System and method for measuring and/or checking the position of a patient in a radio-therapy machine

Claim 1

A method for measuring and checking the position of a patient in a radio-therapy machine having a radiation source and a mount for supporting the radiation source for isocentric motion, the method comprising the steps of (a) positioning the patient on a support surface, (b) scanning a region of the surface of the patient's body with a pivotable light beam having a pivot center which has a known spatial relationship with the radiation source to create a plurality of light spots at a first set of points of incidence, (c) detecting and recording images of the first set of points of incidence of the spots on the surface region, (d) computing the coordinates of the first set of points of incidence relative to the radiation source and relative to the corresponding positions of the light beam, (e) subsequently scanning substantially the same region of the patient's body with the light beam using information on the recorded first set of points of incidence to recreate a plurality of spots of light at a second set of points of incidence corresponding to the first set, (f) detecting the images of the second set of points, (g) determining the coordinates of the second set of points and comparing the coordinates of the second set of points with the coordinates of the first set of points, and (h) if there are differences between the coordinates of the first and second sets of points, repositioning the patients body until the coordinates substantially coincide.

Claim 2

A method for measuring and checking the position of a patient in a radio-therapy machine having a radiation source and a mount for supporting the radiation source for isocentric motion, the method comprising the steps of (a) positioning the patient on a support surface, (b) scanning a region of the surface of the patient's body with a pivotable light beam having a pivot center which has a known spatial relationship with the radiation source to create a plurality of light spots at a first set of points of incidence, (c) detecting and recording images of the first set of points of incidence of the spots on the surface region, (d) computing the coordinates of the first set of points of incidence relative to the radiation source and relative to the corresponding positions of the light beam, (e) subsequently scanning substantially the same region of the patient's body with the light beam using information on the recorded first set of points of incidence to recreate a plurality of spots of light at a second set of points of incidence corresponding to the first set, (f) detecting the images of the second set of points, (g) determining the coordinates of the second set of points and comparing the coordinates of the second set of points with the coordinates of the first set of points, and (h) if there are differences between the coordinates of the first and second sets of points, repositioning the patients body until the coordinates substantially coincide.

Claim 3

A system for measuring and checking the position of a patient in a radio-therapy machine having a radiation source and a mount for supporting the radiation source for isocentric motion, comprising the combination of (a) a support surface for holding the patient, (b) means including a pivotable light beam for scanning a region of the surface of the patient's body to create a plurality of light spots at a first set of points of incidence, said beam having a pivot center at a known spatial location relative to the radiation source; (c) means for detecting and recording images of said first set of points of incidence of the spots on the surface region; (d) means for computing the coordinates of said first set of points of incidence relative to the radiation source and relative to corresponding positions of the light beam, (e) means for detecting images of a second set of points subsequently produced by said light beam, (g) means for determining the coordinates of said second set of points and comparing the coordinates of said second set of points with the coordinates of said first set of points, whereby, if there are differences between the coordinates of said first and second sets of points, the patients body can be repositioned until said coordinates substantially coincide.

Claim 4

A system for measuring and checking the position of a patient in a radio-therapy machine having a radiation source and a mount for supporting the radiation source for isocentric motion, comprising the combination of (a) a support surface for holding the patient, (b) means including a pivotable light beam for scanning a region of the surface of the patient's body to create a plurality of light spots at a first set of points of incidence, said beam having a pivot center at a known spatial location relative to the radiation source; (c) means for detecting and recording images of said first set of points of incidence of the spots on the surface region; (d) means for computing the coordinates of said first set of points of incidence relative to the radiation source and relative to corresponding positions of the light beam, (e) means for detecting images of a second set of points subsequently produced by said light beam, (g) means for determining the coordinates of said second set of points and comparing the coordinates of said second set of points with the coordinates of said first set of points, whereby, if there are differences between the coordinates of said first and second sets of points, the patients body can be repositioned until said coordinates substantially coincide.