Projection of subsurface structure onto an object's surface
An imaging system illuminates an object with infrared light to enhance visibility of buried structure beneath the surface of the object, and projects a visible light image of the buried structure onto the surface of the object. The system may include an infrared light source for generating the infrared light and a structure for diffusing the infrared light. The diffusing structure may include one or more layers of diffusing material for diffusing the light. The system further includes a video imaging device for receiving the infrared light reflected from the object and for generating a video image of the buried structure based on the reflected infrared light. The buried structure may be a subcutaneous blood vessel. A calibration procedure is described as well as embodiments for ensuring that the object is maintained in focus at the correct distance.
1. An apparatus to enhance the visibility of a subcutaneous blood vessel beneath the surface of an object, the apparatus comprising:
an imaging device configured to receive diffuse light reflected from the object and configured to produce an image, wherein the light reflected from the object originates as broad-spectrum ambient light or as diffuse light directed at the object; and
a video projector configured to project a visible light image of the subcutaneous blood vessel onto the surface of the object, wherein the received diffuse light reflected from the object is coaxial with the projected visible light image wherein said projected visible light image includes a recognizable added pattern that is independent of said subcutaneous blood vessel.
2. The apparatus of claim 1 wherein said added pattern is a text border.
3. An apparatus to enhance the visibility of a subcutaneous blood vessel beneath a surface of an object, the apparatus comprising:
an imaging device configured to receive diffuse light reflected from the object and configured to produce an image, wherein the light reflected from the object originates as broad-spectrum ambient light or as diffuse light directed at the object; and
a first laser having a first emitted beam and a second laser having a second emitted beam, said first emitted beam and said second emitted beam being non-parallel with respect to each other and said first and said second emitted beams intersecting at a desired target distance from said apparatus at which, when the intersection of said first and said second emitted beams is visible upon the surface of the object, said subcutaneous blood vessel is in focus to said imaging device.
4. The apparatus as recited in claim 3 , additionally comprising a video projector for projecting a visible light image of the subcutaneous blood vessel onto the surface of the object, wherein the received diffuse light reflected from the object is coaxial with the projected visible light image.
5. A method for enhancing the visibility of a subcutaneous blood vessel beneath a surface of an object, comprising the steps of:
(a) providing an imaging device for receiving diffuse light reflected from the object, wherein the light reflected from the object originates as broad-spectrum ambient light or as diffuse light directed at the object;
(b) producing a received image; then
(c) removing small dark artifacts from the received image while retaining larger dark objects in the received image to produce a processed image; then
(d) projecting the processed image onto the surface of the object in the visible spectrum, wherein the projection of said processed image is properly aligned such that said reflected diffuse light is coaxial with the projected processed image, resulting in the projected processed image accurately overlaying the corresponding subcutaneous blood vessel.
6. The method as recited in claim 5 , additionally comprising, following the production of a processed image and before projecting the processed image, the step of performing adaptive edge enhancement upon the processed image.