An OCT catheter NFC radio frequency identification system and method

Abstract

The present invention discloses an OCT catheter NFC radio frequency identification system and method, including a catheter end assembly and a catheter seat assembly for catheter docking and cooperation; the catheter end assembly includes an S50 tag capable of storing catheter information, and the catheter end assembly includes an NFC circuit board capable of transmitting and receiving magnetic field signals; the catheter end assembly and the catheter seat assembly are fixed by an interlocking structure, and communication is established between the NFC circuit board and the S50 tag to identify OCT catheter information. By designing anti-deformation for the S50 tag at the catheter end of the device, anti-crosstalk design for the NFC circuit board at the control end, blocking to prevent the weakening of the magnetic field by metal materials, and multiple verification and calibration algorithms in software design, this system solves the interference of application environment factors and internal factors on the NFC magnetic field signal, and establishes a stable and reliable communication between the catheter end and the control end of the intravascular tomography system.

Description

Technical Field

[0001] The present invention belongs to the technical field of OCT catheter identification, and in particular relates to an OCT catheter NFC radio frequency identification system and method. Background Art

[0002] The intravascular tomography system is based on intravascular optical coherence tomography (OCT) technology combined with an imaging catheter. OCT technology is a new technology after intravascular ultrasound (IUS).

[0003] OCT is a new intracoronary imaging technology that emerged after IVUS. Compared with IVUS, its extremely high resolution makes it increasingly popular in evaluating vulnerable plaques and guiding stent implantation, especially in the diagnosis and treatment of acute coronary syndrome (ACS).

[0004] The catheter recognition and matching function of OCT imaging catheters has also become a technology worthy of attention in diagnosis and treatment. Traditional catheter information recognition technology mainly relies on the connection and communication between information storage chips and hardware circuits, that is, wired communication. On the other hand, radio frequency identification technology, such as RFID radio frequency identification technology, that is, ultra-high frequency wireless communication, is used. Its characteristics are long communication distance, high power consumption, and communication within a distance of several meters or tens of meters. Relatively speaking, its radio frequency signal is less affected by interference.

[0005] NFC (Near Field Communication) is a short-range wireless communication technology (usually 3 cm, the maximum identification distance can be extended to no more than 10 cm due to device design and environmental influences). It allows contactless point-to-point data transmission and exchange between electronic devices. It achieves fast and secure communication and data exchange at close range through magnetic field inductive coupling. Compared with RFID radio frequency identification technology, its characteristics are: due to the shorter communication distance of NFC, its communication rate is faster, its security is higher, and it has the characteristics of low power consumption, etc., but its transmission signal has weak anti-interference ability.

[0006] During the use of the OCT device, the communication between the controller and the catheter end is established by the controller emitting a magnetic field signal through NFC, generating an induced current with the coil of the S50 tag at the catheter end to provide energy for interactive communication, so as to identify the catheter information and complete the matching between the catheter and the device. The controller then controls the rotating motor to connect with the catheter, and then retracts at high speed to complete the entire treatment process. However, since the OCT device is in the radiation environment of the operating room, it will interfere with the magnetic field signal generated by NFC, resulting in the inability of the control end to establish stable communication with the catheter end, and the device cannot work normally, which poses a great risk. Summary of the invention

[0007] Purpose of the invention: The technical problem to be solved by the present invention is to provide an OCT catheter NFC radio frequency identification system in view of the deficiencies in the prior art, so as to solve the technical problem that the NFC magnetic field signal is interfered with, resulting in the inability to establish communication between the controller and the catheter end.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] An OCT catheter NFC radio frequency identification system comprises a catheter end assembly and a catheter seat assembly for catheter docking; the catheter end assembly comprises an S50 tag that can be used to store catheter information, and the catheter seat assembly comprises an NFC circuit board that can transmit and receive magnetic field signals; the catheter end assembly and the catheter seat assembly are fixed by an interlocking structure, and communication is established between the NFC circuit board and the S50 tag to identify the OCT catheter information.

[0010] Specifically, the OCT catheter information stored in the S50 tag includes at least the catheter type, number of uses and factory date; the S50 tag is composed of a storage chip and an induction coil, and the induction coil obtains energy by receiving the magnetic field signal from the control end and activates the chip to work normally.

[0011] Specifically, the catheter end assembly also includes an external card rotating tooth and a positioning retaining ring; the S50 label is inserted into the outer layer of the catheter outer card body, and the external card rotating tooth is located at the proximal end of the catheter outer card body, and is used to cooperate with the positioning card of the device after the catheter is inserted into the external device, thereby realizing the connection between the catheter and the external device; the external card rotating tooth can rotate and toggle the switch of the external device after docking to trigger an identification signal.

[0012] The material of the S50 tag is soft and easy to deform. Deformation will affect the winding frequency of its own coil and the received magnetic field signal. Therefore, the catheter protective cover is designed according to the size of the S50 tag to prevent the S50 tag from deforming, resulting in inconsistent received magnetic field frequency and causing communication failure.

[0013] Specifically, the positioning retaining ring is located on the outer clamping body of the catheter and is arranged between the S50 label and the outer clamping rotating teeth. When the catheter is inserted into an external device, it serves as a limiting component for the insertion depth and as a mounting limiting piece for the S50 label.

[0014] Furthermore, on the outer surface of the outer clamping body of the catheter at the position of the S50 label, anti-slip grooves are provided; the distal end of the outer clamping body of the catheter is connected to the hollow tail tube, and hollow grooves are arranged at intervals on the circumferential side of the hollow tail tube.

[0015] Specifically, the catheter seat assembly includes a catheter seat outer shell and a catheter seat retaining card; the catheter seat outer shell is connected and interlocked with the outer clamping body of the catheter to fix the catheter; the catheter seat retaining card is arranged between the catheter seat outer shell and the NFC circuit board, and the catheter seat retaining card and the NFC circuit board are sequentially installed on the catheter seat outer shell through a set of self-tapping screws; when the catheter is inserted, the catheter seat retaining card is used to limit the interlocking structure of the outer clamping body of the catheter exceeding the catheter seat outer shell, preventing the S50 label from being out of the magnetic field range due to over-insertion or improper insertion of the catheter. The catheter seat retaining card is located between the NFC circuit board and the S50 label, and it must be made of a non-metallic material to avoid the generation of eddy current effects, which may weaken the magnetic field signal energy and interfere with communication.

[0016] Furthermore, the catheter seat assembly further includes a rocker opening and closing mechanism and an opening and closing mechanism retaining card; the opening and closing mechanism retaining card is located below the catheter seat retaining card and is arranged between the rocker opening and closing mechanism and the catheter seat outer shell; a pair of bolts in the middle of the rocker opening and closing mechanism pass through the opening and closing mechanism retaining card and are fixed to the catheter seat outer shell. The rocker opening and closing mechanism is a positive and negative rotation rocker opening and closing mechanism. To ensure that the fixed structure of the catheter SC head can rotate at high speed in the sheath, the sheath must be quickly fixed. Therefore, an opening and closing mechanism is designed to realize the clamping and loosening of the sheath. The specific structure can be referred to CN208492059U and will not be elaborated here. The opening and closing mechanism retaining card is made of metal and is installed on the catheter seat outer shell made of plastic through screws. The rocker opening and closing mechanism is not directly fixed on the catheter seat outer shell. On the one hand, it prevents the screw holes of the catheter seat outer shell from cracking during the screwing process of the studs of the rocker opening and closing mechanism. On the other hand, because the rocker opening and closing mechanism will cause friction to the catheter seat outer shell during the opening and closing operation, adding a metal material opening and closing mechanism retaining card can reduce friction and increase the mechanical life.

[0017] Specifically, the NFC circuit board comprises a radio frequency chip unit, a crystal oscillator circuit unit, an EMC filter circuit unit, a matching circuit unit, a receiving circuit unit, a terminal communication unit and an inductor coil unit; the matching circuit unit and the inductor coil unit are integrated on the same circuit board, and are connected to the control main board through the terminal communication unit; the crystal oscillator circuit unit, the EMC filter circuit unit, the matching circuit unit and the receiving circuit unit are respectively located on the peripheral circuit of the radio frequency chip unit; the inductor coil unit is wound in a circular ring shape, forming a radio frequency chip transmitting antenna, which is used to transmit and receive radio frequency signals of the S50 tag built into the OCT catheter.

[0018] Specifically, the NFC circuit board is a PCBA that integrates the NFC chip and its peripheral circuits and antenna coil. By calculating the corresponding parameters of the matching devices, the magnetic field strength corresponding to the circuit transmission signal is achieved, thereby realizing two-way communication with the S50 tag.

[0019] Specifically, the NFC chip uses a transmission frequency of 13.56 MHz, an operating mode of SPI communication, and analyzes magnetic field signals through Manchester encoding.

[0020] Specifically, the crystal oscillator circuit unit includes a crystal oscillator X1, a load capacitor C13, and a load capacitor C14. The crystal oscillator circuit unit and the RF chip unit are close to each other and have a reserved distance from the circuit board frame to provide a stable clock signal for the RF chip.

[0021] Specifically, the EMC filter circuit unit includes a power inductor L1, a power inductor L2, and a capacitor C4 and a capacitor C7, which together constitute an LC low-pass filter; wherein the power inductor L1 is connected to the TX1 transmitting pin of the RF chip, the power inductor L2 is connected to the TX2 transmitting pin of the RF chip, and the power inductor L1 and the power inductor L2 are spaced a certain distance from each other to avoid output mutual inductance effect.

[0022] Specifically, the matching circuit unit includes a load capacitor C3, a load capacitor C8, a resonant capacitor C5, a resonant capacitor C9, a resonant capacitor C6, a resonant capacitor C10, and a matching resistor R4 and a matching resistor R6. The load capacitor and the resonant capacitor are adjusted so that the resonant frequency of the inductor coil is 13.56 MHz; the matching circuit unit is symmetrically distributed to reduce the error of the two-way transmission signal; impedance matching is achieved by adjusting the resistance between the NFC chip TX transmission pin to the transmission antenna to be close to the resistance of the S50 tag; and the Q value (quality factor) and bandwidth of the circuit are changed by adjusting the capacitor.

[0023] Specifically, the receiving circuit unit includes a capacitor C11 for filtering out DC signals, and resistors R2 and R3 for forming a voltage divider circuit, so that the sinusoidal DC signal at the RX receiving pin of the radio frequency chip is between 1.5V and 3V.

[0024] Specifically, the terminal communication unit includes a terminal of model SH-8Pin connected to the mainboard, and the terminal is connected to the radio frequency chip using the SPI protocol.

[0025] Specifically, the inductance value of the inductor coil unit is between 1-1.2uH, the number of turns is 4, the diameter is between 28-32mm, and the wiring spacing is between 48-52mil. The inductor coil unit transmits the received magnetic field signal to the NFC chip for analysis. On the one hand, it can emit magnetic field signals to act on the induction coil of the S50 tag to provide energy for tag activation; on the other hand, it can receive magnetic field signals and receive the magnetic field signals returned by the S50 tag.

[0026] Furthermore, the present invention also claims to protect the method of using the above-mentioned system for NFC radio frequency identification of OCT catheters, wherein the catheter end assembly and the catheter seat assembly are docked with each other, the catheter is screwed into the catheter seat to trigger a catheter in place signal, and then the NFC circuit board transmits a magnetic field signal to communicate with the S50 tag on the catheter, parse and read the internally stored information, and thus identify the OCT catheter information.

[0027] Specifically, when the catheter is connected to the device, the MCU on the external device receives a signal from the catheter to turn on the antenna to search for the card, control the NFC circuit board to emit a magnetic field, and identify the S50 tag on the catheter; during this period, the MCU identifies the unique identification code of the S50 tag in the catheter until a stable connection is established with it, and the NFC circuit board receives the returned magnetic field; then, the data of the specified sector in the S50 tag is selected and verified with the set password, and after the verification is passed, the sector information content is read and written; after verifying that the specified length of the information in the sector is in compliance, the sector information is parsed and displayed on the host device, thereby completing the information exchange between the device and the catheter, and realizing the function of stable communication between the catheter end and the control end of the OCT device;

[0028] Among them, a separate thread is designed to drive the NFC circuit board, and the thread priority is set to the highest, and the magnetic field signal returned by the S50 tag is analyzed through anti-collision, encryption, and verification;

[0029] According to the highest priority, NFC communication is started first to ensure that the power of the magnetic field signal emitted by NFC reaches the maximum and prevent the motor movement from occupying the power supply;

[0030] Verify the S50 tag model based on anti-collision. After selecting the tag, avoid misidentification due to interference from other tags.

[0031] Verify according to the tag to ensure that the tag is in the same frequency band as the magnetic field emitted by NFC;

[0032] According to the encryption verification, read the information of the specified sector through the key segment code of the magnetic field signal, and then return the information to the driver. The driver verifies whether the information is correct through the CRC verification algorithm mechanism of the magnetic field return information;

[0033] The key information is the verification mechanism of the S50 tag. The S50 tag is divided into 16 sectors, each sector has 4 blocks, each block has 16 bytes, and each sector corresponds to a different key;

[0034] According to the CRC verification algorithm mechanism, prevent the phenomenon of misidentification caused by the incorrect key segment information of the S50 tag and the scrambled magnetic field signal returned to the driver;

[0035] The whole process is verified three times respectively. Each time a communication is established at three moments: when connecting the catheter, when the driver motor is moving, and when the catheter connection is completed, to ensure the stability of the communication establishment. Beneficial effects

[0036] The system of the present invention solves the interference of the application environment factors and internal factors on the NFC magnetic field signal through the anti-deformation design of the S50 tag at the catheter end of the device, the anti-crosstalk design of the NFC circuit board at the control end, the blocking card to prevent the weakening of the magnetic field by the metal material, and the multiple verification and verification algorithm of the software design, and establishes a stable and reliable communication between the catheter end and the control end of the intravascular tomography system. Description of the drawings

[0037] The following further describes the present invention in detail in conjunction with the drawings and specific embodiments, and the above and / or other advantages of the present invention will become clearer.

[0038] Figure 1 It is a schematic diagram of the outer card body structure of the catheter interface part of the present invention.

[0039] Figure 2 It is a schematic diagram of the catheter seat with an NFC circuit board of the present invention.

[0040] Figure 3 It is a schematic diagram of the circuit board integrating the NFC function of the present invention.

[0041] Figure 4 It is the circuit schematic diagram of the NFC circuit board of the present invention.

[0042] Figure 5 It is the communication structure diagram of the catheter and NFC of the present invention.

[0043] Figure 6It is a workflow diagram of the NFC recognition software algorithm of the present invention. DETAILED DESCRIPTION

[0044] The present invention can be better understood with reference to the following examples.

[0045] The OCT catheter NFC radio frequency identification system of the present invention comprises a catheter end assembly 401 and a catheter seat assembly 402 for catheter docking; the catheter end assembly 401 comprises an S50 tag 101 capable of storing catheter information, and the catheter seat assembly 402 comprises an NFC circuit board 205 capable of transmitting and receiving magnetic field signals; the catheter end assembly and the catheter seat assembly are fixed by an interlocking structure, and communication is established between the NFC circuit board 205 and the S50 tag 101 to identify the OCT catheter information.

[0046] The OCT catheter information stored in the S50 tag 101 includes at least the catheter type, number of uses and production date; the S50 tag 101 is composed of a storage chip and an induction coil, and the induction coil obtains energy by receiving the magnetic field signal from the control end and activates the chip to work normally.

[0047] like Figure 1 As shown, the catheter end assembly also includes an outer card rotating tooth 102 and a positioning retaining ring 103; the S50 label 101 is inserted into the outer layer of the catheter outer card body, and the outer card rotating tooth 102 is located at the proximal end of the catheter outer card body, and is used to cooperate with the positioning card of the device after the catheter is inserted into the external device, so as to achieve the connection between the catheter and the external device; the outer card rotating tooth 102 can rotate and toggle the switch of the external device after docking to trigger the identification signal. At the same time, the positioning card of the device (similar to the dust cover) clamps the outer card rotating tooth 102 to fix the position of the catheter, so that it can maintain a stable working state during the use of the device, and prevent the catheter from loosening due to the high-speed rotation and withdrawal of the catheter.

[0048] The material of the S50 tag is soft and easy to deform. Deformation will affect the winding frequency of its own coil and the received magnetic field signal. Therefore, the catheter protective cover is designed according to the size of the S50 tag to prevent the S50 tag from deforming, resulting in inconsistent received magnetic field frequency and causing communication failure.

[0049] Specifically, the positioning retaining ring 103 is located on the outer card body of the catheter and is arranged between the S50 label 101 and the outer card rotating tooth 102. When the catheter is inserted into an external device, it serves as a limiting component for the insertion depth, and as an installation limiting component for the S50 label 101 to ensure that the catheter is effectively connected to the catheter seat.

[0050] Specifically, without affecting the normal imaging use of the catheter, the S50 tag 101 is placed and sleeved on the outer layer of the outer catheter clamp. The storage chip capacity of the S50 tag 101 is 1KB of EEPROM (1024 Byte), which is divided into 16 sectors. Each sector has 4 blocks, and each block has 16 bytes. The block is used as the access unit, and each sector has an independent set of passwords and access controls. Its size requirements are as follows: the inner diameter of the coil is 26mm, and the outer diameter of the coil is 29mm, which meets the installation and fixation dimensions in the catheter connection protection sleeve, and the induction coil winding meets the 13.56MHz operating frequency.

[0051] The S50 tag 101 is made of soft material, which easily causes the tag to deform. In order to ensure good recognition performance, the installation method of the S50 tag 101 is fixed through the structure of the outer catheter clamp protection sleeve. The top of the protection sleeve is designed with concave and convex particles. On the one hand, it specifies the fixed position of the S50 tag 101, and on the other hand, it increases the friction force so that the S50 tag 101 does not shift and is not easily deformed during use, ensuring the reading and writing stability of the tag.

[0052] In some embodiments, on the outer surface of the outer catheter clamp at the position of the S50 tag 101, an anti-slip groove 104 is provided. The anti-slip groove 104 is the hand-held part during operation and also the installation part of the catheter connection protection sleeve. The purpose of adding concave and convex grooves on its surface is to increase the friction force and prevent the protection sleeve from slipping during the process of screwing the catheter into the catheter seat, affecting the access and use of the catheter. The distal end of the outer catheter clamp is connected to the hollow tail tube 105, and hollow grooves are arranged at intervals on the side circumference of the hollow tail tube 105, so that the catheter can be bent freely, facilitating operation.

[0053] Combined with Figure 2As shown in the figure, the catheter seat assembly 402 includes a catheter seat outer shell 201 and a catheter seat retaining clip 202; the catheter seat outer shell 201 is connected and interlocked with the catheter outer clamping body, thereby fixing the catheter. On the one hand, it ensures the precision and stability of the catheter connection, and on the other hand, it ensures that the distance and position of the S50 tag 101 in the catheter are relatively fixed and will not deviate from the magnetic field range, so as to stably receive the magnetic field signal. The catheter seat retaining clip 202 is arranged between the catheter seat outer shell 201 and the NFC circuit board 205, and cooperates with the positioning retaining ring 103 to provide a second guarantee for the normal access of the catheter. The catheter seat retaining clip 202 and the NFC circuit board 205 are sequentially installed on the catheter seat outer shell 201 through a set of self-tapping screws 206; when the catheter is inserted, the catheter seat retaining clip 202 is used to limit the interlocking structure of the catheter outer clamping body exceeding the catheter seat outer shell 201, preventing the catheter from being over-connected or not connected in place, resulting in the S50 tag not being within the magnetic field range. The catheter seat retaining clip 202 is located between the NFC circuit board and the S50 tag. Since the metal material has conductivity and electromagnetic shielding effect, and NFC is a short-range wireless communication technology with a limited identification distance, the catheter seat retaining clip 202 must be made of non-metallic material to avoid the generation of eddy current effect, resulting in the weakening of the magnetic field signal energy and interference with communication.

[0054] As is well known, the NFC (Near Field Communication) identification distance is limited, and the NFC identification distance is affected by various different factors. First, we select the high-frequency communication working mode with a standard of 13.56 MHz, which is usually only about 3 cm, and the protocol stipulates that the maximum distance does not exceed 10 cm. Mainly, it is affected by environmental factors: when the NFC signal encounters physical obstacles (such as walls, human bodies, etc.) during transmission, it will attenuate, resulting in a shortened identification distance; secondly, factors such as the size, shape, layout, and material of the NFC circuit board antenna will affect the radiation range and intensity of the electromagnetic field, thereby affecting the identification distance. Therefore, the circuit board is fixed as close as possible to the S50 tag.

[0055] In some embodiments, the catheter seat assembly further includes a rocker opening and closing mechanism 204 and an opening and closing mechanism stopper 203; the opening and closing mechanism stopper 203 is located below the catheter seat stopper 202 and is disposed between the rocker opening and closing mechanism 204 and the catheter seat outer housing 201; a pair of bolts in the middle of the rocker opening and closing mechanism 204 pass through the opening and closing mechanism stopper 203 and are fixed to the catheter seat outer housing 201. The rocker opening and closing mechanism 204 is a positive and negative rotation rocker opening and closing mechanism. To ensure that the catheter SC head fixing structure can rotate at high speed within the sheath, the sheath must be quickly fixed. Therefore, an opening and closing mechanism is designed to realize the clamping and loosening of the sheath. The specific structure can be referred to CN208492059U and will not be elaborated here. The opening and closing mechanism stopper 203 is made of metal and is installed on the catheter seat outer housing 201 made of plastic by screws. The rocker opening and closing mechanism 204 is not directly fixed to the catheter seat outer housing 201. On the one hand, it prevents the screw holes of the studs of the rocker opening and closing mechanism 204 from cracking during the screwing process. On the other hand, because the rocker opening and closing mechanism 204 will cause friction to the catheter seat outer housing 201 during the opening and closing operation, adding the metal material opening and closing mechanism stopper 203 can reduce friction and increase the mechanical life.

[0056] As Figure 3 shown, the NFC circuit board 205 includes a radio frequency chip unit 1, a crystal oscillator circuit unit 2, an EMC filter circuit unit 3, a matching circuit unit 4, a receiving circuit unit 5, a wiring terminal communication unit 6, and an inductance coil unit 7; the matching circuit unit 4 and the inductance coil unit 7 are integrated on the same circuit board and are connected to the control main board through the wiring terminal communication unit 6; the crystal oscillator circuit unit 2, the EMC filter circuit unit 3, the matching circuit unit 4, and the receiving circuit unit 5 are respectively located on the peripheral circuits of the radio frequency chip unit 1; the winding method of the inductance coil unit 7 is circular, forming a radio frequency chip transmitting antenna for transmitting and receiving radio frequency signals of the S50 tag built in the OCT catheter.

[0057] Combined with Figure 4 , the NFC circuit board is a PCBA integrating an NFC chip, its peripheral circuits, and an antenna coil. By calculating the corresponding parameters of the matching devices, the magnetic field intensity corresponding to the circuit transmitted signal is achieved, and two-way communication with the S50 tag is realized. The circuit board adopts a double-layer stacked structure. The radio frequency chip unit 1 and its peripheral circuits are placed on the top signal layer, and the inductance coil unit 7 is placed on the bottom signal layer; the radio frequency chip part of the top signal layer is covered with copper foil to enhance the anti-interference ability and obtain a good heat dissipation effect; the bottom signal layer and the inductance coil area are not copper-plated to prevent the metal material of the copper plating from affecting the magnetic field generated during the operation of the inductance coil and causing the performance of the NFC radio frequency identification function to decline.

[0058] In this embodiment, the size of the inductor coil unit 7 matches the outer diameter of the OCT catheter, the supply voltage is fixed, and the recognition distance of NFC is increased by adjusting the matching circuit unit 4 of the chip.

[0059] In this embodiment, the RF chip unit 1 uses an NFC chip with the model number MFRC522, and the RF circuit board is made of RF-4 material.

[0060] In this embodiment, the crystal oscillator circuit unit 2 includes a 27.12 MHz crystal oscillator X1, 10 pf load capacitors C13 and C14. The crystal oscillator circuit unit 2 is close to the RF chip unit 1 and has a reserved distance from the circuit board frame to provide a stable clock signal for the RF chip.

[0061] In this embodiment, the EMC filter circuit unit 3 is calculated by the LC filter formula It can be known that the filtering frequency is preferably kept at 13.56 MHz, including 2.2 uH / 750 mA power inductors L1 and L2, and 56 pf capacitors C4 and C7, which together form an LC low-pass filter; among them, the power inductor L1 is connected to the TX1 transmission pin of the RF chip, the power inductor L2 is connected to the TX2 transmission pin of the RF chip, and the power inductors L1 and L2 are spaced a certain distance from each other to avoid mutual inductance effects.

[0062] In this embodiment, the matching circuit unit 4 includes 16 pf load capacitors C3 and C8, 220 pf resonant capacitors C5 and C9, 43 pf resonant capacitors C6 and C10, and 1.5 Ω matching resistors R4 and R6; the power of the RF circuit is affected by the internal resistance and external impedance of the chip. When the internal resistance and external impedance of the chip are the same, the transmission power efficiency is the highest. Therefore, the inductance coil resonance frequency is set at 13.56 MHz by adjusting the load capacitors and resonant capacitors; the matching circuit unit 4 is arranged symmetrically to reduce the error between the two transmission signals.

[0063] In this embodiment, the receiving circuit unit 5 includes a 1 nf capacitor C11 for filtering DC signals, and 820 Ω resistor R2 and 2.7 K resistor R3 for forming a voltage dividing circuit, so that the sine wave DC signal of the RX receiving pin of the RF chip is between 1.5 - 3V.

[0064] In this embodiment, the terminal communication unit 6 includes a terminal with the model number SH-8Pin connected to the main board, and the working voltage is preferably fixed at 3.3V. It communicates with the RF chip using the SPI protocol, thereby providing the working mode of the RF chip and its flexible application.

[0065] In this embodiment, the inductance value of the inductor coil unit 7 is 1.1uH, the number of turns is 4, the diameter is 30mm, and the line spacing is 50mil. The inductor coil unit 7 transmits the received magnetic field signal to the NFC chip for analysis. On the one hand, it can emit a magnetic field signal to act on the induction coil of the S50 tag to provide energy for tag activation; on the other hand, it can receive a magnetic field signal and receive the magnetic field signal returned by the S50 tag.

[0066] Combination Figure 5 and Figure 6 The method of using the above system for NFC radio frequency identification of OCT catheters is as follows:

[0067] The catheter end assembly 401 and the catheter seat assembly 402 are docked with each other, and the catheter is screwed into the catheter seat to trigger the catheter in place signal. Then the NFC circuit board 205 emits a magnetic field signal to communicate with the S50 tag on the catheter, parse and read the internal stored information, and thus identify the OCT catheter information.

[0068] When the catheter is connected to the device, the MCU on the external device receives the catheter arrival signal, turns on the antenna to search for the card, controls the NFC circuit board to emit a magnetic field, and identifies the S50 tag on the catheter; during this period, the MCU identifies the unique identification code of the S50 tag in the catheter until a stable connection is established with it, and the NFC circuit board receives the returned magnetic field; then, the data of the specified sector in the S50 tag is selected and verified with the set password, and the sector information content is read and written after the verification is passed; after verifying that the specified length of the information in the sector is in compliance, the sector information is parsed and displayed on the host device, thereby completing the information exchange between the device and the catheter, and realizing the function of stable communication between the catheter end and the control end of the OCT device;

[0069] Among them, a separate thread is designed to drive the NFC circuit board, and the thread priority is set to the highest, and the magnetic field signal returned by the S50 tag is analyzed through anti-collision, encryption, and verification;

[0070] According to the highest priority, NFC communication is started first to ensure that the power of the magnetic field signal emitted by NFC reaches the maximum and prevent the motor movement from occupying the power supply;

[0071] Verify the S50 tag model based on anti-collision. After selecting the tag, avoid misidentification due to interference from other tags.

[0072] According to the tag verification, ensure that the magnetic field emitted by the tag and NFC is in the same frequency band;

[0073] According to the encryption check, the key segment code of the magnetic field signal is used to read the information of the specified sector, and then the information is returned to the drive. The drive verifies whether the information returned by the magnetic field is correct through the CRC check algorithm mechanism;

[0074] The key information is the verification mechanism of the S50 tag. The S50 tag is divided into 16 sectors, each sector has 4 blocks, each block is 16 bytes, and each sector corresponds to a different key;

[0075] According to the CRC verification algorithm mechanism, it can prevent the phenomenon of misidentification caused by the wrong key segment information of the S50 tag and the scrambled magnetic field signal returned to the driver.

[0076] The whole process conducts three verifications respectively. That is, when connecting to the catheter, when the driver motor moves, and when the catheter connection is completed, a communication is established at each of the three moments to ensure the stability of the communication establishment.

[0077] The present invention provides an idea and method for an OCT catheter NFC radio frequency identification system and method. There are many methods and ways to specifically implement this technical solution. The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment can be implemented by the prior art.

Claims

1. An OCT catheter NFC radio frequency identification system, characterized in that: The invention comprises a catheter end assembly (401) and a catheter seat assembly (402) for catheter docking; the catheter end assembly (401) comprises an S50 tag (101) capable of storing catheter information, and the catheter seat assembly (402) comprises an NFC circuit board (205) capable of transmitting and receiving magnetic field signals; the catheter end assembly (401) and the catheter seat assembly (402) are fixed by an interlocking structure, and communication is established between the NFC circuit board (205) and the S50 tag (101) to identify OCT catheter information; The catheter end assembly further comprises an external card rotating tooth (102) and a positioning retaining ring (103); the S50 label (101) is inserted into the outer layer of the catheter external card body, and the external card rotating tooth (102) is located at the proximal end of the catheter external card body and is used to cooperate with the positioning card of the device after the catheter is inserted into the external device, thereby realizing the connection between the catheter and the external device; after docking, the external card rotating tooth (102) can rotate and turn the switch of the external device to trigger an identification signal; The positioning retaining ring (103) is located on the outer clamping body of the catheter and is arranged between the S50 label (101) and the outer clamping gear (102), and serves as a limiting component for the insertion depth when the catheter is inserted into an external device, and as an installation limiting component for the S50 label (101); The catheter outer card body is located on the outer surface of the S50 label (101), and is provided with an anti-slip groove (104); the distal end of the catheter outer card body is connected to the hollow tail tube (105), and the hollow tail tube (105) is provided with hollow grooves at intervals on the side circumference; The catheter seat assembly comprises a catheter seat outer shell (201) and a catheter seat stopper (202); the catheter seat outer shell (201) is connected and interlocked with the catheter outer card body, thereby fixing the catheter; the catheter seat stopper (202) is arranged between the catheter seat outer shell (201) and the NFC circuit board (205), and the catheter seat stopper (202) and the NFC circuit board (205) are sequentially mounted on the catheter seat outer shell (201) by a group of self-tapping screws (206); the catheter seat stopper (202) is used to limit the catheter outer card body from exceeding the interlocking structure of the catheter seat outer shell (201) when the catheter is connected.

2. The OCT catheter NFC radio frequency identification system according to claim 1, characterized in that: The OCT catheter information stored in the S50 tag (101) includes at least the catheter type, the number of times it has been used, and the date of manufacture; the S50 tag (101) is composed of a storage chip and an induction coil, wherein the induction coil obtains energy by receiving a magnetic field signal from the control end and activates the chip to work normally.

3. The OCT catheter NFC radio frequency identification system according to claim 1, characterized in that: The catheter seat assembly further comprises a rocker arm opening and closing mechanism (204) and an opening and closing mechanism stopper (203); the opening and closing mechanism stopper (203) is located at the bottom of the catheter seat stopper (202) and is arranged between the rocker arm opening and closing mechanism (204) and the catheter seat outer shell (201); and a pair of bolts in the middle of the rocker arm opening and closing mechanism (204) pass through the opening and closing mechanism stopper (203) and are fixed to the catheter seat outer shell (201).

4. The OCT catheter NFC radio frequency identification system according to claim 1, characterized in that: The NFC circuit board (205) comprises a radio frequency chip unit (1), a crystal oscillator circuit unit (2), an EMC filter circuit unit (3), a matching circuit unit (4), a receiving circuit unit (5), a terminal communication unit (6) and an inductor coil unit (7); the matching circuit unit (4) and the inductor coil unit (7) are integrated on the same circuit board and connected to a control main board via the terminal communication unit (6); the crystal oscillator circuit unit (2), the EMC filter circuit unit (3), the matching circuit unit (4) and the receiving circuit unit (5) are respectively located on the peripheral circuit of the radio frequency chip unit (1); the inductor coil unit (7) is wound in a circular ring shape to form a radio frequency chip transmitting antenna for transmitting and receiving radio frequency signals of an S50 tag built into an OCT catheter.

5. The OCT catheter NFC radio frequency identification system according to claim 4, characterized in that: The crystal oscillator circuit unit (2) comprises a crystal oscillator X1, a load capacitor C13, and a load capacitor C14. The crystal oscillator circuit unit (2) and the radio frequency chip unit (1) are close to each other and have a reserved distance from the frame of the circuit board, so as to provide a stable clock signal for the radio frequency chip. The EMC filter circuit unit (3) comprises a power inductor L1, a power inductor L2, and a capacitor C4 and a capacitor C7, which together form an LC low-pass filter; wherein the power inductor L1 is connected to the TX1 transmitting pin of the radio frequency chip, the power inductor L2 is connected to the TX2 transmitting pin of the radio frequency chip, and the power inductor L1 and the power inductor L2 are spaced a certain distance from each other to avoid output mutual inductance effect; The matching circuit unit (4) comprises a load capacitor C3, a load capacitor C8, a resonant capacitor C5, a resonant capacitor C9, a resonant capacitor C6, a resonant capacitor C10, and a matching resistor R4 and a matching resistor R6. The resonant frequency of the inductor coil is adjusted to 13.56 MHz by adjusting the load capacitor and the resonant capacitor. The matching circuit unit (4) is symmetrically distributed to reduce the error of the two transmission signals. The receiving circuit unit (5) comprises a capacitor C11 for filtering out DC signals, and resistors R2 and R3 for forming a voltage divider circuit, so that the sinusoidal DC signal at the RX receiving pin of the radio frequency chip is between 1.5V and 3V; The wiring terminal communication unit (6) comprises a terminal of model SH-8Pin connected to the mainboard, and is connected to the radio frequency chip by using the SPI protocol for communication; The inductance value of the inductor coil unit (7) is between 1-1.2uH, the number of turns is 4, the diameter is between 28-32mm, and the wiring spacing is between 48-52mil.

6. The method for using the system of claim 1 for NFC radio frequency identification of an OCT catheter, characterized in that: The catheter end assembly and the catheter seat assembly are docked with each other, and the catheter is screwed into the catheter seat to trigger the catheter in place signal. The NFC circuit board then emits a magnetic field signal to communicate with the S50 tag on the catheter, parse and read the internally stored information, and thus identify the OCT catheter information.

7. The method for NFC radio frequency identification of an OCT catheter according to claim 6, characterized in that: When the catheter is connected to the device, the MCU on the external device receives the catheter arrival signal, turns on the antenna to search for the card, controls the NFC circuit board to emit a magnetic field, and identifies the S50 tag on the catheter; during this period, the MCU identifies the unique identification code of the S50 tag in the catheter until a stable connection is established with it, and the NFC circuit board receives the returned magnetic field; then, the data of the specified sector in the S50 tag is selected and verified with the set password, and the sector information content is read and written after the verification is passed; after verifying that the specified length of the information in the sector is in compliance, the sector information is parsed and displayed on the host device, thereby completing the information exchange between the device and the catheter, and realizing the function of stable communication between the catheter end and the control end of the OCT device; Among them, a separate thread is designed to drive the NFC circuit board, and the thread priority is set to the highest, and the magnetic field signal returned by the S50 tag is analyzed through anti-collision, encryption, and verification; According to the highest priority, NFC communication is started first to ensure that the power of the magnetic field signal emitted by NFC reaches the maximum and prevent the motor movement from occupying the power supply; Verify the S50 tag model based on anti-collision. After selecting the tag, avoid misidentification due to interference from other tags. According to the tag verification, ensure that the magnetic field emitted by the tag and NFC is in the same frequency band; According to the encryption check, the key segment code of the magnetic field signal is used to read the information of the specified sector, and then the information is returned to the drive. The drive verifies whether the information returned by the magnetic field is correct through the CRC check algorithm mechanism; The key information is the verification mechanism of the S50 tag. The S50 tag is divided into 16 sectors, each sector is 4 blocks, each block is 16 bytes, and each sector corresponds to a different key; According to the CRC check algorithm mechanism, it can prevent the magnetic field signal from returning garbled code to the drive due to the error of the S50 tag key segment information, causing misidentification; The whole process is verified three times, namely, when the catheter is connected, when the driver motor moves, and when the catheter connection is completed, to ensure the stability of communication establishment.

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