Remote center range finder

Filing Information

• Publication Number: US20060152704
• Application Number: US11030836
• Filing date: 01/07/2005
• Publication date: 07/13/2006
• Predicted expiration date: 01/07/2025

• U.S. Classifications: 356/3.1  · 356/622  · 356/623  ·
• International Classifications: G01C300 · G01C308 · G01C500 · G11B700 · G01B1114 ·
• View document at: (opens new window):
  USPTO  ·  PAIR  ·  esp@cenet  ·  Patent Family

Patent Family

Abstract

A system for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of the object along an axis extending through the first and second points includes one or more light projection assemblies for projecting light stripes onto the surface of the object so that the light stripes pass though the second point. An imaging device detects the position of the second point by sensing the light stripes at the second point. A distance calculator may then calculate the distance between the first point and the second point using the position of the second point detected by the imaging device. The system is calibrated using the cross-ratio of points detected along the axis by the imaging device.

Independent Claims | See all claims (39)

1. 1. A system for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: a first projection assembly for projecting a first plane of light so that the first plane of light contains the first point and intersects the surface of the object to form a first light stripe on the surface; a second projection assembly for projecting a second plane of light so that the second plane of light contains the first point and intersects the surface of the object to form a second light stripe on the surface, the first light stripe intersecting the second light stripe at the second point; and an imaging device for detecting the position of the second point by sensing the intersection of the first light stripe and the second light stripe at the second point, wherein the distance between the first point and the second point is determined from the detected position of the second point.
2. 9. A system for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: a projection assembly for projecting a plane of light onto the surface of the object so that the plane of light intersects the surface to form a light stripe on the surface, the plane of light containing the axis so that the light stripe passes though the second point; an imaging device for detecting the position of the second point by sensing the light stripe at the second point, the imaging device having a sensor oriented for sensing light reflected from points on the object along a line coplanar with the first point, the second point and the focal point of the imaging device; and a distance calculator for calculating the distance between the first point and the second point using the position of the second point detected by the imaging device; wherein the imaging device detects the position of a third point along the axis, the distance between the first point and the third point being predetermined, and the distance calculator determines the distance between the second point and the third point and subtracts the distance between the second point and the third point from the distance between the first point and the third point for determining the distance between the first point and the second point.
3. 15. A radiation treatment device, comprising: a radiation source for projecting a beam of radiation onto the body of a patient being treated; and a range finder for measuring the distance from the radiation source to a second point on the surface of the body of the patient being treated along an axis extending through the radiation source and the second point, the range finder including: a first projection assembly for projecting a first plane of light so that the first plane of light intersects the surface of the body to form a first light stripe on the surface; and a second projection assembly for projecting a second plane of light so that the second plane of light intersects the surface of the body to form a second light stripe on the surface, the first light stripe intersecting the second light stripe at the second point; an imaging device for detecting the position of the second point by sensing the intersection of the first light stripe and the second light stripe at the second point, wherein the distance between the first point and the second point is determined from the detected position of the second point.
4. 22. A radiation treatment device, comprising: a radiation source for projecting a beam of radiation onto the body of a patient being treated; and a range finder for measuring the distance from the radiation source to a second point on the surface of the body of the patient being treated, the range finder including: a projection assembly for projecting a plane of light onto the surface of the object so that the plane of light intersects the surface to form a light stripe on the surface, the plane of light containing the axis so that the light stripe passes though the second point; an imaging device for detecting the position of the second point by sensing the light stripe at the second point, the imaging device having a sensor oriented for sensing light reflected from points on the object along a line coplanar with the first point, the second point and the focal point of the imaging device; and a distance calculator for calculating the distance between the first point and the second point using the position of the second point detected by the imaging device; wherein the imaging device detects the position of a third point along the axis, the distance between the first point and the third point being predetermined, and the distance calculator determines the distance between the second point and the third point and subtracts the distance between the second point and the third point from the distance between the first point and the third point for determining the distance between the first point and the second point.
5. 27. A method for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: projecting a first plane of light so that the first plane of light intersects the surface of the object to form a first light stripe on the surface; projecting a second plane of light so that the second plane of light intersects the surface of the object to form a second light stripe on the surface, the first light stripe intersecting the second light stripe at the second point; and detecting the position of the second point by sensing the intersection of the first light stripe and the second light stripe at the second point, the distance between the first point and the second point being determined from the detected position of the second point.
6. 33. A method for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: projecting a plane of light onto the surface of the object so that the plane of light intersects the surface to form a light stripe on the surface, the plane of light containing the axis so that the light stripe passes though the second point; detecting the position of the second point by sensing the light stripe at the second point via an imaging device, the imaging device having a sensor oriented for sensing light reflected from points on the object along a line coplanar with the first point, the second point and the focal point of the imaging device; and defining a third point along a line extending through the first point and the second point, the distance between the first point and the third point being predetermined; determining the distance between the second point and the third point; and subtracting the distance between the second point and the third point from the distance between the first point and the third point for determining the distance between the first point and the second point.
7. 38. A system for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: means for projecting a first plane of light so that the first plane of light intersects the surface of the object to form a first light stripe on the surface; means for projecting a second plane of light so that the second plane of light intersects the surface of the object to form a second light stripe on the surface, the first light stripe intersecting the second light stripe at the second point; means for detecting the position of the second point by sensing the intersection of the first light stripe and the second light stripe at the second point; and means for calculating the distance between the first point and the second point along the axis using the position of the second point detected by the imaging device, wherein the distance between the first point and the second point is determined from the detected position of the second point.
8. 39. A system for measuring the distance from a first point spaced away from a surface of an object to a second point on a surface of an object along an axis extending through the first point and the second point, comprising: means for projecting a plane of light onto the surface of the object so that the plane of light intersects the surface to form a light stripe on the surface, the plane of light containing the axis so that the light stripe passes though the second point; means for detecting the position of the second point by sensing the light stripe at the second point, the detecting means being oriented for sensing light reflected from points on the object along a line coplanar with the first point, the second point and the focal point of the imaging device; and means for calculating the distance between the first point and the second point using the position of the second point detected by the detecting means, wherein the detecting means detects the position of a third point along the axis, the distance between the first point and the third point being predetermined, and the distance calculator determines the distance between the second point and the third point and subtracts the distance between the second point and the third point from the distance between the first point and the third point for determining the distance between the first point and the second point.