GREGORY JOHNSON, MD
Radiology at Campus Dr, Auburn, WA

7567248, Jul 28, 2009

Apr 28, 2005

11/119302

William R. Mark - Austin TX, US
Gregory S. Johnson - Austin TX, US
Chris Burns - Austin TX, US

G06T 15/00, G06T 15/50

345426

A system and method provide for determining in a computer system the intersections between a plurality of rays residing in three dimensional (3D) space and one or more surface elements residing in the 3D space. The rays or lines corresponding to the rays share a common intersection point. The method includes for each of the rays, storing the intersection point of the ray with a projection surface in the 3D space in a data structure in the computer system. For each of the surface elements, determining using projection a two-dimensional (2D) region representing the projection of the surface element onto the projection surface; and determining using intersection testing which points stored in the data structure are inside the 2D region. The points determined to be inside the 2D region represent intersection points between the surface element and the rays corresponding to the points.

5468216, Nov 21, 1995

Oct 12, 1994

8/322174

Gregory E. Johnson - Austin TX
Uriel G. Ashworth - Chase City VA
Mark Salerno - Huntington NY

Physicians Consulting Incorporated - Austin TX

A61H 100

601 24

A kinetic rehabilitation device employing controlled passive motion for use in the rehabilitation of the lumbar spine. The device includes a frame, a body support secured to the frame, a control panel, a first and second member secured to the support and pivotally attached to diametrically opposed sides of the frame, and a screw drive assembly for pivoting the first and second members about said frame. A first optical sensor assembly is mounted on one of the pivoting members to zero the body support about its longitudinal axis. A second optical assembly is mounted on the screw drive assembly to feed positional information to the control panel.