JP2010069158A - Apparatus and method for detecting abnormal tissue - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect a tumor such as a cancer tissue by a miniaturized structure harmless to the living body. <P>SOLUTION: A UWB transmitter generates UWB pulses composed of broad-band microwaves, and radiates the pulses from an antenna A<SB>i</SB>. The radiated microwaves are received by another antenna A<SB>j</SB>. Receiving signals are A-D converted and recorded in a memory 28. The processing is repeated while the antenna for transmission and the antenna for receiving are alternately changed. The time from the radiation of the microwave pulses till receiving of the reflected waves is found based on the recorded data, and the position of the tumor is identified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and method for detecting abnormal tissue such as cancer by emitting microwaves to a living body.

  Diagnosis of cancer is made, for example, by taking an image of a target region by X-ray or nuclear magnetic resonance imaging (MRI (magnetic resonance imaging)) and analyzing the taken image (for example, Patent Document 1).

Special table 2007-071873

  However, X-rays have the drawback of adversely affecting the living body. Further, both the X-ray apparatus and the MRI apparatus have a problem that the apparatus becomes large. Furthermore, there is a problem that it is essential to visit a specialized institution.

  The same problem exists not only in cancer but also in the case of detecting abnormal tissue such as a tumor in a living body.

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide an apparatus and a method capable of detecting an abnormal tissue such as a cancer tissue with a small configuration that is harmless to a living body.
Another object of the present invention is to provide an apparatus and method that can easily detect abnormal tissue with a simple configuration.

The abnormal tissue detection device according to the first aspect of the present invention is:
Radiation means for radiating microwaves to a living body;
Receiving means for receiving a reflected wave of the emitted microwave;
Signal processing means for performing signal processing for determining the presence or absence of abnormal tissue in the living body based on the received microwave;
It is characterized by providing.

  For example, the radiating means includes means for sequentially radiating microwaves from a plurality of antennas, the receiving means receives microwaves from a plurality of antennas, and the signal processing means is adapted to receive microwaves from microwave radiation. You may comprise so that the means to obtain | require the time until reception and the means to obtain | require the position of abnormal tissue from the time calculated | required regarding the said several antenna may be provided.

  For example, the radiating means includes means for generating a pulse wave including a frequency component in a microwave region, and means for radiating the generated pulse wave. The signal processing means includes the microwave received by the receiving means. Is provided with sampling means for sampling and storing the output.

  For example, it further comprises reference clock signal generating means for generating a reference clock signal, wherein the radiating means radiates a microwave in response to a reference clock signal from the reference clock signal generating means, and the sampling means A phase synchronization circuit that generates an oscillation frequency that is an integral multiple of the reference clock signal and that is synchronized with the reference clock signal, and a predetermined time has elapsed since the generation of the reference clock signal based on the output of the phase synchronization circuit Timing pulse generation means for generating a timing pulse later, and means for sampling the received signal received by the reception means in response to the timing pulse generated by the timing pulse generation means.

  For example, the sampling unit generates one timing pulse for one reference clock signal, generates the same timing pulse for m reference clock signals, and performs sampling.

  For example, the phase-locked loop circuit includes an n-stage ring oscillator composed of inverters coupled in a ring shape, a signal obtained by dividing the oscillation signal of the ring oscillator by 1 / n, and a 1 / n-divided signal and a reference clock. Means for controlling the oscillation frequency of the ring oscillator so as to synchronize with the signal.

In addition, the abnormal tissue detection method of the present invention,
Radiates microwaves to the living body,
Receives the reflected wave of the microwave from the living body,
Based on the received microwave, determine the presence or absence of abnormal tissue in the living body,
It is characterized by that.

  Hereinafter, an abnormal tissue detection apparatus and detection method according to an embodiment of the present invention will be described with reference to the drawings, taking an apparatus for detecting breast cancer as an example.

  First, a method for detecting cancer tissue in the present embodiment will be described with reference to FIG.

First, as schematically shown in FIG. 1, a plurality of antennas A _{1 to} A ₄ are arranged at regular intervals on the surface of a living body.

Subsequently, it radiates microwaves from the antenna A _1. Part of the emitted microwave propagates into the living body. In general, cancer tissue CA is known to have a dielectric constant that is about 5 to 10 times higher than that of normal biological tissue. When cancer tissue CA is present, the cancer tissue CA has different dielectric constants. Microwaves are reflected at the interface, that is, the surface of the cancer tissue CA, and are received by the antennas A _{2 to} A ₄ .

Here, when the time from when the microwave is emitted until the antenna A ₂ receives the reflected wave is T ₁₂ [s], T ₁₂ · c (c: speed of light in the living body) is It becomes the distance.

Accordingly, the cancer tissue CA is the antenna _{A 1} and _{A 2} is the focus, the sum of the distance from the antenna _{A 1} and _{A 2} will be located on an ellipse _{E 12} as a _{T 12} · c.

The same processing is performed on the microwaves received by the antennas A _{3 to} A ₄ , and the position of the cancer tissue CA can be obtained by obtaining the intersections of the plurality of ellipses E _{12 to} E ₁₄ .

Furthermore, by switching the antenna for transmission to A _2, radiating microwaves from an antenna A _2, which was received by the antenna _{A 1, A 3, A 4} , performs the same processing, thereafter, the transmitting antenna While sequentially switching to A ₃ and A ₄ , microwaves are emitted, reflected waves are received by other antennas, and the same processing is performed, whereby the position of the cancer tissue CA can be more accurately specified. .

  In the above example, the description is given in two dimensions for easy understanding, but in reality, the above processing is performed in three dimensions.

  Next, the cancer detection apparatus 10 that determines the presence and position of cancer tissue using such a method will be described.

  As shown in FIG. 2, the cancer detection device 10 includes a main body 11 and a display device 12. For example, the cancer detection device 10 is configured as a portable type having a length of 10 to 20 cm, a width of 5 to 15 cm, and a thickness of about 2 to 4 cm. Yes.

  As shown in FIG. 3, an antenna array 13 and a signal processing circuit 14 are stacked on the main body 11.

Antenna array 13, as shown schematically in FIG. 4, is constructed from the array antenna A ₁ to A _n which are arranged in a matrix.

  As shown in FIG. 5, the signal processing circuit 14 includes a reference clock signal generation circuit 21, a UWB transmitter 22, a transmission antenna selector 23, a reception antenna selector 24, a low noise amplifier (LNA) 25, an A / A The D converter 26, a control unit 27, and a memory 28 are included.

  The reference clock signal generation circuit 21 generates a clock signal CLK having a predetermined cycle (125 MHz in this embodiment) as shown in FIG.

  A UWB (Ultra Wide Band) transmitter 22 is a circuit that forms and transmits a UWB pulse waveform that is a wideband signal in a microwave band (for example, a center frequency of 5 GHz). As shown in FIG. The generating circuit 31, the differentiating circuit 32, and the amplifier 33 are configured.

  As shown in FIG. 7, the triangular wave generation circuit 31 includes AND gates 41, 42, 43, inverters 44, 45, 46, and an exclusive OR gate (EXOR gate) 47.

An enable signal EN is supplied to one input terminal of the AND gates 41 and 42.
On the other hand, the reference clock signal CLK from the reference clock signal generation circuit 21 is supplied to the other input terminal of the AND gate 41. An inverted signal CLK の (bar) of the reference clock signal CLK is supplied to the other input terminal of the AND gate 42 via the inverter 44. The output of the AND gate 41 is supplied to one input terminal of the EXOR gate 47 and one input terminal of the AND gate 43. The output of the AND gate 42 is supplied to the other input terminal of the EXOR gate 47 after being delayed for a predetermined time via the inverters 45 and 46.

  In such a configuration, when the active level enable signal EN is supplied, the AND gates 41 and 42 are opened. As a result, as shown in FIG. 8A, the reference clock signal CLK is supplied to one input terminal of the EXOR gate 47 as the clock signal Clock. 8B, the delayed signal Clock_d of the inverted clock signal CLK is supplied to the other input terminal of the EXOR gate 47.

  The EXOR gate 47 takes the EXOR of the input signal and outputs a pulse signal EX including two pulse trains as shown in FIG. The pulse included in the pulse signal EX has a triangular shape due to the rising and falling characteristics of the EXOR gate 47.

  The AND gate 43 calculates the logical product of the pulse signal generated by the EXOR gate 47 and the clock signal Clock, cuts the latter half of the two pulses, and generates the triangular wave signal TR shown in FIG. Output to the differentiation circuit 32.

The differentiation circuit 32 shown in FIG. 6 differentiates the triangular wave signal TR supplied from the triangular wave generation circuit 31 to include a broadband microwave component (for example, a center frequency of 5 GHz) as illustrated in FIG. A pulse wave having a waveform corresponding to the Gaussian distribution obtained by the second order differentiation is generated.
The amplifier 33 amplifies and outputs the generated pulse wave.

Transmitting antenna selector 23 shown in FIG. 5 is controlled by the control unit 27 selects one of the antennas A _i to be used for transmission of the antennas A ₁ to A _n which constitute the antenna array 13, a pulse from the amplifier 33 Supply waves. The selected antenna A _i radiates the supplied pulse wave.

Since a pulse wave is generated each time the reference clock signal CLK is generated by the reference clock signal generation circuit 21, the antenna _Ai periodically radiates a pulse wave as shown in FIG.

Receiving antenna selector 24 is controlled by the control unit 27, selects an antenna A _{j (j} ≠ i) to be used for reception of one of the antenna A ₁ to A _n which constitute the antenna array 13, the received signal Supply to LNA25.
LNA25 amplifies the received signal of the antenna A _j which is supplied through the receiving antenna selector 24 with low noise.

The A / D converter 26 samples the output of the LNA 25 and performs A / D conversion.
The control unit 27 includes a processor and controls the operation of the signal processing circuit 14. Further, the control unit 27 stores the output of the A / D converter 26 in the memory 28. In addition, the control unit 27 processes the data stored in the memory 28, specifies the presence or absence of cancer tissue, and the position when it exists, and displays it on the display device 12.
Note that the display device 12 may be configured by a touch panel so that any instruction or data can be input to the control unit 27. In addition, an input unit may be provided separately. An external connection terminal may be arranged.

In the above-described configuration, the repetition period of the transmission pulse is 125 MHz, and one period is 8 ns.
A pulse with a center frequency of 5 GHz has a pulse width of 200 ps. During this time, it is difficult to set a plurality of sample timings and A / D convert the input signal in real time.
Therefore, in the present embodiment, the A / D converter 26 as shown in FIGS. 11 and 12 is configured, one sampling is performed for one pulse wave, the pulse wave is repeatedly output, and the sampling timing is relatively set. By moving, a plurality of points can be sampled.

  The A / D converter 26 includes a timing generation circuit 41 shown in FIG. 11 and a conversion circuit 42 shown in FIG.

  As shown in FIG. 11, the timing generation circuit 41 includes a buffer circuit 101, a phase frequency comparator (PFD) 102, an inverter 103, a charge pump (CP) 104, a low-pass filter (LPF) 105, and a ring oscillator. 106, an 8-input 1-output multiplexer 107, a 2-input 1-output multiplexer 108, and frequency divider circuits 109-114.

  A reference clock signal CLK is supplied from the reference clock signal generation circuit 21 to the buffer circuit 101. The buffer circuit 101 amplifies the supplied reference clock signal CLK with unity gain and outputs it.

  The PFD 102 compares the phase of the signal obtained by dividing the oscillation signal of the ring oscillator 106 by 1/16 with the reference clock signal CLK supplied via the buffer circuit 101, and outputs a signal indicating the comparison result. For example, the PFD 102 outputs “1” to the QA terminal if the phase of the received signal supplied from the buffer circuit 101 is advanced, and outputs “1” to the QB terminal if it is delayed.

  Inverter 103 inverts the QA output of PFD 102 and outputs QA￣ (bar).

  The charge pump (CP) 104 charges the low-pass filter 105 as a current source if QA is “1”, and discharges the low-pass filter 105 as a current sink if QB is “1”.

  The low-pass filter 105 generates a potential that is substantially proportional to the charged charge. This potential is input to the ring oscillator 106 as a control voltage.

  The ring oscillator 106 is an effective 16-stage ring oscillator composed of 8-stage inverters I1 to I8 connected in a ring shape, and oscillates at 2 GHz. The pairs I1Q, I1QＩ-I8Q, I8Q￣ of the Q output and Q￣ output of each of the inverters I1-I8 are as shown in FIG.

  The multiplexer 107 selects and outputs a pair of output signals from the eight inverters I1 to I8 constituting the ring oscillator 106 based on the outputs of the frequency dividing circuits 110 to 112.

  The multiplexer 108 selects whether or not to flip the pair of output signals output from the multiplexer 107 based on the output of the frequency dividing circuit 113.

  The frequency dividing circuit 109 divides the pair of oscillation signals of the ring oscillator 106 by 1/16 and outputs the result to the frequency dividing circuit 110. Further, the Q output of the frequency dividing circuit 109 is supplied to the PFD 102.

The frequency dividing circuit 110 divides the pair of output signals of the frequency dividing circuit 109 by 1/64 and outputs the result to the frequency dividing circuit 111 and the multiplexer 107.
The frequency dividing circuit 111 divides the pair of output signals of the frequency dividing circuit 110 by 1/2 and outputs the result to the frequency dividing circuit 112 and the multiplexer 107.
The divider circuit 112 divides the pair of output signals of the divider circuit 111 by 1/2 and outputs the divided signals to the divider circuit 113 and the multiplexer 107.
The frequency divider 113 divides the pair of output signals of the frequency divider 112 by ½ and supplies them to the multiplexer 108.

  The frequency divider circuit 114 divides the pair of output signals of the multiplexer 108 by 1/16 and supplies the result to the conversion circuit 42.

  According to this configuration, the 125 MHz reference clock signal CLK from the reference clock signal generation circuit 21 and the 1/16 frequency-divided signal of the ring oscillator 106 are compared by the PFD 102, and the inverter I1 of the ring oscillator 106 is compared. The Q output is synchronized with the reference clock signal CLK and oscillates at a frequency 16 times the reference clock signal CLK, that is, 2 GHz.

  The multiplexers 107 and 108 output the Q and Q output of the inverter I1 shown in FIG. 13 32 times, the Q8 and Q output of the I8 32 times, and the Q and Q output of the I7 according to the outputs of the frequency dividing circuits 110 to 113, respectively. 32 times. . . Q2 and Q output of I2, 32 times of Q1 and Q output of I1, 32 times of Q and Q output of I8,. . . In this way, a signal delayed by unit time of the ring oscillator 106 is selected.

  The frequency dividing circuit 114 divides the output signal of the multiplexer 108 by 1/16. This signal includes a signal synchronized with the output of the reference clock signal CLK, a signal delayed by unit time from the reference clock signal CLK, a signal delayed by 2 unit time,. . . The signal is delayed by 15 unit times.

  On the other hand, the conversion circuit 42 includes a voltage dividing circuit 121, a comparator group 122, an encoder 123, and an averaging circuit 124, as shown in FIG.

The voltage dividing circuit 121 is composed of 64 resistor elements connected in series, and divides the voltage between the reference voltage + Vref and −Vref in 64 stages.
Each of the comparators constituting the comparator group 122 receives one of the voltages divided by the voltage dividing circuit 121 and the input voltage Vin, and compares both voltages in response to the clock φ. In response to (), the comparison result is output.

The encoder 123 encodes the output of the comparator group 122.
The averaging circuit 124 averages and outputs a plurality of measurement values.

Next, the operation of the cancer detection apparatus 10 configured as described above will be described.
The reference clock signal generation circuit 21 outputs the 125 MHz reference clock signal CLK and its inverted signal CLK as shown in FIG.

  The triangular wave generation circuit 31 in the UWB transmitter 22 processes the reference clock signal CLK, and outputs a triangular wave signal TR having a repetition period of 125 MHz, as shown in FIG. 8D.

  The differentiating circuit 32 differentiates the triangular wave signal TR and outputs a pulse signal having a first-order differentiated Gaussian waveform as shown in FIG. 10 at a repetition cycle of 125 MHz. The amplifier 33 amplifies the supplied signal and outputs it.

On the other hand, the control unit 27 starts the processing of FIG. 14 and first switches the transmission antenna selector 23 and the reception antenna selector 24 to select the antenna A ₁ as the transmission antenna A _i and receives the reception antenna A _j (i ≠ j selecting an antenna _{a 2} as) (step S11 to S13).

Antenna _{A 1,} which is selected, the pulse wave from the UWB transmitter 22 is supplied emits this (step S14).

As described with reference to FIG. 1, the radiated pulse propagates through the living body surface and into the living body, and when cancer tissue exists, it is reflected at the interface with the cancer tissue, and the antenna A ₂ is reached. The antenna A ₂ receives these microwaves, is supplied to the LNA 25 via the reception antenna selector 24, is amplified, is supplied to the A / D converter 26, and becomes the input Vin of the conversion circuit 42 shown in FIG. 12 ( Step S14).

  On the other hand, the timing generation circuit 41 of the A / D converter 26 is supplied with the reference clock signal CLK from the reference clock signal generation circuit 21, and the oscillation signal of the ring oscillator 106 is synchronized with the reference clock signal CLK and 16 It is locked to a state where it oscillates at a double frequency (that is, 2 GHz).

  The multiplexer 107 initially selects the pair of outputs of the inverter I1 according to the outputs of the frequency dividing circuits 110-112. Further, the multiplexer 108 selects the Q and Q￣ outputs of the inverter I 1 according to the output of the frequency dividing circuit 113.

  The Q and Q￣ outputs of the inverter I1 are signals that are synchronized with the reference clock signal CLK and have a frequency 16 times that of the reference clock signal CLK.

  The frequency dividing circuit 114 divides the frequency by 1/16 to generate a timing signal φ and its inverted signal φ￣, and outputs them to the comparator group 122. The timing signals φ and φ￣ are signals synchronized with the reference clock signal CLK and having the same period as the reference clock signal CLK.

  The comparator group 122 compares the voltage Vin of the received signal supplied from the LNA 25 with the reference voltage supplied from the voltage dividing circuit 121 in response to the timing signals φ and φ￣, and the voltage Vin of the input signal is greater. If it is larger, “1” is output, and if the voltage Vin is lower than the reference voltage, “0” is output.

The encoder 123 takes in the output of the comparator group 122, encodes it, and supplies it to the averaging circuit 124. The averaging circuit 124 stores this.
Thus, in response to the output of the first reference clock signal CLK, at the timing at which the pulse wave is synchronized with the reference clock signal CLK with the emitted sampling of the received signal of the antenna A ₂ is performed.

Subsequently, runs the same operation 31 times, each time a pulse wave from the transmitting antenna A ₁ is radiated, the voltage Vin of the received signal of the antenna A ₂ is sampled at a timing synchronized with the reference clock signal CLK ( Step S14).

  The averaging circuit 124 takes in and outputs the encoder outputs sequentially output from the encoder 123 (step S14).

  When the sampling of 32 times is completed, the control unit 27 stores the stored value of the averaging circuit 124 in the memory 28 as the sampling value of the received signal at time t = 0 (output time of the reference clock signal CLK) (step S14). .

  Subsequently, the multiplexer 107 selects the output pair of the inverter I8 according to the outputs of the frequency dividing circuits 110 to 112. Further, the multiplexer 108 selects the Q￣ and Q outputs of the inverter I8 according to the output of the frequency dividing circuit 113.

  As shown in FIG. 13, the Q￣ output of the inverter I8 is a signal delayed by one reference time (ie, 500 ps (2 GHz) /8/2=31.25 ps) from the reference clock signal CLK, and This signal has a frequency 16 times that of the reference clock signal CLK.

  The frequency dividing circuit 114 divides the frequency by 1/16 and outputs it to generate a timing signal φ and its inverted signal φ￣ and output it to the comparator group 122.

  In response to the clock signals φ and φ 受 信, the comparator group 122 compares the voltage Vin of the received signal supplied from the LNA 25 with the reference voltage supplied from the voltage dividing circuit 121, and if the voltage Vin is larger, “ “1” is output, and “0” is output if the voltage Vin is lower.

  The encoder 123 takes in the output of the comparator group 122, encodes it, and supplies it to the averaging circuit 124.

Subsequently, the same operation is performed 31 times, and at each sampling point shifted by 31.25 ps from the reference clock signal CLK every time it is radiated from the transmission antenna A ₁ in response to the reference clock signal CLK, the reception antenna A ₂ The received signal voltage Vin is sampled and encoded.

  The averaging circuit 124 captures and averages the output of the encoder 123 that is sequentially output. When the 32 samplings are completed, the control unit 27 uses the memory 28 as the sampling value of the received signal at the time t = 31.25 ps (when 31.25 ps has elapsed from the output of the reference clock signal CLK). (Step S14).

  Thereafter, the multiplexers 108 and 107 are connected to Q and Q￣ output of the inverter I7 → Q￣ and Q output of the inverter I6 → Q and Q￣ output of the inverter I5 → Q￣ of the inverter I4 and Q output → Q and Q of the inverter I3, respectively. ￣ output → Q￣ of inverter I2, Q output → Q￣ of inverter I1, Q output → Q of inverter I8, Q￣ output → Q￣ of inverter I7, Q output → Q of inverter I6, Q￣ output → inverter I5 Q￣, Q output → Q of inverter I4, Q￣ output → Q￣ of inverter I3, Q output → Q, Q￣ output of inverter I2, 32 times each, and frequency divider 114 The frequency is divided by 1/16 and output to the comparator group 122.

The comparator group 122, the encoder 123, and the averaging circuit 124 sample 32 the voltage Vin of the received signal of the antenna A ₂ when t = 62.5 ps (31.25 × 2) has elapsed from the output of the reference clock signal CLK. The average value is obtained by performing the measurement twice, and the sampling of the voltage Vin of the received signal of the antenna A ₂ is performed 32 times when t = 93.75 ps (31.25 × 3) has elapsed from the output of the reference clock signal CLK. Find the value. . . . , From the output of the reference pulse t = 468.25ps (31.25 × 15) of the elapsed time, the sampling of the voltage Vin of the received signal of the antenna _{A 2} performed 32 times calculate the average.

  At t = 500 ps (31.25 × 16), Q and Q￣ of the inverter I1 are selected again, and the outputs of the multiplexers 107 and 108 go around. However, for the 125 MHz = 8 ns timing signal φ, φ￣ divided by 1/16, 500 ps is only turned by 1/16 period, and thereafter, the Q, Q￣ output of the inverter I1 is output 15 times. 32 times,. . . , I2 Q￣ and Q output 32 times, I1 Q￣ and Q output 32 times,. . . The operation of selecting the Q and Q output of I2 32 times, sampling and encoding the received signal voltage Vin 32 times, and averaging is repeated (step S14).

Thus, the detection process by the combination of the transmission antenna A ₁ and the reception antenna A ₂ is completed, and the sampling value is stored in the memory 28 as illustrated in FIGS. 15A and 15B (step S14). .

Further, in step S15 of FIG. 14, it is determined that j ≠ n (step S15; No), j is incremented by 1 and updated to 3, and the receiving antenna A _j becomes A ₃ (step S16). Subsequently, the process returns to step S12, and thereafter the same operation is repeated.

When reception with all antennas except the antenna A _i is completed, it is determined in step S15 that j = n (step S15; Yes), and then it is determined whether i = n (step S17). Initially, a i ≠ n (Step S17; No), then updates the i and j (step S18), and returns to step S12, and emits a pulse wave from the new antenna _{A i,} in another antenna _{A j} The process of receiving and recording is repeated.

In this manner, by sequentially switching the transmission antenna A _i and the receiving antenna A _j, radiation, receiving, by performing the process of recording, emits a pulse wave from the antenna A _n, received by the antenna A _n-1 treatment When the process is completed, Yes is determined in steps S15 and S17, and the process ends.

  In this manner, the cancer tissue detection apparatus 10 according to the present embodiment is a small and light apparatus and can detect cancer tissue without adversely affecting the living body.

  In addition, in the cancer detection apparatus 10 that requires sampling at an ultra-high speed, an equivalently high sampling rate can be obtained by periodically emitting a pulse wave and repeating sampling while sequentially shifting the relative position. Can do.

  Further, since the average value of the 32 measurement values is taken by the averaging circuit, an error caused by clock jitter can be reduced.

How to process the data stored in the memory 28 in this way is arbitrary.
For example, when the waveform data shown in FIG. 16A is sampled, the influence of the pulse propagated on the living body surface is removed as shown in FIG. 16B, and then the reference clock signal CLK The time T from the output until the reflected wave is received is calculated, this time is converted into a distance, a process for obtaining an elliptical sphere satisfying the condition is performed, and the intersection of the elliptical spheres obtained from a plurality of data is obtained to obtain cancer tissue. What is necessary is just to specify the position of.
This process may be performed by the control unit 27 itself, or may be executed by another device using data stored in the memory 28.

In addition, this invention is not limited to the said embodiment, A various deformation | transformation and application are possible.
For example, the illustrated hardware is an exemplification, and any other configuration can be adopted. For example, the appearance of the cancer detection apparatus 10 and the arrangement of circuits and antennas can be arbitrarily changed.

  Also, the circuit configuration can be arbitrarily changed as long as the same function can be realized. For example, although the repetition cycle of the reference clock signal CLK is 125 MHz, it can be appropriately changed from about 50 MHz to about 400 MHz.

  In the above embodiment, in order to set the equivalent sampling rate to 31.25 ps (32 GHz), the ring oscillator 106 having the 2 GHz oscillation frequency of the timing generation circuit 41 is effectively configured from 16 stages of inverters. The sampling rate is not limited to 32 GHz and is arbitrary. In this case, the effective number of inverters constituting the ring oscillator 106 and the oscillation frequency of the ring oscillator are adjusted according to the sampling rate.

  Further, in consideration of noise, jitter, and the like, the conversion circuit 42 has sampled a signal received at relatively the same timing 32 times and averaged the output. For example, the comparator group 122 The output of each of the comparators constituting the circuit may be monitored a plurality of times, and the output may be determined by majority decision to eliminate the influence of jitter. Similarly, each output of the encoder 123 may be monitored a plurality of times, and the output may be determined by majority vote. In addition, any method for removing the influence of noise and jitter can be adopted.

  The number of times the same data is repeatedly acquired is not limited to 32 times, and can be set as appropriate, such as 16 times or 64 times. In this case, the settings of the frequency dividing circuits 110 to 113 are changed according to the number of times.

  In the above embodiment, an example has been shown in which one antenna is selected by the receiving antenna selector 24 and a radiated wave is received by the selected antenna. However, m (plural) LNAs 25 and A / D converters 26 are prepared. Then, a plurality of antennas may be selected by the reception antenna selector 24, and transmission waves may be received and processed in parallel.

  Further, the present invention is not limited to the example using the ring oscillator 106, and it is possible to use an oscillator having any other configuration that generates a plurality of signals shifted in timing with respect to the reference clock signal CLK.

Further, the present invention is not limited to an example in which an oscillator is used, and the reference clock signal CLK may be sequentially delayed by a plurality of delay lines to obtain sampling timing.
In the above embodiment, the pulse wave of the UWB signal is generated and transmitted. However, the waveform of the signal to be transmitted is arbitrary as long as a correlation can be ensured between the transmission signal and the reception signal.

  Although breast cancer has been exemplified as an object of detection, the present invention can be applied to detection and discrimination of regions having different dielectric constants in the living body, such as other cancers and arbitrary tumors.

  The present invention can be used to detect abnormal tissues such as cancer with a simple apparatus and method.

It is a figure for demonstrating the method of detecting a cancer tissue. It is a figure which shows the external appearance of the cancer detection apparatus which concerns on embodiment. It is a figure which shows the internal structure of the cancer detection apparatus which concerns on embodiment. It is a figure which shows the example of arrangement | positioning of an antenna. It is a block diagram which shows the structural example of a transmission / reception circuit. It is a block diagram which shows the structural example of a UWB transmitter. It is a block diagram which shows the structural example of a triangular wave generation circuit. (A)-(d) is a figure which shows the signal waveform of each part. It is a figure which shows an example of the frequency spectrum of a first-order differential Gaussian waveform. It is a figure which shows an example of an actual transmission waveform. It is a block which shows the structural example of a timing generation circuit. It is a block diagram which shows the structural example of a conversion circuit. It is a wave form diagram of a ring oscillator. It is a flowchart for demonstrating operation | movement. (A) And (b) is a figure which shows the example of the sampled data. It is a figure which shows an example of the acquired data.

Explanation of symbols

10 Cancer detection device
11 Body
12 Display device
13 Antenna array
14 Signal processing circuit
21 Reference clock signal generation circuit
22 UWB transmitter
23 Transmitting antenna selector
24 Receiving antenna selector
25 Low noise amplifier (LNA)
26 A / D converter
27 Control unit
28 memory
31 Triangular wave generator
32 Differentiation circuit
33 Amplifier
41 Timing generation circuit
42 Conversion circuit
101 Buffer circuit
102 Phase frequency comparator (PFD)
104 Charge pump (CP)
105 Low-pass filter (LPF)
106 Ring oscillator
107, 108 Multiplexer
109-114 frequency divider
121 voltage divider
122 comparators
123 Encoder
124 Averaging circuit

Claims (7)

Radiation means for radiating microwaves to a living body;
Receiving means for receiving a reflected wave of the emitted microwave;
Signal processing means for performing signal processing for determining the presence or absence of abnormal tissue in the living body based on the received microwave;
An abnormal tissue detection device comprising: The radiating means includes means for radiating microwaves sequentially from a plurality of antennas,
The receiving means receives microwaves with a plurality of antennas,
The signal processing means includes
Means for determining the time from microwave radiation to microwave reception;
Means for determining the position of the abnormal tissue from the time determined for the plurality of antennas,
The abnormal tissue detection apparatus according to claim 1. The radiating means is
Means for generating a pulse wave including frequency components in the microwave region;
Means for emitting the generated pulse wave,
The signal processing means includes sampling means for sampling and storing the microwave output received by the receiving means,
The abnormal tissue detection device according to claim 1 or 2, wherein Reference clock signal generating means for generating a reference clock signal is further provided,
The radiating means radiates a microwave in response to a reference clock signal from the reference clock signal generating means,
The sampling means includes
A phase synchronization circuit having an oscillation frequency that is an integral multiple of the reference clock signal and generating a signal synchronized with the reference clock signal;
A timing pulse generating means for generating a timing pulse after a predetermined time has elapsed since the generation of the reference clock signal based on the output of the phase synchronization circuit;
Means for sampling the received signal received by the receiving means in response to the timing pulse generated by the timing pulse generating means,
The abnormal tissue detection device according to claim 3. The sampling means includes
One timing pulse is generated for one reference clock signal,
Generate the same timing pulse for m reference clock signals and perform sampling.
The abnormal tissue detection device according to claim 3 or 4, characterized in that. The phase synchronization circuit includes:
An n-stage ring oscillator composed of inverters coupled in a ring shape;
Means for controlling the oscillation frequency of the ring oscillator so that the oscillation signal of the ring oscillator is divided by 1 / n, and the 1 / n-divided signal is synchronized with the reference clock signal;
Comprising
The abnormal tissue detection apparatus according to claim 4, wherein: Radiates microwaves to the living body,
Receives the reflected wave of the microwave from the living body,
Based on the received microwave, determine the presence or absence of abnormal tissue in the living body,
An abnormal tissue detection method characterized by the above.

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