WO2017212564A1 - Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique - Google Patents

Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique Download PDF

Info

Publication number
WO2017212564A1
WO2017212564A1 PCT/JP2016/067030 JP2016067030W WO2017212564A1 WO 2017212564 A1 WO2017212564 A1 WO 2017212564A1 JP 2016067030 W JP2016067030 W JP 2016067030W WO 2017212564 A1 WO2017212564 A1 WO 2017212564A1
Authority
WO
WIPO (PCT)
Prior art keywords
capsule endoscope
antenna
formula
equation
memory
Prior art date
Application number
PCT/JP2016/067030
Other languages
English (en)
Japanese (ja)
Inventor
吉徳 池田
慎一 中島
明広 窪田
Original Assignee
オリンパス株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by オリンパス株式会社 filed Critical オリンパス株式会社
Priority to PCT/JP2016/067030 priority Critical patent/WO2017212564A1/fr
Publication of WO2017212564A1 publication Critical patent/WO2017212564A1/fr

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B1/00—Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; Illuminating arrangements therefor
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/06—Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements
    • 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
    • G01S5/00—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations
    • G01S5/02—Position-fixing by co-ordinating two or more direction or position line determinations; Position-fixing by co-ordinating two or more distance determinations using radio waves
    • G01S5/14—Determining absolute distances from a plurality of spaced points of known location

Definitions

  • Patent Document 1 A method for measuring the position of the capsule endoscope is disclosed in Patent Document 1 and Patent Document 2.
  • the position of the capsule endoscope is determined based on any one of the difference in the reception time of the signal transmitted from the capsule endoscope, the phase difference of the signal, and the arrival direction of the signal. Measured.
  • the relative permittivity of the medium is estimated based on the received signal strength and the signal arrival time, and a predetermined value is used as the conductivity of the medium.
  • the conductivity of the medium differs for each path through which the signal propagates. Since the conductivity used for the calculation is different from the conductivity in the actual path, the detection accuracy of the position of the capsule endoscope is lowered.
  • the capsule endoscope position detection method includes the first step, the second step, the third step, the fourth step, and the fifth step.
  • the equation (1) is obtained from the equation (1), the equation (2), the equation (3), and the memory storing the correlation information, and the reception time is substituted into the equation (1).
  • the equation (2) is acquired from the memory, and the received electric field strength of the antenna is substituted into the equation (2).
  • the correlation information is acquired from the memory.
  • the equation (3) is acquired from the memory.
  • the fifth step includes the equation (1) in which the reception time is substituted in the first step, the equation (2) in which the reception electric field strength is substituted in the second step, and the first step.
  • the position of the capsule endoscope is calculated based on the correlation information acquired from the memory in step 3 and the equation (3) acquired from the memory in the fourth step.
  • the formula (1) is as follows.
  • the formula (2) is as follows.
  • the formula (3) is as follows.
  • the reception time may be the arrival time.
  • the formula (1) may be the following formula (1a).
  • the d k is a distance between the capsule endoscope and the antenna k.
  • the ⁇ r, k is a relative dielectric constant of a medium between the capsule endoscope and the antenna k.
  • the ⁇ k is the arrival time for the antenna k.
  • c is the speed of light in a vacuum.
  • the capsule endoscope position detection method is wirelessly transmitted from the capsule endoscope in the subject and is transmitted by at least four antennas.
  • the position of the capsule endoscope may be detected based on the received signal.
  • the reception time may be a difference between the arrival times for the two antennas.
  • the formula (1) may be the following formula (1d).
  • the d k is a distance between the capsule endoscope and the antenna k.
  • d l is the distance between the capsule endoscope and the antenna l.
  • the antenna l is any one of the at least three antennas and is different from the antenna k.
  • the ⁇ r, k is a relative dielectric constant of a medium between the capsule endoscope and the antenna k.
  • ⁇ r, l is a relative dielectric constant of a medium between the capsule endoscope and the antenna l.
  • the ⁇ k, l is the difference between the arrival times for the antenna k and the antenna l.
  • the antenna k and the antenna l are different from each other.
  • c is the speed of light in a vacuum.
  • the equation (1d), the equation (2), and the equation (3) are defined for each of the at least four antennas.
  • the signal transmitted wirelessly from the capsule endoscope and received by the at least three antennas is: It may be a UWB (Ultra Wide Band) signal.
  • the reception time may be calculated based on a phase of the signal received by the antenna.
  • a capsule endoscope position detection system includes at least three antennas, an antenna selection circuit, a reception time measurement circuit, a reception electric field strength measurement circuit, a first memory, A second memory and a position calculation circuit are included.
  • the at least three antennas receive signals wirelessly transmitted from the capsule endoscope in the subject.
  • the antenna selection circuit sequentially selects one or two of the at least three antennas.
  • the reception time measurement circuit measures information related to reception times of the signals received by the one or two antennas selected by the antenna selection circuit.
  • the reception field strength measurement circuit measures the reception field strength of the signal received by the one or two antennas selected by the antenna selection circuit.
  • the first memory stores the reception time and the reception electric field strength.
  • the formula (3) is as follows.
  • f is a function of d k and ⁇ r, k .
  • the d k is a distance between the capsule endoscope and the antenna k.
  • the ⁇ r, k is a relative dielectric constant of a medium between the capsule endoscope and the antenna k.
  • the antenna k is any one of the at least three antennas.
  • g is a function of ⁇ k .
  • the ⁇ k is the reception time of the antenna k. The reception time relates to the arrival time of the signal from the time when the signal is transmitted by the capsule endoscope to the time when the signal is received by the antenna k.
  • E k is the received electric field strength of the antenna k.
  • E 0 is the transmission electric field strength of the capsule endoscope.
  • ⁇ is the angular frequency of the electromagnetic wave.
  • ⁇ 0 is the vacuum permeability.
  • ⁇ 0 is the dielectric constant of vacuum.
  • ⁇ k is the conductivity of the medium between the capsule endoscope and the antenna k.
  • x is the x coordinate of the capsule endoscope.
  • y is the y coordinate of the capsule endoscope.
  • z is the z coordinate of the capsule endoscope.
  • X k is the x coordinate of the antenna k.
  • Y k is the y coordinate of the antenna k.
  • Z k is the z coordinate of the antenna k.
  • Equation (1), equation (2), and equation (3) are defined for each of the at least three antennas.
  • the correlation information indicates an approximate correlation between the ⁇ r, k and the ⁇ k .
  • the capsule endoscope position detection device wirelessly transmits from a capsule endoscope in a subject and receives a signal received by at least three antennas and a received electric field.
  • the position of the capsule endoscope is detected based on the intensity.
  • the capsule endoscope position detection device includes a memory and a position calculation circuit.
  • the memory stores Equation (1), Equation (2), Equation (3), and correlation information.
  • the position calculation circuit calculates the position of the capsule endoscope.
  • the position calculation circuit acquires the expression (1) from the memory and substitutes the reception time into the expression (1).
  • the position calculation circuit acquires the equation (2) from the memory, and substitutes the reception electric field strength of the antenna into the equation (2).
  • the position calculation circuit acquires the correlation information from the memory.
  • the position calculation circuit acquires the expression (3) from the memory.
  • the position calculation circuit acquires the equation (1) into which the reception time is substituted, the equation (2) into which the reception electric field strength is substituted, the correlation information acquired from the memory, and the memory. Based on the formula (3), the position of the capsule endoscope is calculated.
  • the formula (1) is as follows.
  • the formula (3) is as follows.
  • f is a function of d k and ⁇ r, k .
  • the d k is a distance between the capsule endoscope and the antenna k.
  • the ⁇ r, k is a relative dielectric constant of a medium between the capsule endoscope and the antenna k.
  • the antenna k is any one of the at least three antennas.
  • g is a function of ⁇ k .
  • the ⁇ k is the reception time of the antenna k. The reception time relates to the arrival time of the signal from the time when the signal is transmitted by the capsule endoscope to the time when the signal is received by the antenna k.
  • E k is the received electric field strength of the antenna k.
  • E 0 is the transmission electric field strength of the capsule endoscope.
  • ⁇ is the angular frequency of the electromagnetic wave.
  • ⁇ 0 is the vacuum permeability.
  • ⁇ 0 is the dielectric constant of vacuum.
  • ⁇ k is the conductivity of the medium between the capsule endoscope and the antenna k.
  • x is the x coordinate of the capsule endoscope.
  • y is the y coordinate of the capsule endoscope.
  • z is the z coordinate of the capsule endoscope.
  • X k is the x coordinate of the antenna k.
  • Y k is the y coordinate of the antenna k.
  • Z k is the z coordinate of the antenna k.
  • Equation (1), equation (2), and equation (3) are defined for each of the at least three antennas.
  • the correlation information indicates an approximate correlation between the ⁇ r, k and the ⁇ k .
  • the position of the capsule endoscope is calculated by calculating the position of the capsule endoscope based on correlation information indicating an approximate correlation between the relative dielectric constant of the medium and the electric conductivity of the medium. Detection accuracy is improved.
  • the capsule endoscope position detection system 1 includes at least three antennas 10, an antenna selection circuit 11, a reception time measurement circuit 13, a reception electric field strength measurement circuit 14, a measurement result memory 15 (first memory), A program memory 16 (second memory) and a position calculation circuit 17 are included.
  • At least three antennas 10 receive signals transmitted wirelessly from the capsule endoscope in the subject.
  • the antenna selection circuit 11 sequentially selects one or two of the at least three antennas.
  • the reception time measurement circuit 13 measures the reception time of signals received by one or two antennas 10 selected by the antenna selection circuit 11.
  • the reception field strength measurement circuit 14 measures the reception field strength of signals received by the one or two antennas 10 selected by the antenna selection circuit 11.
  • the measurement result memory 15 stores the reception time and the received electric field strength.
  • the program memory 16 stores formula (1), formula (2), formula (3), and correlation information.
  • the position calculation circuit 17 calculates the position of the capsule endoscope.
  • E k is the received electric field strength of the antenna k.
  • E 0 is the transmission electric field intensity of the capsule endoscope.
  • ⁇ is the angular frequency of the electromagnetic wave.
  • ⁇ 0 is the vacuum permeability.
  • ⁇ 0 is the dielectric constant of vacuum.
  • ⁇ k is the conductivity of the medium between the capsule endoscope and the antenna k.
  • x is the x coordinate of the capsule endoscope.
  • y is the y coordinate of the capsule endoscope.
  • z is the z coordinate of the capsule endoscope.
  • X k is the x coordinate of the antenna k.
  • Y k is the y coordinate of antenna k.
  • the correlation information indicates an approximate correlation of ⁇ r, k and ⁇ k .
  • the capsule endoscope position detection system 1 includes eight antennas 10, an antenna selection circuit 11, a signal shaping circuit 12, a reception time measurement circuit 13, a reception electric field strength measurement circuit 14, A measurement result memory 15, a program memory 16, a position calculation circuit 17, and a control circuit 18 are included.
  • the antenna selection circuit 11 sequentially selects one or two antennas 10 from the eight antennas 10.
  • the signal output from the antenna selection circuit 11 may be amplified by an amplifier circuit (amplifier).
  • the antenna selection circuit 11 outputs the signals output from the selected one or two antennas 10 to the signal shaping circuit 12.
  • the signal shaping circuit 12 has one or two filter circuits.
  • the filter circuit of the signal shaping circuit 12 removes a signal having a frequency other than a predetermined frequency band from the signal output from the antenna selection circuit 11.
  • the signal shaping circuit 12 outputs the processed signal to the reception time measurement circuit 13 and the reception electric field strength measurement circuit 14.
  • the antenna selection circuit 11 may select two antennas 10 simultaneously.
  • the antenna selection circuit 11 outputs a signal output from one of the two antennas 10 selected at the same time to one of the two filter circuits of the signal shaping circuit 12, and the two antennas 10 selected at the same time.
  • the signal output from the other is output to the other of the two filter circuits of the two signal shaping circuits 12.
  • the reception time measurement circuit 13 measures the reception time based on the signal output from the signal shaping circuit 12.
  • the reception time measurement circuit 13 outputs the measured reception time to the measurement result memory 15.
  • the reception time is the arrival time or arrival time difference of signals.
  • the arrival time is the time for the signal to propagate from the capsule endoscope to the antenna 10.
  • the reception time measurement circuit 13 measures the arrival time of a signal by a TOA (Time Of Arrival) method.
  • the arrival time difference is a difference between arrival times for the two antennas 10.
  • the arrival time difference is a difference (time) in time when the same signal transmitted from the capsule endoscope is received by the two antennas 10 selected by the antenna selection circuit 11. That is, the arrival time difference is the difference between the time when the signal is received by one of the two antennas 10 and the time when the signal is received by the other of the two antennas 10.
  • the reception time measurement circuit 13 measures the arrival time difference for each combination of the two antennas 10 selected by the antenna selection circuit 11.
  • the position calculation circuit 17 is an arithmetic circuit.
  • the position calculation circuit 17 calculates the position of the capsule endoscope based on the reception time and reception electric field strength stored in the measurement result memory 15 and the three expressions and correlation information stored in the program memory 16. That is, the position calculation circuit 17 calculates the X coordinate, the Y coordinate, and the Z coordinate of the capsule endoscope.
  • the position calculation circuit 17 outputs the calculated position of the capsule endoscope.
  • the position calculation circuit 17 may be composed of one or a plurality of processors.
  • the processor is a CPU (Central Processing Unit).
  • the position calculation circuit 17 may be configured by one or a plurality of application specific integrated circuits (ASIC) or FPGAs (Field-Programmable Gate Array).
  • ASIC application specific integrated circuits
  • FPGAs Field-Programmable Gate Array
  • At least three antennas 10 are arranged. If the reception time is the arrival time difference, at least four antennas 10 are arranged.
  • the position of the capsule endoscope is determined based on signals transmitted wirelessly from the capsule endoscope in the subject and received by at least three antennas 10.
  • the capsule endoscope position detection method includes a first step, a second step, a third step, a fourth step, and a fifth step.
  • the position calculation circuit 17 acquires the expression (1) from the program memory 16 and substitutes the reception time into the expression (1).
  • the position calculation circuit 17 obtains Expression (2) from the program memory 16 and substitutes the received electric field strength of the antenna 10 into Expression (2).
  • the position calculation circuit 17 acquires correlation information from the program memory 16.
  • the position calculation circuit 17 acquires Expression (3) from the program memory 16.
  • the position calculation circuit 17 includes an expression (1) in which the reception time is substituted in the first step, an expression (2) in which the reception electric field strength is substituted in the second step, The position of the capsule endoscope is calculated based on the correlation information acquired from the program memory 16 by the step and the equation (3) acquired from the program memory 16 by the fourth step.
  • Step S101 The control circuit 18 sets the antenna index to an initial value.
  • the initial value of the antenna index is 0.
  • the initial value of the antenna index may be a value other than zero.
  • Step S102 After the antenna index is set to the initial value, the control circuit 18 outputs the antenna index to the antenna selection circuit 11.
  • the antenna selection circuit 11 selects the antenna 10 specified by the antenna index.
  • a signal is output from the antenna 10 selected by the antenna selection circuit 11 to the signal shaping circuit 12.
  • Step S103 After the antenna 10 is selected by the antenna selection circuit 11, the reception time measurement circuit 13 measures the reception time based on the signal output from the signal shaping circuit 12. The reception time measurement circuit 13 outputs the measured reception time to the measurement result memory 15.
  • Step S104 After the reception time is measured by the reception time measurement circuit 13, the reception field strength measurement circuit 14 measures the reception field strength based on the signal output from the signal shaping circuit 12. The reception field strength measurement circuit 14 outputs the measured reception field strength to the measurement result memory 15. The order in which step S103 and step S104 are executed may be reversed.
  • Step S105 After the received electric field strength is measured by the received electric field strength measuring circuit 14, the control circuit 18 stores the reception time and the received electric field strength together with the antenna index in the measurement result memory 15.
  • Step S106 After the reception time and the received electric field strength are stored in the measurement result memory 15, the control circuit 18 determines whether or not the value of the antenna index is n-1. n is the number of antennas 10, that is, eight. When the value of the antenna index is n ⁇ 1, the measurement of the reception time and the reception electric field strength ends. If the antenna index value is not n ⁇ 1, the process in step S107 is performed.
  • Step S107 The control circuit 18 adds 1 to the antenna index value. After the process in step S107 is performed, the process in step S102 is performed.
  • FIG. 3 shows a first procedure for detecting the position of the capsule endoscope.
  • a first method for detecting the position of the capsule endoscope will be described with reference to FIG.
  • the reception time is the arrival time of the signal.
  • Step S201 The position calculation circuit 17 acquires the arrival time from the measurement result memory 15.
  • the position calculation circuit 17 acquires the first expression from the program memory 16 and substitutes the arrival time into the first expression.
  • the first expression is expression (1a), expression (1b), and expression (1c).
  • the first expression corresponds to the above-described expression (1).
  • d k is a distance between the capsule endoscope and the antenna k.
  • ⁇ r, k is the relative dielectric constant of the medium between the capsule endoscope and the antenna k.
  • ⁇ k is the arrival time for antenna k.
  • d k and ⁇ r, k are unknowns.
  • ⁇ k is a measurement value acquired from the measurement result memory 15.
  • d l is the distance between the capsule endoscope and the antenna l.
  • ⁇ r, l is the relative dielectric constant of the medium between the capsule endoscope and the antenna l.
  • ⁇ l is the arrival time for antenna l.
  • d l and ⁇ r, l are unknowns.
  • ⁇ l is a measurement value acquired from the measurement result memory 15.
  • d m is the distance between the capsule endoscope and the antenna m.
  • ⁇ r, m is the relative dielectric constant of the medium between the capsule endoscope and the antenna m.
  • ⁇ m is the arrival time for the antenna m.
  • d m and ⁇ r, m is an unknown quantity.
  • ⁇ m is a measurement value acquired from the measurement result memory 15.
  • c is the speed of light in vacuum.
  • c is a constant.
  • Each of antenna k, antenna l, and antenna m is any one of at least three antennas 10. The antenna k, the antenna l, and the antenna m are different from each other.
  • the position calculation circuit 17 acquires the first expression from the program memory 16 and substitutes the arrival time in the first expression, the first expression can be used as an equation.
  • Step S201 corresponds to the first step described above.
  • Step S202 The position calculation circuit 17 acquires the received electric field strength from the measurement result memory 15.
  • the position calculation circuit 17 acquires the second expression from the program memory 16 and substitutes the received electric field strength into the second expression.
  • the second formula is formula (2a), formula (2b), and formula (2c).
  • the second expression corresponds to the above-described expression (2).
  • E k is the received electric field strength of antenna k.
  • ⁇ k is the conductivity of the medium between the capsule endoscope and the antenna k.
  • d k, ⁇ r, k , and ⁇ k are unknowns.
  • E k is a measurement value acquired from the measurement result memory 15.
  • El is the received electric field strength of the antenna l.
  • ⁇ l is the conductivity of the medium between the capsule endoscope and the antenna l.
  • d l, ⁇ r, l , and ⁇ l are unknowns.
  • El is a measurement value acquired from the measurement result memory 15.
  • E m is the received field strength of the antenna m.
  • ⁇ m is the conductivity of the medium between the capsule endoscope and the antenna m.
  • dm , [ epsilon] r, m , and [sigma] m are unknowns.
  • Em is a measurement value acquired from the measurement result memory 15.
  • E 0 is the transmission electric field strength of the capsule endoscope.
  • ⁇ is the angular frequency of the electromagnetic wave.
  • ⁇ 0 is the vacuum permeability.
  • ⁇ 0 is the dielectric constant of vacuum.
  • E 0 , ⁇ , ⁇ 0 , and ⁇ 0 are constants.
  • the position calculation circuit 17 acquires correlation information from the program memory 16.
  • the correlation information is Equation (4a), Equation (4b), and Equation (4c).
  • ⁇ and ⁇ are coefficients statistically calculated in advance based on the relationship between the relative permittivity and the conductivity. ⁇ and ⁇ may be calculated by a method such as a least square method.
  • FIG. 4 shows the relationship between relative permittivity and conductivity.
  • the horizontal axis in FIG. 4 is the relative dielectric constant, and the vertical axis in FIG. 4 is the conductivity.
  • Each point in FIG. 4 represents the relative permittivity and conductivity for each tissue of the living body.
  • the relative dielectric constant of blood is 63.80
  • the electrical conductivity (mS / m) of blood is 1360.0.
  • the relative dielectric constant of muscle is 56.90
  • the electrical conductivity (mS / m) of muscle is 805.0.
  • the small intestine has a relative dielectric constant of 65.30, and the small intestine has a conductivity (mS / m) of 1920.0.
  • the illustrated relative permittivity and conductivity are values when the frequency is 433.8 MHz.
  • Step S203 corresponds to the third step described above.
  • the relationship between the relative permittivity and the conductivity may be approximated by a higher order expression.
  • the higher order expression indicating the relationship between the relative permittivity and the conductivity may be calculated by a method such as a spline interpolation method.
  • An approximate solution of relative permittivity and conductivity may be calculated by iterative calculation. In that case, table data in which one of relative permittivity and conductivity is an input and the other of relative permittivity and conductivity is an output may be used.
  • the position calculation circuit 17 acquires the third expression from the program memory 16.
  • the third expression is expression (3a), expression (3b), and expression (3c).
  • the third expression corresponds to the above-described expression (3).
  • X k is the x coordinate of the antenna k.
  • Y k is the y coordinate of antenna k.
  • Z k is the z coordinate of the antenna k.
  • X k , Y k , and Z k are constants.
  • X l is the x coordinate of the antenna l.
  • Y l is the y coordinate of the antenna l.
  • Z l is the z coordinate of the antenna l.
  • X l , Y l , and Z l are constants.
  • X m is the x coordinate of the antenna m.
  • Y m is the y coordinate of the antenna m.
  • Z m is the z coordinate of the antenna m.
  • X m , Y m , and Z m are constants.
  • x is the x coordinate of the capsule endoscope.
  • y is the y coordinate of the capsule endoscope.
  • z is the z coordinate of the capsule endoscope.
  • x, y, and z are unknown numbers.
  • steps S201 to S204 are executed is not limited to the order shown in FIG. Steps S201 to S204 may be executed in any order.
  • Step S205 The position calculation circuit 17 calculates the position of the capsule endoscope by solving simultaneous equations.
  • the simultaneous equations are composed of equations obtained from step S201 to step S204. Thereby, the position calculation circuit 17 calculates the coordinates (x, y, z) of the capsule endoscope.
  • Step S205 corresponds to the fifth step described above.
  • FIG. 5 shows a second procedure for detecting the position of the capsule endoscope.
  • a second method for detecting the position of the capsule endoscope will be described with reference to FIG.
  • the capsule endoscope position detection method detects the position of the capsule endoscope based on signals transmitted wirelessly from the capsule endoscope in the subject and received by at least four antennas 10.
  • the reception time is the difference between the arrival times for the two antennas 10.
  • equations (1), (2), and (3) are defined for each of the at least four antennas 10.
  • Step S301 The position calculation circuit 17 acquires the arrival time difference from the measurement result memory 15.
  • the position calculation circuit 17 acquires the first expression from the program memory 16 and substitutes the arrival time into the first expression.
  • the first expression is expression (1d), expression (1e), and expression (1f).
  • the first expression corresponds to the above-described expression (1).
  • d k is the distance between the capsule endoscope and the antenna k.
  • d l is the distance between the capsule endoscope and the antenna l.
  • ⁇ r, k is the relative dielectric constant of the medium between the capsule endoscope and the antenna k.
  • ⁇ r, l is the relative dielectric constant of the medium between the capsule endoscope and the antenna l.
  • ⁇ kl is the difference between the arrival time for antenna k and the arrival time for antenna l.
  • d k , d l , ⁇ r, k , and ⁇ r, l are unknowns.
  • ⁇ kl is a measurement value acquired from the measurement result memory 15.
  • d m is the distance between the capsule endoscope and the antenna m.
  • ⁇ r, m is the relative dielectric constant of the medium between the capsule endoscope and the antenna m.
  • ⁇ km is the difference between the arrival time for antenna k and the arrival time for antenna m.
  • d k , d m , ⁇ r, k , and ⁇ r, m are unknowns.
  • ⁇ km is a measurement value acquired from the measurement result memory 15.
  • d n is the distance between the capsule endoscope and the antenna n.
  • ⁇ r, n is the relative permittivity of the medium between the capsule endoscope and the antenna n.
  • ⁇ kn is the difference between the arrival time for antenna k and the arrival time for antenna n.
  • d k , d n , ⁇ r, k , and ⁇ r, n are unknowns.
  • ⁇ kn is a measurement value acquired from the measurement result memory 15.
  • c is the speed of light in vacuum.
  • c is a constant.
  • Each of antenna k, antenna 1, antenna m, and antenna n is any one of at least four antennas 10.
  • the antenna k, the antenna l, the antenna m, and the antenna n are different from each other.
  • Step S302 The position calculation circuit 17 acquires the received electric field strength from the measurement result memory 15.
  • the position calculation circuit 17 acquires the second expression from the program memory 16 and substitutes the received electric field strength into the second expression.
  • the second formula is formula (2a), formula (2b), formula (2c), and formula (2d).
  • the second expression corresponds to the above-described expression (2).
  • Equation (2a) is the same as Equation (2a) used in step S202 of FIG.
  • Expression (2b) is the same as Expression (2b) used in step S202 of FIG.
  • Expression (2c) is the same as Expression (2c) used in step S202 of FIG.
  • E n is the received field strength of the antenna n.
  • d n is the distance between the capsule endoscope and the antenna n.
  • ⁇ r, n is the relative permittivity of the medium between the capsule endoscope and the antenna n.
  • ⁇ n is the conductivity of the medium between the capsule endoscope and the antenna n.
  • dn , [ epsilon] r, n , and [sigma] n are unknowns.
  • E n is the measured value obtained from the measurement result memory 15.
  • E 0 is the transmission electric field strength of the capsule endoscope.
  • ⁇ is the angular frequency of the electromagnetic wave.
  • ⁇ 0 is the vacuum permeability.
  • ⁇ 0 is the dielectric constant of vacuum.
  • E 0 , ⁇ , ⁇ 0 , and ⁇ 0 are constants.
  • the position calculation circuit 17 acquires correlation information from the program memory 16.
  • the correlation information is Equation (4a), Equation (4b), Equation (4c), and Equation (4d).
  • Equation (4a) is the same as Equation (4a) used in step S203 of FIG.
  • Expression (4b) is the same as Expression (4b) used in step S203 in FIG.
  • Expression (4c) is the same as Expression (4c) used in step S203 of FIG.
  • Step S303 corresponds to the third step described above.
  • Step S304 The position calculation circuit 17 acquires the third expression from the program memory 16.
  • the third formula is formula (3a), formula (3b), formula (3c), and formula (3d).
  • the third expression corresponds to the above-described expression (3).
  • Equation (3a) is the same as Equation (3a) used in step S204 of FIG.
  • Expression (3b) is the same as Expression (3b) used in step S204 of FIG.
  • Expression (3c) is the same as Expression (3c) used in step S204 of FIG.
  • Xn is the x coordinate of the antenna n.
  • Y n is the y coordinate of antenna n.
  • Z n is the z coordinate of the antenna n.
  • X n , Y n , and Z n are constants.
  • x is the x coordinate of the capsule endoscope.
  • y is the y coordinate of the capsule endoscope.
  • z is the z coordinate of the capsule endoscope.
  • x, y, and z are unknowns.
  • steps S301 to S304 are executed is not limited to the order shown in FIG. Steps S301 to S304 may be executed in an arbitrary order.
  • Step S305 The position calculation circuit 17 calculates the position of the capsule endoscope by solving simultaneous equations.
  • the simultaneous equations are composed of equations obtained from step S301 to step S304. Thereby, the position calculation circuit 17 calculates the coordinates (x, y, z) of the capsule endoscope.
  • Step S305 corresponds to the fifth step described above.
  • the capsule endoscope position detection system may not have a configuration corresponding to at least one of the signal shaping circuit 12 and the control circuit 18.
  • the position calculation circuit 17 uses the correlation between the relative permittivity and the conductivity. By solving the simultaneous equations, the position of the capsule endoscope can be calculated with high accuracy. Therefore, by calculating the position of the capsule endoscope based on the correlation information indicating the approximate correlation between the relative dielectric constant of the medium and the conductivity of the medium, the detection accuracy of the position of the capsule endoscope is improved.
  • the position calculation circuit 17 shown in FIG. 1 may be changed to a position calculation circuit 17a shown in FIG. FIG. 6 shows the configuration of the position calculation circuit 17a.
  • the position calculation circuit 17 a includes a reception time substitution unit 170, a reception electric field strength substitution unit 171, a conductivity approximate conversion unit 172, and a calculation unit 173.
  • the reception time substitution unit 170 acquires the expression (1) from the program memory 16 and substitutes the reception time into the expression (1).
  • the reception time is acquired from the measurement result memory 15.
  • the reception time substitution unit 170 outputs the expression (1) into which the reception time is substituted to the calculation unit 173.
  • the reception electric field strength substitution unit 171 acquires the expression (2) from the program memory 16 and substitutes the reception electric field intensity of the antenna 10 into the expression (2).
  • the received electric field strength is acquired from the measurement result memory 15.
  • the received electric field strength substitution unit 171 outputs the formula (2) into which the received electric field strength is substituted to the conductivity approximate conversion unit 172.
  • the conductivity approximate conversion unit 172 acquires correlation information from the program memory 16.
  • the conductivity approximate conversion unit 172 converts the conductivity included in the equation (2) output from the received electric field strength substitution unit 171 into an approximate relative dielectric constant based on the correlation information.
  • correlation information indicating the relationship between the relative permittivity and the conductivity
  • the conductivity can be approximately expressed by the relative permittivity.
  • conductivity is approximated as a function of relative permittivity.
  • the electrical conductivity may be converted into the relative dielectric constant by table data in which values of the relative dielectric constant and the electrical conductivity are recorded. By converting the electrical conductivity to the relative dielectric constant, the unknowns included in Equation (2) are reduced.
  • the calculation unit 173 acquires the expression (3) from the program memory 16.
  • the computing unit 173 calculates the position of the capsule endoscope based on the expressions (1), (2), and (3). Specifically, the calculation unit 173 calculates the position of the capsule endoscope by solving simultaneous equations composed of Expression (1), Expression (2), and Expression (3).
  • At least one of the reception time substitution unit 170, the reception electric field strength substitution unit 171, the conductivity approximation conversion unit 172, and the calculation unit 173 may be configured by one or a plurality of processors. At least one of the reception time substitution unit 170, the reception electric field strength substitution unit 171, the conductivity approximate conversion unit 172, and the calculation unit 173 may be configured by one or a plurality of ASICs or FPGAs.
  • the capsule endoscope by calculating the position of the capsule endoscope based on correlation information indicating an approximate correlation between the relative dielectric constant of the medium and the electric conductivity of the medium, the capsule endoscope The position detection accuracy is improved.
  • FIG. 7 shows a hardware configuration of the capsule endoscope position detection apparatus 2 according to the second embodiment of the present invention.
  • the capsule endoscope position detection device 2 includes a program memory 20 and a position calculation circuit 21.
  • the capsule endoscope position detection device 2 wirelessly transmits from the capsule endoscope in the subject and receives the position of the capsule endoscope based on the reception time and the received electric field strength of the signals received by at least three antennas. Is detected.
  • the program memory 20 stores formula (1), formula (2), formula (3), and correlation information.
  • the position calculation circuit 21 calculates the position of the capsule endoscope.
  • the position calculation circuit 21 acquires the expression (1) from the program memory 20 and substitutes the reception time into the expression (1).
  • the position calculation circuit 21 acquires the expression (2) from the program memory 20 and substitutes the received electric field strength of the antenna into the expression (2).
  • the position calculation circuit 21 acquires correlation information from the program memory 20.
  • the position calculation circuit 21 acquires Expression (3) from the program memory 20.
  • the position calculation circuit 21 includes an expression (1) in which the reception time is substituted, an expression (2) in which the reception electric field strength is substituted, correlation information acquired from the program memory 20, and an expression acquired from the program memory 20. Based on (3), the position of the capsule endoscope is calculated.
  • the program memory 20 is configured similarly to the program memory 16 shown in FIG.
  • the position calculation circuit 21 is configured similarly to the position calculation circuit 17 shown in FIG. 1 or the position calculation circuit 17a shown in FIG.
  • the position calculation circuit 21 acquires the reception time and the reception electric field strength from the measurement device.
  • the measurement apparatus includes at least the antenna 10, the antenna selection circuit 11, the signal shaping circuit 12, the reception time measurement circuit 13, the reception electric field strength measurement circuit 14, and the measurement result memory 15 shown in FIG.
  • the capsule endoscope position detection device 2 may have a communication device, and the communication device may receive the reception time and the received electric field strength from the measurement device. In this case, the position calculation circuit 21 acquires the reception time and the received electric field strength from the communication device.
  • the position calculation circuit 21 may directly acquire the reception time and the reception electric field intensity from the measurement result memory 15.
  • the position calculation circuit 21 calculates the position of the capsule endoscope according to the procedure shown in FIG. 3 or FIG.
  • the position of the capsule endoscope is detected by calculating the position of the capsule endoscope based on correlation information indicating an approximate correlation between the relative dielectric constant of the medium and the electric conductivity of the medium. Accuracy is improved.
  • the detection accuracy of the position of the capsule endoscope is improved.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Surgery (AREA)
  • Pathology (AREA)
  • Medical Informatics (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biophysics (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Optics & Photonics (AREA)
  • Molecular Biology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
  • Endoscopes (AREA)

Abstract

Le procédé de détection de position de capsule endoscopique selon la présente invention comprend une première étape, une deuxième étape, une troisième étape, une quatrième étape et une cinquième étape. Dans la première étape, la formule (1) est acquise à partir d'une mémoire et un temps de réception est remplacé dans la formule (1). Dans la deuxième étape, la formule (2) est acquise à partir de la mémoire et l'intensité du champ de réception d'une antenne est remplacée dans la formule (2). Dans la troisième étape, des informations de corrélation sont acquises à partir de la mémoire. Dans la quatrième étape, la formule (3) est acquise à partir de la mémoire. Dans la cinquième étape, la position d'une capsule endoscopique est calculée sur la base de la formule (1), de la formule (2), des informations de corrélation et de la formule (3). Les informations de corrélation indiquent une corrélation approximative entre εr, k et σk.
PCT/JP2016/067030 2016-06-08 2016-06-08 Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique WO2017212564A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/067030 WO2017212564A1 (fr) 2016-06-08 2016-06-08 Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2016/067030 WO2017212564A1 (fr) 2016-06-08 2016-06-08 Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique

Publications (1)

Publication Number Publication Date
WO2017212564A1 true WO2017212564A1 (fr) 2017-12-14

Family

ID=60578441

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/067030 WO2017212564A1 (fr) 2016-06-08 2016-06-08 Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique

Country Status (1)

Country Link
WO (1) WO2017212564A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112230185A (zh) * 2020-10-13 2021-01-15 桂林电子科技大学 一种应用于胶囊内窥镜中的高精度定位方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005287888A (ja) * 2004-04-01 2005-10-20 Olympus Corp 被検体内位置検出システム
JP2009061013A (ja) * 2007-09-05 2009-03-26 Fujifilm Corp カプセル内視鏡の位置検出装置、位置検出方法、並びにカプセル内視鏡システム
JP2015043813A (ja) * 2013-08-27 2015-03-12 国立大学法人 名古屋工業大学 インプラント通信端末の位置検出装置および位置推定方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005287888A (ja) * 2004-04-01 2005-10-20 Olympus Corp 被検体内位置検出システム
JP2009061013A (ja) * 2007-09-05 2009-03-26 Fujifilm Corp カプセル内視鏡の位置検出装置、位置検出方法、並びにカプセル内視鏡システム
JP2015043813A (ja) * 2013-08-27 2015-03-12 国立大学法人 名古屋工業大学 インプラント通信端末の位置検出装置および位置推定方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112230185A (zh) * 2020-10-13 2021-01-15 桂林电子科技大学 一种应用于胶囊内窥镜中的高精度定位方法
CN112230185B (zh) * 2020-10-13 2023-07-14 桂林电子科技大学 一种应用于胶囊内窥镜中的高精度定位方法

Similar Documents

Publication Publication Date Title
Wang et al. Performance bounds for RF positioning of endoscopy camera capsules
JP2004219329A (ja) 位置測定方法、位置測定システム、位置測定装置及び生体内無線装置
US20190090778A1 (en) Capsule endoscope position detection method and capsule endoscope position detection apparatus
JP5165161B2 (ja) 位置情報推定システム
US10478091B2 (en) Method and device for detecting position of micro robot using ultra wide-band impulse radar signal
JP2014512526A5 (fr)
US11061102B2 (en) Position estimating apparatus, position estimating method, and terminal apparatus
CN113260875A (zh) 无线通信网络中的无线通信单元和雷达单元的协调
WO2017212564A1 (fr) Procédé de détection de position de capsule endoscopique, système de détection de position de capsule endoscopique et dispositif de détection de position de capsule endoscopique
JP6971384B2 (ja) 位置推定装置、位置推定システム、位置推定方法、およびプログラム
US9696421B2 (en) Through wall sensing system using WiFi/cellular radar
CN101909519B (zh) 用于控制工作空间中医疗设备的位置的方法和装置
WO2014038003A1 (fr) Procédé de détermination, programme de détermination, dispositif de détermination et système de détermination
JP2019197039A (ja) 推定装置、生体数推定装置、推定方法、及び、プログラム
Hany et al. Degree-based WCL for video endoscopic capsule localization
US9081084B2 (en) Ultrasound system and method for processing beam-forming based on sampling data
KR102208687B1 (ko) 측정된 마이크로파 신호 분할에 의한 유방암 검출 장치 및 방법
Hany et al. Non-parametric method of path loss estimation for endoscopic capsule localization
US20220000377A1 (en) Sensor device
US20140152503A1 (en) Direction of arrival estimation using linear array
Hany et al. Moving averaging method of RSSI based distance estimation for wireless capsule localization
JP2015070585A (ja) 通信端末及びプログラム
JP6179894B2 (ja) インプラント通信端末の位置検出装置および位置推定方法
JP2012215444A (ja) 方位測定装置、該方位測定装置に用いられる方位測定方法及び方位測定プログラム
WO2018152987A1 (fr) Système de mesure de température sans fil et son procédé de traitement de signal

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16904599

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16904599

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP