Pressure monitoring device and method for injection of biomaterials into a percutaneous disc

Abstract

The present application relates to the field of intervertebral disc monitoring, and specifically discloses a device and method for pressure monitoring during injection of biomaterials for percutaneous intervertebral discs, comprising: a smart puncture needle assembly, which contains a hollow needle body, a MEMS capacitive pressure sensor arranged in a micro groove on the side wall of the needle tip, a miniature receiving coil and a radio frequency transmitting chip arranged inside the needle seat; a handle connected with the smart puncture needle assembly, which is internally provided with a transmitting coil and an automatic power control module, and is used for providing high-frequency radio frequency alternating energy to the receiving coil; and a central processing terminal, which comprises a radio frequency receiver, a display screen and a control unit. By introducing individual baseline calibration, segmented nonlinear pressure-volume model and pressure change rate dynamic monitoring three mechanisms, compared with the traditional single pressure threshold judgment or simple reliance on imaging experience judgment, the present application can give an early warning and automatically intervene hundreds of milliseconds before the annulus fibrosus rupture occurs, effectively preventing nerve compression accidents caused by excessive injection.

Description

Technical Field

[0001] This invention relates to a pressure monitoring device and method, specifically to a pressure monitoring device and method for percutaneous injection of biomaterials into intervertebral discs, belonging to the field of intervertebral disc monitoring. Background Technology

[0002] Intervertebral disc degeneration is one of the common causes of low back and leg pain. In recent years, treatment methods that involve injecting bio-repair materials such as hydrogels into the nucleus pulposus region through a puncture needle to repair or reconstruct degenerated intervertebral discs have received increasing attention.

[0003] In current disc repair surgery, doctors typically rely on clinical experience or external imaging equipment (such as X-rays and CT scans) to indirectly determine the amount of hydrogel to be injected. However, the above methods have the following significant technical drawbacks: The lack of direct biomechanical perception poses serious safety risks. The load-bearing capacity of the intervertebral disc annulus fibrosus varies significantly from person to person due to differences in age, degree of degeneration, and disc segment. Physicians cannot directly obtain real-time pressure data within the disc based solely on tactile experience, making it impossible to objectively determine whether the annulus fibrosus is nearing its biomechanical limit. Insufficient injection volume results in poor repair outcomes; excessive injection can easily lead to annulus fibrosus rupture, nucleus pulposus leakage, and even compression of the dural sac or nerve roots, causing irreversible secondary nerve damage.

[0004] Existing puncture needles with electronic sensors are bulky and severely interfere with surgical procedures. Most existing injection needles with piezoelectric or strain gauge sensors require physical wires to connect to an external power source and signal processor, or necessitate the inclusion of a micro-battery within the needle body. This not only results in an excessively large outer diameter of the puncture needle, increasing puncture trauma, but the dragging wires also severely interfere with the surgeon's rotation and injection technique during the procedure, affecting puncture accuracy and operational flexibility.

[0005] Existing technologies lack a closed-loop feedback control mechanism for the injection process of intervertebral disc biomaterials, making it impossible to automatically adjust the injection speed or terminate the injection in a timely manner based on real-time pressure changes, thus making it difficult to achieve precise and safe quantitative filling.

[0006] Therefore, there is an urgent need in this field for a technical solution that can sense the pressure inside the intervertebral disc in real time without changing the external dimensions of the standard puncture needle, and automatically guide or control the injection process based on pressure changes. Summary of the Invention

[0007] To address the problems in the prior art, the present invention provides a pressure monitoring device and method for percutaneous intervertebral disc biomaterial injection.

[0008] The objective of this invention can be achieved through the following technical solutions: A pressure monitoring device for percutaneous intervertebral disc biomaterial injection includes: The intelligent puncture needle assembly includes a hollow needle body, a MEMS capacitive pressure sensor disposed in a microgroove on the side wall of the needle tip, a miniature receiving coil and an RF transmitting chip disposed inside the needle hub. The handle connected to the smart puncture needle assembly has a built-in transmitting coil and an automatic power control module for providing high-frequency radio frequency alternating energy to the receiving coil; The central processing terminal includes a radio frequency receiver, a display screen, and a control unit; The control unit is configured to: Receive the real-time pressure value P(t) collected by the pressure sensor, and calculate the individual baseline pressure P0 based on the resting period before injection; The current cumulative injection volume V(t) and safety margin are calculated based on a piecewise nonlinear pressure-volume model. The pressure change rate dP / dt is calculated in real time, and a deceleration command is output when the pressure change rate exceeds the first threshold. An emergency lock command is output when the real-time pressure exceeds the preset safe pressure limit or when the pressure change rate suddenly jumps negatively.

[0009] Preferably, the pressure sensor surface within the microgroove on the needle tip sidewall is coated with a Parylene conformal insulating coating, and this coating is integrally smooth with the outer wall of the needle.

[0010] Preferably, the handle is equipped with a current sampling feedback module; the automatic power control module calculates the coupling strength of the receiving coil in reverse according to the change in the input current of the transmitting coil detected by the current sampling feedback module, and dynamically adjusts the transmitting power accordingly; when the input current is detected to be lower than the preset coupling threshold, the transmitting power is linearly increased; when the input current exceeds the safety limit, overload protection is performed and the output is cut off.

[0011] Preferably, the receiving coil outputs a DC voltage to the pressure sensor and the radio frequency transmitting chip after rectification and voltage regulation; the frequency of the high-frequency radio frequency alternating energy is 13.56MHz ISM band.

[0012] Preferably, the radio frequency (RF) transmitter chip adopts an OOK on / off keying modulation method and intermittently transmits pressure data at a sampling frequency of 100Hz to 200Hz. The RF transmitter chip is in a dormant state during non-transmission periods.

[0013] Preferably, the display screen is used to plot a real-time pressure-time waveform and estimate the maximum safe volume V based on preoperative images. max A dynamically updated safety pressure envelope is generated. When the real-time pressure touches the safety pressure envelope, a color gradient warning is triggered on the screen.

[0014] Preferably, it also includes an intelligent injection pump electrically connected to the central processing terminal. The intelligent injection pump has a built-in stepper motor. The deceleration command controls the stepper motor to linearly decrease from the standard flow rate to the peristaltic flow rate, and the emergency lock-up command controls the stepper motor to brake instantaneously.

[0015] The method for monitoring pressure during percutaneous intervertebral disc biomaterial injection, applied to the aforementioned device, further includes the following steps: S1: After the puncture is completed, the static calibration phase begins. Multiple pressure samples are collected to calculate the individual baseline pressure P0, and the maximum safe volume V of the target intervertebral disc is calculated based on preoperative imaging data. max ; S2: Start the injection pump to inject the biomaterial at a preset initial flow rate and obtain the current pressure P(t) in real time; S3: Based on the current pressure range, invoke the piecewise nonlinear pressure-volume model to estimate the current cumulative injection volume and the approximate maximum safe volume V in real time. max The percentage, where a logarithmic model P(t) = P0 + α·ln(1 + β·V(t)) is used during the gradual pressure rise phase, and an exponential model P(t) = P0 + γ·[V(t) / V] is used during the rapid pressure rise phase. max ] k α, β, γ, and k are mechanical correction coefficients pre-set based on intervertebral disc viscoelasticity experiments; S4: Calculate the pressure change rate dP / dt in real time. If the pressure change rate is less than the first change rate threshold, maintain the current injection speed. If the pressure change rate is greater than or equal to the first change rate threshold and less than the second change rate threshold, control the injection pump to linearly reduce its speed. If the current pressure is greater than the preset maximum safe pressure or the pressure change rate shows an instantaneous negative pulse, control the injection pump to lock instantly and trigger an alarm.

[0016] Preferably, the specific process of controlling the linear reduction of the injection pump in step S4 is as follows: the central processing terminal adopts a PID control algorithm to calculate the speed correction of the stepper motor based on the difference between the current pressure and the preset maximum safe pressure, so as to achieve smooth stepless adjustment of the injection speed.

[0017] The beneficial effects of this invention are: 1. Significantly improved safety. By introducing a triple mechanism of individualized baseline calibration, piecewise nonlinear pressure-volume model, and dynamic monitoring of pressure change rate, compared to traditional single pressure threshold judgment or reliance on imaging experience, this invention can issue an early warning and automatically intervene hundreds of milliseconds before the annulus fibrosus ruptures, effectively preventing nerve compression accidents caused by over-injection.

[0018] 2. Truly minimally invasive design. Utilizing 13.56MHz ISM band wireless power supply and 433MHz radio frequency telemetry technology, it maintains the slim profile of a standard puncture needle, allowing doctors to operate without dragging, and ensuring that flexibility and precision are not compromised.

[0019] 3. High measurement accuracy and strong anti-interference capability. The Parylene conformal coating effectively isolates the infiltration of body fluids, preventing sensor short circuits and signal drift.

[0020] 4. Highly integrated functions. The same puncture needle simultaneously performs three functions: extraction and sampling of the diseased nucleus pulposus, injection of biomaterials for repair, and real-time monitoring of the pressure inside the intervertebral disc. This simplifies the surgical procedure, shortens the operation time, and reduces patient suffering. Attached Figure Description

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the handle structure of the present invention.

[0023] In the diagram: 1. Handle; 2. Smart puncture needle assembly; 3. Pressure sensor. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figure 1 As shown, a pressure monitoring device and method for percutaneous intervertebral disc biomaterial injection are described. This monitoring device mainly consists of three parts: an intelligent puncture needle assembly 2, a handle 1 that is detachably connected to the intelligent puncture needle assembly 2, and an externally located central processing terminal.

[0026] (a) Intelligent puncture needle assembly 2; The intelligent puncture needle assembly 2 includes a hollow needle body, a MEMS capacitive pressure sensor 3, a miniature receiving coil, and an RF transmitting chip.

[0027] The needle body is made of medical-grade stainless steel, with an outer diameter that matches the 18G standard puncture needle specification and an inner diameter of approximately 0.84mm. It retains a hollow channel for extracting the nucleus pulposus and injecting hydrogel.

[0028] A microgroove is created on the sidewall of the needle body approximately 2-5 mm behind the needle tip using laser processing technology. The microgroove is approximately 0.15 mm deep, 0.5 mm wide, and 1.0 mm long. A MEMS capacitive absolute pressure sensor 3 is embedded within the microgroove. This pressure sensor 3 is a commercially available MEMS pressure sensing chip known in the art, integrating signal conditioning circuitry and a 12-bit analog-to-digital converter, which can directly convert changes in capacitance into digital pressure values.

[0029] To prevent body fluid infiltration from causing short circuits and signal drift in pressure sensor 3, a medical-grade Parylene conformal coating with a thickness of 3-10 μm is applied to the surface of the microgroove using a chemical vapor deposition (CVD) process. Parylene exhibits excellent biocompatibility, chemical resistance, and electrical insulation.

[0030] The needle holder integrates a miniature receiving coil and an RF transmitting chip. The receiving coil and transmitting coil achieve resonant coupling at a frequency of 13.56MHz. A serpentine printed antenna, physically isolated from the receiving coil, is also located inside the needle holder for transmitting 433MHz RF signals. The miniature receiving coil powers the pressure sensor 3 via insulated wires embedded in the inner wall of the needle body.

[0031] (2) Handle 1; Handle 1 incorporates a built-in toroidal air-core transmitting coil and an automatic power control module. The transmitting coil is designed for the 13.56MHz ISM band. The automatic power control module includes a current sampling feedback circuit that calculates the coupling strength of the receiving coil by monitoring the changes in the input current of the transmitting coil in real time.

[0032] Specifically, the automatic power control module dynamically adjusts the transmit power (range 1W~3W) based on the current detection value to ensure a regulated 3.3V DC output at the receiver. When the input current is detected to be lower than the preset coupling threshold, the system linearly increases the transmit power; when the input current exceeds the safety limit, the system performs overload protection and cuts off the output. A removable battery is installed inside the handle 1 to power the toroidal air-core transmitting coil and the automatic power control module.

[0033] (iii) Central processing terminal; The central processing unit includes a 433MHz radio frequency receiver, a display screen, a control unit, and a communication interface connected to the injection pump.

[0034] The RF receiver is responsible for capturing the 433MHz modulated signal emitted by the RF transmitter chip, demodulating, filtering, and amplifying it to reconstruct the digital pressure value. The RF transmitter chip uses OOK (on / off keying) modulation. To reduce power consumption and minimize interference with the power supply electromagnetic field, the RF transmitter chip operates in an intermittent mode: the sampling frequency is set to 100Hz~200Hz, each sampling is completed within microseconds and data packets are transmitted in bursts, and the RF transmitter chip enters a sleep state at other times.

[0035] The display screen is used to plot pressure-time waveforms in real time. The system estimates the target intervertebral disc maximum safe volume V based on preoperative CT / MRI 3D reconstructed images. max A dynamically updated safety pressure envelope is superimposed on the waveform graph. When the real-time pressure waveform touches the envelope, the screen background color gradually changes from green to yellow and then to red, providing a tiered warning.

[0036] The control unit incorporates a piecewise nonlinear pressure-volume model and a PID control algorithm. It is responsible for calculating control commands based on real-time pressure data and sending the commands to the intelligent injection pump via a communication interface.

[0037] The intelligent infusion pump has a built-in stepper motor that receives instructions from the central processing terminal and executes corresponding injection actions: under normal conditions, it injects at a standard flow rate (e.g., 0.05 ml / s); upon receiving a deceleration command, it linearly decreases to a peristaltic flow rate; upon receiving an emergency stop command, it instantly brakes and remains in a locked state. The intelligent infusion pump is independent of handle 1 and the central processing terminal, but can be used in conjunction with handle 1.

[0038] The workflow of this invention is as follows: Step S1: Puncture and baseline calibration; After the doctor inserts the intelligent puncture needle into the target intervertebral disc, a small amount of diseased nucleus pulposus is extracted through the hollow channel of the needle for pathological examination. Once extraction is complete, the system enters a static calibration phase: all injection and extraction operations are paused, and the system waits 3-5 seconds to eliminate stress relaxation effects. During this period, the MEMS sensor continuously collects 20 pressure samples, and the average value is taken as the patient's individual baseline pressure P0.

[0039] The introduction of individual baseline pressure is one of the key innovations of this invention, because different patients have different degrees of intervertebral disc degeneration, and their internal nucleus pulposus has significant individual differences in water content, viscoelasticity, and resting pressure. The calibration of individual baseline pressure P0 ensures that all subsequent pressure judgments are "personalized," eliminating the interference of individual differences on injection decisions.

[0040] Simultaneously, based on the patient's preoperative CT / MRI 3D reconstructed images, the system automatically calculates the nucleus pulposus volume of the target intervertebral disc segment and multiplies it by a safety factor (usually 0.8~0.9) to obtain the maximum safe volume V. max .

[0041] Step S2: Injection initiation and real-time monitoring; Medical staff activate the intelligent infusion pump to begin injecting biomaterials (such as hydrogel) at an initial flow rate (e.g., 0.05 ml / s). During the injection process, the MEMS capacitive pressure sensor 3 continuously collects the current pressure data P(t) at a frequency of 100 Hz to 200 Hz.

[0042] Pressure data is modulated onto a 433MHz carrier wave by the RF transmitter chip inside the needle holder and transmitted outward through a serpentine printed antenna. The RF receiver of the external central processing terminal captures the signal, demodulates and restores it, and sends the real-time pressure value to the control unit.

[0043] Step S3: Piecewise nonlinear pressure-volume model estimation; The control unit uses different mathematical models to estimate the current cumulative injection volume V(t) and the approximate maximum safe volume V based on the current pressure P(t) range. max The percentage.

[0044] Based on the viscoelastic mechanical properties of the intervertebral disc, this invention establishes a piecewise nonlinear pressure-volume model: Filling phase (gradual pressure rise): In the initial stage of injection, the biomaterial mainly fills the voids inside the nucleus pulposus, and the annulus fibrosus has not yet been significantly stretched, resulting in a relatively gradual increase in pressure. A logarithmic model is used at this time: P(t) = P0 + α·ln(1 + β·V(t)); Where V(t) is the cumulative injection volume, and α and β are the elastic modulus correction coefficients pre-set based on the in vitro intervertebral disc mechanical experiment.

[0045] Tension phase (pressure surge stage): When the filler approaches the limit of the annulus fibrosus's inner wall, the annulus fibrosus is significantly stretched, and the pressure increases exponentially with the increase of injection volume. An exponential model is used at this stage. P(t) = P0 + γ·[V(t) / V max ] k ; Where V max The maximum safe volume is given by γ, where γ is the stiffness coefficient of the fiber ring and k is the nonlinear exponent (k>1).

[0046] The aforementioned mechanical correction coefficients α, β, γ, and k were obtained through pressure-volume testing experiments on excised intervertebral discs from individuals of different ages and degeneration levels, and are pre-loaded into the system's parameter library. In clinical use, the system automatically matches the appropriate parameters based on the patient's age and degeneration grade.

[0047] Step S4: Multivariable logic decision and closed-loop control; The control unit calculates the pressure change rate dP / dt = [P(t)-P(t-Δt)] / Δt in real time, where Δt is the sampling interval. The system presets three state intervals, corresponding to three control strategies: Status 1: Normal injection (green). When the pressure change rate dP / dt is less than the first change rate threshold (e.g., 2.0 kPa / s) and the current pressure P(t) is lower than the median safe pressure, the system determines that the injection process is normal, the display shows a green background, and the current injection speed remains unchanged.

[0048] State 2: Approaching Saturation / Warning (Yellow). When the pressure change rate dP / dt is greater than or equal to the first change rate threshold (2.0 kPa / s) and less than the second change rate threshold (4.0 kPa / s), it indicates that the fiber ring is being rapidly stretched and approaching its mechanical bearing limit. The system issues an audible and visual warning (the screen background gradually turns yellow, and the indicator light flashes), and uses a PID control algorithm to linearly reduce the stepper motor speed of the injection pump from the standard flow rate to the peristaltic flow rate (e.g., 40% of the initial flow rate), achieving smooth and stepless adjustment of the injection speed and avoiding pressure overshoot.

[0049] State 3: Danger Edge / Emergency Lock (Red) When the current pressure P(t) is greater than the preset maximum safe pressure (e.g., 300 kPa), or when the pressure change rate dP / dt shows a momentary negative jump (i.e., the pressure suddenly drops in a very short time, which is a typical mechanical indicator of annulus fibrosus rupture), the system determines that annulus fibrosus rupture has occurred or is about to occur, and immediately triggers an unresettable emergency alarm (the screen background turns red and the buzzer sounds continuously). At the same time, an emergency lock command is sent to the intelligent infusion pump, controlling the stepper motor to brake instantaneously and maintain the lock state until the doctor manually releases it.

[0050] The following is a specific surgical example to illustrate the implementation process of this invention: A patient was diagnosed with L4 / L5 disc degeneration with mild herniation. Preoperative MRI 3D reconstruction showed that the volume of the L4 / L5 nucleus pulposus region was approximately 4.5 ml, and the system was set to the maximum safe volume V. max It contains 4.0ml (with a safety margin of approximately 11%).

[0051] During the procedure, the surgeon used an 18G-sized intelligent puncture needle from this invention to percutaneously puncture the central region of the L4 / L5 intervertebral disc. After the puncture was completed, the needle was left to stand for 5 seconds, and the system collected 20 pressure samples, calculating P0 = 12 kPa.

[0052] The doctor extracted approximately 0.3 ml of the diseased nucleus pulposus through the hollow channel of the needle for pathological examination. A syringe was then connected, and the intelligent infusion pump was activated, with the initial flow rate set at 0.05 ml / s.

[0053] When the cumulative injection volume reaches approximately 2.0 ml, the current pressure P(t) rises to approximately 55 kPa. The system determines that it is in the filling phase, calls the logarithmic model to estimate the current filling rate to be approximately 50%, and the pressure change rate dP / dt is approximately 1.2 kPa / s (below the first threshold of 2.0 kPa / s). The screen displays green, and the injection proceeds normally.

[0054] When the injection volume reaches approximately 3.5 ml, the current pressure P(t) rises to approximately 195 kPa, and the system switches to the tension-phase exponential model. At this point, the pressure change rate dP / dt rises to 3.5 kPa / s, exceeding the first threshold (2.0 kPa / s). The screen background gradually turns yellow, and an audible and visual warning, "Approaching the maximum capacity, please slow down," is issued. The control unit uses a PID algorithm to linearly reduce the stepper motor speed to 40% of the initial flow rate (approximately 0.02 ml / s).

[0055] After the injection rate decreased, the pressure change rate dP / dt dropped to approximately 1.8 kPa / s, and the pressure stabilized. When the cumulative injection volume reached 3.8 ml, the system indicated that the injection was complete and automatically stopped the injection. No emergency stop was triggered during the entire process, and the procedure was successfully completed.

[0056] Postoperative imaging showed that the hydrogel was evenly distributed, with no signs of rupture or leakage of the annulus fibrosus.

[0057] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A pressure monitoring device for percutaneous intervertebral disc biomaterial injection, characterized in that, include: The intelligent puncture needle assembly includes a hollow needle body, a pressure sensor disposed in a microgroove on the side wall of the needle tip, a receiving coil disposed inside the needle hub, and a radio frequency transmitting chip. The handle connected to the smart puncture needle assembly has a built-in transmitting coil and an automatic power control module for providing high-frequency radio frequency alternating energy to the receiving coil; The central processing terminal includes a radio frequency receiver, a display screen, and a control unit; The control unit is configured to: Receive the real-time pressure value collected by the pressure sensor and calculate the individual baseline pressure based on the resting period before injection; The current cumulative injection volume and safety margin are calculated based on a piecewise nonlinear pressure-volume model. The pressure change rate is calculated in real time, and a deceleration command is output when the pressure change rate exceeds the first threshold. An emergency lock command is output when the real-time pressure exceeds the preset safe pressure limit or when the pressure change rate suddenly jumps negatively.

2. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, The pressure sensor surface within the microgroove on the sidewall of the needle tip is coated with an insulating coating.

3. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, The handle is equipped with a current sampling feedback module; the automatic power control module calculates the coupling strength of the receiving coil in reverse based on the change in the input current of the transmitting coil detected by the current sampling feedback module, and dynamically adjusts the transmitting power accordingly. When the input current is detected to be lower than the preset coupling threshold, the transmission power is increased linearly. When the input current exceeds the safety limit, overload protection is performed and the output is cut off.

4. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, The receiving coil outputs DC voltage to the pressure sensor and RF transmitting chip after rectification and voltage regulation; the frequency of the high-frequency RF alternating energy is 13.56MHz ISM band.

5. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, The radio frequency (RF) transmitter chip uses an on / off keying modulation method and intermittently transmits pressure data at a sampling frequency of 100Hz to 200Hz. The RF transmitter chip is in a dormant state during non-transmission periods.

6. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, The display screen is used to draw a real-time pressure-time waveform and generate a dynamically updated safety pressure envelope based on the maximum safe volume estimated from preoperative images. When the real-time pressure touches the safety pressure envelope, the screen triggers a color gradient warning.

7. The pressure monitoring device for percutaneous intervertebral disc biomaterial injection according to claim 1, characterized in that, It also includes an intelligent injection pump that is electrically connected to the central processing terminal. The intelligent injection pump has a built-in stepper motor. The deceleration command controls the stepper motor to linearly decrease from the standard flow rate to the peristaltic flow rate, and the emergency lock-up command controls the stepper motor to brake instantaneously.

8. A method for monitoring pressure during percutaneous intervertebral disc biomaterial injection, applied to the device as described in any one of claims 1-7, characterized in that, It also includes the following steps: S1: After the puncture is completed, the static calibration stage is entered. Multiple pressure samples are collected to calculate the individual baseline pressure P0, and the maximum safe volume of the target intervertebral disc is calculated based on the preoperative imaging data. S2: Start the injection pump to inject the biomaterial at a preset initial flow rate and obtain the current pressure in real time; S3: Based on the current pressure range, call the piecewise nonlinear pressure-volume model to estimate the current cumulative injection volume and the percentage close to the maximum safe volume in real time. The logarithmic model is used during the pressure rise phase, and the exponential model is used during the pressure rise phase. S4: Calculate the pressure change rate in real time. If the pressure change rate is less than the first change rate threshold, maintain the current injection speed. If the pressure change rate is greater than or equal to the first change rate threshold and less than the second change rate threshold, control the injection pump to linearly reduce its speed. If the current pressure is greater than the preset maximum safe pressure or a momentary negative pulse appears in the pressure change rate, control the injection pump to lock momentarily and trigger an alarm.

9. The method according to claim 8, characterized in that, The specific process of controlling the linear reduction of the injection pump in step S4 is as follows: The central processing terminal adopts a PID control algorithm to calculate the speed correction of the stepper motor based on the difference between the current pressure and the preset maximum safe pressure, so as to achieve smooth stepless adjustment of the injection speed.

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