CN112485786A - Capsule endoscope wireless positioning method based on hybrid positioning - Google Patents
Capsule endoscope wireless positioning method based on hybrid positioning Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/86—Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01C—MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY
- G01C21/00—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00
- G01C21/10—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration
- G01C21/12—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning
- G01C21/16—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation
- G01C21/165—Navigation; Navigational instruments not provided for in groups G01C1/00 - G01C19/00 by using measurements of speed or acceleration executed aboard the object being navigated; Dead reckoning by integrating acceleration or speed, i.e. inertial navigation combined with non-inertial navigation instruments
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
- G01S13/06—Systems determining position data of a target
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
- G01S7/285—Receivers
- G01S7/292—Extracting wanted echo-signals
- G01S7/2923—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/28—Details of pulse systems
- G01S7/285—Receivers
- G01S7/292—Extracting wanted echo-signals
- G01S7/2923—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods
- G01S7/2927—Extracting wanted echo-signals based on data belonging to a number of consecutive radar periods by deriving and controlling a threshold value
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Abstract
本发明涉及一种基于混合定位的胶囊内窥镜无线定位方法，其步骤如下：(1)获取基带脉冲信号；(2)窄波束周期性向胶囊内窥镜方向发射电磁波信号；(3)接收回波信号并对其进行信号处理，判断胶囊内窥镜是否在窄波束范围内；如在，则计算出胶囊内窥镜位置测量值；(4)获取胶囊内窥镜的位置信息，利用测量值形成胶囊内窥镜的运动点迹，进一步判断胶囊内窥镜是否在窄波束范围内；如在，输出胶囊内窥镜位置，并调整窄波束的方向，使窄波束中心对准步骤(3)计算的胶囊内窥镜位置所对应方位；若不存在，则进入步骤(2)。该定位方法不但能够应对人体内复杂的电磁环境，而且可以降低发射功率，减少电波对人体的损害，最终精确有效且灵活地测算人体内胶囊内窥镜的位置。
The present invention relates to a wireless positioning method for capsule endoscope based on hybrid positioning. wave signal and perform signal processing on it to determine whether the capsule endoscope is within the narrow beam range; if so, calculate the position measurement value of the capsule endoscope; (4) obtain the position information of the capsule endoscope and use the measurement value Form the movement point trace of the capsule endoscope, and further judge whether the capsule endoscope is within the narrow beam range; if so, output the position of the capsule endoscope, and adjust the direction of the narrow beam to align the center of the narrow beam in step (3) The orientation corresponding to the calculated position of the capsule endoscope; if it does not exist, go to step (2). The positioning method can not only deal with the complex electromagnetic environment in the human body, but also can reduce the transmission power, reduce the damage of radio waves to the human body, and finally accurately, effectively and flexibly measure the position of the capsule endoscope in the human body.
Description
Technical Field
The invention relates to the technical field of capsule endoscopes, in particular to a capsule endoscope wireless positioning method based on hybrid positioning.
Background
In the in vivo positioning technique of capsule endoscope, magnetic positioning or radioactive isotope labeling method is usually adopted. The magnetic positioning method uses a permanent magnet as an excitation source, and uses a magnetic field sensor to measure a magnetic field so as to realize positioning and orientation. A small cylindrical magnet is packaged in a capsule, the small magnet is approximately regarded as a magnetic dipole, a magnetic field generated by the cylindrical magnet is a function of the central position and the south-north polar direction vectors, magnetic field sensors are arranged around the dipole to measure the magnetic field of a plurality of fixed points, and the position of the capsule and the direction of lens alignment can be solved through a linear algorithm, a nonlinear algorithm or a method combining the linear algorithm and the nonlinear algorithm. The method of radioactive isotope labeling is to label a research object with a radionuclide as a tracer.
With the increasing requirements of medical workers on the capsule positioning efficiency, the flexibility, safety, accuracy and cost of the two methods can not meet the requirements gradually. Meanwhile, with the development and popularization of millimeter wave and terahertz technologies, the application of a wireless positioning technology to the positioning of the capsule endoscope becomes possible. However, the capsule endoscope positioning is completely different from the traditional radio positioning, and the human body not only has a complex in-vivo electromagnetic environment, but also has strict limits on the intensity of the electromagnetic radiation which can be borne. Therefore, there is a need to design an in vivo positioning method of a capsule endoscope, which has accurate and flexible positioning and meets the safety standard.
Disclosure of Invention
The invention aims to provide a capsule endoscope wireless positioning method based on hybrid positioning, so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme:
a capsule endoscope wireless positioning method based on hybrid positioning comprises the following steps:
(1) obtaining a baseband pulse signal;
(2) forming narrow beams by using an external transceiving array to the baseband pulse signals, then periodically transmitting electromagnetic wave signals to the capsule endoscope, and reflecting part of the electromagnetic wave signals back to form echo signals;
(3) receiving echo signals and processing the echo signals, detecting output signals through the strength and cancellation of multipoint echo signals, and judging whether the capsule endoscope is in a narrow beam range; if so, calculating a capsule endoscope position measurement value and storing the result;
(4) acquiring position information of the capsule endoscope, forming a motion point trace of the capsule endoscope by using the measured value of the position of the capsule endoscope at each moment stored in the step (3), and further judging whether the capsule endoscope is in a narrow beam range; if so, outputting the position of the capsule endoscope, and adjusting the direction of the narrow beam to align the center of the narrow beam with the position corresponding to the position of the capsule endoscope calculated in the step (3); if not, go to step (2).
Further, the baseband pulse signal satisfies: the bandwidth is one tenth of the center frequency of the transmitted signal.
In a further scheme, the in-vitro transceiving array comprises an in-vitro antenna and a feeder line, wherein one end of the in-vitro antenna is connected with the skin of a human body through a dielectric layer, and the other end of the in-vitro antenna is connected with the feeder line; the antenna housing is arranged at the upper ends of the external antenna and the dielectric layer, and the top end of the feeder line penetrates through the antenna housing and is positioned outside the antenna housing; the electromagnetic property of the dielectric layer is similar to that of human skin.
The human body is an electromagnetic field with varying electrical parameters such as current, voltage, resistance, impedance, vibration, frequency spectrum, heat, etc. The electromagnetic property of the dielectric layer is consistent with or similar to that of human skin, and influence is avoided.
If the antenna is directly in contact with the skin of the human body, there is inevitably an air gap, and the conduction path of the electromagnetic waves from the antenna to the human body is: the antenna (metal) -air (in the gap) -human skin causes the electromagnetic waves to pass out of the antenna and then through the air to the human skin, during which attenuation occurs. In the present application, a dielectric layer is coated between the antenna and the skin of the human body, and the transmission path of the electromagnetic wave is: antenna-dielectric layer-human skin. Because the electromagnetic property of the dielectric layer is similar to that of human skin, the smaller the attenuation of electromagnetic waves on the interface of the dielectric layer is, the electromagnetic wave transmission can be simply equivalent to an antenna-human skin, namely, air gaps are eliminated.
According to a further scheme, the dielectric layer is prepared by stirring and mixing the following substances in percentage by mass:
wherein a relaxant is added to the test solution to shorten the relaxation time of the test nuclei without producing significant line shifts and broadening. Such as: chromium acetylacetonate (Cr (acac)3)、Mn(acac)2、Cu(acac)2、Gd(acac)2。
The surfactant is conventional stearic acid, oleic acid, lauric acid, sodium dodecylbenzenesulfonate, sodium dodecylsulfate, etc.
The dielectric layer is not a protection point of the invention, and the application only needs to select the dielectric layer with electromagnetic characteristics similar to those of human skin, and the invention includes: the dielectric layer is made of relaxation agent and CaCl2When the oil-in-water emulsion is used, the oil-in-water emulsion is coated on the surface of human skin to form a thin liquid layer, so that air gaps are eliminated, and the electromagnetic wave transmission effect is improved.
According to the further scheme, the narrow beam is formed by superposing two paths of electromagnetic wave orthogonal signals, wherein the carrier frequency point of one path of electromagnetic wave orthogonal signal is positioned in the low return loss frequency band of the endoscope antenna in the capsule endoscope; the carrier frequency point of the other path of electromagnetic wave orthogonal signal is positioned in the high return loss frequency band of the endoscope antenna in the capsule endoscope;
the wavelength of the electromagnetic wave is millimeter wave or terahertz.
In a further scheme, the signal processing in the step (3) is to demodulate the echo signals to a baseband according to the transmitted carrier frequency respectively, and take a plurality of continuous baseband pulse signals as input signals of one processing period; taking one part of baseband data in one processing period as a background interference signal generated by tissues in a human body, and taking the other part of the baseband data in one processing period as a superposition signal of the background interference and the echo of the capsule endoscope; and then, the two parts of signals are cancelled, the baseband pulse signals of a plurality of processing periods are output and subjected to coherent accumulation, and then the signals are processed to obtain a detection signal for constant false alarm detection.
The number of pulses in one processing period is about 1000-2000, the specific number is limited by the computing capability of equipment, and the processing needs to be completed by computing within a millimeter-scale distance of capsule movement.
In a further scheme, the constant false alarm detection means that in each signal processing period, the power of background interference in a signal is measured in advance, and a threshold required by detecting the capsule endoscope is calculated in a self-adaptive manner and is dynamically adjusted in combination with a preset false alarm rate and a signal-to-noise ratio; comparing the threshold to a detection signal for constant false alarm detection; if the detection signal exceeds the threshold, judging that the capsule endoscope exists in the narrow beam range, otherwise, judging that the capsule endoscope does not exist.
In a preferred embodiment, the reprocessing includes matched filtering and receive beamforming;
the background interference signal comprises a baseband signal output at a carrier frequency fx of a narrow beam; the superimposed signal includes a baseband signal output at a carrier frequency fy of a narrow beam.
Further, the step (3) of calculating the measured value of the position of the capsule endoscope means that the measured value of the position of the capsule endoscope is obtained according to a distance window and a direction window of a detection unit where the capsule endoscope is located; where the range window is the distance calculated from the echo time and the azimuth window is the azimuth inversely derived from the beamforming weight vector.
Further, the step (4) of obtaining the position information of the capsule endoscope refers to obtaining the position information of the capsule endoscope by demodulating a positioning signal which is sent by an antenna in the capsule endoscope and contains the autonomous positioning position information through a demodulator.
Compared with the prior art, the invention has the beneficial effects that:
the invention adopts a wireless-inertial navigation hybrid positioning technology, and provides a scheme of laying an antenna array on the surface of the skin of a human body in order to improve the positioning precision and the energy use efficiency, so that the antenna array is suitable for the complicated in-vivo electromagnetic environment of the human body and the bearable electromagnetic radiation intensity.
In order to adaptively solve the background interference signal generated by the complex electromagnetic environment in the human body, the method utilizes the adaptive cancellation method to inhibit the echo signal and the background interference signal of the human tissue in the echo signal; in order to obtain the background interference signal of the human tissue echo in real time, the frequency point of one path of transmission signal carrier frequency in the narrow beam is designed in the frequency band of the antenna passband in the capsule endoscope, and the echo loss in the frequency band is low, so that the background interference signal only containing the human tissue echo can be obtained in real time; and a signal to be processed containing both capsule endoscope echo and background interference;
in order to make the volume of the system object meet the swallowing requirement, the capsule endoscope adopts the integration of the micro-system integration technology, so that the volume is small.
The capsule body positioning method has high flexibility, can well adapt to the change of the posture and the body position of a patient, has strong accuracy and small harmfulness, and the electromagnetic radiation energy is lower than the normal standard.
The invention adopts a hybrid positioning technology combining radio positioning and inertial positioning. And a scheme for suppressing the background interference of the human tissue echo in the echo signal by utilizing a cancellation method is provided. And self-adaptive human clutter cancellation processing is realized. The positioning method not only can adapt to the complicated electromagnetic environment in the human body, but also can reduce the transmitting power, reduce the damage of electric waves to the human body and finally accurately, effectively and flexibly measure and calculate the position of the capsule endoscope in the human body.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a graph of return loss | S11| -frequency f of the capsule endoscope antenna of the present invention;
fig. 3 is a schematic diagram of the structure of the external antenna of the present invention.
In the figure: 1-antenna housing, 2-external antenna, 3-feeder line, 4-dielectric layer, and 5-human skin.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A capsule endoscope wireless positioning method based on hybrid positioning is disclosed, as shown in fig. 1, and comprises the following steps:
(1) obtaining a baseband pulse signal; the baseband pulse signal satisfies that the bandwidth is one tenth of the central frequency of the transmitted signal;
(2) forming narrow beams by using an external transceiving array to the baseband pulse signals, then periodically transmitting electromagnetic wave signals to the capsule endoscope, and reflecting part of the electromagnetic wave signals back to form echo signals;
the narrow wave beam is formed by superposing two paths of electromagnetic wave orthogonal signals x and y, wherein a carrier frequency point fx of one path of electromagnetic wave orthogonal signal is positioned in a low return loss frequency band of an endoscope antenna in the capsule endoscope; the carrier frequency point fy of the other path of electromagnetic wave orthogonal signal is positioned in the high return loss frequency band of the endoscope antenna in the capsule endoscope;
the wavelength of the electromagnetic wave is millimeter wave or terahertz.
(3) Receiving echo signal, processing the echo signal, outputting the echo signal after the strength and offset of multi-point echo signal, detecting the output signal, and judging whether the capsule endoscope is narrow or notWithin a beam range; if so, obtaining a measured value of the position of the capsule endoscope according to a distance window and an orientation window of a detection unit where the capsule endoscope is located, and storing the result; wherein the distance window is the distance calculated according to the echo time, i.e. the delay time Deltat of the output signal of the detection unit relative to the time of transmitting the baseband pulse signal is firstly measured and then is calculated according to the echo time
The distance window of the detection unit is calculated, where c is the propagation velocity of the electromagnetic wave in the human tissue (known to be investigated).
The azimuth window is an azimuth inversely derived from a narrow beam forming weight vector, and the narrow beam forming weight vector is a measurement azimuth corresponding to the azimuth window when a system is initialized and a required azimuth is input. The method comprises the following steps: electromagnetic wave signal at incident angle
Reaches the external transmitting-receiving array (theta,
The pitch angle and the azimuth angle formed by the narrow beam) and then the narrow beam forming weight vector of the azimuth is obtained according to the space phase difference and the unit direction vector of the signal. This is also a known calculation method.
The signal processing means that echo signals are respectively demodulated to a baseband according to the transmitted carrier frequency, a plurality of continuous baseband pulse signals are used as input signals of a processing period, one part of baseband data in the processing period is used as a background interference signal generated by tissues in a human body, and the other part of baseband data is used as a superimposed signal of the background interference and the echo of the capsule endoscope; and then, the two parts of signals are cancelled, baseband pulse signals of a plurality of processing periods are output and are subjected to coherent accumulation, and then the signals are subjected to reprocessing such as matched filtering and receiving beam forming to obtain detection signals for constant false alarm detection.
The number of pulses in one processing period is about 1000-2000, the specific number is limited by the computing capability of equipment, and the processing needs to be completed by computing within a millimeter-scale distance of capsule movement.
The constant false alarm detection means that the power of background interference in a signal is measured in advance in each signal processing period, and a threshold required by detecting the capsule endoscope is calculated in a self-adaptive manner and is dynamically adjusted in combination with a preset false alarm rate and a signal-to-noise ratio; comparing the threshold to a detection signal for constant false alarm detection; if the detection signal exceeds the threshold, judging that the capsule endoscope exists in the narrow beam range, otherwise, judging that the capsule endoscope does not exist.
The background interference signal comprises a baseband signal output at a carrier frequency fx of a narrow beam; the superimposed signal includes a baseband signal output as a carrier fy of a narrow beam.
(4) The positioning signal which is sent by an antenna in the capsule endoscope and contains the self-positioning position information is demodulated by a demodulator to obtain the position information of the capsule endoscope, the movement trace of the capsule endoscope is formed by utilizing the measured value of the position of the capsule endoscope at each moment stored in the step (3), and whether the capsule endoscope is in the narrow beam range is further judged; if so, outputting the position of the capsule endoscope, and adjusting the direction of the narrow beam to align the center of the narrow beam with the position corresponding to the position of the capsule endoscope calculated in the step (3); if not, go to step (2).
As shown in fig. 3, the external transmit-receive array comprises an external antenna 2 and a feeder 3, wherein one end of the external antenna 2 is connected with the skin 5 of the human body through a dielectric layer 4, and the other end is connected with the feeder 3; the antenna housing 1 is arranged at the upper ends of the external antenna 2 and the dielectric layer 4, and the top end of the feeder line 3 penetrates through the antenna housing 1 and is positioned outside the antenna housing 1; the electromagnetic properties of the dielectric layer are similar to those of human skin.
The human body is an electromagnetic field with varying electrical parameters such as current, voltage, resistance, impedance, vibration, frequency spectrum, heat, etc. The electromagnetic property of the dielectric layer is consistent with that of human skin, and influence is avoided.
If the antenna is directly in contact with the skin of the human body, there is inevitably an air gap, and the conduction path of the electromagnetic waves from the antenna to the human body is: the antenna (metal) -air (in the gap) -human skin causes the electromagnetic waves to pass out of the antenna and then through the air to the human skin, during which attenuation occurs. In the present application, a dielectric layer is coated between the antenna and the skin of the human body, and the transmission path of the electromagnetic wave is: antenna-dielectric layer-human skin. Because the electromagnetic property of the dielectric layer is similar to that of human skin, the smaller the attenuation of electromagnetic waves on the interface of the dielectric layer is, the electromagnetic wave transmission can be simply equivalent to an antenna-human skin, namely, air gaps are eliminated.
Examples of the invention are: the dielectric layer is made of relaxation agent and CaCl2When the oil-in-water emulsion is used, the oil-in-water emulsion is coated on the surface of human skin to form a thin liquid layer, so that air gaps are eliminated, and the electromagnetic wave transmission effect is improved.
The method specifically comprises the following steps: the medium layer is prepared by stirring and mixing the following substances in percentage by mass:
the components are stirred and mixed according to the proportion to obtain dielectric layer slurry, and then the dielectric layer slurry is coated on the surface of human skin to form a thin liquid layer, namely the dielectric layer. Thereby eliminating air gaps and improving the electromagnetic wave transmission effect.
In this example, the signal generator generates a narrow pulse with a pulse width of 1-2ns and a repetition period of about 1us as a baseband pulse signal, and calibrates the external transmit-receive array and prestores the beamforming weight vector to be used. The in-vitro receiving and transmitting array forms the baseband pulse signals into narrow beams, transmits electromagnetic wave signals and periodically scans the human skin on the human abdomen.
The narrow wave beam is obtained by digital wave beam forming and is formed by superposing two paths of orthogonal signals, wherein a carrier frequency point fx of one path of signal is positioned in a frequency band of an antenna passband of the endoscope in the capsule endoscope, and the signal x is recorded as the low return loss; and the carrier frequency point fy of the other path of signal is positioned in the frequency band of the antenna stop band in the capsule endoscope, and the return loss is high and is recorded as a signal y. The single-path baseband signal is modulated to two different radio frequency points fx and fy in the signal transceiving module, and then is transmitted through the external transceiving array.
As shown in fig. 2, since the return loss parameter | S11| of the human skin 5 reflecting the ability to reflect (absorb) electromagnetic waves changes relatively slowly with frequency, it can be considered that the power of the return waves of the signals x and y in the human tissue is similar under the same other conditions; the frequency band characteristic of the endoscope antenna in the capsule endoscope is much larger than the change of human skin in the parameter, so the echo loss of the endoscope antenna at the fy frequency is much larger than fx. The echo power of the signal x in the echo signal reflected by the endoscope antenna as a reflecting surface is not only smaller than that of the signal y, but also the difference between the two is much larger than that of the echo of the human tissue, so that the signal-to-noise ratio is improved by utilizing cancellation, and the background interference signal derived from the echo of the human tissue is suppressed. The effect is more pronounced when the endoscope antenna is conformal to the capsule shell.
The external antenna receives the reflected echo signals, demodulates the echo signals to a baseband according to the transmitted carrier frequency, takes baseband data of a part of channels as background interference signals generated by tissues in a human body, and records the background interference signals as C, wherein the baseband signals comprise baseband signals output by demodulation at demodulation frequency fx; taking the baseband data of the other part of channels as a superposed signal of background interference and capsule endoscope echo, and recording the superposed signal as D, wherein the superposed signal comprises a baseband signal demodulated and output by a demodulation frequency fy; in the present example, C includes only the baseband signal demodulated at the demodulation frequency fx; d only includes the baseband signal output by demodulation at the demodulation frequency fy. After the low-pass filter is used for inhibiting the high-frequency interference, the main components in the two paths of signals are considered to be a background interference signal C derived from the echo of human tissue and a signal to be detected containing all echo components respectively. In order to obtain better processing effect, two paths of signals are preprocessed before cancellation processing, and the preprocessing comprises receiving beam forming, matched filtering and coherent accumulation. The input signal C is subtracted from the signal D to obtain an output signal E (C-D ═ E). And then judging whether the capsule endoscope exists or not by using the output signal E, and if so, calculating a measured value of the position of the capsule endoscope. In this example, the decision threshold is calculated adaptively by using CFAR (constant false alarm detection), which has the advantage that the detected false alarm rate does not fluctuate greatly with the change of interference, and then the decision threshold is used to preliminarily decide whether the capsule endoscope exists in the narrow beam, that is, if the decision threshold is exceeded, the target is preliminarily decided to exist, that is, the capsule endoscope is in the narrow beam range.
Finally, the measured values of the positions of the capsule endoscope at all the detected and stored moments form moving traces of the capsule endoscope by positioning signals containing self-positioning position information sent by an endoscope antenna of the capsule endoscope; comparing the positioning signal of the capsule endoscope with the motion trace, if the positioning signal of the capsule endoscope is overlapped with the motion trace, judging that the capsule endoscope exists in the narrow beam, outputting the position of the capsule endoscope, and then adjusting the narrow beam of the external transmit-receive array to align the center of the narrow beam to the corresponding direction of the calculation result; if the beams do not coincide with each other, the capsule endoscope does not exist in the narrow beam, and the scanning is required to be continued.
The capsule endoscope in the application is available, adopts a micro-system SiP integration process, realizes the wireless positioning, is small in size and is convenient for a person to swallow.
Although the present description is described in terms of embodiments, not every embodiment includes only a single embodiment, and such description is for clarity only, and those skilled in the art should be able to integrate the description as a whole, and the embodiments can be appropriately combined to form other embodiments as will be understood by those skilled in the art.
Therefore, the above description is only a preferred embodiment of the present application, and is not intended to limit the scope of the present application; all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101053517A (en) * | 2007-05-18 | 2007-10-17 | 深圳先进技术研究院 | Method and system for tracking internal mini device |
| JP2009061013A (en) * | 2007-09-05 | 2009-03-26 | Fujifilm Corp | Capsule endoscope position detection device, position detection method, and capsule endoscope system |
| US20090124871A1 (en) * | 2005-08-22 | 2009-05-14 | Khalil Arshak | Tracking system |
| JP2012161567A (en) * | 2011-02-09 | 2012-08-30 | Olympus Medical Systems Corp | Reception unit, information processor, and intra-subject introducing system |
| CN102657530A (en) * | 2012-04-26 | 2012-09-12 | 沈阳工业大学 | Human body respiratory frequency detection method based on distance domain filtering |
| CN102933154A (en) * | 2010-06-04 | 2013-02-13 | 株式会社日立医疗器械 | Ultrasound diagnosis device |
| CN103339523A (en) * | 2011-02-03 | 2013-10-02 | 基文影像公司 | System and method for determining location and orientation of a device in-vivo |
| CN106725259A (en) * | 2016-12-20 | 2017-05-31 | 中国电子科技集团公司第四十三研究所 | A kind of medical electric capsule |
| CN213993560U (en) * | 2020-11-20 | 2021-08-20 | 中国电子科技集团公司第四十三研究所 | A wireless positioning system for capsule endoscope based on hybrid positioning |
-
2020
- 2020-11-20 CN CN202011310960.XA patent/CN112485786B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090124871A1 (en) * | 2005-08-22 | 2009-05-14 | Khalil Arshak | Tracking system |
| CN101053517A (en) * | 2007-05-18 | 2007-10-17 | 深圳先进技术研究院 | Method and system for tracking internal mini device |
| JP2009061013A (en) * | 2007-09-05 | 2009-03-26 | Fujifilm Corp | Capsule endoscope position detection device, position detection method, and capsule endoscope system |
| CN102933154A (en) * | 2010-06-04 | 2013-02-13 | 株式会社日立医疗器械 | Ultrasound diagnosis device |
| CN103339523A (en) * | 2011-02-03 | 2013-10-02 | 基文影像公司 | System and method for determining location and orientation of a device in-vivo |
| JP2012161567A (en) * | 2011-02-09 | 2012-08-30 | Olympus Medical Systems Corp | Reception unit, information processor, and intra-subject introducing system |
| CN102657530A (en) * | 2012-04-26 | 2012-09-12 | 沈阳工业大学 | Human body respiratory frequency detection method based on distance domain filtering |
| CN106725259A (en) * | 2016-12-20 | 2017-05-31 | 中国电子科技集团公司第四十三研究所 | A kind of medical electric capsule |
| CN213993560U (en) * | 2020-11-20 | 2021-08-20 | 中国电子科技集团公司第四十三研究所 | A wireless positioning system for capsule endoscope based on hybrid positioning |
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