Electromagnetic navigation positioning device and multi-parameter synchronous detection method

Abstract

The application relates to an electromagnetic navigation positioning device which comprises an electromagnetic navigation sensing probe and a control terminal, the electromagnetic navigation sensing probe is installed at one end of a surgical tool placed in an airway, a single elastic spiral induction coil is arranged in the electromagnetic navigation sensing probe, a pressure sensing diaphragm is connected at the tail end of the induction coil, the edge of the pressure sensing diaphragm is fixedly connected with the inner wall of the electromagnetic navigation sensing probe, and a signal line led out from the induction coil is connected with the control terminal; the single elastic spiral induction coil is integrated with positioning, temperature measurement and pressure measurement sensing functions, the control terminal collects voltage signals influenced by an alternating magnetic field, cavity pressure and cavity temperature, carries out Fourier transformation according to voltage amplitudes, splits out frequency spectrum components corresponding to positions, pressures and temperatures in parallel, and calculates parameters, the probe coordinate position, airway temperature and cavity pressure can be synchronously obtained by using only a single coil, the probe structure is small and simple enough, is suitable for minimally invasive operation in a narrow airway, and can avoid signal interference of multiple sensors.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an electromagnetic navigation and positioning device and a multi-parameter synchronous detection method. Background Technology

[0002] Medical electromagnetic navigation and positioning is a minimally invasive intraoperative precision positioning and guidance technology that integrates electromagnetic induction spatial tracking, three-dimensional medical image reconstruction, and multi-coordinate system registration algorithms. The system constructs a stable and controllable low-frequency alternating three-dimensional electromagnetic field in the human operating area through an external magnetic field transmitter. Miniature electromagnetic sensing coils are mounted on the tips of minimally invasive instruments such as interventional catheters, endoscopic probes, and puncture instruments. The sensors generate induced electrical signals by cutting magnetic lines of force within the magnetic field. The main unit collects and analyzes the signal amplitude and phase changes, calculating the sensor's coordinates, pitch, and deflection attitude in three-dimensional space in real time. Simultaneously, preoperative CT and MRI tomographic images of the patient are imported into the system to complete the reconstruction of a three-dimensional anatomical model. A spatial registration algorithm is then used to align the electromagnetic positioning coordinate system with the human anatomical images. The system achieves one-to-one mapping, synchronously overlaying the real-time position of the instrument tip onto the virtual three-dimensional anatomical view, forming a visual navigation interface similar to an in-body GPS. Doctors can use real-time image guidance to avoid key tissues such as blood vessels and nerves, and directly reach deep target areas such as lung nodules, intracranial lesions, and vascular lesions along a preset safe path to complete operations such as biopsy, ablation, and puncture. This technology is not affected by soft tissue obstruction or slight interference from respiratory micro-movements. It also features high positioning accuracy, strong adaptability of flexible instruments, low radiation dose, and minimal trauma. It is widely used in various minimally invasive diagnosis and treatment scenarios such as respiratory intervention, neurosurgery, cardiovascular intervention, and gastrointestinal endoscopy, and can realize an integrated precision diagnosis and treatment closed loop of preoperative path planning, real-time tracking throughout the procedure, and postoperative target location verification. Current electromagnetic navigation devices only support position feedback and cannot determine the actual intracavitary force conditions, such as the degree of contact between the probe and the narrow airway wall. Furthermore, during ablation surgery, they cannot promptly alert doctors to reduce instrument heat output. The monitoring dimension is limited, and doctors rely solely on experience and touch, which greatly increases the risk of punctures or thermal injuries, posing significant safety hazards. If simultaneous monitoring of airway temperature and pressure is desired, current technology requires additional independent temperature and pressure sensors to be added to the probe, leading to several drawbacks: 1. The additional sensing elements and associated signal lines directly increase the overall outer diameter of the probe, making it difficult to insert smoothly into narrow airways, which does not meet the requirements of minimally invasive procedures; 2. Multiple sensing elements concentrated in a confined space generate electromagnetic interference, resulting in the inability to synchronously and accurately acquire position, temperature, and pressure signals. To address the aforementioned problems, this invention proposes an electromagnetic navigation and positioning device and a multi-parameter synchronous detection method. Summary of the Invention

[0003] The purpose of this invention is to overcome the technical problem that existing electromagnetic navigation devices only support position feedback. If it is necessary to monitor the temperature and pressure inside the airway cavity at the same time, an independent temperature sensor and pressure sensor must be installed on the probe, which will bring multiple defects. To this end, this invention provides an electromagnetic navigation positioning device and a multi-parameter synchronous detection method.

[0004] To achieve the objectives of this invention, the technical solution adopted is as follows: In a first aspect, the present invention provides an electromagnetic navigation and positioning device, comprising an electromagnetic navigation sensing probe and a control terminal. The electromagnetic navigation sensing probe is installed at one end of a surgical instrument inserted into the airway. The electromagnetic navigation sensing probe has a single elastic spiral induction coil built into it. A pressure-sensitive diaphragm is connected to the end of the induction coil. The edge of the pressure-sensitive diaphragm is fixed to the inner wall of the electromagnetic navigation sensing probe, and a signal line led out from the induction coil is connected to the control terminal. The control terminal is configured to collect the voltage change signal of the induction coil, and distinguish the voltage components corresponding to position, temperature, and pressure according to the amplitude of the voltage change, and simultaneously calculate the position, temperature, and pressure parameters of the electromagnetic navigation sensing probe in the airway.

[0005] Preferably, the electromagnetic navigation sensor probe is a hollow tubular structure, the induction coil is arranged along the axial direction of the electromagnetic navigation sensor probe, and the outer diameter of the induction coil is fitted to the inner wall of the electromagnetic navigation sensor probe.

[0006] Preferably, the pressure-sensitive diaphragm is located at the foremost opening of the electromagnetic navigation sensor probe, and the end of the elastic spiral induction coil is positioned corresponding to the center of the pressure-sensitive diaphragm.

[0007] Preferably, the control terminal is equipped with a timing control unit, which is used to drive the X, Y, and Z axis orthogonal transmitting coils in the magnetic field generating component to output directional alternating magnetic fields individually in a time-division manner.

[0008] Secondly, the present invention also provides a multi-parameter synchronous detection method for an electromagnetic navigation and positioning device, comprising the following steps: Step S1: Insert the electromagnetic navigation sensor probe into the target cavity of the human airway along with the surgical tools for flaw detection, and continuously input a constant DC current into the induction coil. Step S2: Within a unit time, the X, Y, and Z orthogonal transmitting coils sequentially output directional alternating magnetic fields so that the control terminal can collect the voltage change signal of the induction coil. Step S3: Based on the amplitude of the continuous voltage data change, distinguish the voltage components corresponding to position, temperature, and pressure, and analyze the different voltage components to obtain the position, temperature, and pressure parameters of the electromagnetic navigation sensor probe in the airway.

[0009] Preferably, step S3 includes: Step S31: After amplifying and filtering the continuous voltage data, perform a Fourier transform to obtain the differentiated spectral characteristics of the high voltage amplitude range, medium voltage amplitude range, and low voltage amplitude range. Step S32: Match the spectral characteristics of the medium-pressure amplitude range with a preset pressure spectrum database to obtain pressure parameters; Step S33: Match the spectral characteristics of the low-pressure amplitude range with a preset temperature spectrum database to obtain temperature parameters; Step S34: Substitute the spectral characteristics of the high-voltage amplitude range into the preset three-axis magnetic field spatial position calculation algorithm to calculate the position parameters of the electromagnetic navigation sensor probe.

[0010] Beneficial effects: This invention provides an electromagnetic navigation and positioning device and a multi-parameter synchronous detection method. It integrates positioning, temperature measurement, and pressure measurement sensing functions using a single elastic spiral induction coil. The control terminal collects voltage signals affected by alternating magnetic fields, cavity pressure, and cavity temperature, and performs Fourier transform to decompose the voltage amplitude into corresponding position, pressure, and temperature spectral components for parallel parameter calculation. Only a single coil is needed to simultaneously obtain the probe coordinate position, airway temperature, and intracavitary pressure, making the probe structure sufficiently small and simple, suitable for minimally invasive operations in narrow airways, and avoiding interference from multiple sensor signals. During surgery, instrument navigation and vital sign assessment can be achieved simultaneously, improving the accuracy and safety of airway surgery. Attached Figure Description

[0011] Figure 1 This is a three-dimensional structural diagram of an electromagnetic navigation and positioning device according to the present invention; Figure 2 This is a cross-sectional view of the electromagnetic navigation sensor probe in an electromagnetic navigation and positioning device according to the present invention. Figure 3 This is a flowchart of a multi-parameter synchronous detection method for an electromagnetic navigation and positioning device according to the present invention; Figure 4 This is a flowchart of step S3 in the multi-parameter synchronous detection method of an electromagnetic navigation and positioning device of the present invention; Reference numerals in the attached diagram: 1. Electromagnetic navigation sensor probe; 2. Control terminal; 3. Induction coil; 4. Pressure-sensitive diaphragm; 5. Signal line; 6. Magnetic field generating component. Detailed Implementation

[0012] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0013] Reference Figure 1-4This invention provides an electromagnetic navigation and positioning device, including an electromagnetic navigation sensing probe 1 and a control terminal 2. The electromagnetic navigation sensing probe 1 is installed at one end of a surgical instrument inserted into the airway. The electromagnetic navigation sensing probe 1 has a single elastic spiral induction coil 3 built into it. The end of the induction coil 3 is connected to a pressure-sensitive diaphragm 4. The edge of the pressure-sensitive diaphragm 4 is fixed to the inner wall of the electromagnetic navigation sensing probe 1, and a signal line 5 led out from the induction coil 3 is connected to the control terminal 2. The control terminal 2 is configured to collect the voltage change signal of the induction coil 3, and distinguish the voltage components corresponding to position, temperature, and pressure according to the amplitude of the voltage change, and simultaneously calculate the position, temperature, and pressure parameters of the electromagnetic navigation sensing probe 1 in the airway. Specifically, the electromagnetic navigation sensor probe 1 is fixedly installed at the end of the surgical instrument (bronchoscope or interventional catheter) and delivered to the target location of the airway through the natural cavity along with the instrument. The induction coil 3 synchronously collects electrical signals generated by three different physical effects and transmits them back to the control terminal 2 through the same signal line 5. The control terminal 2 is a computer equipped with a display screen, a data processing motherboard and an interactive interface.

[0014] In a preferred embodiment of the present invention, the electromagnetic navigation sensor probe 1 is a hollow tubular structure, the induction coil 3 is arranged along the axial direction of the electromagnetic navigation sensor probe 1, and the outer diameter of the induction coil 3 is fitted to the inner wall of the electromagnetic navigation sensor probe 1. Specifically, the body temperature can be conducted to the induction coil 3 through the electromagnetic navigation sensor probe 1, thereby affecting the resistance change of the induction coil 3. The electromagnetic navigation sensor probe 1 is made of medical-grade stainless steel (such as 316L) or biocompatible metals such as titanium alloy, and the surface of the induction coil 3 is coated with an insulating varnish such as polyurethane or polyimide.

[0015] In a preferred embodiment of the present invention, the pressure-sensitive diaphragm 4 is disposed at the foremost opening of the electromagnetic navigation sensing probe 1, and the end of the elastic spiral induction coil 3 is disposed corresponding to the center position of the pressure-sensitive diaphragm 4. Specifically, the pressure-sensitive diaphragm 4 can be made of medical-grade silicone rubber or polyurethane film, or an ultra-thin stainless steel or titanium alloy metal diaphragm, which can convert changes in body pressure into deformation of the induction coil 3.

[0016] In a preferred embodiment of the present invention, the control terminal 2 is provided with a timing control unit, which is used to drive the X, Y, and Z orthogonal transmitting coils in the magnetic field generating component 6 to output directional alternating magnetic fields individually in a time-division manner. Specifically, the magnetic field generating component 6 is divided into three groups of mutually orthogonal transmitting coils, which are arranged in three dimensions along the X-axis, Y-axis and Z-axis of the spatial rectangular coordinate system. The three are perpendicular to each other in geometric space and their axes intersect at the same point, forming a standard three-axis orthogonal frame structure. The three-axis orthogonal physical configuration allows the magnetic field vector at any position in space to be uniquely decomposed into the projection components of the three orthogonal axes.

[0017] The present invention also provides a multi-parameter synchronous detection method for an electromagnetic navigation and positioning device, comprising the following steps: Step S1: Insert the electromagnetic navigation sensor probe 1 into the target cavity of the human airway along with the surgical tools for flaw detection, and continuously input a constant DC current into the induction coil 3. Specifically, the impedance change caused by pressure and the resistance drift caused by temperature need to be reflected by the small fluctuations in the voltage across the coil. If no current flows through the coil, the latter two will not be able to generate an effective voltage signal that can be collected. A constant DC feed ensures that the coil is always energized, making it both an induction element in the alternating magnetic field and an active impedance sensor.

[0018] Step S2: Within a unit time, the X, Y, and Z orthogonal transmitting coils sequentially output directional alternating magnetic fields so that the control terminal 2 can collect the voltage change signal of the induction coil 3. Specifically, the timing control unit built into the control terminal 2 sequentially and individually drives the three sets of orthogonal transmitting coils (X-axis, Y-axis, and Z-axis) in the magnetic field generating component 6 within a unit time cycle according to a preset clock rhythm. This allows the three coils to independently output directional alternating magnetic fields of a specific frequency in a time-division multiplexing manner, rather than being excited simultaneously. When a transmitting coil in a certain axis operates alone, the magnetic field direction and gradient distribution at any location in space are unique and known. At this time, the elastic helical induction coil in the electromagnetic navigation sensor probe cuts the magnetic field lines in that specific direction, and the amplitude of the induced electromotive force generated purely reflects the probe's position at that location. The control terminal 2 collects the real-time voltage change signal at both ends of the induction coil simultaneously at a high sampling rate within the time window of the alternating magnetic field output in each axis, without mixing in the magnetic field components of other axes. This signal is transmitted to the front-end conditioning circuit through the signal line 5. Since the three-axis magnetic fields are strictly staggered and do not overlap in time, the control terminal 2 can accurately distinguish the continuously collected voltage sequence into three independent response data corresponding to the X-axis, Y-axis and Z-axis respectively based on the timestamp in the subsequent signal processing. This provides the amplitude basis in three orthogonal directions for the final three-dimensional spatial coordinate calculation.

[0019] Step S3: Based on the amplitude of the continuous voltage data change, distinguish the voltage components corresponding to position, temperature and pressure, and analyze the different voltage components to obtain the position, temperature and pressure parameters of the electromagnetic navigation sensor probe 1 in the airway. Specifically, the external magnetic field directly induces the strongest main electromotive force in induction coil 3, occupying the high-voltage amplitude range; the pressure change is transformed into a violent fluctuation in coil impedance through the mechanical amplification effect of the elastic spiral structure, and its voltage response amplitude is the second strongest, falling in the medium-voltage amplitude range; the temperature only causes a slow thermal drift in the coil's DC resistance, with the weakest effect, corresponding to the low-voltage amplitude range. Based on the preset amplitude threshold, each exclusive spectral component is accurately extracted from the amplitude spectrum, which can achieve hard decoupling of the three sets of physical quantities. The three decoupling results are calculated in parallel and independently, and finally the position, temperature and pressure parameters are synchronously output to the control terminal 2 interface.

[0020] In a preferred embodiment of the present invention, step S3 includes: Step S31: After amplifying and filtering the continuous voltage data, perform a Fourier transform to obtain the differentiated spectral characteristics of the high voltage amplitude range, medium voltage amplitude range, and low voltage amplitude range. Specifically, the original voltage signal picked up by the induction coil 3 is a complex time-domain hybrid waveform formed by the superposition of three physical effects: spatial positioning, intracavitary pressure, and airway temperature. It is first amplified to increase the signal strength, and then filtered by bandpass filtering to remove irrelevant frequency band noise, ensuring that the signal entering the control terminal 2 is pure and reliable.

[0021] Step S32: Match the spectral characteristics of the medium-pressure amplitude range with a preset pressure spectrum database to obtain pressure parameters; Specifically, the minute deformation of the induction diaphragm 4 is converted into the axial expansion and contraction of the induction coil, which significantly changes the coil pitch, total length, and coupling state between each turn, thereby causing a significant change in the coil's AC impedance. This can transform the originally extremely weak displacement into a significant fluctuation in the coil's electrical parameters, which greatly increases the voltage response amplitude caused by pressure. Ultimately, the voltage amplitude spectrum stably falls into the preset medium-voltage amplitude range, forming a clear boundary on the order of magnitude with the strong positioning signal directly induced by the external alternating magnetic field and the weak resistance drift caused by temperature.

[0022] Step S33: Match the spectral characteristics of the low-pressure amplitude range with a preset temperature spectrum database to obtain temperature parameters; Specifically, the voltage change caused by temperature belongs to a quasi-static or extremely low frequency signal. Based on the preset amplitude threshold and frequency band window, the spectral components of this low voltage amplitude range are accurately extracted, thereby completely separating the weak electrical characteristics caused by thermal effect from the position and pressure signals in the frequency domain, ensuring that temperature extraction is not subject to strong electromagnetic interference.

[0023] Step S34: Substitute the spectral characteristics of the high-voltage amplitude range into the preset three-axis magnetic field spatial position calculation algorithm to calculate the position parameters of the electromagnetic navigation sensor probe 1. Specifically, during the calculation, the control terminal 2 extracts three sets of independent amplitude data corresponding to the X, Y, and Z axes orthogonal transmitting coils being individually excited by the high voltage spectrum component within a unit time, according to the preset timing control logic. Subsequently, the control terminal 2 substitutes these three sets of amplitude data into the preset three-axis magnetic field spatial position calculation algorithm. This algorithm is based on the magnetic field mathematical model constructed according to the law of electromagnetic induction (Faraday's law of electromagnetic induction): it pre-calibrates the magnetic field gradient distribution generated by the magnetic field generating component 6 at each point in the working space, and establishes a set of multivariate nonlinear mapping equations for the amplitude, phase, spatial distance, and direction of the induced voltage. By substituting the measured X, Y, and Z axis voltage amplitudes, the algorithm uses numerical solution methods such as the least squares method or Newton's iteration method to inversely calculate the specific spatial coordinates (X, Y, Z) of the electromagnetic navigation sensor probe 1 in the three-dimensional magnetic field coordinate system. At the same time, combined with the phase difference of the multi-axis amplitudes, it can further calculate the pitch and yaw attitude angles of the probe, and finally convert the voltage physical quantity into accurate real-time spatial pose data.

[0024] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. An electromagnetic navigation and positioning device, comprising an electromagnetic navigation sensor probe (1) and a control terminal (2), wherein the electromagnetic navigation sensor probe (1) is installed at one end of a surgical instrument inserted into the airway, characterized in that, The electromagnetic navigation sensor probe (1) has a single elastic spiral induction coil (3) built in. The end of the induction coil (3) is connected to a pressure-sensitive diaphragm (4). The edge of the pressure-sensitive diaphragm (4) is fixed to the inner wall of the electromagnetic navigation sensor probe (1), and the signal line (5) led out from the induction coil (3) is connected to the control terminal (2). The control terminal (2) is configured to collect the voltage change signal of the induction coil (3), and distinguish the voltage components corresponding to position, temperature and pressure according to the amplitude of the voltage change, and simultaneously calculate the position, temperature and pressure parameters of the electromagnetic navigation sensor probe (1) in the airway.

2. The electromagnetic navigation and positioning device as described in claim 1, characterized in that, The electromagnetic navigation sensor probe (1) is a hollow tubular structure. The induction coil (3) is arranged along the axial direction of the electromagnetic navigation sensor probe (1), and the outer diameter of the induction coil (3) is fitted to the inner wall of the electromagnetic navigation sensor probe (1).

3. The electromagnetic navigation and positioning device as described in claim 1, characterized in that: The pressure-sensitive diaphragm (4) is located at the frontmost opening of the electromagnetic navigation sensor probe (1), and the end of the elastic spiral induction coil (3) is positioned corresponding to the center of the pressure-sensitive diaphragm (4).

4. The electromagnetic navigation and positioning device as described in claim 1, characterized in that, The control terminal (2) is equipped with a timing control unit, which is used to drive the X, Y, and Z three-axis orthogonal transmitting coils in the magnetic field generating component (6) to output directional alternating magnetic fields separately in a time-division manner.

5. A multi-parameter synchronous detection method for an electromagnetic navigation and positioning device as described in any one of claims 1-4, characterized in that, Includes the following steps: Step S1: Insert the electromagnetic navigation sensor probe (1) into the target cavity of the human airway along with the surgical tool for inspection, and continuously input a constant DC current into the induction coil (3); Step S2: Within a unit time, the X, Y, and Z orthogonal transmitting coils sequentially output directional alternating magnetic fields so that the control terminal (2) can collect the voltage change signal of the induction coil (3); Step S3: Based on the amplitude of the continuous voltage data change, distinguish the voltage components corresponding to position, temperature and pressure, and analyze the different voltage components to obtain the position, temperature and pressure parameters of the electromagnetic navigation sensor probe (1) in the airway.

6. The multi-parameter synchronous detection method for the electromagnetic navigation and positioning device as described in claim 5, characterized in that: Step S3 includes: Step S31: After amplifying and filtering the continuous voltage data, perform a Fourier transform to obtain the differentiated spectral characteristics of the high voltage amplitude range, medium voltage amplitude range, and low voltage amplitude range. Step S32: Match the spectral characteristics of the medium-pressure amplitude range with a preset pressure spectrum database to obtain pressure parameters; Step S33: Match the spectral characteristics of the low-pressure amplitude range with a preset temperature spectrum database to obtain temperature parameters; Step S34: Substitute the spectral characteristics of the high-voltage amplitude range into the preset three-axis magnetic field spatial position calculation algorithm to calculate the position parameters of the electromagnetic navigation sensor probe (1).

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