Bladder pressure closed-loop control system and method with optical fiber sensing magnetic attraction interface

Abstract

The application discloses a bladder pressure closed-loop control system and method with a fiber-optic sensor magnetic suction interface, and belongs to the technical field of medical devices. The application sets an independent backward-inclined fiber-optic sensor magnetic suction interface in a holding dead zone of a proximal end hub of an inner sheath, and guides the fiber-optic sensor to a distal end through a metal microtube welded by a laser in a wall of the inner sheath; a "metal-ceramic composite reinforcement" structure is adopted to embed a fiber-optic Fabry-Perot pressure sensor in a lateral wall of a ceramic beak, and an induction diaphragm of the sensor is configured to face away from a central flow passage of the inner sheath and face a radial periphery of the ceramic beak; the layout realizes complete decoupling of a monitoring path and a surgical execution path in a physical space, and guarantees in-situ and real-time monitoring of intravesical pressure in a strong electromagnetic interference environment. Meanwhile, a millisecond active pressure relief is triggered by a system host when pathological spasm is monitored, and a pressure-time integral (PTI) is calculated in real time to quantify a liquid absorption risk.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a closed-loop control system and method for bladder pressure with fiber optic sensing magnetic interface. Background Technology

[0002] Bladder cancer is a common malignant tumor of the urinary system, and transurethral resection of bladder tumor (TURBT) is its standard treatment. Whether using traditional monopolar or modern bipolar / plasma kinetic resection, continuous irrigation with flushing fluid is required during the procedure to expand the bladder and maintain visualization. However, existing fluid management systems have serious "blind spots" and safety risks:

[0003] First, most existing systems employ a "proximal monitoring" approach, where the pressure sensor is located at the pump outlet. Due to the approximately 2-3 meter long tubing from the pump tip to the bladder interior (distal), and the narrow inlet channel for the electrocautery endoscope, fluid flow causes significant pressure loss along the flow path. When the physician increases the pump rate to flush out bleeding, the high pressure displayed at the pump tip (e.g., 100 mmHg) may not reflect the true low intrabladder pressure (e.g., 20 mmHg), leading to misdiagnosis. Conversely, when the instrument tip becomes blocked, the pump alarm will sound and shut down, but the bladder may collapse due to dehydration, resulting in loss of vision and accidental instrument injury.

[0004] Secondly, one of the core tools in TURBT surgery is the monopolar high-frequency electrosurgical unit, which generates a high-frequency, high-voltage arc (300kHz-3MHz, peak voltage of several kilovolts) during operation, making it a strong source of electromagnetic interference (EMI). If traditional electronic pressure sensors (such as piezoresistive MEMS) are placed at the surgical tip, their metal leads will couple high-frequency interference, causing signal drift or even circuit breakdown. Although bipolar electrosurgical resection reduces the risk of current passing through the body, the high-frequency, high-density plasma field generated at the electrode tip during operation remains a strong source of interference. Therefore, current technology struggles to achieve precise in-situ pressure measurement while performing electrosurgical resection.

[0005] Third, the limitations of passive safety mechanisms: Obturator Jerk or bladder spasm that may occur during surgery can cause intravesical pressure to surge to over 150 mmHg within milliseconds, leading to life-threatening bladder perforation. Existing peristaltic pumps only have an "overpressure stop pump" function and cannot release the high pressure already sealed within the cavity.

[0006] Fourth, the risk of fluid absorption (TUR syndrome): Prolonged perfusion at slightly higher than venous pressure (10-15 mmHg) can lead to the absorption of perfusion fluid into the bloodstream, causing transurethral resection syndrome. Monopolar surgery using non-conductive fluids may cause hyponatremia, while bipolar surgery using saline avoids hyponatremia, but excessive absorption can lead to volume overload, causing acute heart failure or pulmonary edema. Current equipment lacks quantitative monitoring of this cumulative absorption risk. Furthermore, the management of existing endoscopic cables is a major challenge. Adding wired sensors easily leads to cables becoming entangled with the beam guide and electrosurgical wires, limiting the surgeon's freedom of movement, especially when rotating the endoscope to remove lateral wall tumors. Summary of the Invention

[0007] To address the aforementioned shortcomings in existing technologies, this invention provides a closed-loop control system and method for bladder pressure with an optical fiber sensing magnetic interface. This solution addresses the problems in existing TURBT procedures, such as bladder pressure monitoring deviations, inability to achieve accurate in-situ pressure measurement due to strong electromagnetic interference, inability to release sudden high pressure, lack of quantitative monitoring of the risk of irrigation fluid absorption, and cable entanglement limiting operational freedom.

[0008] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a bladder pressure closed-loop control system with fiber optic sensing magnetic interface, comprising: an improved electrocautery endoscope, a photoelectric signal processing host, and an irrigation control module.

[0009] The improved electrosurgical resection mirror includes: a front-end sensing module, which includes: a tubular metal sheath, a smart inner sheath proximal hub assembly, and a distal ceramic insulating beak. The smart inner sheath proximal hub assembly is connected to the distal ceramic insulating beak through the tubular metal sheath.

[0010] The irrigation control module includes: a peristaltic pump, a peristaltic pump driver, an inlet pipe, an active pressure relief solenoid valve, and an outlet pipe; the photoelectric signal processing host is electrically connected to the peristaltic pump driver and the active pressure relief solenoid valve respectively; the peristaltic pump is electrically connected to the peristaltic pump driver; one end of the inlet pipe is connected to the peristaltic pump, and the other end is connected to the modified electrocautery mirror; the outlet pipe is connected to the modified electrocautery mirror.

[0011] Furthermore, the intelligent inner sheath proximal hub assembly includes: an inner sheath proximal hub, on which a fiber optic sensor magnetic interface is provided;

[0012] The fiber optic sensor magnetic interface is located on the circumferential side wall of the inner sheath near the hub, in the area between 1:30 and 2:00 or between 10:30 and 11:00.

[0013] Furthermore, the magnetic interface of the fiber optic sensor integrates a beam expander global lens.

[0014] The magnetic interface of the fiber optic sensor has an annular protrusion on the end face of the housing, and the axial height of the annular protrusion is higher than the installation height of the internal sapphire window.

[0015] When the male and female components of the fiber optic sensor magnetic interface are magnetically connected via neodymium iron boron magnetic rings, a constant non-contact air gap is formed between the annular protrusion and the sapphire window at the opposite end.

[0016] Furthermore, a U-shaped micro-groove is formed on the side wall of the distal ceramic insulating beak; an optical fiber pressure sensor is embedded in the U-shaped micro-groove and encapsulated by an insulating epoxy resin, with the outer surface of the epoxy resin flush with the outer surface of the distal ceramic insulating beak.

[0017] Furthermore, the distal ceramic insulating beak is a metal-ceramic composite structure, including a zirconia ceramic body and a metal reinforcing base connected to the interior of the zirconia ceramic body by active brazing;

[0018] The depth of the U-shaped micro-grooves extends to expose the support surface of the metal-reinforced base;

[0019] The fiber optic pressure sensor is fixed to the support surface of the metal-reinforced base, and the mechanical stress is borne by the metal-reinforced base.

[0020] Furthermore, the U-shaped micro-groove is located on the side at the 3 o'clock or 9 o'clock position of the distal ceramic insulating beak;

[0021] The normal direction of the pressure-sensing diaphragm of the fiber optic pressure sensor is perpendicular to the axis of the tubular metal sheath and is positioned to the side.

[0022] A closed-loop control method for bladder pressure with a fiber optic sensing magnetic interface includes the following steps:

[0023] S1. Output EFPI interference spectrum signal and FBG reflection wavelength signal through fiber optic pressure sensor;

[0024] S2. In the demodulation module, the EFPI cavity length change and FBG wavelength drift are read from the EFPI interference spectrum signal and FBG reflection wavelength signal, a system of two linear equations is established, and the inverse matrix is ​​used to solve the real pressure.

[0025] S3. Obtain the noise fundamental frequency based on the speed signal from the peristaltic pump motor encoder;

[0026] S4. Based on the noise fundamental frequency, construct a second-order IIR notch filter, input the real pressure into the second-order IIR notch filter, and obtain the real-time bladder pressure;

[0027] S5. Calculate the pressure change rate and cumulative pressure-time integral based on real-time bladder pressure;

[0028] S6. When the rate of change of pressure exceeds the preset spasm threshold, check the rate of change of the PWM drive command of the peristaltic pump. When the rate of change of the PWM drive command is not positive, it is determined to be pathological spasm, triggering the peristaltic pump to stop and controlling the active pressure relief solenoid valve to open fully. When the rate of change of the PWM drive command is positive, the pressure relief action is suppressed.

[0029] S7. When the cumulative pressure-time integral exceeds the preset safety threshold, a liquid absorption risk classification alarm is triggered.

[0030] Furthermore, the expression for the matrix of the system of two linear equations in S2 is: ,

[0031] in, For the EFPI cavity length variation, For FBG wavelength drift, This is the pressure sensitivity coefficient. This is the temperature cross-sensitivity coefficient. This is the temperature sensitivity coefficient. This represents the actual change in bladder pressure. This represents the actual temperature change in the bladder.

[0032] Furthermore, the expression for the second-order IIR notch filter in S4 is: ,

[0033] ,

[0034] in, For transfer functions, Let be the radius of the pole. The center angular frequency of the notch filter. The fundamental frequency of the noise. Sampling frequency, For the z-domain delay operator, It is a cosine function.

[0035] Furthermore, the formula for calculating the cumulative pressure-time integral in S5 is as follows: ,

[0036] in, To accumulate pressure-time integral, For a moment Real-time bladder pressure, The preset pelvic venous pressure reference value, The time step of a single sampling period. For the length of time, It is a time variable.

[0037] The beneficial effects of this invention are as follows:

[0038] 1. This invention achieves in-situ monitoring of intrabladder pressure by modifying the front-end sensing module of the electroresection endoscope. The distal ceramic insulated beak of the front-end sensing module can extend directly into the bladder (distal end), eliminating the need for proximal monitoring via the pump end and completely avoiding pressure loss along the 2-3 meter tubing and the electroresection endoscope's water inlet channel. Compared to existing pump-end monitoring methods that cannot reflect the true intrabladder pressure, this invention can directly collect real-time intrabladder pressure data, ensuring the accuracy of the pressure information obtained by the surgeon. This avoids misjudgment of high pressure at the pump end and low pressure inside the bladder when the pump speed increases, and also prevents loss of vision and instrument injury caused by bladder dehydration and collapse when the instrument tip is blocked, significantly improving the precision and safety of surgical procedures.

[0039] 2. This invention employs fiber optic sensing technology, combined with an improved electroresection endoscope structural design, to achieve anti-interference in-situ pressure measurement: The front-end sensing module uses fiber optic sensing to replace traditional electronic pressure sensors with metal leads (such as piezoresistive MEMS), effectively avoiding the problem of high-frequency interference from metal lead coupling; at the same time, the distal ceramic insulated beak has excellent insulation performance, further isolating electromagnetic interference from high-frequency electric arcs and plasma fields, ensuring accurate and stable monitoring of in-situ pressure within the bladder during monopolar and bipolar electroresection surgery, without the risk of signal drift or circuit breakdown, breaking the limitation of existing technologies that cannot achieve accurate in-situ pressure measurement during electroresection.

[0040] 3. This invention constructs an active safety mechanism through the closed-loop control of the active pressure relief solenoid valve of the irrigation control module and the photoelectric signal processing host: The photoelectric signal processing host receives bladder pressure data collected by the front-end sensing module in real time. When the pressure is detected to rise above the safety threshold, the active pressure relief solenoid valve can be quickly opened without manual intervention to release the high pressure in the bladder cavity in time, rather than just stopping the peristaltic pump irrigation. This fundamentally avoids life-threatening dangers such as bladder perforation caused by high pressure, makes up for the deficiencies of existing passive safety mechanisms, and improves the safety of the operation.

[0041] 4. On the one hand, this invention achieves quantitative control of the risk of perfusion fluid absorption through closed-loop linkage between the photoelectric signal processing host and the perfusion control module: the photoelectric signal processing host analyzes the pressure data of the front-end sensing module, the perfusion speed of the peristaltic pump, and the perfusion duration in real time, quantitatively calculates the cumulative absorption of perfusion fluid, and provides timely risk warnings, making it easier for doctors to adjust perfusion parameters and effectively reducing the risk of complications such as transurethral resection syndrome, acute heart failure, and pulmonary edema. On the other hand, addressing the pain point of wired sensor cables tangling and restricting the doctor's freedom of operation, this invention adopts a magnetic interface design (combined with the intelligent inner sheath proximal hub assembly of the improved electrosurgical endoscope) to replace the traditional wired connection, avoiding tangling of sensor cables with the beam guide and electrosurgical wire. Especially when the doctor rotates the endoscope to remove lateral wall tumors, it can significantly improve the degree of freedom of operation, reduce the difficulty of operation, and improve surgical efficiency. Attached Figure Description

[0042] Figure 1 This is a system block diagram of a closed-loop control system for bladder pressure with a fiber optic sensing magnetic interface.

[0043] Figure 2 This is a schematic diagram of the intelligent inner sheath proximal hub assembly;

[0044] Figure 3 This is a schematic diagram of the magnetic interface of a fiber optic sensor.

[0045] Figure 4 A schematic diagram of the structure of the distal ceramic insulating beak;

[0046] The components include: 1. Improved electrosurgical resection mirror; 2. Optoelectronic signal processing host; 3. User interface; 4. Demodulation module; 5. Fiber optic cable; 6. Peristaltic pump driver; 7. Peristaltic pump; 8. Irrigation fluid; 9. Inlet pipe; 10. Active pressure relief solenoid valve; 11. Outlet pipe; 12. Inner sheath proximal hub; 13. Fiber optic sensor magnetic interface; 14. Inlet valve port; 15. Outlet valve port; 16. Fiber optic ferrule; 17. Beam expander global lens; 18. Sapphire window; 19. Parallel beam expander optical path; 20. Air gap; 21. Neodymium iron boron magnetic ring; 22. Annular protrusion; 23. Zirconia ceramic body; 24. Metal reinforcement base; 25. U-shaped micro groove; 26. Fiber optic pressure sensor; 27. Epoxy resin. Detailed Implementation

[0047] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0048] like Figure 1 As shown, a closed-loop control system for bladder pressure with fiber optic sensing magnetic interface includes: a modified electrocautery endoscope 1, a photoelectric signal processing host 2, and an irrigation control module.

[0049] The improved electrosurgical resection mirror 1 includes: a front-end sensing module, which includes: a tubular metal sheath, a smart inner sheath proximal hub assembly, and a distal ceramic insulating beak. The smart inner sheath proximal hub assembly is connected to the distal ceramic insulating beak through the tubular metal sheath.

[0050] The irrigation control module includes: a peristaltic pump 7, a peristaltic pump driver 6, an inlet pipe 9, an active pressure relief solenoid valve 10, and an outlet pipe 11; the photoelectric signal processing host 2 is electrically connected to the peristaltic pump driver 6 and the active pressure relief solenoid valve 10 respectively; the peristaltic pump 7 is electrically connected to the peristaltic pump driver 6; one end of the inlet pipe 9 is connected to the peristaltic pump 7, and the other end is connected to the modified electrocautery mirror 1; the outlet pipe 11 is connected to the modified electrocautery mirror 1.

[0051] The outlet of the perfusion fluid 8 is connected to the inlet of the peristaltic pump 7 via a pipeline; the photoelectric signal processing host 2 is operated through the user interface 3, one end of the fiber optic cable 5 is connected to the demodulation module 4, and the other end is connected to the front sensing module of the improved electrosurgical resection mirror 1.

[0052] The photoelectric signal processing host 2 is connected to the demodulation module 4 via a cable and is used to demodulate the optical signal and calculate the real-time bladder pressure. The irrigation control module includes a peristaltic pump 7 for injecting fluid into the bladder and an active pressure relief solenoid valve 10 installed on the water outlet pipe 11. The photoelectric signal processing host 2 is configured to execute closed-loop control logic: based on the real-time bladder pressure, the peristaltic pump driver 6 is controlled to adjust the speed of the peristaltic pump 7, and when an abnormal increase in pressure is detected and the pump-pressure interlock condition is met, the active pressure relief solenoid valve 10 is triggered to open.

[0053] The photoelectric signal processing host 2 runs an adaptive notch filter algorithm based on speed feedback. The algorithm is configured to receive the speed signal of the peristaltic pump 7 motor in real time, calculate the fluid pulsation fundamental frequency and its harmonic frequencies based on the speed, and dynamically adjust the center frequency of the series digital notch filter to filter out fluid pulsation noise in real time.

[0054] The active pressure relief valve, active pressure relief solenoid valve 10, is a normally open solenoid clamp valve. When the system is powered off or malfunctions, the active pressure relief valve, active pressure relief solenoid valve 10, automatically resets to the open state to release bladder pressure. Under normal operating conditions, the valve is in the closed state and only opens when emergency control is triggered, and the fully open response time is less than 20ms.

[0055] In this embodiment, the front-end sensing module is the core hardware foundation of the system. In order to introduce a fourth channel without increasing the outer diameter of the standard 26Fr (approximately 8.7mm outer diameter) electrosurgical resection mirror, this invention abandons the traditional double-layer tube extrusion process and innovatively adopts the "hypotube embedded micro-welding" technology.

[0056] The tubular metal sheath body is made of medical-grade 304 stainless steel tubing. A semi-circular microgroove extending axially, with a depth of 0.3mm, is machined on the inner side of the inner sheath wall using precision CNC milling. A custom-made 304 stainless steel hypo tube is selected, with an outer diameter of 0.35mm, a wall thickness of 0.05mm, and an inner diameter of 0.25mm. After embedding the hypo tube into the microgroove, intermittent spot welding is performed using a high-frequency nanosecond fiber laser. Laser parameters: laser power set to 50W, pulse width 20ns, repetition frequency 100kHz. These high-frequency, short-pulse parameters precisely control the weld depth within 0.1mm, ensuring a strong connection between the hypo tube and the sheath while avoiding welding through the extremely thin sheath wall or causing deformation due to a large heat-affected zone (HAZ). Surface treatment: After welding, the inner surface of the inner sheath undergoes electrolytic polishing. This process removes tiny weld beads and burrs, ensuring a smooth inner surface roughness. This not only prevents frictional resistance during insertion of the working device but also eliminates microscopic blind spots for bacterial growth, meeting stringent medical device cleaning and disinfection standards. Electromagnetic shielding effect: Compared to polymer catheters, the embedded metal hypotube forms a natural Faraday cage. Although the optical fiber itself is immune to electromagnetic interference, the metal tube effectively shields the strong electric field generated by the high-frequency electrosurgical unit from the thermal effects that may occur on the fiber cladding, and provides excellent mechanical protection, preventing the fiber from breaking during instrument bending or cleaning.

[0057] like Figure 2 As shown, the intelligent inner sheath proximal hub assembly includes: an inner sheath proximal hub 12, on which a fiber optic sensor magnetic interface 13 is provided;

[0058] The fiber optic sensor magnetic interface 13 is located on the circumferential sidewall of the inner sheath near the hub 12, in the quadrant region from 1:30 to 2:00 (preferably) or from 10:30 to 11:00 on the circumference of the hub, which is defined as the dead zone for hand grip.

[0059] The intelligent inner sheath proximal hub assembly also includes: an inlet valve 14 and an outlet valve 15.

[0060] The axis of the fiber optic sensor magnetic interface 13 is tilted 30 to 45 degrees proximally relative to the central axis of the tubular metal sheath, forming a compliance angle to guide the connected fiber optic cable 5 to extend backward and naturally converge with the endoscope camera cable.

[0061] The front-end sensing module is a transurethral resectoscope inner sheath assembly, with an axially extending independent optical fiber channel integrated within the tubular metal sheath wall.

[0062] The operation of an electrosurgical resection endoscope is highly dependent on the surgeon's tactile sense. When the surgeon's left hand supports the proximal hub 12 of the inner sheath, the thumb is typically positioned between the 6 and 9 o'clock positions, while the index and middle fingers are positioned between the 12 and 3 o'clock positions to assist in stabilizing or manipulating the obturator. Analysis revealed a natural "tiger's mouth gap" in the area between 1:30 and 2:00 (i.e., the upper right quadrant), a "dead zone" in which the fingers cannot reach. This invention places the independent fiber optic sensor magnetic interface 13 in this location, completely avoiding the problem of the interface pressing on the surgeon's fingers or obstructing the view. The interface axis is not vertically led out, but rather tilted at a 45-degree angle proximally (rearward) relative to the sheath's central axis. This "compliance angle" design allows the fiber optic cable to flow naturally backward along the back of the hand and converge with the endoscope camera cable located in the central rear, forming a "top cable bundle." When the surgeon rotates the instrument to resect a lateral wall tumor, this cable bundle rotates as a whole with the instrument, preventing relative entanglement and effectively solving the problem of traditional lateral interface cables wrapping around the arm.

[0063] like Figure 3 As shown, the magnetic interface 13 of the fiber optic sensor integrates a beam expander global lens 17.

[0064] The end face of the housing of the fiber sensor magnetic interface 13 is provided with an annular protrusion 22, and the axial height of the annular protrusion 22 is higher than the installation height of the internal sapphire window 18.

[0065] When the male and female components of the fiber optic sensor magnetic interface 13 are magnetically connected via the neodymium iron boron magnetic ring 21, a constant non-contact air gap 20 is formed between the annular protrusion 22 and the sapphire window 18 at the opposite end.

[0066] The fiber optic sensor magnetic interface 13 adopts a magnetic connection structure and integrates a beam expander global lens 17 to expand and collimate the beam diameter of the fiber optic transmission, achieving non-contact optical coupling. The end face of the housing of the fiber optic sensor magnetic interface 13 is provided with an annular protrusion 22, the axial height of which is greater than the installation height of the internal sapphire window 18. When the male and female connector assemblies are magnetically attracted by the N52 grade neodymium iron boron magnetic ring 21 embedded in their housings, the physical contact of the annular protrusion 22 defines a constant non-contact air gap 20 between the opposing sapphire windows 18 to eliminate interface wear and collision, and to provide radial self-alignment force to compensate for optical axis misalignment.

[0067] Operating room environments are humid, and water residue may remain on the connectors during cleaning and disinfection. Traditional PC (Physical Contact) fiber optic connectors rely on physical contact between the fiber end faces; once contaminated with even tiny dust particles or water droplets (on the order of a few micrometers), it can cause light scattering, drastically worsening return loss and resulting in signal interruption. The fiber optic sensor magnetic interface 13 integrates a beam expander lens system. (See attached image) Figure 3As shown, a spherical lens or beam expander global lens 17 is fused to the fiber optic end at the socket end (inner sheath side). The diverging beam output from the single-mode fiber ferrule 16 (core diameter 9μm) is collimated into a parallel beam expander optical path 19 with a diameter of approximately 300μm after passing through the beam expander global lens 17. A symmetrical receiving lens is provided at the plug end (cable side) to refocus and couple the parallel light into the transmission fiber. The beam cross-sectional area is increased by approximately 1000 times. According to optical principles, the same dust or water droplet obstruction will only cause a very small energy attenuation (<0.5dB) in the expanded optical path, rather than completely blocking the signal as it would in a narrow beam. Therefore, this beam expansion design gives the system extremely high tolerance to minute dust or water mist on the surface of the sapphire window 18. Figure 3 As shown, in this embodiment, the outer periphery of the male and female connector assemblies has an annular protrusion 22 on its end face. The axial height of the annular protrusion 22 is slightly greater than the mounting height of the sapphire window 18, thus forming a limit by physical contact of the end faces of the housings when the left and right assemblies are engaged. This design ensures that a constant non-contact air gap 20 is always maintained between the two sets of sapphire windows, achieving efficient beam expansion coupling while completely avoiding interface wear and mechanical collision damage during insertion and removal. An N52-grade neodymium iron boron magnetic ring 21 is provided on the outside of the interface, combined with a conical mechanical guide surface. Since the beam expansion optical path is not sensitive to lateral offset, doctors only need to bring the cable plug close to the interface in a dimly lit surgical environment, and the magnetic force will automatically engage. This connection method greatly improves operational convenience while ensuring micron-level alignment.

[0068] like Figure 4 As shown, a U-shaped micro-groove 25 is provided on the side wall of the distal ceramic insulating beak; an optical fiber pressure sensor 26 is embedded in the U-shaped micro-groove 25 and encapsulated by an insulating epoxy resin 27, the outer surface of the epoxy resin 27 being flush with the outer surface of the distal ceramic insulating beak.

[0069] The U-shaped micro-groove 25 is preferably positioned at the 3 o'clock or 9 o'clock position on the distal ceramic insulating beak. The 3 o'clock and 9 o'clock positions are typically the "neutral axis" of the structure, where stress is most stable, and are usually in a relatively "suspended" or pressure-balanced region. This results in more representative bladder pressure measurements, reducing the likelihood of false positives due to physical compression of local tissues. Alternatively, it can be positioned at the 1:30 or 10:30 position to achieve a completely straight-line route for the optical fiber inside the sheath, minimizing micro-losses under complex bending conditions and improving the signal-to-noise ratio.

[0070] The pressure-sensing diaphragm of the fiber optic pressure sensor 26 has a normal direction perpendicular to the sheath axis and faces to the side to avoid the dynamic pressure impact of the axial inlet fluid. This achieves "spatial non-plane" alignment between the monitoring path and the instrument's working path, and also completely eliminates the mechanical interference of fluid turbulence generated by the movement of the electric cutting ring on the pressure waveform.

[0071] In this embodiment, the distal ceramic insulating beak is the insulating beak that directly contacts the bladder tissue, such as... Figure 4 As shown, the distal ceramic insulating beak employs a metal-ceramic composite structure. This structure includes an outer zirconia ceramic body 23 (3Y-TZP, yttrium-stabilized zirconia) and a metal reinforcing base 24 pre-fixed inside the ceramic via an active brazing process. The metal reinforcing base 24 extends distally, forming a robust mechanical support frame to resist lateral compression that may be encountered during electrical cutting operations.

[0072] The distal ceramic insulating beak is a metal-ceramic composite structure, including a zirconia ceramic body 23 and a metal reinforcing base 24 connected to the interior of the zirconia ceramic body 23 by active brazing.

[0073] The depth of the U-shaped micro-groove 25 extends to expose the support surface of the metal-reinforced base 24;

[0074] The fiber optic pressure sensor 26 is fixed to the support surface of the metal-reinforced base 24, and the metal-reinforced base 24 bears the mechanical stress.

[0075] The U-shaped micro-groove 25 is located on the side at the 3 o'clock or 9 o'clock position of the distal ceramic insulating beak.

[0076] The normal direction of the pressure-sensing diaphragm of the fiber optic pressure sensor 26 is perpendicular to the axis of the tubular metal sheath and is positioned to the side.

[0077] A U-shaped microgroove 25 is formed on the sidewall (at the 3 o'clock or 9 o'clock position) of the zirconia ceramic body 23. The cutting depth of the U-shaped microgroove 25 penetrates the ceramic layer, directly exposing the extended support surface of the metal-reinforced base 24. In this embodiment, femtosecond laser cold ablation technology is used to form this sensor groove. Laser source configuration: A Ti:Sapphire femtosecond laser is used, with a center wavelength of 800nm, a pulse width of 120fs (femtosecond level), and a repetition frequency of 1kHz. Processing mechanism: The energy density of the ultrashort pulse laser is extremely high, injecting energy into the material in a very short time. Electrons instantly absorb photon energy and ionize, causing the chemical bonds in the material to break and eject heat in the form of plasma. This process is faster than the lattice heat conduction time, so almost no thermal effect is generated (Heat Affected Zone, HAZ ≈ 0). Groove parameters: The processed U-shaped microgroove 25 is located at the 3 o'clock or 9 o'clock position of the ceramic beak, with a groove width of 0.35mm, a depth of 0.35mm, and a length of 10mm. This ensures the structural integrity of the ceramic beak when subjected to repeated impacts and thermal cycling from the electro-cutting ring.

[0078] The fiber optic pressure sensor 26 is not bonded to the ceramic, but is directly fixed to the exposed surface of the metal-reinforced base 24. The technical advantages of this "deeply nested" design are:

[0079] Mechanical protection: Ceramic materials are brittle and easily broken under pressure; while the metal-reinforced base 24 has a high elastic modulus. By fixing the fiber optic pressure sensor 26 to the metal-reinforced base 24, the toughness of the metal can absorb the impact stress generated by the collision, thus achieving stress decoupling between the sensor and the ceramic layer.

[0080] Thermal stability: The metal-reinforced base 24 provides a more stable heat sink, which helps the EFPI sensor maintain thermal balance and reduce temperature drift during electrosurgical operation.

[0081] The U-shaped micro-grooves 25 are filled with a medical-grade epoxy resin potting layer 27. For example... Figure 4 As shown, the cured surface of the potting layer is completely flush with the outer circumferential surface of the ceramic body. This design ensures an extremely smooth surface for the beak, preventing physical damage to the mucosa during transurethral propulsion.

[0082] Meanwhile, the sensor's integrated position maintains a specific distance both radially and circumferentially from the main inlet channel at the 12 o'clock position. This layout effectively avoids turbulence interference generated by the inlet pump, enabling the fiber optic pressure sensor 26 to capture real bladder physiological pressure.

[0083] like Figure 4 As shown, the sensing diaphragm of the fiber optic pressure sensor 26 is configured to face away from the main water inlet channel of the inner sheath and toward the radial outer periphery of the ceramic beak. This arrangement achieves complete physical decoupling between the monitoring path (outer wall side) and the surgical execution path (inner wall side).

[0084] The main inlet channel is responsible for frequent saline flushing during surgery, with the internal fluid in a high-speed turbulent state, accompanied by periodic pulse pressure generated by the infusion pump. By facing the sensing surface of the fiber optic pressure sensor 26 towards the outer wall of the inner sheath, and utilizing the composite wall thickness of the zirconia ceramic body 23 and the metal-reinforced base 24 as a physical barrier, the direct mechanical impact of the internal flushing fluid turbulence on the sensor is effectively blocked. Compared with the inner wall pressure measurement scheme, this invention can significantly eliminate high-frequency noise in the pressure waveform, resulting in a higher signal-to-noise ratio for the measured intrabladder hydrostatic pressure signal.

[0085] Since the movement range of the electrosurgical resection ring, observation mirror, and auxiliary surgical instruments is strictly limited to the cavity enclosed by the inner wall of the inner sheath, installing the fiber optic pressure sensor 26 in the U-shaped micro-groove 25 facing the outer wall ensures that the sensing diaphragm of the fiber optic pressure sensor 26 is not affected by mechanical friction, lateral compression, or high-frequency vibration of the electrodes caused by the reciprocating motion of the instruments. This "back-to-back" design logic eliminates false positive pressure peaks caused by surgical operations, ensuring the continuity and accuracy of real-time pressure monitoring during surgery.

[0086] External physiological pressure is vertically coupled to the fiber optic pressure sensor diaphragm 26 through an epoxy resin encapsulation layer 27 that is completely flush with the outer wall of the ceramic. Because the encapsulation layer is in direct contact with the urethral mucosa or bladder fluid, it senses the actual intra-organ pressure environment. Simultaneously, this outward-facing flush design ensures the absolute flatness of the inner sheath wall, allowing for the smooth entry and exit of surgical instruments and enabling bidirectional, interference-free operation of both monitoring and surgical functions.

[0087] A closed-loop control method for bladder pressure with a fiber optic sensing magnetic interface includes the following steps:

[0088] S1. Output EFPI interference spectrum signal and FBG reflection wavelength signal through fiber optic pressure sensor 26;

[0089] S2. In demodulation module 4, the EFPI cavity length change and FBG wavelength drift are read from the EFPI interference spectrum signal and FBG reflection wavelength signal, a matrix of two linear equations in two variables is established, and the inverse matrix is ​​used to solve the real pressure.

[0090] S3. Obtain the noise fundamental frequency based on the speed signal from the encoder of the peristaltic pump 7 motor;

[0091] S4. Based on the noise fundamental frequency, construct a second-order IIR notch filter, input the real pressure into the second-order IIR notch filter, and obtain the real-time bladder pressure;

[0092] S5. Calculate the pressure change rate and cumulative pressure-time integral based on real-time bladder pressure;

[0093] S6. When the rate of change of pressure exceeds the preset spasm threshold, check the rate of change of the PWM drive command of the peristaltic pump 7. When the rate of change of the PWM drive command is not positive, it is determined to be pathological spasm, triggering the peristaltic pump 7 to stop urgently and controlling the active pressure relief solenoid valve 10 to fully open. When the rate of change of the PWM drive command is positive, the pressure relief action is suppressed.

[0094] S7. When the cumulative pressure-time integral exceeds the preset safety threshold, a liquid absorption risk classification alarm is triggered.

[0095] The system first filters out pump pulsation noise using a second-order IIR notch filter to obtain the pure real-time bladder pressure. Then, it performs two parallel processing steps: one calculates the cumulative pressure-time integral (PTI) based on the pure pressure and provides tiered warnings based on thresholds—a yellow warning is triggered when PTI is in the 1000-2000 mmHg·min range, indicating an increased risk of absorption; a red warning is triggered when PTI ≥ 2000 mmHg·min, indicating that fluid absorption is approaching a critical value. The other step calculates the bladder pressure change rate (dP / dt). If dP / dt > 40 mmHg / s, the system determines the cause of high pressure based on the direction of the pump PWM command: if the pump PWM command is increasing, it is determined to be a doctor's active operation, and PID regulation is executed while pressure relief is prohibited; if the pump PWM command is not increasing, it is determined to be abnormally high pressure, and the active pressure relief valve (active pressure relief solenoid valve 10) is immediately opened to perform emergency treatment and quickly release the bladder pressure.

[0096] Pump-pressure interlock verification: When dP / dt is detected to exceed the preset spasm threshold, the change rate of the PWM drive command of the current peristaltic pump 7 is checked simultaneously; Emergency execution: If dP / dt exceeds the threshold and the change rate of the PWM command is not positive (indicating non-human pressure), it is determined to be pathological spasm, and the peristaltic pump is immediately triggered to stop and the active pressure relief valve solenoid valve 10 is fully opened; If the change rate of the PWM command is positive (indicating human flushing), the pressure relief action is suppressed.

[0097] In this embodiment, the safety threshold is set to 2000 mmHg·min.

[0098] The fiber optic pressure sensor 26 employs an intrinsic fiber optic Fabry-Perot (EFPI) sensor with an outer diameter controlled within 0.25 mm. The fiber optic pressure sensor 26 consists of a single-mode fiber, a capillary tube, and a pressure-sensing diaphragm. A Fabry-Perot cavity is formed by the fiber end face (reflecting surface R1) and the inner surface of the pressure-sensing diaphragm (reflecting surface R2). When broadband light is incident on the cavity, the two reflected beams interfere. When external pressure is applied to the diaphragm, the cavity length changes, leading to a phase shift in the interference spectrum. ,in, The length of the cavity after being subjected to pressure. The initial cavity length, For the sensitivity of the pressure-sensitive diaphragm, Due to external pressure.

[0099] Because it is an optical measurement, the optical signal is not affected by electromagnetic fields during transmission. The demodulator is located at the main unit far from the operating table. It calculates the pressure through spectral analysis. No matter how strong the electric arc generated by the high-frequency electric cutter, the photon transmission remains stable, completely solving the problem of electrical signal drift. After the fiber optic pressure sensor 26 is embedded in the U-shaped micro-groove 25, a perfect hydrodynamic surface must be achieved to avoid turbulence noise and blood clot adhesion.

[0100] The adhesive used is EPO-TEK 353ND medical-grade epoxy resin. This material has the following key characteristics:

[0101] High glass transition temperature (Tg): >120℃, capable of withstanding hospital-standard 134℃ autoclave sterilization.

[0102] Low coefficient of thermal expansion (CTE): The CTE is low after curing, which has good compatibility with the ceramic matrix and reduces thermal stress.

[0103] Biocompatibility: Certified by ISO 10993 and USP Class VI, with no cytotoxicity.

[0104] Color indication: After curing, it will be amber in color, making it easy to visually inspect for air bubbles.

[0105] Application process: Dispensing is performed under vacuum to eliminate micro-bubbles within the adhesive. After curing, precision grinding and polishing are used to ensure that the height difference between the adhesive surface and the outer surface of the distal ceramic insulating beak is less than 5μm, achieving true "flush encapsulation".

[0106] Although the EFPI sensor is pressure-sensitive, temperature changes can cause the cavity material to expand and contract, resulting in false pressure readings (temperature drift). During TURBT procedures, the temperature of the irrigation fluid (typically room temperature or heated to 37°C) may vary. This system employs a composite probe structure with a fiber Bragg grating (FBG) and an EFPI sensor connected in series. Principle: The FBG is temperature-sensitive but pressure-insensitive (in this encapsulation), while the EFPI is sensitive to both pressure and temperature.

[0107] In this embodiment, the photoelectric signal processing host 2 uses the demodulation module to simultaneously read the EFPI cavity length change and FBG wavelength drift, and constructs the expression of the matrix of the system of two linear equations in two variables as follows: ,

[0108] in, For the EFPI cavity length variation, For FBG wavelength drift, This is the pressure sensitivity coefficient. This is the temperature cross-sensitivity coefficient. This is the temperature sensitivity coefficient. This represents the actual change in bladder pressure. This represents the actual temperature change in the bladder.

[0109] The photoelectric signal processing host 2 uses an inverse matrix to calculate the real pressure value in real time, eliminates temperature interference, and ensures that the measurement accuracy is better than ±1cmH2O.

[0110] The photoelectric signal processing host 2 is the "brain" of the system, running complex signal processing and control algorithms. It preferably uses a high-performance microcontroller (such as the STM32H7 series) or FPGA chip based on the ARM Cortex-M7 core, with a built-in floating-point unit (FPU) to meet the real-time filtering and PID calculation requirements of high-frequency pressure signals. To ensure surgical safety, the main control unit is designed with dual hardware watchdog circuits. When the system detects a software malfunction or a system crash caused by electromagnetic interference exceeding 10ms, it immediately forces a system reset and cuts off the drive power to the perfusion control module, achieving fault-oriented safety.

[0111] Fiber Optic Sensor Interface Module / Demodulation Module 4: This module integrates a broadband light source (SLED, center wavelength 850nm, bandwidth 40nm) and a miniature spectrometer.

[0112] The fiber optic sensor interface module / demodulation module 4 is connected to the independent fiber optic sensor magnetic interface 13 via fiber optic cable 5 to receive the optical interference signal from the remote sensor. White light interferometry demodulation technology is used to decode the returned optical interference signal, acquiring the Fabry-Perot (FP) cavity length change in real time. This demodulation scheme exhibits extremely high anti-interference capability, with a measurement accuracy of ±1 mmHg, and is unaffected by fiber bending loss or light source fluctuations.

[0113] An adaptive notch filter based on RPM feedback: When the peristaltic pump 7 is working, the rollers squeezing the pump tube will generate periodic pressure pulsations that are strictly related to its rotational speed and the number of rollers. The amplitude of these pulsations can reach 20-30 mmHg, severely masking the true intrabladder pressure and causing oscillations in the control system. Instead of using a simple low-pass filter (which would cause signal delay and affect emergency response), this system employs a frequency tracking adaptive notch filter.

[0114] Frequency calculation: The system reads the speed signal from the peristaltic pump motor encoder in real time and calculates the noise fundamental frequency. ,in, The fundamental frequency of the noise. For rotational speed, This refers to the number of rollers in peristaltic pump 7.

[0115] In this embodiment, the expression for the second-order IIR notch filter in S4 is: ,

[0116] ,

[0117] in, For transfer functions, The radius of the pole (controls the notch width, usually taken as 0.95). The center angular frequency of the notch filter. The fundamental frequency of the noise. Sampling frequency, For the z-domain delay operator, It is a cosine function. The system is every 10m... s Update once This allows for the precise "removal" of pulsation frequencies that vary with pump speed, while preserving the rapid changes in real pressure characteristics (such as coughing and spasms).

[0118] A single pressure change rate (dP / dt) alarm is highly prone to false alarms. For example, when a doctor rapidly injects irrigation fluid, the pressure may rise sharply. If this is mistakenly interpreted as a spasm and the pressure is released, it will interfere with the surgery.

[0119] This system introduces "pump command status verification" logic:

[0120] Scenario A (False Alarm): When dP / dt > 40 mmHg / s is detected, and the pump PWM command is increasing ( The system determines this as "doctor's active operation," does not trigger pressure relief, and only adjusts the PID parameters to prevent overshoot.

[0121] Scenario B (Real Spasm): When dP / dt > 40 mmHg / s is detected, but the pump PWM command is stable or decreases, the system determines it as "bladder spasm / obturator reflex" and immediately triggers emergency treatment.

[0122] Active pressure relief actuator: The peristaltic pump 7 stops (brakes) and simultaneously de-energizes the active pressure relief solenoid valve 10. Since this valve is normally open, when the valve is de-energized (or energized), the spring mechanism instantly opens the water outlet pipe 11, which is directly connected to the atmosphere. The high pressure in the bladder is used to quickly expel the liquid, and the pressure is released within 20ms.

[0123] Liquid absorption approximately follows Darcy's law: ,

[0124] in, The area of ​​the open venous sinuses. This refers to the pelvic venous pressure (usually around 15 mmHg). For a moment Real-time bladder pressure, This refers to the amount of liquid absorbed. The duration of pressure is a factor. Existing equipment only focuses on instantaneous pressure, ignoring the time dimension. Prolonged moderate high pressure (e.g., 30 mmHg for 1 hour) is more dangerous than short-duration extremely high pressure (e.g., 80 mmHg for 1 minute).

[0125] Therefore, to prevent TUR syndrome, the system introduces a cumulative stress-time integral: ,

[0126] in, To accumulate pressure-time integral, For a moment Real-time bladder pressure, The preset pelvic venous pressure reference value, The time step of a single sampling period. For the length of time, It is a time variable.

[0127] Set as the critical value for pelvic venous pressure (usually 15 mmHg). Risk only accumulates when bladder pressure exceeds this value.

[0128] Early warning mechanism: Clinical data shows a positive correlation between the duration of high pressure and fluid absorption. The system implements a tiered early warning system.

[0129] Level 1 (Yellow Alert): When 1000 mmHg·min < PTI < 2000 mmHg·min, it indicates that the risk is increased due to the prolonged operation time.

[0130] Level 2 (Red Alert): When PTI ≥ 2000 mmHg·min, it strongly warns physicians that fluid absorption may be approaching the critical value, and recommends monitoring the patient's serum sodium concentration or accelerating or even stopping surgery. This indicator fills a gap in the field of TUR syndrome prevention.

[0131] A first aspect of the present invention provides a system comprising a front-end sensing module, a photoelectric signal processing host 2, and an irrigation control module. The front-end sensing module is based on an improved "four-channel" electrosurgical endoscope sheath. In addition to the traditional inlet, outlet, and instrument channels, independent optical fiber channels are integrated within the metal sheath wall via laser micro-welding.

[0132] To address the cable tangling issue, this invention provides an independent fiber optic sensor magnetic interface 13 in the quadrant region from 1:30 to 2:00 (or 10:30 to 11:00) near the inner sheath's hub. This area is a "dead zone" for hand grip, thus not interfering with operation. The interface axis is tilted backward at 30°-45° (compliance angle) to guide the fiber optic cable to flow naturally backward and converge with the camera cable, thereby eliminating tangling.

[0133] The independent fiber optic sensor magnetic interface 13 adopts a beam-expanding magnetic design, which uses a lens to expand the beam to achieve non-contact coupling, is resistant to contamination such as water droplets and dust, and has an automatic tripping function under force.

[0134] The fiber optic pressure sensor 26 adopts an intrinsic fiber optic Fabry-Perot (EFPI) structure, which uses optical signals to transmit pressure data and physically isolates it from electrical high-voltage interference.

[0135] The EFPI pressure sensor is embedded in a U-shaped micro-groove 25 on the side wall of the distal ceramic beak. The U-shaped micro-groove 25 is located at the 3 o'clock or 9 o'clock position to avoid the influence of dynamic pressure from the inlet water jet. It is flush-sealed with a metal-ceramic composite structure and high-temperature resistant epoxy resin. This utilizes ceramic to isolate high frequency and high pressure, and the internal metal base enhances the structural strength to prevent ceramic breakage.

[0136] By aligning the sensing surface of the fiber optic pressure sensor 26 with the outer wall of the inner sheath, this invention achieves "spatial non-planarization" of the monitoring path and the working path of the instrument, thereby completely eliminating the mechanical interference of fluid turbulence generated by the movement of the electric cutting ring on the pressure waveform.

[0137] In terms of control algorithms, the host computer runs an adaptive notch filter algorithm, which uses the peristaltic pump speed feedback to filter out fluid pulsation noise in real time.

[0138] The system has a pump-pressure interlock emergency logic: when the pressure change rate (dP / dt) is abnormally increased (preferably, such as >40mmHg / s) and the pump command is not increased, it is determined to be a pathological spasm, and the active pressure relief valve is triggered to fully open the active pressure relief solenoid valve 10 in milliseconds to physically release the bladder pressure.

[0139] In addition, the system incorporates a pressure-time integral (PTI) model to quantify the risk of liquid absorption in real time.

[0140] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A closed-loop control system for bladder pressure with an optical fiber sensing magnetic interface, characterized in that, include: Improved electrosurgical resection mirror (1), photoelectric signal processing host (2), and perfusion control module; The improved electrosurgical resection mirror (1) includes: a front-end sensing module, which includes: a tubular metal sheath, a smart inner sheath proximal hub assembly and a distal ceramic insulating beak, wherein the smart inner sheath proximal hub assembly is connected to the distal ceramic insulating beak through the tubular metal sheath; The irrigation control module includes: a peristaltic pump (7), a peristaltic pump driver (6), an inlet pipe (9), an active pressure relief solenoid valve (10), and an outlet pipe (11); the photoelectric signal processing host (2) is electrically connected to the peristaltic pump driver (6) and the active pressure relief solenoid valve (10) respectively; the peristaltic pump (7) is electrically connected to the peristaltic pump driver (6); one end of the inlet pipe (9) is connected to the peristaltic pump (7), and the other end is connected to the modified electrocautery mirror (1); the outlet pipe (11) is connected to the modified electrocautery mirror (1); The intelligent inner sheath proximal hub assembly includes: an inner sheath proximal hub (12), on which a fiber optic sensor magnetic interface (13) is provided. The optical fiber sensor magnetic interface (13) integrates a beam expander global lens (17). The outer shell end face of the magnetic interface (13) of the fiber optic sensor is provided with an annular protrusion (22), and the axial height of the annular protrusion (22) is higher than the installation height of the internal sapphire window (18). When the male and female components of the optical fiber sensor magnetic interface (13) are magnetically connected by the neodymium iron boron magnetic ring (21), a constant non-contact air gap (20) is formed between the annular protrusion (22) and the sapphire window (18) at the opposite end.

2. The bladder pressure closed-loop control system with fiber optic sensing magnetic interface according to claim 1, characterized in that, The fiber optic sensor magnetic interface (13) is located on the circumferential side wall of the inner sheath near the hub (12), in the region from 1:30 to 2:00 or from 10:30 to 11:

00.

3. The bladder pressure closed-loop control system with fiber optic sensing magnetic interface according to claim 1, characterized in that, The sidewall of the distal ceramic insulating beak is provided with a U-shaped micro groove (25); an optical fiber pressure sensor (26) is embedded in the U-shaped micro groove (25) and encapsulated by an insulating epoxy resin (27), the outer surface of the epoxy resin (27) being flush with the outer surface of the distal ceramic insulating beak.

4. The bladder pressure closed-loop control system with fiber optic sensing magnetic interface according to claim 3, characterized in that, The distal ceramic insulating beak is a metal-ceramic composite structure, including a zirconia ceramic body (23) and a metal reinforcing base (24) connected to the interior of the zirconia ceramic body (23) by active brazing. The depth of the U-shaped micro-groove (25) extends to expose the support surface of the metal-reinforced base (24); The fiber optic pressure sensor (26) is fixed on the support surface of the metal reinforcement base (24), and the mechanical stress is borne by the metal reinforcement base (24).

5. The bladder pressure closed-loop control system with fiber optic sensing magnetic interface according to claim 4, characterized in that, The U-shaped micro-groove (25) is located at the 3 o'clock or 9 o'clock position on the side of the distal ceramic insulating beak. The normal direction of the pressure-sensing diaphragm of the fiber optic pressure sensor (26) is perpendicular to the axis of the tubular metal sheath and is positioned to the side.

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