JP2009279019A - Body motion monitoring system in radiotherapy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a body motion monitoring system in radiotherapy capable of attaching a sensor to an affected part inside and outside the body and having little influence on data communication by a shielding object and observing a patient's body motion with high accuracy. To do.
A sensor member attached to at least a part of a human body of a patient P, having acceleration measuring means capable of measuring accelerations in XYZ triaxial directions orthogonal to each other, and observed by the acceleration measuring means An acceleration sensor 1 having a transmitter capable of wirelessly transmitting the acceleration data; a receiving device 2 for receiving acceleration data transmitted from the transmitter of the acceleration sensor 1; and based on the acceleration data received by the receiving device 2 And an analysis software 3 for calculating body position coordinate data of the patient P; an electronic computer 4 equipped with the analysis software 3; and a radiation irradiation device 5 capable of outputting radiation for treatment.
[Selection] Figure 1

Description

  The present invention is an improvement of radiation therapy, more specifically, a sensor can be attached to an affected part inside and outside the body, and there is little influence on the data communication by the shield, and the body movement of the patient can be observed with high accuracy. The present invention relates to a body motion monitoring system in radiotherapy.

  When performing radiation therapy, the radiation irradiation position must not be displaced from the affected area, but since the human body inevitably moves due to breathing, heartbeat, etc., in order to synchronize radiation irradiation with this movement Therefore, it is necessary to monitor the movement every moment and accurately measure the position of the affected part.

  For example, the following patent documents disclose techniques for confirming the position of an affected area by monitoring the movement of the patient as described above in the treatment of irradiating radiation or the like.

  <Patent Document 1> (Japanese Patent Laid-Open No. 2005-185336) discloses a system that understands a target motion based on a three-dimensional tissue vector of a treatment target by real-time frame analysis using an ultrasound image.

  However, the invention of this document is for motion recognition of only a treatment target. In general, in an ultrasound diagnostic imaging apparatus, air, bone, or the like exists between the ultrasound probe and the treatment target. In a region (for example, lung, head, etc.), there is a problem that image generation is difficult because signal attenuation is significant.

  <Patent Document 2> (Japanese Patent Laid-Open No. 1-250272) has a retroreflecting light reflecting member attached to the body surface, and a light flux generating source for irradiating a constant light flux toward the body and the reflecting light reflecting member. An apparatus for recognizing the movement of a patient's position with a reflection detector that receives the emitted light is disclosed.

  However, this document invention does not mention three-dimensional motion or four-dimensional motion with a time axis. In addition, when a physical shield that blocks light (for example, a jig for fixing a patient or a radiation detector) exists between the body surface and the light beam, it is impossible to send and receive signals. There is. Furthermore, there is no mention of angle detection associated with human body movement.

  <Patent Document 3> (Japanese Patent Laid-Open No. 7-255717) uses a CT scanner and a respirometer or an electrocardiograph sensor to detect and correct the movement of the patient's body position in real time, and to take into account correction of the treatment plan simulation A radiation therapy system is disclosed.

  However, the invention of this document does not mention a specific signal detection method using a sensor, and also mentions a change in a respiratory waveform and a heartbeat by the sensor and a collimator correction associated therewith. There is no mention of data acquisition techniques in 3D or 4D motion.

  <Patent Document 4> (Japanese Patent Laid-Open No. 2004-57559) discloses an X-ray imaging apparatus that measures the amount of change with a laser and a laser distance meter projected onto the body surface of the chest or abdomen of the subject. A system for detecting a respiratory cycle is disclosed.

  However, the invention of this document is directed to an X-ray diagnostic apparatus and is not referred to radiotherapy. In addition, since the main focus is on distance measurement, there is no mention of change, movement, or rotation of the patient's body position. Furthermore, when there is a physical shield between the laser oscillator and the body surface or between the laser beam receiver and the body surface, there is a problem that it is difficult to detect the amount of change.

  <Patent Document 5> (Japanese Patent Laid-Open No. 6-154348) includes a wave transmitter / receiver installed outside and inside the human body, with one of the human body and the outside of the human body being a transmitter and the other being a receiver, and the outside of the human body and the human body surface. The position of the transmitter or receiver on the surface of the human body is calculated using the wave arrival time between and the position between the affected part and the human body surface, and the position of the affected part is calculated using the wave arrival time. A system is disclosed.

  However, the invention of this document has a problem of being invasive and burdensome on the patient because it is necessary to install a transmitter or receiver in the body. In addition, since the wave transmitted from the transmitter is received by the receiver and the distance is calculated from the arrival time, if there is a material that attenuates the wave or non-uniform material between the transmitter and receiver, It is difficult to measure the arrival time.

  Furthermore, in order to detect three-dimensional or four-dimensional motion, three or more receivers or transmitters are required. In addition, since the support rod is present so as to surround the patient, there is a problem that it is possible to limit the treatment direction and to obstruct treatment plan simulation.

  <Patent Document 6> (Japanese Patent Application Laid-Open No. 2000-201922) discloses the movement of a light source unit light emitter (infrared light emitting diode) installed on the body surface using a semiconductor position detecting element (hereinafter referred to as “PSD”). A system for automatic detection is disclosed.

  However, in the invention of this document, when a physical shield exists between the light emitter and the PSD, it is difficult to detect the signal. In addition, since the light emitter and the PSD require an electric driving force, many wires are required around the patient, which is complicated.

In addition, since it is necessary to adjust the moving range of the illuminant to be within the detection range of the PSD, it takes time to install, and detection is impossible when the illuminant moves out of the recognition range of the PSD. . Furthermore, since detection by PSD is limited to two-dimensional motion, it is impossible to detect three-dimensional motion and angle.
JP 2005-185336 A JP-A-1-250272 Japanese Patent Laid-Open No. 7-255717 JP 2004-57559 A JP-A-6-154348 JP 2000-201922 A

  The present invention was made in view of the above-described problems in conventional radiotherapy, and the object of the present invention is that a sensor can be attached to an affected part inside and outside the body, and It is an object of the present invention to provide a body movement monitoring system in radiotherapy that can observe a patient's body movement with high accuracy, with little influence on data communication by a shield.

  Means employed by the present inventor for solving the above-described problems will be described with reference to the accompanying drawings.

That is, the present invention is a system for measuring and monitoring the body position following the body movement of the patient P in radiotherapy,
A sensor member attached to at least a part of the human body of the patient P, having acceleration measurement means capable of measuring each acceleration in the XYZ triaxial directions orthogonal to each other, and acceleration data observed by the acceleration measurement means An acceleration sensor 1 having a transmitter capable of wireless transmission;
A receiving device 2 for receiving acceleration data transmitted from a transmitter of the acceleration sensor 1;
Analysis software 3 for calculating the body position coordinate data of the patient P based on the acceleration data received by the receiving device 2;
An electronic computer 4 in which the analysis software 3 is installed;
The body motion monitoring system in the radiotherapy was completed by adopting the technical means comprising the radiation irradiating device 5 capable of outputting the radiation for treatment.

  In order to solve the above problems, the present invention transmits the body position coordinate data of the patient P calculated by the analysis software 3 to the irradiation control means 51 of the radiation irradiation apparatus 5 in addition to the above means as necessary. A technique for accurately irradiating an affected area by controlling at least one of irradiation position shift, irradiation ON / OFF, and irradiation range of the radiation irradiated by the radiation irradiation device 5 Adopted the means.

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means in which the acceleration measuring means of the acceleration sensor 1 is of a piezoresistive type in addition to the above means as necessary.

  Furthermore, in order to solve the above-described problems, the present invention employs technical means for allowing the acceleration sensor 1 to adhere to the skin surface of the patient P in addition to the above means as necessary.

  Furthermore, in order to solve the above-described problems, the present invention is provided with a bed 6 on which the patient P lies, in addition to the above-described means as necessary, and the posture coordinate data of the patient P calculated by the analysis software 3 is provided. The technical means of transmitting to the position control means 61 of the bed 6 so that the position of the bed 6 can be moved was adopted.

  In the present invention, the sensor member is attached to at least a part of the human body of the patient, and has an acceleration measuring means capable of measuring each acceleration in the XYZ triaxial directions orthogonal to each other, and is observed by the acceleration measuring means. An acceleration sensor having a transmitter capable of wirelessly transmitting the acceleration data; a receiving device for receiving the acceleration data transmitted from the transmitter of the acceleration sensor; and a patient's posture based on the acceleration data received by the receiving device. Analysis software that calculates coordinate data; an electronic computer equipped with this analysis software; and a radiation irradiation device that can output radiation for treatment, so that it can be applied to the affected area both inside and outside the body. Even if a sensor can be installed and there is a shield between the sensor and the receiver, there is little impact on data communication. Ku, it is possible to observe the motion of the patient with a high degree of accuracy.

  In addition, since the acceleration sensor itself can perform three-dimensional measurement, it is possible to detect a three-dimensional or four-dimensional motion and to detect an angle even by installing only one acceleration sensor.

  Further, in the present invention, since the acceleration sensor can be installed outside the body, it is also possible to recognize the human body contour movement, and to acquire data in the three-dimensional or four-dimensional motion of the human body contour, and non-invasively. And patient burden is small.

  In addition, the battery-powered acceleration sensor and the receiver can wirelessly transmit acceleration data wirelessly, so even if there is a physical shield between them, there is no limitation on the measurement, and the receiver Since it is not necessary to install the device around the patient, the treatment site can be simplified in layout.

  Furthermore, since it is possible to change the irradiation direction of the radiation irradiation device by feedback of this acceleration data and to correct the patient's body position by moving the bed as needed, the practical use value in radiation therapy is very high.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described in more detail with reference to the drawings specifically shown as follows.

“First Embodiment”
1st Embodiment of this invention is described based on FIG. 1 and FIG. In the figure, what is indicated by reference numeral 1 is an acceleration sensor, and this acceleration sensor 1 is a sensor member attached to at least a part of the human body of the patient P, and each acceleration in the XYZ 3-axis directions orthogonal to each other. It has a measurable acceleration measuring means and a transmitter capable of wirelessly transmitting the acceleration data observed by the acceleration measuring means.

  Also, what is indicated by reference numeral 2 is a receiving device, and this receiving device 2 can receive acceleration data transmitted from the transmitter of the acceleration sensor 1.

  Furthermore, what is indicated by reference numeral 3 is analysis software, and the analysis software 3 can calculate the body position coordinate data of the patient P based on the acceleration data received by the receiving device 2. In this embodiment, the analysis software 3 created by “Visual C ++ 2005” manufactured by Microsoft Corporation is used.

  Furthermore, what is indicated by reference numeral 4 is an electronic computer. The electronic computer 4 has the analysis software 3 installed (installed). In this embodiment, a computer for control analysis (general-purpose computer) manufactured by DELL is used. Computer).

  Furthermore, what is indicated by reference numeral 5 is a radiation irradiation device, and this radiation irradiation device 5 can output radiation for treatment, for example, a cobalt irradiation device (γ ray), a gamma knife (γ ray). , Linac (X-ray), Novalis (X-ray), cyberknife (X-ray), electron beam irradiation device and the like.

  Therefore, the procedure for using the body motion monitoring system in the radiation therapy of the present invention will be described below. First, the acceleration sensor 1 is attached in the vicinity of the affected part to be irradiated with radiation in the patient P. In this embodiment, as shown in FIG. 1, the affected part is on the head, and a member having adhesiveness or adhesiveness can be provided on the sensor body and attached to the skin surface near the affected part.

  The acceleration sensor 1 of the present embodiment has acceleration measuring means and can measure accelerations in the XYZ triaxial directions orthogonal to each other (in the present embodiment, the two horizontal directions perpendicular to each other and the vertical direction). As described above, the acceleration sensor 1 itself can measure the accelerations in the three-axis directions, and the position can be measured only by using the acceleration sensor 1 alone.

In this embodiment, an “H48C” evaluation kit manufactured by Hitachi Metals, Ltd. is used as the wireless triaxial acceleration sensor of the acceleration sensor 1. Specific specifications are as follows.
Package size 4.8mm x 4.8mm
Package thickness 1.5mm
Volume 35mm ³
Acceleration detection range ± 3G
Power supply voltage 2.2-3.6V
Current consumption 0.6mA (Power supply voltage 3V, 25 ℃)
Detection sensitivity 333 ± 21mV / G (Power supply voltage 3V, 25 ℃)
Offset voltage 0 ± 35mV (Power supply voltage 3V, 25 ℃)
Impact resistance 5000G (action time 0.2ms)
Drop detection Outputs pulse signal from flag terminal when drop (zero G) is detected Lead-free soldering Compatible operating temperature range -25 ° C to + 75 ° C

  In this embodiment, a piezoresistive type can be employed as the acceleration measuring means of the acceleration sensor 1. A piezoresistive element is formed on a silicon single crystal substrate by a semiconductor process such as an ion implantation apparatus, and has a characteristic that the resistance value of the element increases or decreases when tensile or compressive stress is applied by a mechanical external force or the like. By making a structure in which stress is applied to the piezoresistive element when acceleration is applied, the acceleration can be detected as a resistance change of the piezoresistive element.

  Thus, the acceleration data obtained from the acceleration sensor 1 attached to the patient P is transmitted with the position of the first patient P as an initial value. The position of the affected part of the patient P is wirelessly transmitted by the battery-driven transmitter with the acceleration data measured by the acceleration measuring means of the acceleration sensor 1. At this time, the transmitted radio wave can perform, for example, 2.4 GHz band advanced low power data communication.

  By performing wireless transmission in this way, even if there is an obstacle between the acceleration sensor 1 and the receiver 2, the transmission is hardly affected, and smooth and reliable data communication can be performed.

  And when the affected part of the patient P moves from the initial position, the acceleration measurement means of the acceleration sensor 1 wirelessly transmits the acceleration data measured in real time according to the movement by the transmitter.

  Then, the acceleration data transmitted from the transmitter of the acceleration sensor 1 is received by the receiving device 2, and based on the acceleration data received by the receiving device 2, the body position coordinate data (velocity vector and position data) of the patient P. Is calculated by the analysis software 3.

  At this time, the receiving device 2 and the computer 4 equipped with the analysis software 3 can be connected using a USB cable (for example, 2.0 / 1.1 transfer rate 115.2 Kbps).

  The acceleration sensor 1 preferably performs drift correction, posture correction, gravity acceleration correction, and the like in advance, and confirms acceleration data (waveform data) from the acceleration sensor 1 according to the motion of the affected part P.

  At this time, since the detection error of the acceleration sensor 1 itself may be accumulated, for correction of detection error, the data acquired immediately before is converted into a linear function by the least square method and corrected as a speed offset, A relatively good pattern can be obtained.

  By configuring such a system, even if the affected part of the patient P moves, the position of the patient can be monitored following this movement.

  In the present embodiment, the posture coordinate data of the patient P calculated by the analysis software 3 is transmitted to the irradiation control means 51 of the radiation irradiation apparatus 5, and the irradiation position of the radiation irradiated by the radiation irradiation apparatus 5 is moved. By controlling at least one of irradiation ON / OFF and irradiation range, it is possible to accurately irradiate the affected area with radiation.

  Further, in the present embodiment, as shown in FIG. 2, when the acceleration sensor 1 is attached to the chest, the acceleration sensor 1 is a part where the movement due to the lung movement due to breathing or the heart movement due to the heartbeat is particularly large. By installing a plurality of 1s, monitoring can be performed with higher accuracy.

“Second Embodiment”
Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the bed 6 on which the patient P lies is provided, and the body position coordinate data calculated by the analysis software 3 is transmitted to the position control means 61 of the bed 6 (for example, a motor-type ball screw used for a turntable). Thus, the position of the bed 6 can be moved.

  By comprising in this way, it can be made to follow a motion of an affected part similarly to 1st Embodiment, and a radiation can be irradiated to an affected part exactly.

  The present invention is generally configured as described above. However, the present invention is not limited to the illustrated embodiment, and various modifications can be made within the description of “Claims”. Is not limited to the piezoresistive type, and a capacitance type and a heat detection type can be adopted and belong to the technical scope of the present invention.

It is the schematic showing the system of 1st Embodiment of this invention. It is the schematic showing the system of 1st Embodiment of this invention. It is the schematic showing the system of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Acceleration sensor 2 Receiver 3 Analysis software 4 Electronic computer 5 Radiation irradiation device 6 Bed P Patient A Affected part

Claims (5)

In radiation therapy, a system for measuring and monitoring the posture following the body movement of the patient P,
A sensor member attached to at least a part of the human body of the patient P, having acceleration measurement means capable of measuring each acceleration in the XYZ triaxial directions orthogonal to each other, and acceleration data observed by the acceleration measurement means An acceleration sensor 1 having a transmitter capable of wireless transmission;
A receiving device 2 for receiving acceleration data transmitted from a transmitter of the acceleration sensor 1;
Analysis software 3 for calculating the body position coordinate data of the patient P based on the acceleration data received by the receiving device 2;
An electronic computer 4 in which the analysis software 3 is installed;
A body movement monitoring system in radiation therapy, comprising a radiation irradiation device 5 capable of outputting radiation for treatment.   The posture coordinate data of the patient P calculated by the analysis software 3 is transmitted to the irradiation control means 51 of the radiation irradiating device 5, and the irradiation position of the radiation irradiated by the radiation irradiating device 5 is moved, irradiation ON / OFF, 2. The body movement monitoring system in radiation therapy according to claim 1, wherein the affected area can be accurately irradiated by controlling at least one of the irradiation ranges.   3. The body motion monitoring system in radiation therapy according to claim 1, wherein the acceleration measuring means of the acceleration sensor is of a piezoresistive type.   The body motion monitoring system in radiation therapy according to any one of claims 1 to 3, wherein the acceleration sensor 1 can be attached to the skin surface of the patient P.   The bed 6 on which the patient P lies is provided, and the position coordinate data of the patient P calculated by the analysis software 3 is transmitted to the position control means 61 of the bed 6 so that the position of the bed 6 can be moved. The body movement monitoring system in the radiation therapy according to any one of claims 1 to 4.

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