment mode. The coarse adjustment mode is for cases where the intracavity pressure is in an extreme situation. The fine adjustment mode is for cases where the intracavity pressure deviates from the pressure control value by a small margin. The hybrid adjustment mode is for cases where the intracavity pressure has not reached an extreme situation but the deviation value is large.

[0039] In some embodiments, when the pressure difference between the intracavity pressure and the pressure control value is in an extreme case, such as exceeding ±20 mmHg, a coarse adjustment mode is activated; when the pressure difference exceeds ±3 mmHg but is within ±8 mmHg, a fine adjustment mode is activated; and when a pressure difference exceeding ±8 mmHg but within ±20 mmHg is detected, a hybrid adjustment mode is activated.

[0040] In some embodiments, the coarse adjustment mode includes the following steps: when the intracavitary pressure exceeds the maximum warning line, the main control unit controls the reduction of the perfusion flow rate and controls the suction pressure threshold so that the suction flow rate is greater than the perfusion flow rate; when the pressure difference in the intracavitary pressure exceeds the minimum warning line, the perfusion process level is increased, the pressure relief valve is opened, and the suction pressure threshold is adjusted to the threshold value in a stable state to achieve a rapid balancing effect and allow the intracavitary pressure to get out of the extreme state as soon as possible.

[0041] In some embodiments, the fine-tuning mode includes the following steps: maintaining the infusion setting in operation and keeping the pressure relief valve closed, and adjusting the pressure by fine-tuning the suction pressure threshold.

[0042] In some embodiments, when the pressure difference exceeds -3 mmHg but is within -8 mmHg, the injection flow rate is kept constant, the pressure relief valve is kept closed, and the injection continues to operate as before. The trend of the uploaded data is observed. If it is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased by a greater margin than the increase in the suction pressure threshold during the upward phase. Thus, during the data adjustment process, there is an overall trend of decreasing the suction pressure threshold, achieving a pressure boosting effect through fine-tuning. When the pressure difference exceeds 3 mmHg but is within 8 mmHg, the injection continues to operate at the current level, and the trend of the uploaded data is observed. If it is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased by a smaller margin than the increase in the suction pressure threshold during the upward phase. During the data adjustment process, there is an overall trend of increasing the suction pressure threshold, achieving a pressure reduction effect.

[0043] In some embodiments, the hybrid adjustment mode includes the following steps: by combining the adjustment of the infusion flow rate setting, the pressure relief valve and the suction pressure threshold, the fine adjustment of the infusion flow rate, the fine adjustment of the pressure relief valve and the fine adjustment of the suction pressure threshold are combined to work together on the intracavitary pressure to achieve the effect of pressurization or depressurization.

[0044] In some embodiments, when a pressure differential exceeding 8 mmHg but within 20 mmHg is detected, the infusion flow rate is appropriately reduced, and the trend of the uploaded data is observed. If the pressure differential is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased, with the decrease being less than the increase in the suction pressure threshold during the upward phase. Thus, during data adjustment, there is an overall trend of increasing the suction pressure threshold, achieving a pressure reduction effect. When a pressure differential below -8 mmHg but within -20 mmHg is detected, the infusion flow rate remains at its current level, and the pressure relief valve is opened intermittently. The trend of the uploaded data is observed; if the pressure differential is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased, with the decrease being greater than the increase in the suction pressure threshold during the upward phase. Thus, during data adjustment, there is an overall trend of decreasing the suction pressure threshold, achieving a pressure increase effect.

[0045] In some embodiments, the adjustment range of the suction pressure threshold increases as the pressure difference between the intracavitary pressure and the pressure control value increases.

[0046] This invention installs the pressure detection device at the proximal end of the sheath, firstly solving the problem of excessively long and inaccurate pressure detection tubing in traditional methods. Secondly, since the sheath remains within the cavity during actual operation, doctors will not accidentally touch it, thus avoiding pressure detection errors caused by accidental collisions with the pressure measurement tubing. Finally, by placing the pressure detection device at the proximal end of the sheath, this invention avoids detecting instantaneous high pressure caused by laser lithotripsy, detecting only the stable pressure within the cavity, resulting in small detection errors and high accuracy.

[0047] The sheath device provided by this invention combines the sheath and pressure detection components. Based on the relationship between the voltage and pressure of the gauge pressure sensor, and after passing through a voltage adjustment circuit and an operational amplifier circuit, the voltage signal is converted into a specific pressure value by a microcontroller, realizing real-time monitoring of the intracavitary pressure with high detection accuracy and high sensitivity. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the structure of the sheath provided by the present invention;

[0049] Figure 2-6 A schematic diagram of the pressure detection device is provided for this invention;

[0050] Figure 7 A schematic diagram illustrating the working principle of the pressure detection device provided by the present invention;

[0051] Figure 8 This is a schematic diagram of the structure of the pressure detection component provided by the present invention;

[0052] Figure 9 This is a schematic diagram of the structure of the sheath body provided by the present invention;

[0053] Figure 10 This is a schematic diagram of the infusion system provided by the present invention;

[0054] Figure 11 A circuit diagram of the gauge pressure sensor provided by the present invention;

[0055] Figure 12 A schematic diagram of the voltage adjustment circuit provided by the present invention;

[0056] Figure 13 A schematic diagram of the operational amplifier circuit provided by the present invention;

[0057] Figure 14-16 A process curve diagram of the control method provided by the present invention. Detailed Implementation

[0058] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "inner," "outer," "near," and "far," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of those features.

[0059] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] Example 1

[0061] Please see Figure 1-9This invention provides a sheath with pressure measurement function. The sheath includes a sheath body 1 and a pressure detection device. The sheath body has a main channel 11 extending from the proximal end to the distal end and a pressure measurement channel 12. The main channel 11 is used for instrument insertion, infusion, and suction. The proximal end of the pressure measurement channel 12 has an interface 121. The pressure detection device is mounted at the interface to detect the pressure within the pressure measurement chamber. Thus, this invention installs the pressure detection device at the proximal end of the sheath, solving the problem of excessively long and inaccurate pressure measurement lines in traditional methods. Furthermore, since the sheath remains within the chamber during actual operation, doctors will not accidentally touch it, thus avoiding pressure measurement errors caused by accidental collisions with the pressure measurement line. This embodiment places the pressure detection device at the proximal end of the sheath, preventing the detection of instantaneous high pressure caused by laser lithotripsy, and detecting only the stable pressure within the chamber, resulting in small detection errors and high accuracy. Current pressure detection devices suffer from technical problems such as difficult assembly, inaccurate detection, large errors, and low sensitivity. This is particularly true for gauge pressure sensors detecting intrarenal pelvic pressure, where the directly monitored pressure is a μV-level voltage. Direct amplification by an operational amplifier circuit fails to meet the amplification requirements of the circuit, and the voltage difference must increase proportionally to the pressure during amplification. Therefore, the pressure detection device provided in this embodiment includes a housing 2, an aerogel insulator 3, and a pressure detection component 5. The housing 2 has a pressure measuring chamber 21 and a mounting chamber 20. The pressure measuring chamber 21 has an air inlet 22 for communication with the sheath pressure measuring interface and a vent 23 for communication with the outside. A switch is provided at the vent 23. The pressure detection component 5 is disposed in the mounting chamber 22. The pressure measuring chamber 21 is aligned with the pressure detection component 5 to form an outlet 210, which is sealed by the aerogel insulator 3. The aerogel insulator 3 transmits the pressure from the pressure measuring chamber 21 to the pressure detection component 5.

[0062] like Figure 7 As shown, the vent 23A end is connected to the switch. Opening it allows the pressure detection device to be connected to the atmosphere for zeroing; closing it allows pressure measurement. The air inlet 22B end is connected to the interface 121 of the sheath body. After zeroing, closing the switch at end A, when pressure comes in at end B, the pressure passes through the polycarbonate insulating gel and is converted into a signal output by the gauge pressure sensor. Opening the switch opens the air inlet, and subsequent pressure measurements are based on the current pressure. Each sensor has certain differences and is calibrated using software. The calibration data is stored in the microcontroller and is retained even when power is off; therefore, each sensor only needs to be calibrated once.

[0063] The pressure detection component provided in this embodiment includes a gauge pressure sensor, a voltage adjustment circuit, an operational amplifier circuit, and a conversion circuit. The gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit, and conversion circuit are electrically connected. The gauge pressure sensor converts the pressure signal in the pressure measuring chamber into a voltage signal. The voltage adjustment circuit increases the voltage difference of the voltage signal, and the operational amplifier circuit amplifies the increased voltage difference by a factor of two. The conversion circuit converts the amplified voltage signal into a pressure value. In this embodiment, the pressure is converted to voltage, the pressure difference is adjusted by pull-up and pull-down resistors, amplified, and then further amplified by the operational amplifier circuit before being transmitted to a microcontroller for AD conversion to obtain the specific collected pressure value.

[0064] like Figure 11 As shown in the diagram, this is the detection circuit inside the gauge pressure sensor. Its main function is to convert the pressure signal into a voltage signal, with a conversion relationship of 5μV / V / mmHg. If this signal is directly acquired using a 12-bit AD converter, the voltage difference between the voltage and pressure is too small to be directly amplified. Therefore, we need to amplify the signal. The 12-bit AD acquisition accuracy of the microcontroller is 3.3V / 4096 = 8.056mV, which is much larger than the pressure-voltage relationship of the gauge pressure sensor (5μV / V / mmHg). Therefore, this implementation increases the voltage difference between the positive terminal V+ and the negative terminal V- of the analog signal output, while maintaining a linear relationship between voltage and pressure.

[0065] The aforementioned gauge pressure sensor has an input voltage positive terminal (+vin), an input voltage negative terminal GND (-vin), an analog signal output voltage positive terminal (+out), and an analog signal output voltage negative terminal (-out); such as Figure 12 As shown, the voltage adjustment circuit includes a first resistor (R1) and a second resistor (R3). The first resistor (R1) is connected in parallel between the positive terminal of the input voltage (+vin) and the positive terminal of the analog signal output voltage (+out). R1 ​​is applied between V+ and VDD6V. This resistor is connected in parallel with the pull-up resistor inside the sensor. After the resistors are connected in parallel, the resistance decreases, so the voltage of V+ is greater than the sensor output V+ voltage. The first resistor (R2) is connected in parallel between the negative terminal of the input voltage GND (-vin) and the negative terminal of the analog signal output voltage (-out). R3 is applied between V- and GND, and is connected in parallel with the pull-down resistor inside the sensor. Therefore, the voltage of V- is less than the sensor V- voltage. This part of the circuit increases the voltage difference between V+ and V-, preparing for the next step of operational amplifier.

[0066] like Figure 13 As shown, in order to maintain the linear relationship between sensor pressure and voltage, the GS8332 precision operational amplifier chip is used to amplify the voltage difference by 100 times.

[0067] Optionally, the operational amplifier circuit is a GS8332 precision operational amplifier chip, which amplifies the voltage difference by 100 times. The resistance values ​​of the first resistor (R1) and the second resistor (R3) are 100K. The conversion circuit is an STM32F103C8T6 microcontroller.

[0068] The detection method of the present invention includes the following steps:

[0069] Step 1) Conversion stage: The gauge pressure sensor converts the pressure signal into a voltage at the μV level.

[0070] Step 2) Increase voltage difference stage: By connecting the first resistor (R1) in parallel between the positive terminal of the input voltage (+vin) and the positive terminal of the analog signal output voltage (+out), and connecting the second resistor (R3) in parallel between the negative terminal of the input voltage GND (-vin) and the negative terminal of the analog signal output voltage (-out), the voltage difference is increased to meet the minimum voltage difference requirement of the operational amplifier circuit.

[0071] Step 3) Operational Amplifier Stage: The voltage difference is amplified by 100 times through the operational amplifier circuit to reach the V (volt) level;

[0072] Step 4) In the conversion stage, the voltage difference from step 4) is converted into a pressure value output through a conversion circuit;

[0073] Step 5) Acquisition stage: The gauge pressure sensor acquires data multiple times, and the microcontroller removes extreme values, calculates the average, and converts it into a pressure value output.

[0074] For example,

[0075] Part One:

[0076] Please see Figure 11 The positive terminal V+ and the negative terminal V- of the analog signal output are connected to R6, R7, R4, R6, R7, and R10, all of which are 10KΩ. The voltage at C8 is VOUT. According to the op-amp formula VOUT - (V+ / 2) = (V+ / 2) - (V-), we get VOUT = (V+) - (V-). Therefore, this part of the function is to calculate the voltage difference between the positive terminal V+ and the negative terminal V- of the analog signal output.

[0077] Part Two:

[0078] Please see Figure 12 R9 = 1kΩ, R8 = 100kΩ. These two resistors are mainly used to amplify the voltage difference between V+ and V-. Based on the relationship between R8 and R9, the amplification factor of the voltage difference is 100 times. The final output voltage range is 0.5V-3.0V, which is in line with the AD acquisition range of STM32F103C8T6.

[0079] The pressure detection device provided by this invention has the following advantages compared with the prior art: 1. Data can be saved after sensor calibration. 2. Calibration accuracy can be adjusted (by controlling the pull-up and pull-down resistors). 3. Analog signals are converted into digital signals and sent to the host computer by the microcontroller via serial port, increasing sensor compatibility. 4. The sensor module is independent, making it applicable to more scenarios.

[0080] In this embodiment, the housing includes a base 3, a top cover 4, a PCB board 5, a control button 6, and a connecting cable 7. The base 1 is provided with a pressure measuring tube 21 for forming a pressure measuring chamber. One end of the pressure measuring tube 21 is provided with an air inlet 22, and the other end forms a vent hole 23. The pressure measuring tube 21 has an outlet 210 for the gas inside the pressure measuring tube to flow out. The top cover 4 is located above the base. The PCB board 5 is located inside the base and fixed on the top cover. The PCB board integrates a pressure detection component and a control circuit. The pressure detection component is positioned directly over the outlet 210 and is sealed by an aerogel insulator 3. The control button is located on the housing and is communicatively connected to the control circuit. The connecting cable 7 is connected to a conversion circuit to output pressure test values. The connecting cable has an aviation connector 71.

[0081] Specifically, the PCB board, pressure detection component and control circuit are installed in the housing 50, and a through hole is formed on the housing. The through hole is sealed with polycarbonate insulating gel and is positioned opposite the outlet 210.

[0082] In some embodiments, the pressure detection component further includes a control circuit connected to a main controller to control the infusion device and the suction device.

[0083] The sheath device provided by this invention combines the sheath and pressure detection components. Based on the relationship between the voltage and pressure of the gauge pressure sensor, and after passing through a voltage adjustment circuit and an operational amplifier circuit, the voltage signal is converted into a specific pressure value through AD conversion, avoiding pressure deviation caused by long pipelines, and finally realizing real-time monitoring of intracavitary pressure.

[0084] Example 2

[0085] Please see Figure 10 This embodiment provides an intelligent constant pressure controlled perfusion and aspiration system. The system includes the sheath, endoscope 8, perfusion device, aspiration device, and main control unit 100 as described in Embodiment 1. The sheath also has an aspiration channel. In this embodiment, the aspiration channel and the main channel are the same channel. The endoscope 8 is inserted into the sheath, and a fluid delivery channel is formed inside the endoscope 8. The perfusion device 10 is connected to the fluid delivery channel to inject perfusion fluid into the body cavity.

[0086] The suction device is used to draw waste liquid and stones in the cavity through the sheath tube under negative pressure from the main unit. The waste liquid and stones are collected into the collector through the negative pressure suction tubes 2 and 1. The infusion device works in conjunction with the suction device to maintain the cavity at a suitable pressure.

[0087] The infusion device includes an inlet pipe 101, a storage tank 102, and an infusion pump. The infusion pump 103 is connected to the storage bag through the inlet pipe 101. The infusion pump 103 is connected to the 8 delivery channels of the endoscope through the outlet pipe 103.

[0088] The suction device includes a suction pump, a first negative pressure suction tube 91, a suction container 93, a second negative pressure suction tube 92, and a pressure sensor. One end of the first negative pressure suction tube 91 is connected to the outer sheath tube 1, and the other end is connected to the suction container 93. One end of the second negative pressure suction tube 92 is connected to the suction container 93, and the other end is connected to the suction pump. The pressure sensor is used to detect the pressure inside the cavity of the suction container 93. The suction container 93 is equipped with a pressure relief valve.

[0089] The main controller 100 is communicatively connected to the conversion circuit, the infusion device, and the suction device. The main controller controls the flow rate and pressure of the infusion device and the suction device according to the pressure value output by the conversion circuit. In this embodiment, the infusion pump and the suction pump are integrated with the main controller. Optionally, the infusion pump is a peristaltic pump and the suction pump is a diaphragm pump.

[0090] The pressure detection device provided in this embodiment is also equipped with a control circuit. The control circuit is connected to the main controller 100 through a cable connector 71. The microcontroller transmits the pressure value to the main controller. The main controller adjusts the flow rate and pressure of the infusion device and the suction device according to the pressure output value to regulate the pressure in the chamber.

[0091] The system also includes a display that can show the pressure output value.

[0092] In one embodiment of the present invention, a constant pressure intelligent control method is provided, the method comprising the following steps:

[0093] Step 1) The pressure output of the pressure detection device is sent to the main control unit. The main control unit compares the pressure with the preset ideal pressure. If the pressure does not meet the ideal pressure requirement, the main control unit controls the injection and aspiration parameters, namely proportional pressure, temperature and flow rate.

[0094] Step 2) The pressure detection device is equipped with a control button, which can be used to directly control the infusion device and the suction device to regulate the intracavitary pressure.

[0095] In a preferred embodiment of the present invention, the suction device further includes a pressure sensor for detecting the intracavitary pressure within the suction container 93, the suction container 93 being provided with a pressure relief valve.

[0096] The main control unit controls the change of the suction pressure threshold. When the pressure of the suction container 93 is greater than the suction pressure threshold, the suction pump stops. When the pressure of the suction container is less than the suction pressure threshold and the current cavity pressure is greater than "pressure control value - 3 mmHg", the suction pump is turned on. The pressure of the suction container is adjusted by changing the suction pressure threshold. Different pressures of the suction container result in different suction flow rates. By adjusting the suction flow rate and the infusion flow rate, a certain pressure is maintained in the cavity to achieve a dynamic balance between infusion and suction.

[0097] The main control unit further presets the maximum warning pressure value, minimum warning pressure value, pressure control value, and infusion flow rate level. Here, "pressure control value" refers to the preset ideal pressure value or pressure range within the cavity. "Warning pressure value" refers to the state where the pressure difference between the cavity pressure and the pressure control value exceeds this value. The pressure detection device checks the cavity pressure every 0.25 seconds. When the cavity pressure is not within "pressure control value ± 8 mmHg," it indicates that the pressure is too high or too low compared to the "pressure control value," and the pressure difference is too large. In this case, coarse adjustment is needed to adjust the pressure over a wide range, such as by adjusting the infusion level or the pressure relief valve, to quickly adjust the cavity pressure to approach or reach the pressure control value. However, when the cavity pressure is within "pressure control value ± 8 mmHg," the pressure difference between the cavity pressure and the pressure control value is small. If coarse adjustment is continued, such as by adjusting the infusion level or the pressure relief valve, it is easy to cause the cavity pressure to go to another extreme, making it difficult to reach or approach the control value. Furthermore, the suction pressure of the suction pump in the suction device is relatively high. If the pressure is directly adjusted through the suction pump, it is also difficult to achieve the effect of fine adjustment. Based on this, the present invention finely adjusts the pressure threshold of the suction container. In summary, the present invention aims to obtain the dynamic balance of pressure in the cavity and maintain the pressure in the cavity at a dynamic balance state of pressure control value through the combination of coarse and fine adjustment.

[0098] This invention provides a constant pressure control method for an infusion suction system, the method comprising the following steps:

[0099] Step 1) Preset the maximum warning pressure value, minimum warning pressure value, pressure control value, and injection flow rate level;

[0100] Step 2) The main control unit controls the infusion fluid delivery of the infusion device and the suction device for extraction, and collects the intracavitary pressure and negative pressure suction pressure:

[0101] Step 3) The pressure detection device collects the pressure inside the cavity and transmits it to the main control unit. The main control unit automatically adjusts the corresponding status system based on the real-time monitored pressure value and the pressure value change trend to keep the current cavity pressure balanced at the pressure control value. When the data exceeds the limit, the system will automatically adjust its infusion and suction status to quickly reach a balanced state of infusion and suction while maintaining a certain cavity pressure. The infusion parameters include the infusion flow rate level, and the suction parameters include the opening of the pressure relief valve and the suction pressure threshold.

[0102] The main control unit's pressure regulation modes include a coarse adjustment mode, a fine adjustment mode, and a hybrid adjustment mode. The coarse adjustment mode is for cases where the intracavity pressure is in an extreme state. The fine adjustment mode is for cases where the intracavity pressure deviates slightly from the pressure control value. The hybrid adjustment mode is for cases where the intracavity pressure has not reached an extreme state but deviates significantly. For example, if the pressure difference between the intracavity pressure and the pressure control value is in an extreme state, such as exceeding ±20 mmHg, the coarse adjustment mode is activated. If the pressure difference exceeds ±3 mmHg but is within ±8 mmHg, the fine adjustment mode is activated. If the pressure difference exceeds ±8 mmHg but is within ±20 mmHg, the hybrid adjustment mode is activated.

[0103] The pressure control value can be a single point value or an interval value. Please refer to some embodiments of the present invention. Figure 14-16 The pressure control value is 10 mmHg. When the pressure difference between the cavity pressure and the pressure control value is within ±3 mmHg, the pressure regulation process is initiated.

[0104] Please see Figure 14 If the intracavitary pressure exceeds the maximum warning line (i.e., the pressure difference between the intracavitary pressure and the pressure control value is in an extreme situation, such as greater than 20 mmHg), the main controller reduces the infusion flow rate and controls the suction pressure threshold to ensure that the suction flow rate is greater than the infusion flow rate. When the intracavitary pressure difference exceeds the minimum warning line, the infusion process is adjusted to the maximum, the pressure relief valve is opened, and the suction pressure threshold is adjusted to the stable threshold value to achieve a rapid balancing effect, allowing the equipment to quickly escape the current state. This speeds up the system response and reduces static error, but this adjustment method increases overshoot and reduces stability. In this embodiment, the infusion process is adjusted to the lowest or highest level to accelerate pressure recovery. At the same time, to avoid excessive pressure adjustment, the suction pressure threshold is adjusted to the stable suction pressure threshold value, which refers to the suction pressure threshold value corresponding to the intracavitary pressure reaching the pressure control value range recorded by the main controller.

[0105] Please see Figure 15When a pressure difference exceeding ±3 mmHg but within ±8 mmHg is detected, it indicates that the pressure difference within the cavity is not significant. To maintain the infusion requirements during operation and keep the infusion flow rate constant, the infusion is dynamically balanced by controlling the suction pressure threshold, and the internal pressure is controlled within the "pressure control value." In this state, no adjustment of the infusion or opening of the pressure relief valve is necessary, as these two adjustment methods would cause significant data fluctuations and easily disrupt the current dynamic balance. Therefore, at this stage, the system's fine-tuning mode needs to be activated, maintaining the infusion setting and keeping the pressure relief valve closed. Pressure regulation is achieved through fine-tuning the suction pressure threshold. Furthermore, during the infusion suction process, there are many pipelines within the cavity, resulting in significant pressure fluctuations and frequent pressure detection. Therefore, the suction pressure threshold setting also needs to be adjusted in real-time based on data trends. In one embodiment of the present invention, when the pressure difference exceeds -3 mmHg but is within -8 mmHg, the infusion flow rate is kept constant, the pressure relief valve is kept closed, and the infusion continues to operate as before. The trend of the uploaded data is observed. If it is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased by a greater margin than the increase during the upward phase. Thus, during the data adjustment process, there is an overall trend of decreasing the suction pressure threshold, achieving a pressurization effect through fine-tuning. When the pressure difference exceeds 3 mmHg but is within 8 mmHg, the infusion continues to operate at the current level, and the trend of the uploaded data is observed. If it is in an upward phase, the suction pressure threshold is increased; if it is in a downward phase, the suction pressure threshold is decreased by a smaller margin than the increase during the upward phase. Thus, during the data adjustment process, there is an overall trend of increasing the suction pressure threshold, achieving a decompression effect. By judging the current pressure detection value status and data change trend, the suction pressure threshold is adjusted to show an upward or downward trend, reducing the damage to the body cavity caused by large pressure fluctuations.

[0106] In some embodiments of the present invention, when a pressure difference exceeding ±8 mmHg but within ±20 mmHg is detected, the infusion flow rate setting, the pressure relief valve, and the suction pressure threshold are adjusted in combination. This fine-tuning of the infusion flow rate, the pressure relief valve, and the suction pressure threshold works together to exert pressure on the cavity, achieving either pressurization or depressurization. Specifically, when a pressure difference exceeding 8 mmHg but within 20 mmHg is detected, the infusion flow rate setting is reduced, and the trend of the uploaded data is observed. If the data is rising, the suction pressure threshold is increased; if it is falling, the suction pressure threshold is decreased, with the decrease being less than the increase during the rising phase. Thus, during data adjustment, there is an overall trend of increasing the suction pressure threshold, achieving depressurization. Effect: When the pressure difference is detected to exceed -8 mmHg but is within -20 mmHg, the perfusion flow rate is maintained at the current level, and the pressure relief valve is opened in stages. The trend of the uploaded data is observed. If it is in the rising stage, the suction pressure threshold is increased; if it is in the falling stage, the suction pressure threshold is decreased, and the decrease is greater than the increase in the suction pressure threshold during the rising stage. In this way, during the data adjustment process, there is an overall trend of decreasing the suction pressure threshold, achieving a pressurization effect. In this embodiment, the adjustment range of the suction pressure threshold increases with the increase of the pressure difference between the intracavitary pressure and the pressure control value. Thus, by adjusting the suction pressure threshold, a combination of coarse and fine adjustment is achieved, so that the intracavitary pressure quickly reaches the pressure control value, avoiding tissue damage caused by excessive pressure fluctuations in the body.

[0107] For example, the relationship between the negative pressure suction flow rate (unit: ml / min) corresponding to the suction pressure threshold and the suction pressure threshold was statistically analyzed and divided into 12 categories. These are -5mmHg, -10mmHg, -15mmHg, -20mmHg, -25mmHg, -30mmHg, -35mmHg, -40mmHg, -45mmHg, -50mmHg, -60mmHg, and -70mmHg. This value is generally used as the default initial value when the system is started. Later, the value of the equilibrium point will be updated as a dynamic equilibrium process is carried out, thereby achieving the effect of dynamic equilibrium.

[0108] The pressure difference (Pa) between the internal pressure and the pressure control value was statistically analyzed and then classified. The internal pressure exhibited the following 13 states: 1: >20, 2: 15... <Pa<=20,3:10<Pa<=15,4:8<Pa<=10,5:5<Pa<=8,6:3<Pa<=5,7:-3<Pa<=3,8:-5<Pa<=-3,9:-8<Pa<=-5,10:-10<Pa<=-8,11:-15<Pa<=-10,12:-20<Pa<=-15 13:-20<Pa。

[0109] According to the above statistical classification, the newly collected intracavitary pressure data is compared with historical data, so that based on the change trend of the historical data, dynamic balance between perfusion and suction can be quickly achieved by adjusting the perfusion, suction and pressure relief valve.

[0110] According to the pressure difference Pa (unit: mmhg) between the intracavitary pressure and the pressure control value, the present embodiment provides the following processing methods:

[0111] 1. (Pa > 20): Perfusion operates at current gear - 4, the suction pressure is increased, and the suction flow is enhanced according to the negative pressure suction flow corresponding to the statistically obtained suction pressure threshold, so that the suction flow is greater than the perfusion flow; the change trend of the uploaded data is observed. If the pressure continues to rise, the perfusion is adjusted to the lowest gear, and the suction pressure threshold is adjusted to the threshold in the equilibrium state until the current intracavitary pressure returns to the "pressure control value", and the perfusion flow is restored. If the pressure continues to drop, the perfusion flow is adjusted according to the change requirement, and the suction pressure threshold is increased to achieve the decompression effect;

[0112] 2. (15 < Pa ≤ 20): Perfusion operates at current gear - 3, the change trend of the uploaded data is observed. If the pressure is in an upward stage, increase the "suction pressure threshold + 5"; if the pressure is in a downward trend, decrease the "suction pressure threshold - 2". In this way, during the data adjustment process, there is an overall trend of increasing the "suction pressure threshold" to achieve the decompression effect;

[0113] 3. (10 < Pa ≤ 15): Perfusion operates at current gear - 2, the change trend of the uploaded data is observed. If the pressure is in an upward stage, increase the "suction pressure threshold + 5"; if the pressure is in a downward trend, decrease the "suction pressure threshold - 3". In this way, during the data adjustment process, there is an overall trend of increasing the "suction pressure threshold" to achieve the decompression effect;

[0114] 4. (8 < Pa ≤ 10): Perfusion operates at current gear - 1, the change trend of the uploaded data is observed. If the pressure is in an upward stage, increase the "suction pressure threshold + 4"; if the pressure is in a downward trend, decrease the "suction pressure threshold - 1". In this way, during the data adjustment process, there is an overall trend of increasing the "suction pressure threshold" to achieve the decompression effect;

[0115] 5. (5 < Pa ≤ 8): Perfusion maintains current operation, the change trend of the uploaded data is observed. If the pressure is in an upward stage, increase the "suction pressure threshold + 3"; if the pressure is in a downward trend, decrease the "suction pressure threshold - 1". In this way, during the data adjustment process, there is an overall trend of increasing the "suction pressure threshold" to achieve the decompression effect;

[0116] 6. (3 < Pa ≤ 5): Observe the change trend of the uploaded data. If the trend is upward, increase the "suction pressure threshold" by +2; if the trend is downward, decrease the "suction pressure threshold" by -1. In this way, during the data adjustment process, there is an overall trend of increasing the "suction pressure threshold", so as to achieve a decompression effect;

[0117] 7. (-3 < Pa ≤ 3): Maintain the current state, perform timing and record data. When a certain duration is reached, record the current suction pressure threshold (that is, the suction pressure threshold corresponding to the stable state) and update it in real time. When the state is damaged, restart timing, and the modified saved value can be used in the dynamic adjustment process to quickly restore the balance state;

[0118] 8. (-5 < Pa ≤ -3): Perfusion maintains current operation. Observe the change trend of the uploaded data. If the trend is upward, increase the "suction pressure threshold" by +1; if the trend is downward, decrease the "suction pressure threshold" by -2. In this way, during the data adjustment process, there is an overall trend of decreasing the "suction pressure threshold", so as to achieve a pressurization effect;

[0119] 9. (-8 < Pa ≤ -5): Perfusion maintains current operation. Observe the change trend of the uploaded data. If the trend is upward, increase the "suction pressure threshold" by +1; if the trend is downward, decrease the "suction pressure threshold" by -3. In this way, during the data adjustment process, there is an overall trend of decreasing the "suction pressure threshold", so as to achieve a pressurization effect;

[0120] 10. (-10 < Pa ≤ -8): Perfusion maintains current operation, and opens the pressure relief valve in stages. Observe the change trend of the uploaded data. If the trend is upward, increase the "suction pressure threshold" by +1; if the trend is downward, decrease the "suction pressure threshold" by -4. In this way, during the data adjustment process, there is an overall trend of decreasing the "suction pressure threshold", so as to achieve a pressurization effect;

[0121] 11. (-15 < Pa ≤ -10): Perfusion maintains current operation, and opens the pressure relief valve in stages. Observe the change trend of the uploaded data. If the trend is upward, increase the "suction pressure threshold" by +3; if the trend is downward, decrease the "suction pressure threshold" by -5. There is an overall trend of decreasing the "suction pressure threshold", so as to achieve a pressurization effect;

[0122] 12. (-20 < Pa ≤ -15): Perfusion operates at current gear +3, opens the pressure relief valve, and sets the "suction pressure threshold"

[0123] Adjust the threshold to a stable state. Observe the trend of the uploaded data. If it is in an upward phase, increase the "suction pressure threshold +2"; if it is in a downward trend, decrease the "suction pressure threshold -5". This way, during the data adjustment process, there is an overall trend of decreasing the "suction pressure threshold," achieving a pressurization effect.

[0124] 13. (Pa<-20) Fill the current gear +4 and run, open the pressure relief valve, and adjust the suction pressure threshold to the value of the stable state to achieve a rapid balancing effect and allow the equipment to get out of the current state as soon as possible.

[0125] As mentioned above, by analyzing historical data, the pressure value, pressure control value and pressure threshold in the cavity are analyzed, thereby dynamically adjusting the infusion flow rate and suction flow rate to achieve a balance of pressure in the cavity.

[0126] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "specific embodiment," "optional embodiment," "example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0127] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A sheath with pressure measurement function, characterized in that, The sheath includes a sheath body, the sheath body having a main channel extending from a proximal end to a distal end and a pressure measuring channel inside, the proximal end of the pressure measuring channel having an interface; the sheath also includes a pressure detection device, the pressure detection device being assembled at the interface, the pressure detection device comprising: The housing has a pressure measuring chamber and a mounting chamber. The pressure measuring chamber has an air inlet for communicating with an interface and a vent for communicating with the outside. A switch is provided at the vent. A pressure detection assembly is disposed in the mounting cavity and includes a gauge pressure sensor, a voltage adjustment circuit, an operational amplifier circuit, and a conversion circuit. The gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit, and conversion circuit are electrically connected. The gauge pressure sensor converts the pressure signal in the pressure measurement cavity into a voltage signal. The voltage adjustment circuit increases the voltage difference of the voltage signal, and the operational amplifier circuit amplifies the increased voltage difference by a factor of two. The conversion circuit converts the amplified voltage signal into a pressure value. An aerogel insulating component is encapsulated on the surface of the pressure detection assembly to transmit pressure. The pressure measuring chamber is aligned with the pressure detection component to form an outlet, and the outlet is sealed by the aerogel insulator.

2. The sheath according to claim 1, characterized in that, The pressure sensor has a positive input voltage terminal (+vin), a negative input voltage terminal GND (-vin), a positive analog signal output voltage terminal (+out), and a negative analog signal output voltage terminal (-out). The voltage adjustment circuit includes at least a first resistor (R1) and a second resistor (R3). The first resistor (R1) is connected in parallel between the positive input voltage terminal (+vin) and the positive analog signal output voltage terminal (+out), and the second resistor (R3) is connected in parallel between GND (-vin) and the negative analog signal output voltage terminal (-out).

3. The sheath according to claim 1, characterized in that, The operational amplifier circuit is a GS8332 precision operational amplifier chip, which amplifies the voltage difference by 100 times.

4. The sheath according to claim 2, characterized in that, The resistance values ​​of the first resistor (R1) and the second resistor (R3) are 100K.

5. The sheath according to claim 1, characterized in that, The aforementioned conversion circuit is a single-chip microcontroller STM32F103C8T6.

6. The sheath according to claim 1, characterized in that, The housing includes: The base has a pressure measuring tube for forming a pressure measuring chamber. One end of the pressure measuring tube has an air inlet, and the other end forms a vent hole. The pressure measuring tube has an outlet for the gas inside the pressure measuring tube to flow out. The upper cover is disposed above the base; The PCB board is located inside the base and fixed on the top cover. The PCB board integrates a pressure detection component and a control circuit. The pressure detection component is positioned directly over the outlet and is sealed by an aerogel insulator. The control buttons are mounted on the housing and are communicatively connected to the control circuit. A connecting cable is provided, which is connected to a conversion circuit to output a pressure test value.

7. The sheath according to any one of claims 1-6, characterized in that, The sheath is subjected to the following testing method: Step 1) Conversion stage: The gauge pressure sensor converts the pressure signal into a voltage in the μV range; Step 2) Increase voltage difference stage: Connect the first resistor (R1) in parallel between the positive terminal of the input voltage (+vin) and the positive terminal of the analog signal output voltage (+out), and connect the second resistor (R3) in parallel between the negative terminal of the input voltage GND (-vin) and the negative terminal of the analog signal output voltage (-out) to increase the voltage difference to the mV level to meet the minimum voltage difference requirement of the op amp circuit; Step 3) Operational Amplifier Stage: The voltage difference is amplified 100 times through the operational amplifier circuit to reach the V (volt) level; range (0.5-3.0V). Step 4) In the conversion stage, the voltage difference from step 3) is converted into a pressure value output through a conversion circuit; Step 5) Acquisition stage: The gauge pressure sensor acquires data multiple times, and the microcontroller removes extreme values, calculates the average, and converts it into a pressure value output.

8. A pressure detection device, characterized in that, The pressure detection device is installed at the proximal end of the sheath and includes: The housing has a pressure measuring chamber and a mounting chamber. The pressure measuring chamber has an air inlet for communicating with the pressure measuring interface of the sheath and a vent for communicating with the outside. A switch is provided at the vent. A pressure detection assembly is disposed in the mounting cavity, and the pressure detection assembly includes a gauge pressure sensor, a voltage adjustment circuit, an operational amplifier circuit, and a conversion circuit. The gauge pressure sensor, voltage adjustment circuit, operational amplifier circuit, and conversion circuit are electrically connected. The gauge pressure sensor converts the pressure signal in the pressure measuring cavity into a voltage signal. The voltage adjustment circuit is used to increase the voltage difference of the voltage signal, and the operational amplifier circuit amplifies the increased voltage difference by a factor of two; the conversion circuit is used to convert the amplified voltage signal into a pressure value. Aerogel insulation, which is encapsulated on the surface of a pressure sensing component to transmit pressure; The pressure measuring chamber is aligned with the pressure detection component to form an outlet, and the outlet is sealed by the aerogel insulator.

9. The pressure detection device according to claim 8, characterized in that, The pressure sensor has a positive input voltage terminal (+vin), a negative input voltage terminal GND (-vin), a positive analog signal output voltage terminal (+out), and a negative analog signal output voltage terminal (-out). The voltage adjustment circuit includes at least a first resistor (R1) and a second resistor (R3). The first resistor (R1) is connected in parallel between the positive input voltage terminal (+vin) and the positive analog signal output voltage terminal (+out), and the second resistor (R3) is connected in parallel between GND (-vin) and the negative analog signal output voltage terminal (-out).

10. The pressure detection device according to claim 9, characterized in that, The housing includes: The base has a pressure measuring tube for forming a pressure measuring chamber. One end of the pressure measuring tube has an air inlet, and the other end forms a vent hole. The pressure measuring tube has an outlet for the gas inside the pressure measuring tube to flow out. The upper cover is disposed above the base; The PCB board is located inside the base and fixed on the top cover. The PCB board integrates a pressure detection component and a control circuit. The pressure detection component is positioned directly over the outlet and is sealed by an aerogel insulator. The control buttons are mounted on the housing and are communicatively connected to the control circuit. A connecting cable is provided, which is connected to a conversion circuit to output a pressure test value.

11. An intelligent constant-pressure controlled perfusion and suction system, characterized in that, The system includes: The sheath as described in any one of claims 1 to 6; An endoscope, wherein the endoscope is inserted into a sheath and a fluid delivery channel is formed inside the endoscope; An infusion device, wherein the infusion device is connected to a delivery channel for injecting infusion fluid into a body cavity; A suction device, wherein the suction device is connected to a suction channel for extracting fluid from a human cavity, and an infusion device cooperates with the suction device to maintain a suitable pressure within the cavity; The main controller is communicatively connected to the conversion circuit, the infusion device, and the suction device. The main controller controls the flow rate and pressure of the infusion device and the suction device based on the pressure value output by the conversion circuit.

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