Implantable catheter type oximeter and monitoring method thereof

Abstract

The invention relates to an implantable catheter type oximeter and a monitoring method thereof. The implantable catheter type oximeter is suitable for continuous blood oxygen monitoring of central veins or arteries of a human body. The oximeter comprises a flexible catheter body, an optical sensing element, a signal processing unit, a wireless transmission unit and a power supply assembly, the optical sensing element is arranged in an inner cavity or a wall part of the catheter and comprises a transmitting end for transmitting optical signals with different wavelengths and a receiving end for receiving optical signals absorbed and scattered by blood, so that a transmission-type or reflection-type optical detection path is formed; the signal processing unit collects the light intensity signal output by the receiving end, calculates the proportion of oxygenated hemoglobin and reduced hemoglobin in the blood according to the absorption characteristic of the multi-wavelength light, and generates an oxyhemoglobin saturation signal; the wireless transmission unit sends the blood oxygen signal to external equipment for displaying or alarming, and the power supply assembly can supply power to the system in a micro battery or catheter power supply mode; according to the invention, in-vivo continuous, high-precision and low-interference blood oxygen monitoring is realized.

Description

Technical Field

[0001] The present invention relates to the field of medical technologies, and particularly to an implantable catheter - type oximeter and its monitoring method. Background Art

[0002] In clinical monitoring and anesthesia management, blood oxygen saturation ( ) as an important physiological index reflecting tissue oxygen supply status is widely used in various intensive care monitoring and intraoperative management scenarios. Currently, the commonly used blood oxygen monitoring devices are mainly non - invasive devices, such as finger - clip type, forehead patch type or earlobe - type oximeters. These devices are usually based on photoplethysmography (PPG), and detect the blood light absorption characteristics through an external light source penetrating the skin and tissues, and then estimate the blood oxygen level. In addition, there are also some devices that achieve in - vivo blood oxygen monitoring through catheters or optical fibers, such as mixed venous blood oxygen catheters and pulmonary artery catheters, etc. Their structures are relatively complex and the application scenarios are limited.

[0003] However, there are many limitations in the prior art. For example, non - invasive oximeters are easily affected by patient movement, low perfusion state or ambient light interference, resulting in unstable or discontinuous measurements; while existing invasive catheter systems mostly use external optical fibers connected to large - scale processing units, the intubation operation is complex, which is not conducive to wide deployment, and the system has a large volume and high power consumption, making it difficult to achieve flexible deployment and long - term use. In addition, existing devices mostly rely on wired communication, do not have the function of remote wireless transmission, and also lack adaptability to different clinical scenarios.

[0004] In view of the above limitations in the prior art, there is an urgent need to provide a blood oxygen detection solution suitable for continuous in - vessel monitoring, with a simple structure, stable signal and convenient for clinical application. Summary of the Invention

[0005] The present application provides an implantable catheter - type oximeter and its monitoring method to achieve continuous in - vessel monitoring and improve the measurement stability and accuracy.

[0006] The present application provides an implantable catheter - type oximeter, including: A flexible catheter body configured to be inserted into a human central vein or artery for carrying blood flow; An optical sensing element arranged in the lumen or the catheter wall of the flexible catheter body. The optical sensing element includes a transmitting end and a receiving end. The transmitting end is used to emit optical signals with different wavelengths to irradiate the blood in the catheter, and the receiving end is used to receive the remaining light intensity after the optical signals are absorbed and scattered by the blood to form a transmission - type or reflection - type optical path for blood oxygen detection; A signal processing unit, connected to the receiving end, is configured to obtain the optical intensity signal output by the receiving end, calculate the relative ratio of oxyhemoglobin to reduced hemoglobin in the blood based on the absorption differences of optical signals of different wavelengths, and generate a blood oxygen saturation signal; A wireless transmission unit, communicatively connected to the signal processing unit, is configured to wirelessly transmit the blood oxygen saturation signal to an external receiving device for display, recording, or alarming; A power supply component is configured to provide operating power for the transmitting end, receiving end, signal processing unit, and wireless transmission unit. The power supply component includes a micro battery or a wired power supply port connected via a catheter.

[0007] Furthermore, an optical stability structure is integrated in the flexible catheter body within the setting area of its optical sensing element. The optical stability structure includes a low refractive index light guiding layer, a locally enhanced support band, and an inner wall anti-interference coating; Among them, the light guiding layer is coated on the inner wall surface of the catheter between the transmitting end and the receiving end, and is configured to guide the transmitted light to propagate to the target detection area in the blood along a relatively stable path, and guide part of the backward or transmitted light after being absorbed and scattered by the blood to the receiving end. The material of the light guiding layer is selected from flexible polymers with high transparency and biocompatibility, and its refractive index is close to that of plasma to reduce signal fluctuations caused by interface reflection and optical path changes; The locally enhanced support band is embedded in the outer layer or middle layer of the catheter wall around the sensing area, and is configured to improve the anti-bending performance of the catheter structure in this area during the implantation process, and limit the lateral deformation amount of the sensing area under human activities or blood flow impact, so as to stabilize the relative position of the optical device and its coupling relationship with the blood flow; The inner wall anti-interference coating is located on the inner wall of the catheter and covers the light guiding layer to suppress the interference of floating substances or blood cell deposition in the blood on the light path, and has hydrophobic or low adsorption characteristics to reduce the risk of signal drift after blood contact.

[0008] Furthermore, the signal processing unit includes a multi-channel sampling controller, a light intensity signal ratio calculation module, a blood oxygen saturation estimation unit, a noise adaptive filtering unit, and a signal stability correction module; Among them, the multi-channel sampling controller is configured to control the transmitting end to sequentially emit at least two different wavelengths of optical signals, including red light and infrared light, and cooperate with the receiving end to complete independent sampling at each wavelength to obtain the received light intensity signals under different spectral conditions; The light intensity signal ratio calculation module is configured to normalize the received light intensity signals at different wavelengths and calculate their ratios to reflect the absorption characteristic differences between oxyhemoglobin and reduced hemoglobin in the blood; The blood oxygen saturation estimation unit converts the light intensity ratio into a blood oxygen saturation value according to a preset calibration curve or mathematical model, and outputs a blood oxygen saturation signal; The noise adaptive filtering unit is used to dynamically select an appropriate filtering window size and filtering function parameters based on the noise power spectral density, autocorrelation function or signal change rate of the current sampling sequence, and trigger a long window smoothing mechanism when sudden high-frequency interference, catheter vibration or abnormal pulsation mode is detected; The signal stability correction module is used to monitor the absolute intensity change trend of the received light intensity during the sampling process. When the light intensity shows baseline drift, amplitude jitter or abnormal decrease in average brightness in multiple consecutive cycles, it is identified as a slight deviation of the sensor position or local blood flow abnormality, and accordingly adjusts the correction factor of the ratio calculation or temporarily freezes the updated output blood oxygen value to ensure the clinical usability and decision-making safety of the data output.

[0009] Furthermore, the signal processing unit includes an initial calibration module and an individualized adaptation model construction module; Among them, the initial calibration module is used to correlate and compare multiple groups of original light intensity signals collected within a limited calibration time after the oximeter is first implanted and the control blood oxygen values collected by a corresponding external standard oximeter, and fits the mapping relationship between the light intensity ratio and blood oxygen saturation of the current individual by minimizing the estimation error; The individualized adaptation model construction module generates an individualized blood oxygen estimation model based on the calibration result. The model includes wavelength weight factors, nonlinear response adjustment coefficients and interference suppression weight parameters, and stores them in a non-volatile memory for use during subsequent long-term monitoring; Furthermore, the calibration module still retains the ability to perform long-term fine-tuning after the initial modeling. When it is detected that the patient is in a resting state and the change range of blood oxygen is small, samples are collected for comparison with the output result of the current model. If a long-term drift trend is found, the model parameters are corrected in a low-weight manner on the premise of meeting the stability standard; Among them, the initial calibration process is completed by linking with the data of hospital monitoring equipment. During the operation or the initial postoperative period, the control blood oxygen data is collected by a standard monitor and synchronized to the signal processing unit of the oximeter to automatically complete the initial model training process.

[0010] Furthermore, the signal processing unit includes a catheter positioning status monitoring module and a measurement compensation calculation module; Among them, the catheter positioning state monitoring module analyzes the periodic characteristic information related to blood flow direction, flow rate, and pulsation morphology in the light intensity signal sequence collected by the receiving end to identify whether there is a significant change in the positional relationship between the catheter body and the blood vessel axis, including longitudinal displacement, lateral offset, torsion angle change, or change in the exposed state of the receiving end; combines the optical signal baseline, pulsation period, peak morphology, and fluctuation range in the historical stable state to construct an in-catheter optical signal stability model, and compares the difference between the current data and the model during subsequent operation. When the change exceeds the preset threshold, it is determined as a catheter or sensor position offset event; After identifying the catheter micro-displacement event, the measurement compensation calculation module does not directly discard the current sampling data, but introduces an optical path offset compensation algorithm. The optical path offset compensation algorithm is based on the average light intensity before and after the change, the absorption coefficient adjustment factor, and the deduced possible optical path offset length, and weights and corrects the input of the comparison value calculation module, so as to output an estimation result closer to the actual blood oxygen level; If the system detects that the catheter offset trend persists and the optical signal gradually decays to near the noise floor, it can issue a prompt signal to advise medical staff to check the catheter implantation position, and in extreme cases, automatically suspend data upload to prevent misleading alarms.

[0011] Furthermore, the wireless transmission unit is configured with an event-driven multi-level communication scheduling module. The multi-level communication scheduling module dynamically adjusts the transmission frequency, transmission power, and data packet structure of wireless data according to the change trend of the blood oxygen saturation signal and the communication status of external devices; The multi-level communication scheduling module includes a stable state transmission mode, a trend change response mode, and an emergency event reporting mode. Among them, in the stable state transmission mode, if the change amplitude of the blood oxygen saturation signal is lower than the first set threshold within multiple sampling periods, the communication scheduling module controls the wireless unit to perform periodic data transmission in a low-frequency and low-power manner, transmitting once every 5 to 10 minutes, and can combine multiple sampling results to form a compressed data packet to reduce the communication duration; in the trend change response mode, if the change rate of the blood oxygen value exceeds the preset rate threshold, the system switches to the medium-frequency transmission mode, transmitting once every 30 seconds to capture potential clinical change processes; in the emergency event reporting mode, if it is detected that the blood oxygen saturation suddenly drops, suddenly rises, or other situations where the deviation from the set reference value exceeds the second threshold, a high-frequency emergency upload instruction is triggered, and the complete sampling sequence before and after the abnormal event is packaged, encrypted, and timestamped and sent to the external terminal for doctors or the monitoring system to use for traceability analysis.

[0012] Furthermore, the power supply component includes a micro battery pack, a power supply mode control circuit, and a catheter power supply interface; Among them, the power supply mode control circuit is used to automatically switch between the local battery power supply mode and the external power supply mode through the catheter according to the device operating state, and to monitor the system power consumption, remaining battery level, voltage fluctuation, and power supply continuity in real time; in the normal operating state, the micro battery pack serves as the main power source, and the power supply mode control circuit dynamically adjusts the voltage output amplitude and power supply priority according to the current power consumption loads of the signal processing unit and the wireless transmission unit to reduce the overall energy consumption; when it is detected that the external medical platform provides wired power supply through the catheter interface, the control circuit automatically switches to the external power supply mode and simultaneously performs a constant voltage and current limiting charging operation for the micro battery pack.

[0013] Furthermore, the power supply assembly further includes a low battery prediction module, which is used to predict the remaining available duration based on the voltage drop rate and the current power consumption mode during the historical operation cycle of the blood oxygen meter. If the predicted remaining duration is lower than the set threshold, it actively sends a low battery warning signal to the external terminal, and temporarily adjusts the wireless transmission frequency or suspends the high power consumption functional module according to the power supply state evaluation result to extend the device battery life.

[0014] This application provides a blood oxygen monitoring method based on an implantable catheter type blood oxygen meter, including: Insert a flexible catheter into the central vein or artery of the human body, arrange the catheter along the blood vessel direction, and allow blood to flow inside the catheter; Through the transmitting end in the optical sensing element arranged in the inner cavity or the wall of the catheter, emit optical signals with two or more different wavelengths into the blood inside the catheter. After the optical signals pass through or are reflected by the blood, they are received by the receiving end in the same optical sensing element, forming a transmission type or reflection type optical path based on the blood absorption characteristics. Collect the optical intensity signal output by the receiving end, and input the optical intensity signal into the signal processing unit. The signal processing unit calculates the ratio of the optical intensity signals at different wavelengths, and based on the absorption characteristics of hemoglobin at different wavelengths, determines the relative proportion between oxyhemoglobin and reduced hemoglobin in the blood, thereby generating a blood oxygen signal representing the blood oxygen saturation. Transmit the blood oxygen signal wirelessly to an external receiving device through the wireless transmission unit for real-time display, recording, or triggering an alarm by the external device. Provide a continuous working power supply for the transmitting end, receiving end, signal processing unit, and wireless transmission unit through a micro battery or a wired power supply port connected through the catheter to ensure the continuous collection and transmission of the blood oxygen signal.

[0015] Compared with the prior art, this application has the following beneficial effects: (1) By arranging the optical sensing element inside the catheter body, the optical signal directly acts on the flowing blood, avoiding interference from external factors such as skin and tissues, and achieving real-time, stable, and continuous monitoring of blood oxygen saturation, which is applicable to critical patients or scenarios with high-precision requirements during surgery. (2) The present invention integrates the transmitting end and the receiving end in a flexible catheter structure, avoiding external optical fiber connections or complex structural designs. It has a small overall size and good flexibility, can be implanted into blood vessels through conventional catheter intubation methods, facilitating doctor operation, reducing the trauma risk to patients, and is suitable for long-term indwelling monitoring. (3) By configuring a wireless transmission unit, the blood oxygen saturation signal can be transmitted to an external receiving device in real time, realizing remote monitoring, data recording, and risk alarm without physical connection, which helps the intelligent integration and information closed-loop management of the ICU, operating room, and telemedicine system. (4) The power supply component can select a micro battery or a transcatheter power supply method according to the clinical scenario, which not only meets the independent operation in short-term mobile scenarios but also can combine with an external power supply platform to achieve the ability of low-power and long-time continuous operation, enhancing the versatility and adaptability of the system. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of an implantable catheter-type blood oxygen meter provided by the first embodiment of the present application.

[0017] Figure 2 It is a flowchart of a blood oxygen monitoring method based on an implantable catheter-type blood oxygen meter provided by the second embodiment of the present application. Detailed Description of the Embodiments

[0018] Many specific details are set forth in the following description in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0019] The first embodiment of the present application provides an implantable catheter-type blood oxygen meter. Please refer to Figure 1 , which is a schematic diagram of the first embodiment of the present application. The following will describe in detail an implantable catheter-type blood oxygen meter provided by the first embodiment of the present application in combination with Figure 1 .

[0020] The implantable catheter-type blood oxygen meter includes a flexible catheter body 101, an optical sensing element 102, a signal processing unit 103, a wireless transmission unit 104, and a power supply component 105.

[0021] The flexible catheter body 101 is configured to be inserted into the central vein or artery of the human body and is used to carry the blood flow.

[0022] The flexible catheter body 101 is the basic component of the entire implantable catheter - type blood oxygen monitor. Its design not only needs to meet the physical size requirements for intravascular implantation but also takes into account flexibility, biocompatibility, and integration support for subsequent functional components. The flexible catheter body 101 is used to guide blood flow in the body and simultaneously carry key components such as optical sensing elements, signal acquisition paths, power transmission lines, and wireless communication channels. Therefore, the material selection, shape design, and multi - layer structure configuration of the flexible catheter body 101 all need to be comprehensively optimized to achieve high - performance and high - reliability blood oxygen monitoring functions.

[0023] The material of the flexible catheter body 101 is preferably a medical - grade flexible polymer, such as polytetrafluoroethylene (PTFE), polyurethane (PU), or silicone rubber, etc. These materials have excellent flexibility, compressive resistance, and biocompatibility, can withstand the pulsating pressure brought by arterial and venous blood flow in the body, and at the same time have good anti - bending performance, being suitable for smoothly inserting into the central vein (such as the internal jugular vein, subclavian vein) or artery (such as the femoral artery) and maintaining a stable position in the body. The outer diameter of the catheter can be customized according to specific clinical uses, generally controlled between 1 mm and 5 mm, and the inner cavity diameter should be sufficient to ensure smooth blood flow without generating significant blood resistance or turbulent flow.

[0024] In order to embed the optical sensing element 102, the wall of the flexible catheter body 101 can be pre - set with an integrated channel or groove structure for accommodating the transmitting end and the receiving end. This structure can reserve an inner - embedded layer between the multi - layer walls of the catheter or directly adopt a packaging window structure on the flexible catheter wall. In the reflective design, the transmitting end and the receiving end can be set on the same side of the catheter wall, and the optical signal is reflected by the blood and then returns to the receiving end; in the transmissive design, the transmitting end and the receiving end are set on opposite sides of the catheter wall, so that the optical signal passes through the blood and reaches the receiving end. No matter which method is adopted, the transparency and optical properties of the flexible catheter body 101 need to be specially treated to avoid the material itself from absorbing or scattering the optical signal. Optionally, the embedding area on the wall of the catheter body can form an optical window through injection molding or laser grooving process, and then cover it with a thin layer of transparent polymer with high light transmittance to provide a stable optical channel.

[0025] In addition, to ensure the stability of the blood oxygen monitor after long - term implantation, the surface of the flexible catheter body 101 can be provided with an anticoagulant coating, such as heparin or other biocompatible coatings, to reduce the risk of thrombus formation and ensure that the optical window is clean for a long time and not covered by blood components. At the same time, the catheter body also needs to support the pre - embedding of signal transmission and power supply channels. For example, ultra - fine wires or thin - film conductive layers can be arranged inside the catheter wall to connect the optical elements to the signal processing unit 103 and the power supply component 105, so as to achieve functional integration without significantly increasing the overall size of the catheter.

[0026] The flexible catheter body 101 should also have a certain anti-twisting ability to avoid excessive deformation during patient movement, coughing, or body position change, which may affect the optical measurement path. Optionally, a helical reinforcing wire or a tensile fiber interlayer can be integrated into the catheter structure. These reinforcing structures are embedded in the middle layer of the catheter wall and are only provided outside the optical sensing area, which can enhance the mechanical properties without interfering with the light path.

[0027] Finally, for the convenience of clinicians' operation and positioning, the flexible catheter body 101 can also have a radiopaque function. A certain proportion of X-ray contrast agent (such as barium sulfate or iodide) can be doped into the catheter wall, making it visible under image guidance for intubation positioning, ensuring that the optical sensing area is placed within the target blood vessel segment. This design not only improves the positioning accuracy of the oximeter but also contributes to postoperative management and repositioning operations.

[0028] In summary, the flexible catheter body 101 is not only a physical stent but also a carrier platform for each functional unit of the present invention. Its structural design, material selection, and integration ability directly determine the signal stability, service life, clinical applicability, and patient comfort of the oximeter. Therefore, it is the key foundation for the implementation of the technical solution of the present invention.

[0029] Furthermore, an optical stabilization structure is integrated within the area where the optical sensing element of the flexible catheter body is disposed. The optical stabilization structure includes a low-refractive-index light guiding layer, a local strengthening support band, and an inner wall anti-interference coating. Among them, the light guiding layer covers the inner wall surface of the catheter between the transmitting end and the receiving end, and is used to guide the transmitted light to propagate to the target detection area in the blood along a relatively stable path, and guide part of the backward or transmitted light after being absorbed and scattered by the blood to the receiving end. The material of the light guiding layer is selected from flexible polymers with high transparency and biocompatibility, and its refractive index is close to that of plasma to reduce signal fluctuations caused by interface reflection and optical path changes. The local strengthening support band is embedded in the outer layer or the middle layer of the catheter wall around the sensing area, and is used to improve the anti-bending performance of the catheter structure in this area during implantation, and limit the lateral deformation amount of the sensing area under human activities or blood flow impact, thereby stabilizing the relative position of the optical device and its coupling relationship with the blood flow. The inner wall anti-interference coating is located on the inner wall of the catheter and covers the light guiding layer to inhibit the interference of floating substances or blood cell deposition in the blood on the light path, and has hydrophobic or low adsorption characteristics to reduce the risk of signal drift after contact with blood.

[0030] In a preferred embodiment of the present invention, an optical stabilization structure is further integrated in the region of the flexible catheter body where the optical sensing element is provided to improve the coupling efficiency, propagation consistency, and reception reliability of the optical signal, thereby enhancing the stability and accuracy of the blood oxygen measurement result. The optical stabilization structure is entirely located in a local area of the catheter body and cooperates with the optical sensing element to form an optimized measurement optical path unit, which can effectively cope with interference factors such as catheter deformation, optical path disturbance, and blood adhesion in the implanted state.

[0031] This structure first includes a light guide layer provided on the inner wall surface of the catheter between the transmitting end and the receiving end. The light guide layer is made of a flexible transparent polymer material with a low refractive index. This material needs to have high optical transmittance, low scattering rate, and good biocompatibility, preferably fluorinated polymer, modified polyurethane, or medical-grade silicone-based elastomer. The light guide layer is fixed to the inner wall of the catheter by micro-injection molding, spraying, or lamination, and its thickness is controlled between dozens of microns and hundreds of microns, which neither affects the flow of the main blood channel nor can effectively construct a stable light propagation channel. During the propagation of the multi-wavelength optical signal emitted from the light-emitting end to the blood target area, the light guide layer can reduce the refraction and reflection losses between the tube wall and the blood interface. Especially because its refractive index is close to that of plasma, it can significantly reduce the Fresnel reflection effect and ensure that more light energy enters the blood medium. At the same time, when the optical signal returns after being absorbed and scattered by the blood, the light guide layer can also serve as a re-coupling channel to assist in guiding the useful transmitted light or reflected light to the receiving end, improving the receiving efficiency and enhancing the system signal-to-noise ratio.

[0032] To ensure the position stability and functional reliability of the above light guide layer in the physiological environment, a local enhanced support band is also embedded in the catheter wall outside the sensing area. The support band is preferably made of a high-modulus but flexible reinforcing material, such as an aramid fiber band, an ultra-thin metal mesh layer, or a woven polyester fiber cloth, and is embedded in the middle or outer layer structure of the catheter by insert molding, interlayer composite, or thermocompression bonding. Its function is to improve the bending resistance and deformation recovery force of the catheter in the sensing area during implantation or use. Especially under the action of patient movement, blood vessel pulsation, or external traction, it restricts the local twisting or lateral compression of the catheter in the optical device area, maintains the relative position stability between the transmitting end and the receiving end, and ensures the optical path consistency and signal flux constancy. In addition, the structural arrangement of the local enhanced support band can also be locally optimized according to the catheter size and the blood vessel bending path, so that while improving the rigidity, it does not prevent the overall flexibility.

[0033] Furthermore, to reduce the interference of blood components on the optical path, an anti-interference coating is also provided on the surface of the light guide layer covering the inner wall of the catheter. This coating is preferably a hydrophilic or hydrophobic polymer material with low adsorption, low protein adhesion, and anti-blood contamination properties, such as polyethylene glycol (PEG) derivatives, phosphocholine polymers, fluorinated polymers, etc. The coating can be formed by plasma treatment, ultraviolet cross-linking, or chemical grafting, etc., and is firmly attached to the surface of the light guide layer. Its function is to prevent suspended particles, blood cells, plasma proteins, or other microparticles in the blood from depositing, adhering, or forming a film in the light guide area, thereby avoiding a decrease in light flux, an increase in scattering interference, or measurement drift caused by surface contamination. This coating can also have a certain anticoagulant effect, extend the functional life of the sensing area, and reduce the maintenance or replacement frequency.

[0034] Through the synergistic composition of the above light guide layer, support band, and anti-interference coating, the optical stable structure not only improves the optical purity and physical stability of the blood oxygen measurement path but also enhances the robustness of the device in a dynamic human environment.

[0035] An optical sensing element 102 is arranged in the inner cavity or the wall part of the flexible catheter body. The optical sensing element includes a transmitting end and a receiving end. The transmitting end is used to emit light signals with different wavelengths to irradiate the blood in the catheter, and the receiving end is used to receive the remaining light intensity after the light signals are absorbed and scattered by the blood, so as to form a transmissive or reflective optical path for blood oxygen detection.

[0036] The optical sensing element 102 is the core component for obtaining blood oxygen signals and is usually integrated into the inner cavity or wall structure of the flexible catheter body 101. The optical sensing element 102 includes two parts, a transmitting end and a receiving end. An optical path is formed between them through the blood medium. Based on the selective absorption characteristics of different types of hemoglobin in the blood for light of specific wavelengths, the estimation of blood oxygen saturation is realized.

[0037] The transmitting end is used to emit light signals with different wavelengths into the blood in the catheter. In a preferred embodiment, the transmitting end is composed of two or more groups of light-emitting diodes (LEDs), which work in the red light band of about 660 nm and the near-infrared band of about 940 nm respectively. These two wavelengths are selected based on the differences in the absorption spectra of oxyhemoglobin ( ), and reduced hemoglobin (Hb), and can be effectively used to establish a blood oxygen absorption ratio model. The light-emitting unit of the transmitting end should have good directivity and be effectively coupled with the blood flow area in the catheter to ensure that the light signals can fully penetrate or irradiate the blood area. The transmitting end can be controlled by a low-power driving circuit for periodic pulsed light emission. Each time, a light signal of one wavelength is emitted alternately, which helps to reduce the thermal effect and improve the signal acquisition efficiency.

[0038] The receiving end is used to receive the remaining light intensity signal after passing through or being scattered by blood. Preferably, a photosensitive diode or a photodetector is adopted, and its response band covers all the working wavelengths emitted by the transmitting end. The position of the receiving end can be selected according to the optical path design to be arranged opposite to the transmitting end (forming a transmissive structure) or on the same side as the transmitting end (forming a reflective structure), and the present invention is applicable to both structures. In the transmissive structure, the blood is completely located between the transmitting end and the receiving end, and the penetration path is longer, which is suitable for the case where the blood vessel diameter is small and the catheter transparency is high; while in the reflective structure, the light is scattered in the blood and partially returns to the receiving end, which is suitable for the case where the catheter structure allows the sensing element to be arranged on the same side. To improve the signal-to-noise ratio of the received signal, a signal amplifier can be added at the receiving end and cooperate with an analog-to-digital conversion circuit to convert the light intensity signal into an electrical signal and then transmit it to the subsequent signal processing unit.

[0039] To ensure the accuracy and stability of optical measurement, the transmitting end and the receiving end need to maintain a fixed positional relationship in the catheter. For this purpose, the catheter wall can be preset with a packaging groove or a guiding channel, and the optical element is fixedly arranged therein by means of injection molding packaging, optical glue bonding or insert molding. Preferably, a transparent window layer is further arranged outside the sensing element. The window layer is made of a medical-grade polymer with high light transmittance, such as polycarbonate or polymethyl methacrylate (PMMA), and covers the surfaces of the transmitting and receiving areas, playing a dual role of physical protection and optical transmission. To further enhance the suppression of ambient light interference, a light shielding coating can be arranged around the sensing element to prevent lateral stray light from entering the receiving end.

[0040] During long-term clinical use, to avoid the deposition of blood components on the surface of the optical element and affect the light signal transmittance, the surface of the optical sensing element should be subjected to anti-pollution treatment or provided with an anti-thrombotic nano-coating, such as using a hydrophilic coating, a heparin fixation layer or other low-adhesion energy surface materials to prevent red blood cells and platelets from aggregating on the window surface, so as to keep the measurement channel clean and available for a long time. This structure enables the blood oxygen monitoring function of the present invention to be effective not only in the initial stage but also to maintain the measurement stability in the medium- and long-term implanted state.

[0041] This embodiment can also be optionally equipped with a temperature compensation structure for the optical sensing element, because the body temperature change or local microcirculation abnormality during implantation may cause an offset in the light emission intensity and the receiving sensitivity. The temperature compensation structure can include a combination of a thermistor and a correction algorithm to adjust the light intensity signal in real time and further improve the accuracy of blood oxygen estimation.

[0042] In summary, through the collaborative design of integrating the transmitting and receiving optical paths, the fixed coupling structure, the optical protection material and the biosafety coating, the optical sensing element 102 realizes the function of stable, efficient and clinically applicable blood oxygen signal acquisition.

[0043] The signal processing unit 103, connected to the receiving end, is configured to obtain the optical intensity signal output by the receiving end, calculate the relative ratio of oxyhemoglobin to reduced hemoglobin in the blood based on the absorption differences of optical signals of different wavelengths, and generate a blood oxygen saturation signal.

[0044] In this embodiment, the signal processing unit 103 undertakes the core processing function of obtaining the blood oxygen saturation ( ) signal generation from the original optical signal, and is a key link for completing physiological parameter analysis and data output in the entire device. This signal processing unit is electrically connected to the receiving end in the optical sensing element 102, and is used to receive the electrical signals output by it in real time and perform multi-level data processing on these signals to accurately extract the optical characteristics related to the contents of oxyhemoglobin and reduced hemoglobin in the blood, and then calculate the current blood oxygen saturation value.

[0045] The signal processing unit 103 is preferably integrated in the microcircuit board of the catheter body or its connection part, and has the characteristics of low power consumption, high integration and high signal-to-noise ratio, which is convenient for long-term stable operation in implantable applications. During its operation, first, the optical intensity signal output by the receiving end is input to the pre-stage analog signal conditioning module, which includes a low-noise amplifier (LNA), an automatic gain control circuit (AGC) and a low-pass filter, etc., for amplifying the weak optoelectronic conversion signal and removing high-frequency noise and stray interference to ensure a stable and reliable signal baseline is obtained in the subsequent digital signal processing stage.

[0046] The conditioned analog signal will be sampled and digitized by an analog-to-digital converter (ADC). The sampling rate is preferably set in the range of dozens to hundreds of Hertz, which can not only ensure the time resolution of the pulsatile blood flow change, but also avoid excessive data redundancy. The digitized multi-channel optical intensity data is input to the ratio calculation module in the processor. This module calculates the transmittance or reflectance corresponding to each wavelength based on the optical intensity signals of the red light and near-infrared light channels collected, and constructs an optical intensity ratio relationship. This ratio reflects the absorption difference of the two wavelengths in the blood, and this difference is exactly closely related to the ratio of oxyhemoglobin to reduced hemoglobin in the blood, so it is the basic parameter for estimating .

[0047] On this basis, the signal processing unit further includes a blood oxygen estimation model, which can be in the form of a look-up table (based on an empirically calibrated curve) or a functional form (such as a modified Lambert-Beer law), and is used to convert the light intensity ratio into the corresponding percentage value of blood oxygen saturation. Preferably, the model also supports the correction of influencing factors such as temperature, light source drift, and power supply voltage fluctuation, so as to improve the consistency and accuracy of the estimation results under different physiological states and working conditions. In addition, the signal processing unit may also include a pulsation extraction sub-module, which extracts the arterial component by using the periodic fluctuation signal of the light intensity changing with the heartbeat and filters out the interference of the venous and tissue components, so as to achieve more accurate arterial blood oxygen estimation.

[0048] To meet the low-power operation requirements in the long-term implanted state, the signal processing unit supports an intermittent sampling mode, a dynamic processing frequency adjustment mechanism, and an abnormal event-driven processing logic. For example, when the patient's physiological parameters are stable, the sampling frequency and processing frequency can be reduced to save energy, while when a drastic fluctuation of the light intensity signal or a rapid decrease in the blood oxygen level is detected, it automatically switches to a high-frequency sampling and continuous calculation mode, and cooperates with the wireless transmission unit 104 to upload high-priority data.

[0049] The signal processing unit is also equipped with a non-volatile memory or a buffer storage module, which is used to cache the historical blood oxygen data and the original light intensity data within a short period of time for external devices to perform trend analysis or retrospective analysis of emergencies. In some embodiments, the processing unit may also integrate an initial calibration function, and adaptively adjust the algorithm parameters through synchronous comparison with an external blood oxygen meter at the initial stage of device implantation, and establish an individualized blood oxygen estimation model to improve the cross-patient consistency.

[0050] In summary, through the coordinated operation of multiple functional modules such as analog signal conditioning, digital sampling, ratio analysis, model estimation, and dynamic response control, the signal processing unit 103 not only realizes the effective conversion of the original optical signal and high-precision blood oxygen estimation, but also provides comprehensive support in terms of system operation efficiency, power consumption management, and adaptability to abnormal states. Through the cooperation of the above technical structures and algorithm mechanisms, those skilled in the art can construct a blood oxygen signal processing system that meets different clinical needs and realizes the core function of the blood oxygen meter of the present invention.

[0051] Furthermore, the blood oxygen saturation estimation unit calculates the blood oxygen saturation using the following dynamic model value: ; wherein, and are the received light intensity values at wavelengths of 660 nm and 940 nm respectively, which have been normalized; is the dynamic stability compensation factor output by the signal stability correction module, representing the average amplitude of the light intensity offset trend in consecutive periods; is the current signal variance calculated by the noise adaptive filtering unit; and are model parameters generated based on the individual initial calibration results, used for personalized modeling of different physiological structures, catheter positions, and blood flow characteristics. The parameters are stored in a non-volatile memory and can be updated with low weights according to the model fine-tuning strategy during long-term monitoring.

[0052] Through the above non-linear correction model, the blood oxygen estimation process can respond in real time to changes in the optical path stability and fluctuations in the noise level, thereby improving the monitoring accuracy under conditions of catheter micro-displacement, low perfusion, or motion interference, and ensuring the stable output and comparability of clinical data.

[0053] In a preferred embodiment of the present invention, in order to improve the stability and accuracy of blood oxygen saturation estimation, especially in the implantable catheter environment facing complex factors such as signal noise, optical path drift, and individual physiological differences, the signal processing unit in the blood oxygen meter not only includes conventional ratio calculation and model mapping mechanisms, but also further introduces a dynamic compensation estimation model. This model constructs a blood oxygen saturation calculation formula with adaptive and personalized adjustment capabilities by combining various data characteristics derived from the optical signal processing module.

[0054] This formula is based on two key optical receiving channels, that is, the transmitter sequentially emits red light of 660 nm and near-infrared light signal of 940 nm, and the remaining light intensity values corresponding to them are received by the receiver after being absorbed and scattered by the blood. Denote the received light intensities at these two wavelengths as and . In order to eliminate the influence of factors such as unstable light source output and receiver sensitivity fluctuations, both of these values have been normalized based on the reference light intensity. The basic ratio relationship is , and this logarithmic ratio itself can reflect the absorption differences of oxyhemoglobin and reduced hemoglobin for light of different wavelengths, and is the core variable of the traditional ratio type model.

[0055] However, in the implant environment, the light intensity signal is often affected by factors such as local catheter vibration, blood velocity fluctuation, cell deposition, and position offset, resulting in estimation errors even when the ratio values are the same. To solve this problem, two dynamic compensation factors are introduced in the present invention, namely the signal stability correction value and the noise level index .

[0056] Among them, It comes from the signal stability correction module, which evaluates indicators such as the average value of the received optical intensity, the baseline fluctuation range, and the periodic morphological similarity in consecutive sampling periods, and quantifies the result into a stability offset coefficient. This indicator reflects the non-ideal changes of the recent signal under spatial optical path, catheter attitude, or physiological fluid disturbance.

[0057] It is an indicator reflecting signal stability, and its calculation process depends on the results of multiple samplings within a continuous period of time. Usually, the last 10 to 30 consecutive sampling periods are selected. First, the system will statistically analyze the change trend of the average value of the received optical intensity signal in this period. If it is found that the average value shows an obvious upward or downward trend among multiple periods instead of fluctuating slightly around a stable baseline, it is preliminarily determined that there is unstable behavior. Secondly, the system will calculate the baseline fluctuation range of this period of signal, that is, the difference between the maximum value and the minimum value, to reflect the amplitude change characteristics of the signal under spatial drift or slight catheter bending. Moreover, the system will also analyze whether this period of signal maintains a good periodic morphology, such as whether there is a periodic waveform consistent with the heartbeat pulsation. If the waveforms of adjacent periods are inconsistent in shape, duration, or amplitude, it is regarded as abnormal signal morphology. The above three factors are unified, standardized, and weighted and fused to finally form a value representing the overall stability state of the optical signal in the current catheter measurement area.

[0058] It is the variance of the current sampling sequence calculated by the noise adaptive filtering unit, used to measure the intensity of non-periodic and high-frequency disturbance components in the signal, and the unit is the normalized intensity unit (NRU). Its acquisition method is based on the dynamic variance estimation value obtained by combining multiple features such as the residual of the autocorrelation function of each segment of the signal, the energy ratio of the low-frequency part to the high-frequency energy of the power spectral density.

[0059] It is an indicator used to measure the intensity of high-frequency noise components in the current received optical intensity signal. Its calculation process is also based on a sampling sequence, usually continuous samples within a few seconds. First, the system will strip this period of signal from its main periodic waveform, for example, after removing the main component representing the heartbeat fluctuation, and retain the remaining high-frequency components. Then the system judges whether it belongs to noise by analyzing the fluctuation degree of these high-frequency components. More specifically, the system will compare the similarity between this period of signal and several delayed versions of itself. If there are significant differences, it indicates strong high-frequency interference. In addition, the system will compare the energy distribution ratio between the low-frequency region (for example, less than 5 Hz) and the high-frequency region (for example, greater than 20 Hz) of this period of signal. If the high-frequency energy increases significantly, it can also be used as a feature of enhanced noise. Finally, these quantified features are comprehensively judged to generate a noise level score value.

[0060] The present invention uses the following estimation formula to generate the blood oxygen saturation value: ; In the above formula, for the numerator part, on the basis of the original logarithmic ratio, a stability compensation term is added to form an active weighting for the risk of signal offset; while for the denominator part, a noise term coefficient is added to the normalization structure of the traditional model to increase the inhibitory effect of the ratio on the final result in a high-noise state, thereby forming a more interference-resistant dynamic non-linear response.

[0061] The meanings of each coefficient are as follows: Coefficient is a scaling factor used to calibrate the final output result to the range of 0% to 100%, and the recommended value is from 1.03 to 1.08; Coefficient is a stability correction coefficient that controls the degree to which signal instability drags down the estimated value, and the recommended value range is from 0.15 to 0.25, with a default of 0.20; Coefficient is an offset constant to prevent the denominator from approaching zero and at the same time reflects the overall saturation response of the model, and the recommended range is from 0.30 to 0.50; Coefficient is a noise weight factor used to suppress the influence of a high-variance state on the estimated value, and the recommended value range is from 0.8 to 1.5, which is dynamically adjusted according to the signal quality.

[0062] These coefficients can be obtained through the initial calibration module at the initial stage of device implantation, and combined with the standard readings provided by hospital monitoring equipment, and compared and fitted with the actually measured signals of this device. Methods such as least mean square error fitting, BFGS optimization or support vector regression can be used for model training. Finally, the individualized coefficients are stored in the non-volatile memory for subsequent long-term monitoring calls and support periodic low-weight fine-tuning.

[0063] This estimation model can still maintain continuous, stable and reliable output of blood oxygen values under conditions such as catheter micro-displacement, low perfusion, slight sensor loosening or short-term interference, which is significantly better than the estimation method based only on the static ratio model, and is especially suitable for high-reliability scenarios such as ICU, intraoperative implantation, and remote distributed intensive care monitoring.

[0064] The signal processing unit further includes an abnormal event recognition module and an emergency response control module, which are used to implement real-time recognition, sampling strategy upgrade and data protection operations in the scenario of rapid blood oxygen change; wherein, the abnormal event recognition module constructs a comprehensive change index by analyzing in real time the change rate, amplitude, trend slope of the blood oxygen saturation signal, and the distribution characteristics of local extreme points in the short term, and compares it with a preset multi-level threshold model. When the comprehensive index exceeds the set abnormal threshold range, it is determined that an abnormal blood oxygen event has occurred; in response to the above judgment result, the emergency response control module immediately switches the working state of the blood oxygen monitor to the high-frequency sampling mode, shortens the sampling period to half or less of the original sampling period, ensures continuous recording of the whole process of event development, and at the same time activates the local caching mechanism, packs and caches the complete data of several consecutive sampling periods before and after the event occurs, and uploads it to the external terminal through the wireless transmission unit with high priority, along with time stamp, event type mark and stability score information; further, the emergency response control module can also trigger a preset alarm channel to send a warning message to the nursing workstation, mobile terminal or remote medical platform bound to the external receiving device, so that medical personnel can intervene and handle it in time; in addition, if the wireless communication channel is temporarily interrupted during the event, the system will automatically delay the transmission and resend it after the communication is restored, ensuring the data integrity and traceability during the critical period.

[0065] In a preferred embodiment of the present invention, to cope with the possible rapid change of blood oxygen level in clinical practice, the signal processing unit further integrates an abnormal event recognition module and an emergency response control module. These two modules work together, enabling the present invention to not only have the conventional blood oxygen monitoring function, but also have the capabilities of active recognition of emergencies, dynamic sampling adjustment, data protection and abnormal warning, significantly improving the clinical application value of the implantable blood oxygen monitor in high-risk scenarios such as intensive care, intraoperative management, and telemedicine.

[0066] The abnormal event recognition module continuously monitors the blood oxygen saturation signal output by the signal processing link, and extracts a series of dynamic features in each sampling period, including the change rate of the blood oxygen value, the amplitude difference between consecutive periods, the trend slope, and the occurrence frequency and distribution pattern of local extreme points within a specific time window. These features are fused into a comprehensive index reflecting the current severity of blood oxygen signal change. The generation of this index is based on a sliding window mechanism, which does not rely on single-point mutations, but combines the trend changes of multiple periods to reduce the misjudgment rate.

[0067] The system pre - defines a set of hierarchical threshold models, covering four types of states: mild fluctuation, suspicious anomaly, definite anomaly, and extreme emergency. The thresholds for each level can be adjusted individually according to patient type, treatment stage, or doctor settings. For example, for patients in the postoperative recovery period or in a critical condition, the system can set a more stringent slope detection threshold; while for scenarios with more body movements or greater data volatility, a higher tolerance fluctuation threshold can be set. When the comprehensive change index exceeds the set threshold within a short period and conforms to a specific fluctuation pattern, the system determines that an abnormal event has occurred and immediately notifies the emergency response control module to initiate subsequent operations.

[0068] Upon receiving the abnormal recognition signal, the emergency response control module immediately switches the working mode of the pulse oximeter to the high - frequency sampling mode. At this time, the original regular sampling period, such as once every ten seconds, can be shortened to once every five seconds, two seconds, or even one second, ensuring that the system can completely capture the occurrence process, development trajectory, and subsequent recovery of the abnormal event. During this period, the module also activates the local caching mechanism, starting from several sampling points before event recognition, continuously recording the original data of the entire abnormal process, and packing them together to form an event data segment.

[0069] This data segment includes not only the blood oxygen value sequence but also a timestamp, an abnormal type marker (such as a sharp drop, a sharp rise, unstable fluctuations, etc.), and a signal stability score, which are used to assist doctors in judging the cause of the abnormality and the intervention requirements. Once the data is ready, the system will immediately upload it with high priority through the wireless transmission unit to ensure that the event information can reach the external monitoring terminal or the backend server first.

[0070] To further enhance the event response effect, the system can also link to preset alarm channels. For example, it can send sound and graphic alarms to the bound nursing workstation, or push the abnormal event to the doctor's mobile terminal, the nurse's portable receiving device, or the remote medical platform via Bluetooth, Wi - Fi, mobile cellular networks, etc., to achieve remote warning in the first time, facilitating medical staff to make rapid interventions.

[0071] In addition, considering that the communication link may be temporarily interrupted or the signal blocked during clinical use, the emergency response control module is designed with a disconnection fault - tolerance mechanism. When it detects that the wireless channel is unavailable, the system will cache the complete event data segment in the local temporary storage area and periodically poll the communication status. Once the link is restored, the system will immediately resend the event data and attach a recovery marker to ensure that the data of critical abnormal events is not missed or lost, meeting the stringent requirements for the integrity of medical records and traceability analysis.

[0072] Through the above - mentioned module design, the present invention can provide intelligent, fast, and reliable response capabilities in the case of a sharp change in blood oxygen, not only improving the clinical value of monitoring data but also enhancing the prevention and control capabilities of patients' sudden risks.

[0073] A wireless transmission unit 104, communicatively connected to the signal processing unit, is configured to wirelessly transmit the blood oxygen saturation signal to an external receiving device for display, recording, or alarming.

[0074] The wireless transmission unit 104 is configured to transmit the blood oxygen saturation signal generated by the signal processing unit 103 to an external receiving device in real time and reliably, thereby realizing functions such as clinical monitoring, data recording, or abnormal alarming. The wireless transmission unit is a key module constituting the information output link of the implantable catheter-type blood oxygen meter of the present invention, and its design must meet multiple requirements such as low power consumption, small size, stable transmission, and medical data security.

[0075] The wireless transmission unit is preferably integrated in a circuit board electrically connected to the signal processing unit, and physically can be encapsulated in the connection part at the end of the catheter, inside the medical connector, or the area adjacent to the skin exit of the catheter. This unit uses a low-power communication protocol for data transmission, and preferably supports Bluetooth Low Energy (BLE), ZigBee, LoRa, or a dedicated medical wireless protocol (such as IEEE802.15.6), etc. The specific protocol can be selected according to the device compatibility of the hospital and the clinical application scenario. The BLE protocol is suitable for short-distance high-frequency communication, especially suitable for real-time data interaction with bedside monitors and mobile terminals (such as tablets, smartphones); while LoRa or other low-frequency wide-area communication solutions are suitable for long-distance transmission or remote medical monitoring scenarios, especially having advantages in ward centralized monitoring or home care systems.

[0076] The wireless transmission unit is internally provided with a data packet buffering module, which is configured to receive the blood oxygen saturation value and related metadata from the signal processing unit, such as sampling timestamp, signal stability marker, device status information, etc., and construct them into a structured data frame so that the receiving end can completely restore the diagnostic elements of each monitoring cycle. This unit is configured with a transmission scheduling controller, which dynamically adjusts the data transmission frequency according to the device power consumption mode and communication network status. For example, when the blood oxygen signal is in a stable state, the transmission frequency can be reduced to once per minute to enter the energy-saving mode; while in the event of abnormal events such as severe signal fluctuations or rapid drops, the transmission frequency is automatically increased to once per second or higher to ensure the timely reporting of critical physiological events.

[0077] To improve the transmission reliability, the wireless transmission unit supports multiple redundancy mechanisms, such as data packet retransmission, error detection coding (such as CRC check), and temporary storage buffering. If a channel interruption or the external receiving device goes offline during data transmission, the system will temporarily cache the data and immediately complete the retransmission after the communication is restored to avoid information loss. In addition, this unit can also establish a handshaking mechanism with external devices to ensure the exclusivity and security of data transmission through pairing confirmation, effectively avoiding external interference or signal conflicts.

[0078] Considering the privacy protection requirements of medical data, the wireless transmission unit is equipped with a data encryption module to encrypt the blood oxygen data to be sent. Preferably, a symmetric encryption algorithm (such as AES) or a public key encryption mechanism is used to ensure the confidentiality and integrity of the data during transmission. The system can support the identity authentication function, and only allows the pre-bound receiving terminal to decrypt and read the data, preventing the data from being illegally intercepted or tampered with in the wireless channel.

[0079] At the physical level, the circuit size of the entire wireless transmission unit should be strictly limited by the space constraints of the implantable device. Preferably, a system-on-chip (SoC) form is used to integrate the communication protocol stack, radio frequency module, power control circuit, etc., to reduce the number of components and improve the system integration. The antenna structure can be designed as a flexible printed antenna, a patch ceramic antenna or a conformal coil structure, embedded in the outer wall or the tail end housing of the catheter body, which not only meets the antenna performance requirements, but also takes into account the catheter flexibility and patient comfort.

[0080] To ensure communication stability, especially in the complex electromagnetic environment where multiple devices are running simultaneously in the medical scenario, the wireless transmission unit can support channel hopping technology, dynamic spectrum scanning mechanism and interference avoidance algorithm to improve the anti-interference ability and ensure that the blood oxygen signal can be stably and efficiently transmitted to the target terminal. If the present invention is deployed in a centralized care or remote medical system, this module can also support gateway relay and distributed node networking methods to realize the centralized management and hierarchical transmission of data of multiple blood oxygen monitoring terminals.

[0081] In summary, the wireless transmission unit 104 realizes the wireless signal transmission function with low power consumption, high reliability and high data security by integrating multiple sub-modules such as data acquisition buffer, communication protocol processing, encryption security management and transmission scheduling control. Its application in the present invention enables the blood oxygen meter to break away from the traditional wired limitation, has stronger clinical adaptability and intelligent level, and is convenient for doctors to remotely receive data, conduct trend analysis and give timely warning responses.

[0082] Furthermore, the wireless transmission unit is configured with a multi-level communication scheduling module based on event-driven. The multi-level communication scheduling module dynamically adjusts the sending frequency, sending power and data packet structure of the wireless data according to the change trend of the blood oxygen saturation signal and the communication status of external devices; The multi-level communication scheduling module includes a steady-state transmission mode, a trend change response mode, and an emergency event reporting mode. Among them, in the steady-state transmission mode, if the change amplitude of the blood oxygen saturation signal is lower than the first set threshold within multiple sampling periods, the communication scheduling module controls the wireless unit to perform periodic data transmission in a low-frequency and low-power manner, transmitting once every 5 to 10 minutes, and multiple sampling results can be combined to form a compressed data packet to reduce the communication duration; in the trend change response mode, if the change rate of the blood oxygen value exceeds the preset rate threshold, the system switches to the medium-frequency transmission mode, transmitting once every 30 seconds to capture potential clinical change processes; in the emergency event reporting mode, if it is detected that the blood oxygen saturation suddenly drops, suddenly rises, or other situations where the deviation from the set reference value exceeds the second threshold, a high-frequency emergency upload instruction is triggered, and the complete sampling sequence before and after the abnormal event is packaged, encrypted, and timestamped and then sent to an external terminal for doctors or monitoring systems to use for traceability analysis.

[0083] In the implantable catheter-type blood oxygen meter of the present invention, the wireless transmission unit not only undertakes the basic task of sending the blood oxygen saturation signal to an external device, but also is configured with a key functional module, namely an event-driven multi-level communication scheduling module. This module aims to adapt to the changes in the patient's blood oxygen state and the fluctuations in the external communication environment, and reasonably allocate communication resources under limited power conditions, so as to achieve a dynamic balance among data transmission efficiency, energy consumption control, and clinical response speed.

[0084] This multi-level communication scheduling module automatically selects an appropriate transmission mode according to the change trend of the blood oxygen saturation signal generated by the signal processing unit, combined with the communication status feedback of the external device. Specifically, the module includes three different communication strategies: a steady-state transmission mode, a trend change response mode, and an emergency event reporting mode. This hierarchical scheduling mechanism enables the system to be as energy-efficient as possible when there is no abnormality, and can quickly increase the communication frequency in the event of potential risks or emergencies, ensuring the timeliness of medical response and the integrity of data.

[0085] When the patient's blood oxygen saturation remains stable, that is, the change amplitude within multiple consecutive sampling periods is lower than the preset first threshold, the system enters the steady-state transmission mode. In this mode, the communication scheduling module controls the wireless transmission unit to perform periodic data transmission in a low-frequency and low-power manner, preferably transmitting once every 5 to 10 minutes. This frequency is sufficient to support the basic clinical understanding of trends and can significantly reduce the power consumption of the wireless module. In addition, the system can batch compress and combine multiple sampling results in this mode to form a structured compressed data packet containing blood oxygen data at multiple time points, thereby reducing the wireless transmission duration and energy consumption.

[0086] Once the blood oxygen saturation signal shows a continuous upward or downward trend and the change rate exceeds the preset rate threshold, the system automatically switches to the trend change response mode. In this mode, the communication scheduling module increases the data transmission frequency to once every 30 seconds and adjusts the wireless transmission power to a medium level to ensure that the process information of the changing blood oxygen level can be continuously captured and transmitted. This strategy is particularly applicable to scenarios where the patient's condition is unstable, in the early stage of postoperative recovery, or during drug intervention, and can help doctors promptly identify the turning trend of the blood oxygen level or potential downward risks.

[0087] When an emergency is detected, that is, when the blood oxygen saturation value changes violently within a very short period of time, such as a sharp drop, rise, or deviation from the set reference value range exceeding the second threshold, the system immediately activates the emergency reporting mode. In this mode, the communication scheduling module triggers a high-frequency emergency upload command, increases the data transmission frequency to once every few seconds, or maintains real-time communication when necessary, and uploads the complete data sequence before and after the occurrence of the abnormality to the external terminal within the shortest time. These data include blood oxygen saturation values, signal change trends, original light intensity values, system status information, etc. The system also compresses and encrypts these data and attaches accurate timestamps and event tags to ensure their traceability and medical usability. These data can be used by doctors for postoperative analysis, risk tracing, or automatically triggering a remote alarm mechanism, greatly enhancing the timeliness of clinical intervention.

[0088] The multi-level communication scheduling mechanism in the present invention not only focuses on the changes in the signal itself, but also can be extended to combine the quality judgment of the wireless communication link, such as parameters like signal strength, packet loss rate, and external device response delay for comprehensive judgment, further optimizing the transmission decision logic. At the same time, this module can be linked with the power management system. When the system power is insufficient, it preferentially retains the emergency mode or low-frequency transmission function to extend the battery life of the core monitoring ability.

[0089] Through this event-driven multi-level transmission strategy, the implantable catheter-type blood oxygen monitor can flexibly respond to changes in the patient's condition in a dynamic clinical environment, while avoiding the energy consumption waste caused by unnecessary high-frequency communication, providing solid support for the realization of miniaturized, low-power, and intelligent implantable monitoring devices.

[0090] A platform-level communication interface module is configured between the wireless transmission unit and an external receiving device. This module includes a data structuring and processing unit, a communication encryption unit, and a remote platform docking unit, and is used to achieve standardized, structured, and physiological semantic-level data interaction between the oximeter and a hospital information system (HIS), an electronic medical record system (EMR), or a telemedicine platform. Among them, the data structuring and processing unit formats the blood oxygen saturation signal, sampling timestamp, stability score, abnormal event marker, catheter status identifier, etc. output by the signal processing unit, and generates a structured data packet according to the internationally common medical data exchange standard. The communication encryption unit encrypts the data packet based on symmetric or asymmetric encryption algorithms to ensure the integrity and confidentiality of patient privacy data during wireless transmission. The remote platform docking unit establishes a secure channel through an authentication mechanism with a hospital network or a remote cloud platform, uploads the encrypted structured data to a designated server, and at the same time supports linkage with a clinical decision support system, and attaches a prompt label when an abnormal event is uploaded to trigger a risk assessment process on the platform side.

[0091] In an implementation manner of the present invention, to achieve efficient docking of blood oxygen monitoring data with a clinical information system and improve the practical application value of the oximeter in hospital internal information integration and telemedicine, a platform-level communication interface module is further configured between the wireless transmission unit and an external receiving device. This module not only completes the traditional data sending task, but also has the capabilities of structured encoding, encryption protection, and remote platform linkage, enabling the monitoring data from the implantable oximeter to be safely and stably integrated into the electronic medical ecosystem in a standardized, parsable, and traceable manner.

[0092] The platform-level communication interface module is mainly composed of three core functional units, namely a data structuring and processing unit, a communication encryption unit, and a remote platform docking unit. The data structuring and processing unit is responsible for structuring various output information from the signal processing unit according to the internationally common medical data standard. These information include but are not limited to the blood oxygen saturation value, the corresponding sampling timestamp, the signal scoring index calculated by the signal stability module, the risk marker information generated by the abnormal event identification module, and the catheter operation status label provided by the catheter positioning status monitoring module.

[0093] The structured processing process follows the coding rules of standardized communication formats such as HL7 (Health Level Seven) or IEEE 11073, mapping each indicator to a data field and packing it into a hierarchical medical data object. This process not only ensures the consistency and parsability of data between the transmission end and the receiving end, but also provides a semantic basis for subsequent data analysis, archiving storage, and clinical decision support. For example, the system assigns a unique identifier and a complete timestamp to each piece of blood oxygen data, marks the data generation source, stability level, and signal integrity score, and at the same time indicates whether it belongs to an abnormal event segment through a tag field for the hospital information system to perform quick screening and classification processing at the receiving end.

[0094] After the data structuring is completed, the communication encryption unit will perform an encryption operation on the entire data packet to ensure that it cannot be illegally accessed or tampered with during wireless transmission. This module supports symmetric encryption (such as AES-256) and asymmetric encryption (such as RSA, ECC) algorithms. The encryption key can be uniformly distributed by the hospital platform or dynamically generated by the security chip embedded in the blood oxygen monitor and the key exchange is completed. The data encryption process is combined with an integrity verification mechanism, such as digital signature or checksum, which can effectively prevent packet loss, replay, or forgery of data during transmission.

[0095] The task of the remote platform docking unit is to establish a legal, secure, and continuous communication channel with the hospital or cloud platform. Before sending data, this unit will perform two-way authentication with the target platform, using methods such as the TLS-based handshake protocol, hospital intranet VPN authentication, API key verification, or OAuth 2.0 token mechanism to complete identity verification. Once the channel is established, this module will upload the encrypted structured data to the specified server or platform interface address in real-time or at regular intervals. It should be noted that when the uploaded data contains abnormal event markers, the system will automatically attach a risk warning label to trigger the clinical decision support process (CDSS) on the remote platform side. For example, by analyzing the abnormal event trend, combining the patient's historical indicators and other complication information, corresponding intervention suggestions are generated or warning messages are automatically pushed to the attending doctor.

[0096] This platform-level communication interface module not only improves the system integration of the implantable blood oxygen monitor, enabling its data to be seamlessly connected to the hospital information system (HIS), electronic medical record system (EMR), or telemedicine platform, but also enhances the compliance of data at the legal, ethical, and security levels, providing a complete communication foundation and system support for scenarios such as chronic disease management, remote monitoring, and critical care warning. Those skilled in the art can select appropriate structured protocol standards and encryption methods according to the hospital information system interface specifications in actual applications, and configure the data upload frequency and fault-tolerant retransmission strategy based on the platform capabilities, so as to ensure the feasibility and reliability of this communication interface module in actual deployment.

[0097] A power supply component 105 is used to provide operating power for the transmitting end, receiving end, signal processing unit, and wireless transmission unit. The power supply component includes a micro battery or a wired power supply port connected through a catheter.

[0098] In this embodiment, the power supply component 105 is the basis for ensuring the continuous and stable operation of the implantable catheter - type blood oxygen meter. Its design needs to fully consider the multiple requirements of the implant environment for the power supply volume, power consumption, safety, and battery life. The power supply component 105 is used to provide the necessary operating voltage and current for the transmitting end, receiving end, signal processing unit 103, and wireless transmission unit 104 to maintain the energy supply for the entire process of optical signal transmission, acquisition, processing, and transmission.

[0099] The power supply component preferably adopts two methods: a micro battery or a wired power supply port connected through a catheter, and is selected or combined according to specific clinical application scenarios. In the micro - battery scheme, the selected battery should meet basic conditions such as high energy density, low self - discharge rate, good biocompatibility, and encapsulation tightness. Commonly used types can be medical - grade lithium - ion batteries, lithium - polymer batteries, or flexible lithium batteries. Such batteries can be encapsulated at the catheter tail end, inside the connection joint, or independently placed in a subcutaneous pocket. The size can be controlled at the millimeter level, the voltage is usually between 3.0V and 3.7V, and the capacity is determined according to the power consumption configuration, usually between dozens and hundreds of milliampere - hours to meet the continuous operation requirements of several hours to several days. To improve safety, the battery housing should be encapsulated with sealed ceramics, titanium alloys, or polymer materials and have functions of anti - leakage, explosion - proof, and high - temperature power - off protection to prevent electrochemical leakage from damaging patient tissues.

[0100] In specific situations, the power supply component can also be connected to an external power supply through a catheter for wired power supply. This power - supply method is often applicable to the surgical period or short - term monitoring scenarios and can avoid the interference caused by frequent battery replacement. In this configuration, the catheter can be provided with a plug - in electrode port at its near - skin exit or interface part to connect to the external power supply or the central monitoring platform, provide a stable voltage for the blood oxygen meter through a special cable, and simultaneously complete the data communication function. The wire is wrapped with a multi - layer insulating sheath and has high flexibility, tensile strength, and anti - biodegradation performance, and can be placed in the body for a long time without causing a significant immune response.

[0101] To meet complex monitoring requirements, a power management module can be further integrated inside the power supply component 105. This module includes a voltage regulation circuit, a low-voltage power-off protection circuit, a dynamic power consumption scheduling logic, and a power detection unit. The voltage regulation circuit ensures that the supply voltage fluctuates within a set range, preventing unstable emission of optical devices or calculation errors in the signal processing unit due to abnormal voltage. The low-voltage power-off protection circuit automatically shuts down high-power consumption modules, such as the wireless transmission unit, when the battery power is detected to be below the safety limit, so as to extend the retention time of the core monitoring function. The dynamic power consumption scheduling logic can adjust the power supply priority and activation frequency of each module according to the working state. For example, it reduces the pulse frequency of the transmitter during the signal stable period and resumes full-speed operation during abnormal events. In addition, the power detection unit regularly measures the remaining voltage and power consumption rate, evaluates the available battery life in real time, and sends a low-battery warning signal to external devices through the wireless unit to prompt battery replacement or connection to a wired power supply.

[0102] In some embodiments, the power supply component 105 can also support wireless charging function, especially with a receiving coil or a capacitive coupling interface provided at the catheter tail end or the subcutaneous extension module. By emitting an electromagnetic field or a resonant electric field through an external device, percutaneous energy transfer is achieved, and the charging operation can be completed without removing the catheter or surgical intervention, greatly improving the flexibility of energy management during long-term monitoring.

[0103] In addition, to prevent electromagnetic interference from affecting the acquisition and transmission of blood oxygen signals, the wiring and electromagnetic shielding measures of the power supply component need to be reasonably configured. The wires can adopt a twisted pair structure to reduce common-mode interference, and a metal shielding layer or magnetic absorption material is provided around key components, thereby improving the electromagnetic compatibility of the power supply system.

[0104] Generally speaking, the power supply component 105 not only provides the basic function of power supply, but also undertakes multiple responsibilities such as power consumption management, fault protection, battery life optimization, and safety guarantee. Its structural layout, power supply method, and control logic can all be flexibly adjusted according to the patient's condition, monitoring period, clinical process, and device level, with high adaptability and implementation feasibility.

[0105] Furthermore, the power supply component includes a micro battery pack, a power supply mode control circuit, and a catheter-based power supply interface; Among them, the power supply mode control circuit is used to automatically switch between the local battery power supply mode and the external power supply mode through the catheter according to the device operating state, and to monitor the system power consumption, remaining battery level, voltage fluctuation and power supply continuity in real time; in the normal operating state, the micro battery pack serves as the main power source, and the power supply mode control circuit dynamically adjusts the voltage output amplitude and power supply priority according to the current power consumption load of the signal processing unit and the wireless transmission unit to reduce the overall energy consumption; when it is detected that the external medical platform provides wired power supply through the catheter interface, the control circuit automatically switches to the external power supply mode and simultaneously performs a constant voltage and current-limiting charging operation for the micro battery pack.

[0106] In a preferred embodiment of the present invention, the power supply assembly is not only used to provide continuous and stable electrical energy for the transmitter, receiver, signal processing unit and wireless transmission unit, but is also specially designed as an intelligent power supply structure with a dual power supply path to adapt to the energy management strategies in different stages and with different requirements in clinical applications. The power supply assembly includes a micro battery pack, a power supply mode control circuit and a catheter-based power supply interface. These three work together to support the independent operation of the device when it is disconnected from the external power supply, and can seamlessly switch to the external power supply and charge the battery when needed, ensuring that the device has high availability, low power consumption and the energy guarantee ability to adapt to multiple scenarios.

[0107] The micro battery pack preferably uses a medical-grade lithium polymer battery or a flexible solid-state lithium battery, which is small in size and the thickness can be controlled within a few millimeters. The capacity is matched according to the system power consumption, generally between dozens and hundreds of milliamperes per hour, which is sufficient to support the device to operate continuously for several hours or even dozens of hours when the external power supply is disconnected. The battery pack is encapsulated with a multi-layer insulation structure and has functions of anti-leakage, anti-short circuit and overheat protection, and is suitable for the complex environment of long-term implantation or the body surface transition area. In order to prevent the battery performance from degrading, the battery can be charged and discharged cyclically hundreds of times or more, and it supports maintaining a stable output performance after multiple charges.

[0108] The power supply mode control circuit is located at the core of the power supply assembly. Its main function is to intelligently switch the power supply mode and dispatch the power distribution according to the device operating state, the access situation of the power supply path and the system power consumption requirements. The control circuit integrates multiple monitoring and control modules, including a real-time voltage detection unit, a current load sensing module, a battery remaining power estimation logic and a voltage adjustment module. When the device is in the normal operating state and the external catheter power supply is not connected, the control circuit defaults to using the battery power supply, and at the same time dynamically evaluates the working state of each functional module, especially the periodic power consumption fluctuations of the wireless transmission unit and the signal processing unit, and adjusts the output voltage level and the load power supply priority in real time, so as to avoid resource waste and extend the battery life.

[0109] Once it is detected that an external medical platform accesses the wired power supply through the catheter interface, the power supply mode control circuit will automatically identify this state and quickly switch to the external power supply mode. During the switching process, the system operation will not be interrupted, ensuring a smooth transition of the power supply for each working unit. At the same time, the control circuit will start the charging program for the micro battery pack, adopting a constant voltage and current-limiting charging strategy. According to the current battery charge, cell temperature and internal impedance, it dynamically controls the charging voltage and current to avoid overcharging or overheating, extend the battery life and ensure patient safety. In the case of unstable or interrupted external power supply, the system can also quickly fall back to the battery power supply mode to ensure that critical monitoring tasks are not interrupted.

[0110] Through the above dual-mode power supply strategy, the device can give priority to using external power supply during surgery to ensure high-frequency data acquisition and transmission. When the patient leaves the operating table or is in a transportation or observation state, it can rely on the built-in battery to work independently. Such a configuration is particularly suitable for occasions that require long-term continuous monitoring but are not convenient for frequent equipment replacement, such as intensive care, postoperative recovery period, telemedicine or home care environment.

[0111] This structure not only improves the stability of the system operation and the intelligent level of energy management, but also provides technical support for the clinical deployment and industrial application of the present invention.

[0112] Furthermore, the power supply component further includes a low battery prediction module, which is used to predict the remaining available duration based on the voltage drop rate and the current power consumption mode in the historical operation cycle of the oximeter. If the predicted remaining duration is lower than the set threshold, it will actively send a low battery warning signal to the external terminal, and temporarily adjust the wireless transmission frequency or suspend the high-power consumption functional module according to the power supply state evaluation result to extend the device battery life.

[0113] In a preferred embodiment of the present invention, to further improve the power use efficiency and the intelligent level of energy management of the implantable catheter oximeter during actual application, a functional module, namely a low battery prediction module, is added to the power supply component. The design concept of this module is based on the dynamic changes of the working state of the oximeter and the actual power consumption law to predict in advance the risk of insufficient battery power that the power supply system may face, so that the device can issue a warning independently, and through the system-level power consumption adjustment strategy, achieve the optimal allocation and use of the remaining power, ensuring the continuity of the monitoring task and the safety of clinical operations.

[0114] The low battery prediction module mainly relies on the recording and modeling of the battery voltage drop rate of the device during its historical operation cycle. It analyzes the voltage change trend under specific power consumption modes by continuously monitoring the relationship between the battery output voltage and the device load. For example, when the wireless transmission unit is in a high-frequency working state, the voltage drops significantly faster than in the low-power standby state. By capturing the power consumption characteristics in different working modes in real time and combining with the current remaining battery voltage value, this module comprehensively judges the power consumption speed of the system and estimates the length of time that the current battery power can support under the existing working mode, that is, the remaining available duration.

[0115] When the remaining available duration calculated by the low battery prediction module is lower than a preset safety threshold, such as less than 30 minutes or less than 10% of the theoretical capacity, the system will immediately actively trigger the warning mechanism. This warning mechanism sends a low battery prompt message to the external receiving device through the wireless transmission unit 104, notifying the doctor or the monitoring system that the current device is in a low battery state, so as to prepare in advance for replacing the power supply, adjusting the monitoring strategy or terminating unnecessary operations, and avoiding data interruption or clinical response delay caused by sudden power failure.

[0116] At the same time, to ensure that the remaining battery power can be used as much as possible for the core task of blood oxygen monitoring, the low battery prediction module also cooperates with the system power consumption scheduling logic. According to the power supply status evaluation result, the module can temporarily adjust the wireless transmission frequency. For example, it can reduce the frequency of uploading data from once every 30 seconds to once every 5 minutes, only retaining the trend data transmission to reduce the energy consumption burden of wireless communication. Furthermore, when necessary, this module can also instruct to temporarily turn off or suspend the operation of non-critical modules, such as suspending background cache synchronization, data encryption processing or the operation of high-precision signal filtering algorithms, to free up more power for the core measurement link to continue running.

[0117] Such low battery prediction and response mechanisms can not only significantly extend the effective operation time of the device under extreme conditions, but also improve the overall intelligent response ability of the blood oxygen monitor, enabling it to have the self-regulating ability to face emergencies. In addition, the accuracy of this module can be further enhanced through algorithm optimization in the later stage, such as introducing influencing factors such as temperature, current change rate, and battery internal resistance estimation to build a more refined battery state model.

[0118] Through the low battery prediction module in the present invention, the implantable catheter-type blood oxygen monitor can still achieve energy management efficiency and clinical stability comparable to high-end medical devices while ensuring miniaturization of volume.

[0119] In the above embodiments, an implantable catheter-type blood oxygen monitor is provided. Correspondingly, the present application also provides a blood oxygen monitoring method based on the implantable catheter-type blood oxygen monitor. Please refer to Figure 2, which is a schematic diagram of an embodiment of a blood oxygen monitoring method based on an implantable catheter - type blood oxygen meter according to the present application. Since this embodiment, i.e., the second embodiment, is basically similar to the first embodiment, the description is relatively simple. For related parts, refer to the partial description of the first embodiment. The system embodiments described below are merely illustrative.

[0120] The second embodiment of the present application provides a blood oxygen monitoring method based on an implantable catheter - type blood oxygen meter, including: Step S201: Insert a flexible catheter into the central vein or artery of the human body, arrange the catheter along the blood vessel direction, and allow blood to flow inside the catheter; Step S202: Through the transmitting end in the optical sensing element arranged in the inner cavity or the wall part of the catheter, emit optical signals with two or more different wavelengths into the blood inside the catheter. After the optical signals pass through or are reflected by the blood, they are received by the receiving end in the same optical sensing element, forming a transmission - type or reflection - type optical path based on the blood absorption characteristics; Step S203: Collect the optical intensity signals output by the receiving end, and input the optical intensity signals into a signal processing unit. The signal processing unit calculates the ratio of the optical intensity signals at different wavelengths, and based on the absorption characteristics of hemoglobin for different wavelengths, determines the relative ratio between oxyhemoglobin and reduced hemoglobin in the blood, thereby generating a blood oxygen signal representing blood oxygen saturation; Step S204: Transmit the blood oxygen signal wirelessly to an external receiving device through a wireless transmission unit for real - time display, recording, or triggering an alarm by the external device; Step S205: Provide a continuous working power supply for the transmitting end, receiving end, signal processing unit, and wireless transmission unit through a micro - battery or a wired power supply port connected by the catheter to ensure continuous acquisition and transmission of the blood oxygen signal.

[0121] The third embodiment of the present application provides an electronic device, and the electronic device includes: A processor; A memory for storing a program, which when read and executed by the processor, executes a blood oxygen monitoring method based on an implantable catheter - type blood oxygen meter provided in the second embodiment of the present application.

[0122] The fourth embodiment of the present application provides a computer - readable storage medium, on which a computer program is stored. When the program is executed by a processor, it executes a blood oxygen monitoring method based on an implantable catheter - type blood oxygen meter provided in the second embodiment of the present application.

[0123] Although the present application is disclosed above in preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application shall be subject to the scope defined by the claims of the present application.

Claims

1. An implantable catheter oximeter, characterized in that: include: A flexible catheter body configured to be inserted into a central vein or artery of a human body for carrying blood flow; An optical sensing element arranged in the inner cavity of the flexible catheter body or in the wall of the catheter, the optical sensing element comprising a transmitting end and a receiving end, the transmitting end is used to transmit light signals with different wavelengths to illuminate the blood in the catheter, and the receiving end is used to receive the residual light intensity of the light signal after being absorbed and scattered by the blood, so as to form a transmission or reflection optical path for blood oxygen detection; A signal processing unit connected to the receiving end, used to obtain the light intensity signal output by the receiving end, and calculate the relative ratio of oxygenated hemoglobin to reduced hemoglobin in the blood based on the absorption difference of light signals of different wavelengths, and generate a blood oxygen saturation signal; A wireless transmission unit, which is in communication with the signal processing unit and is used to wirelessly transmit the blood oxygen saturation signal to an external receiving device for display, recording or alarm; A power supply component is used to provide working power for the transmitting end, the receiving end, the signal processing unit and the wireless transmission unit. The power supply component includes a micro battery or a wired power supply port connected via a catheter.

2. The implantable catheter oximeter according to claim 1, characterized in that: The flexible catheter body is integrated with an optically stable structure in the area where the optical sensing element is arranged, and the optically stable structure includes a low refractive index light-guiding layer, a local enhanced support belt and an inner wall anti-interference coating; The light-guiding layer is coated on the inner wall surface of the catheter between the transmitting end and the receiving end, and is used to guide the emitted light to propagate to the target detection area in the blood in a relatively stable path, and guide the reverse or transmitted light part absorbed and scattered by the blood to the receiving end. The light-guiding layer material is selected from a flexible polymer with high transparency and biocompatibility, and its refractive index is close to that of plasma, so as to reduce the signal fluctuation caused by interface reflection and optical path change; The local reinforcement support band is embedded in the outer layer or middle layer of the catheter wall around the sensing area, and is used to improve the bending resistance of the catheter structure in this area during implantation, and to limit the lateral deformation of the sensing area under human activity or blood flow impact, thereby stabilizing the relative position of the optical device and its coupling relationship with the blood flow; The inner wall anti-interference coating is located on the inner wall of the catheter and covers the light-guiding layer to suppress interference of floating matter or blood cell deposition in the blood on the light path, and has hydrophobic or low adsorption properties to reduce the risk of signal drift after contact with blood.

3. The implantable catheter oximeter according to claim 1, characterized in that: The signal processing unit includes a multi-channel sampling controller, a light intensity signal ratio calculation module, a blood oxygen saturation estimation unit, a noise adaptive filtering unit and a signal stability correction module; The multi-channel sampling controller is used to control the transmitting end to sequentially transmit at least two optical signals of different wavelengths, including red light and infrared light, and cooperate with the receiving end to complete independent sampling at each wavelength to obtain received light intensity signals under different spectral conditions; The light intensity signal ratio calculation module is used to normalize the received light intensity signals at different wavelengths and calculate their ratios to reflect the difference in absorption characteristics between oxygenated hemoglobin and reduced hemoglobin in the blood; The blood oxygen saturation estimation unit converts the light intensity ratio into a blood oxygen saturation value according to a preset calibration curve or mathematical model, and outputs a blood oxygen saturation signal; The noise adaptive filtering unit is used to dynamically select an appropriate filter window size and filter function parameters based on the noise power spectrum density, autocorrelation function or signal change rate of the current sampling sequence, and trigger a long window smoothing mechanism when sudden high-frequency interference, catheter vibration or abnormal pulsation mode is detected; The signal stability correction module is used to monitor the absolute intensity change trend of the received light intensity during the sampling process. When the light intensity shows baseline drift, amplitude jitter or abnormal decrease in average brightness within multiple consecutive cycles, it is identified as a slight offset in the sensor position or local blood flow abnormality, and the correction factor of the ratio calculation is adjusted accordingly or the output blood oxygen value is temporarily frozen and updated to ensure the clinical availability of the data output and the safety of decision-making.

4. The implantable catheter oximeter according to claim 1, characterized in that: The signal processing unit includes an initial calibration module and an individualized adaptation model building module; The initial calibration module is used to correlate and compare the collected multiple groups of original light intensity signals and the control blood oxygen values ​​collected by the corresponding external standard oximeter within a limited calibration time after the oximeter is first implanted, and fit the mapping relationship between the light intensity ratio and blood oxygen saturation of the current individual by minimizing the estimation error; The individualized adaptation model building module generates an individualized blood oxygen estimation model based on the calibration result, the model including a wavelength weight factor, a nonlinear response adjustment coefficient and an interference suppression weight parameter, and stores it in a non-volatile memory for use in subsequent long-term monitoring.

5. The implantable catheter oximeter according to claim 4, characterized in that: The calibration module retains the ability to fine-tune for a long time after the initial modeling is completed. When it is detected that the patient is in a resting state and the blood oxygen variation is small, samples are collected for comparison with the current model output results. If a long-term drift trend is found, the model parameters are corrected in a low-weight manner under the premise of meeting the stability standard. Among them, the initial calibration process is completed through data linkage with the hospital monitoring equipment. During the operation or in the early postoperative period, the control blood oxygen data is collected through the standard monitor and synchronized to the signal processing unit of the oximeter to automatically complete the initial model training process.

6. The implantable catheter oximeter according to claim 1, characterized in that: The signal processing unit includes a catheter positioning state monitoring module and a measurement compensation calculation module; The catheter positioning state monitoring module analyzes the periodic characteristic information related to the blood flow direction, flow velocity, and pulsation shape in the light intensity signal sequence collected by the receiving end to identify whether the positional relationship between the catheter body and the blood vessel axis has changed significantly, including longitudinal displacement, lateral offset, torsion angle change, or change in the exposure state of the receiving end; combines the baseline, pulsation period, peak shape, and fluctuation range of the light signal under the historical stable state to construct a light signal stability model in the catheter, and compares the difference between the current data and the model in subsequent operations. When the change exceeds the preset threshold, it is judged as a catheter or sensor position offset event; After identifying the catheter micro-movement event, the measurement compensation calculation module does not directly discard the current sampling data, but introduces an optical path offset compensation algorithm. The optical path offset compensation algorithm performs weighted correction on the input of the contrast calculation module based on the average light intensity before and after the change, the absorption coefficient adjustment factor and the derived possible optical path offset length, thereby outputting an estimation result that is closer to the actual blood oxygen level; If the system detects that the catheter deviation trend persists and the optical signal gradually decays to near the noise floor, it can send a prompt signal to advise medical staff to check the catheter implantation position and automatically suspend data upload in extreme cases to prevent misleading alarms.

7. The implantable catheter oximeter according to claim 1, characterized in that: The wireless transmission unit is configured with an event-driven multi-level communication scheduling module, which dynamically adjusts the transmission frequency, transmission power and data packet structure of the wireless data according to the change trend of the blood oxygen saturation signal and the communication status of the external device; The multi-level communication scheduling module includes a stable state transmission mode, a trend change response mode and an emergency event reporting mode, wherein, in the stable state transmission mode, if the change amplitude of the blood oxygen saturation signal within multiple sampling cycles is lower than the first set threshold, the communication scheduling module controls the wireless unit to perform periodic data transmission in a low-frequency, low-power manner, transmitting once every 5 to 10 minutes, and can merge multiple sampling results to form a compressed data packet to reduce the communication time; in the trend change response mode, if the change rate of the blood oxygen value exceeds the preset rate threshold, the system switches to a medium-frequency transmission mode, transmitting once every 30 seconds to capture potential clinical changes; in the emergency event reporting mode, if a sudden drop, sudden rise or other deviation from the set reference value exceeding the second threshold is detected in the blood oxygen saturation, a high-frequency emergency upload instruction is triggered, and the complete sampling sequence before and after the abnormal event is packaged, encrypted and timestamped and sent to an external terminal for doctors or monitoring systems to use for traceability analysis.

8. The implantable catheter oximeter according to claim 1, characterized in that: The power supply assembly includes a micro battery pack, a power supply mode control circuit, and a transcatheter power supply interface; Among them, the power supply mode control circuit is used to automatically switch between the local battery power supply mode and the catheter external power supply mode according to the working status of the equipment, and monitor the system power consumption, remaining power, voltage fluctuation and power supply continuity in real time; under normal operating conditions, the micro battery pack serves as the main power supply source, and the power supply mode control circuit dynamically adjusts the voltage output amplitude and power supply priority according to the current power consumption load of the signal processing unit and the wireless transmission unit to reduce the overall energy consumption; when it is detected that the external medical platform provides wired power supply through the catheter interface, the control circuit automatically switches to the external power supply mode, and simultaneously performs constant voltage and current limiting charging operations for the micro battery pack.

9. The implantable catheter oximeter according to claim 1, characterized in that: The power supply component also includes a low-battery prediction module, which is used to predict the remaining available time based on the voltage drop rate in the historical operation cycle of the oximeter and the current power consumption mode. If the predicted remaining time is lower than the set threshold, a low-battery warning signal is actively sent to the external terminal, and the wireless transmission frequency is temporarily adjusted or the high-power consumption functional module is suspended according to the power supply status evaluation result to extend the battery life of the device.

10. A blood oxygen monitoring method based on an implantable catheter oximeter, characterized in that: include: inserting a flexible catheter into a central vein or artery of a human body, arranging the catheter along the blood vessel, and allowing blood to flow in the catheter; The optical signal having two or more different wavelengths is emitted to the blood in the catheter through the transmitting end of the optical sensor element arranged in the inner cavity of the catheter or the wall of the catheter, and the optical signal is received by the receiving end of the same optical sensor element after passing through or being reflected by the blood, thereby forming a transmission or reflection optical path based on the absorption characteristics of the blood; Collecting the light intensity signal output by the receiving end, and inputting the light intensity signal into a signal processing unit, the signal processing unit performs ratio calculation on the light intensity signals at different wavelengths, and determines the relative ratio between oxygenated hemoglobin and reduced hemoglobin in the blood based on the absorption characteristics of hemoglobin at different wavelengths, thereby generating a blood oxygen signal representing blood oxygen saturation; The blood oxygen signal is wirelessly transmitted to an external receiving device through a wireless transmission unit, so that the external device can display, record or trigger an alarm in real time; A micro battery or a wired power supply port connected through a catheter provides continuous working power to the transmitting end, receiving end, signal processing unit and wireless transmission unit to ensure continuous collection and transmission of blood oxygen signals.

Images