JP2538611B2 - Light flux forming device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiation diagnosis and treatment apparatus, and more particularly, to positioning of a patient during diagnosis and treatment and monitoring of positional shift of the patient due to body movement after positioning. The present invention relates to a light flux forming device having a function.

[Conventional technology]

As a conventional technique, for example, there is a technique disclosed in Japanese Patent Application Laid-Open No. 57-11336, but one light source and one photoelectric detector are provided in order to have a function of monitoring the displacement of a patient. It has a linearly diffused luminous flux that forms a bright luminous spot-like luminous flux, and the luminous flux that is focused in parallel in the patient's spot-like shape is reflected by a reflective tape, and a single photoelectric detector is used. It has been a method of monitoring the position shift of the patient by detecting and positioning and body movement after positioning.

[Problems to be solved by the invention]

The above-described conventional light flux forming apparatus has only one light flux generation source, and one half mirror and one mirror diffuse the light flux emitted from the light flux generation source into one linear light flux and a point light flux. Since it is formed by the light flux, there is a drawback (1) that the positioning work is difficult as compared with the case where two linearly diffused light fluxes intersect at a right angle and cross light fluxes are formed.

In addition, even if the light flux is reflected by a reflective tape having the property of retroreflecting, the light flux is unavoidably scattered, but the reflected light is detected by a single photoelectric detector. It has a drawback (2) that the range of angles where the reflected light flux can be detected is extremely narrow when the reflective tape is attached to the surface of the nose or jaw which is not perpendicular to the direction in which the light flux travels.

Furthermore, since the light source for positioning and the light source for monitoring are common, it is difficult to distinguish the reflected light of the straight line part and the reflected light of the dot-shaped part from the reflected light from the reflective tape, so the S / N ratio is poor. Had (3). By the way, when an experiment is conducted with a device manufactured by Cammex, the reflected light beam can be detected only within a range of about ± 5 °.

[Means for solving problems]

The light flux forming device of the present invention includes a light flux generation source 1 capable of generating a light flux modulated at a certain frequency, a lens 2 for focusing the light flux in parallel in a point shape, and two lenses for distributing the light flux in two directions. The half mirrors 3, 5 and the two cylindrical lenses 4, which are arranged at right angles to each other and diffuse the two light beams reflected by the half mirrors 3, 5 into two linear light beams intersecting at right angles,
6, a mirror 7 that reflects the light flux that has passed through the half mirrors 3 and 5 and directs the light flux toward the intersection of the two light fluxes that intersect in the orthogonal direction, and a light flux that is reflected by the mirror 7 and is a point-parallel light flux. Lens 8 for converging the light beam, a reflection tape 13 for retroreflecting the above-mentioned modulated point-like parallel light beam 23, and a plurality of photoelectric detections for detecting the light beam 24 reflected by the reflection tape. And a container 11.

〔Example〕

FIG. 1 is a vertical sectional view of an embodiment of the present invention. Among the light fluxes emitted from the light flux generation source 1 and modulated at a certain frequency, the two light fluxes 21 and 22 reflected by the half mirror 3 and the half mirror 5 intersect at right angles with each other, and the intersection point 25 is the patient 3
Used to position 1. Of the modulated light flux emitted from the light flux generation source 1, the light flux reflected by the mirror 7 becomes a point-like parallel light flux 23, which is used to monitor the body movement of the positioned patient 31. The lens 2 and the lens 7 are used for focusing the light flux into a point-like parallel light flux, the lens 4 and the lens 6 are used for linearly diffusing the light flux, and the lens 4 and the lens 6 are at right angles to each other. Is arranged.

The reflection tape 13 is a patient 31 indicated by the intersection 25 of the light flux 21 and the light flux 22.
The light flux 23 reflected on the surface of is reflected retroactively. Luminous flux source 1
When the distance L26 between the optical axis of
The optical axis of the light beam 23 can be adjusted by changing the angle of the mirror 7 so that the optical axis of 3 and the optical axis of the intersection point 25 become substantially the same locus.

The reflection tape 13 has the property of retroreflecting the light flux 23 as shown in FIG. 2, and is placed on the intersection 25 of the light flux 21 and the light flux 22 of the positioned patient 31, and the light flux 23 is reflected by the reflection tape 13. It becomes the diffused luminous flux 24, and the luminous flux 24 is the luminous flux exit 14
It is efficiently received by a plurality of photoelectric detectors 11 arranged around. The electric signal received and converted by the photoelectric detector 11 is detected and filtered to detect the patient.
Used to determine if 31 is in the correct position. Since the luminous flux 23 is modulated, the reflected luminous flux contained in the luminous flux 24 due to natural light and the electric light in the room can be distinguished from the reflected luminous flux from the luminous flux 23. Further, since the luminous flux 21 and the luminous flux 22 are linearly diffused, the illuminance of the reflected luminous flux from the luminous flux 21 and the luminous flux 22 is smaller than the illuminance of the reflected luminous flux from the luminous flux 23 and can be ignored.

The relationship among the patient 31, the radiation apparatus 32, the main body 12 of the apparatus, the luminous flux 22, the luminous flux 23 and the luminous flux 24 will be described with reference to FIG.

FIG. 4 is a block diagram showing an example of an electric circuit for detecting a positional shift due to the body movement of the patient. The output signal of the oscillator 51 is used for modulation and demodulation of laser light. The output of the oscillator 51 is sent to the variable amplifier 52, and at a suitable level, the differential amplifier 53
Is supplied to. Oscillator by differential amplifier 53, laser drive circuit 54 and laser die auto 55 with monitor die auto
The laser light 23 amplified and modulated at the output frequency of 51 is output. The modulated laser light 23 is retroreflected by the reflection tape 13 and becomes a light flux 26, which is received by the photoelectric detector 11. Luminous flux
26 is converted into an electric signal by the photoelectric detector 11 and then amplified by the amplifier 56.

The phase detector 57 uses the oscillation signal output of the oscillator 51,
The output of the amplifier 56 is phase-detected and sent to the comparator 58.
The sensitivity of the comparator 58 can be varied by the reference signal generating circuit, and the output of the comparator 58 can warn the operator of the device of the positional shift due to the body movement of the patient by the alarm buzzer 60 and the relay circuit 60.

〔The invention's effect〕

As described above, according to the present invention, a light flux generation source 1 capable of generating a modulated light flux, a lens 2 for focusing the light flux in parallel in a point shape, and two light flux sources arranged in series for distributing the light flux in two directions. Half mirrors 3, 5 and two cylindrical lenses 4, 6 arranged at right angles to each other for diffusing the two light beams reflected by the half mirror into a linear light beam intersecting at right angles.
The light flux that has passed through the two half mirrors 3 and 5 arranged in series is a reflection mirror 7, a lens 8 that focuses the light flux reflected by the mirror 7 in a point-like shape, and a modulated point-like shape. A patient at the time of radiation treatment or diagnosis by having a reflective tape 13 that retroreflects a bundle of parallel-focused light flux 23 almost in the incident direction and a plurality of photoelectric detectors 11 that detect the light flux reflected by the reflection tape 13. Is easier to position by the cross-shaped intersection 25, and a plurality of photoelectric detectors 11 and the modulated light flux
The reflected light flux 24 from the reflective tape 13 having the retroreflective performance attached to the surface of the patient's nose, jaw, or the like that is not perpendicular to the traveling direction of the light flux can be detected with a high S / N ratio by 23, so the reflected light flux can be detected. Large angle range (± 45 ° in the example)
There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a view showing a reflection tape portion in the embodiment, and FIG. 3 is a relationship between a patient, a radiation apparatus, a main body and each luminous flux in the embodiment. FIG. 4 and FIG. 4 are circuit configuration diagrams for detecting the positional deviation due to the body movement of the patient in the embodiment. 1 ... Light source, 2 ... Lens, 3 ... Half mirror, 4 ... Cylindrical lens, 5 ... Half mirror, 6 ... Cylindrical lens, 7 ... Mirror, 8 ... Lens, 11 ... Photoelectric Detector, 12 ... Main body (box), 13 ... Reflective tape, 14 ... Ejection port, 21 ... Light flux, 22 ... Light flux, 23 ... Light flux, 24 ... Light flux, 25 ... Light flux, 26 ... … Distance L, 31… Patient, 32 …… Treatment (diagnosis) device, 41 …… Glass beads, 42 …… Light reflecting layer,
43 …… Binder, 44 …… Adhesive, 51 …… Oscillator, 52 …… Variable amplifier, 53 …… Differential amplifier, 54 …… Driving unit, 55 …… With monitor diode, Laser diode, 56 …… Amplifier , 57 …… phase detector, 58 …… comparator, 59 …… reference generation circuit, 60 …… output (alarm buzzer or relay circuit).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G01C 15/06 G01C 15/06 T G01V 8/14 9406-2G G01V 9/04 B Examiner Shinya Aramaki (56) References JP-A-57-11336 (JP, A) JP-A-59-31402 (JP, A) Actual opening S51-67742 (JP, U) Actual opening S62-14417 (JP, U) Special Kohei 8-27191 (JP, B2)

Claims (1)

(57) [Claims] 1. A light flux generating source capable of generating a modulated light flux, a lens for focusing the light flux generated by the light flux generating source in parallel in a point shape, and 2 for distributing the light flux in two directions.
Half mirrors, two cylindrical lenses arranged at right angles to each other to diffuse the two light beams reflected by the two half mirrors into a linear light beam intersecting at right angles, and the above two Mirror that reflects the light flux that has passed through the half mirror, a lens that focuses the light flux that is reflected by the mirror into a point-parallel light flux, and a modulated, point-parallel parallel light flux that returns almost in the incident direction. A light flux forming device, comprising: a reflective tape that reflects the light; and a plurality of photoelectric detectors that detect the reflected light flux.