What is claimed is: .[.1. A trackable medical instrument for use in a computer assisted image guided surgery system having a digitizer for tracking the position of the instrument in three dimensional space and a display providing an indication of the position of the instrument with respect to images of a body part take preoperatively, the instrument comprising: a guide member having an emitter array mounted thereon for being tracked by a digitizer; and a drive shaft contained within the guide member, the drive shaft having a longitudinal axis and a proximal and a distal end, the drive shaft being rotatable within the guide member while being fixable within the guide member in a direction of the longitudinal axis, the proximal end of the drive shaft having a first connector for interchangeably receiving at least one drive source for transmitting torque to the drive shaft causing rotation of the drive shaft relative to the guide member, and the distal end having a second connector for interchangeably receiving at least one instrument tip..]. .[.2. The instrument according to claim 1, further comprising at least one instrument tip for removable connection to the distal end of the drive shaft..]. .[.3. The instrument according to claim 2, wherein the at least on drive source comprises a drive handle for removable connection to the proximal end of the drive shaft for transmitting torque to the drive shaft and the instrument tip to cause rotation of the instrument tip..]. .[.4. The instrument according to claim 3, wherein the drive handle and the drive shaft include a male-female socket joint to removably connect the drive shaft to the drive handle..]. .[.5. The instrument according to claim 3, wherein the drive handle includes a ratchet..]. .[.6. The instrument according to claim 3, wherein the drive handle includes a motor for imparting torque to the drive shaft..]. .[.7. The instrument according to claim 2, wherein the instrument tip and the drive shaft include a male-female socket joint to removably connect the drive shaft to the instrument tip..]. .[.8. The instrument according to claim 2, wherein the instrument tip is an awl..]. .[.9. The instrument according to claim 2, wherein the instrument tip is a tap..]. .[.10. The instrument according to claim 2, wherein the instrument tip has a shaped end for mating with a workpiece to be rotated by said drive shaft..]. .[.11. The instrument according to claim 2, wherein the instrument tip is a drill bit..]. .[.12. The instrument according to claim 1, wherein the emitter array includes at least one LED array for emitting light signals..]. .[.13. The instrument according to claim 12, wherein the LED array includes a base and a plurality of LED emitters disposed on the base..]. .[.14. The instrument according to claim 1, wherein at least one bushing is provided in the guide member to reduce friction between the guide member and drive shaft..]. .[.15. The instrument according to claim 1, wherein the instrument includes a sensor which senses the removal and connection of an instrument tip to the instrument..]. .[.16. The instrument according to 15, wherein the sensor includes an electromechanical switch on the guide member electrically connected to the system..]. .[.17. A trackable medical instrument for use in a computer assisted image guided surgery system having a digitizer for receiving signals representing a position of the instrument during surgery, a computer for processing the signals received, and a display for providing an image representing the position of the instrument in three dimensional space during surgery, the instrument comprising: guiding means for guiding the instrument in three dimensional space, the guiding means including signaling means for providing a signal representing the trajectory of the instrument and the location of the instrument; and driving means for driving the instrument contained within the guiding means, the driving means having a longitudinal axis and being fixable in relation to the guiding means in a direction of the longitudinal axis while being rotatable in relation to the guiding means, the driving means having a first end adapted to interchangeably receive at least one medical instrument tip and an opposite end adapted to interchangeably receive at least one drive source..]. .[.18. The instrument according to claim 17, wherein the instrument includes a sensing means for sensing the removal and the connection of an instrument tip to the instrument..]. .[.19. The instrument according to 18, wherein the sensing means includes an electromechanical switch on the guiding means connected to the means for processing..]. .[.20. The instrument according to claim 17, wherein the guiding means comprises a housing for receiving the driving means, the driving means being rotatable within the housing while being retained axially within the housing..]. .[.21. The instrument according to claim 20 wherein the signaling means comprises an LED array..]. .[.22. The instrument according to claim 21, further comprising an instrument tip for connection to the first end of the driving means..]. .[.23. The instrument according to claim 22, further comprising a drive handle for connection to the opposite end of the driving means for transmitting torque to the instrument tip to cause rotation of the instrument tip..]. .[.24. The instrument according to claim 20, wherein the driving means comprises a drive shaft having mating connectors on both ends for connection to corresponding connectors disposed on an instrument tip and a drive source..]. .[.25. The instrument according to claim 24, wherein at least one bushing is provided between the housing and the drive shaft to reduce friction between the guide handle and drive shaft..]. .[.26. The instrument according to claim 22, wherein the instrument tip is an awl..]. .[.27. The instrument according to claim 22, wherein the instrument tip is a tap..]. .[.28. The instrument according to claim 22, wherein the instrument tip has a shaped end for mating with a workpiece..]. .[.29. A trackable medical instrument for use in a computer assisted image guided surgery system having a digitizer for tracking the position of the instrument in three dimensional space and a display providing an indication of the position of the instrument with respect to images of a body part take preoperatively, the instrument comprising: a guide member having an emitter array mounted thereon for being tracked by a digitizer; a drive shaft contained within the guide member, the drive shaft having a longitudinal axis and a proximal and a distal end, the drive shaft being rotatable within the guide member while being fixable within the guide member in a direction of the longitudinal axis; an instrument tip extending from the proximal end of the drive shaft; wherein the instrument tip rotates freely relative to the guide member while being fixable axially relative to the guide member; and a drive handle extending from the distal end of the drive shaft for guiding the instrument, including the guide member, and for imparting rotary motion to the drive shaft and the instrument tip independent of the guide member..]. .[.30. The instrument according to claim 29, further comprising a proximal coupler for interchangeably coupling the drive source to the drive shaft..]. .[.31. The instrument according to claim 30, wherein the proximal coupler comprises a male-female socket joint disposed on the drive shaft and the drive source to removably connect the drive source to the drive shaft..]. .[.32. The instrument according to claim 29, wherein the drive handle includes a ratchet..]. .[.33. The instrument according to claim 29, wherein the drive handle includes a motor for imparting rotary motion to the drive shaft..]. .[.34. The instrument according to claim 29, further comprising a distal coupler for interchangeably coupling the instrument tip to the drive shaft..]. .[.35. The instrument according to claim 34, wherein the distal coupler includes a male-female socket joint disposed on the drive shaft and the instrument tip to removably connect the instrument tip to the drive shaft..]. .[.36. The instrument according to claim 29, wherein the instrument tip is an awl..]. .[.37. The instrument according to claim 29, wherein the instrument tip is a tap..]. .[.38. The instrument according to claim 29, wherein the instrument tip has a shaped end for mating with a workpiece to be rotated by said drive shaft..]. .[.39. The instrument according to claim 29, wherein the instrument tip is a drill bit..]. .[.40. The instrument according to claim 29, wherein the emitter array includes at least one LED array for emitting light signals..]. .[.41. The instrument according to claim 29, wherein the at least one LED array includes a base and a plurality of LED is emitters disposed on the base..]. .[.42. The instrument according to claim 29, wherein at least one bushing is provided in the guide member to reduce friction between the guide member and drive shaft..]. .[.43. A trackable medical instrument for use in a computer assisted image guided surgery system having a digitizer for tracking the position of the instrument in three dimensional space and a display providing an indication of the position of the instrument with respect to images of a body part taken preoperatively, the instrument comprising: a guide member having a tracking device mounted thereon for being tracked by a digitizer; a drive shaft contained within the guide member, the drive shaft having a longitudinal axis and a proximal and a distal end, the drive shaft being rotatable within the guide member while being fixable within the guide member in a direction of the longitudinal axis; an instrument tip extending from the proximal end of the drive shaft; wherein the instrument tip rotates freely relative to the guide member while being fixable axially relative to the guide member; and a drive handle extending from the distal end of the drive shaft for guiding the instrument, including the guide member, and for imparting rotary motion to the drive shaft and the instrument tip independent of the guide member..]. .[.44. The instrument according to claim 43, wherein the tracking device includes a passive signal generator..]. .[.45. The instrument according to claim 44, wherein the instrument comprises at least one reflective surface for reflecting signals to be tracked by the digitizer..]. .[.46. The instrument according to claim 44, wherein the instrument comprises at least three reflective surfaces for reflecting signals to be tracked by the digitizer..]. .[.47. The instrument according to claim 43, further comprising a proximal coupler for interchangeably coupling the drive source to the drive shaft..]. .[.48. The instrument according to claim 47, wherein the proximal coupler comprises a male-female socket joint disposed on the drive shaft and the drive source to removably connect the drive source to the drive shaft..]. .[.49. The instrument according to claim 43, further comprising a distal coupler for interchangeably coupling the instrument tip to the drive shaft..]. .[.50. The instrument according to claim 49, wherein the distal coupler includes a male-female socket joint disposed on the drive shaft and the instrument tip to removably connect the instrument tip to the drive shaft..]. .Iadd.51. A method to track a medical instrument system for use in a computer assisted image guided surgery system, comprising: tracking a tracking device mounted on a guide member, wherein a drive shaft is contained within the guide member, the drive shaft having a proximal end and a distal end, the distal end having a first connector for interchangeably receiving a first instrument tip and a second instrument tip, wherein the first instrument tip is calibrated to the computer assisted image guided surgery system; and recalibrating the second instrument to the computer assisted image guided surgery system after removing the first instrument tip from first connector and connecting the second instrument tip to the connector; wherein the proximal end of the drive shaft has a second connector for interchangeably receiving at least one drive source for transmitting torque to the drive shaft..Iaddend. .Iadd.52. The method of claim 51, further comprising: operating the at least one drive source to cause rotation of the drive shaft relative to the guide member..Iaddend. .Iadd.53. The method of claim 52, further comprising: rotating the drive shaft within the guide member while having the drive shaft fixed in a direction of the longitudinal axis within the guide member..Iaddend. .Iadd.54. A method to track a medical instrument system for use in a computer assisted image guided surgery system, comprising: providing a guide member having a tracking device mounted thereon for being tracked; and providing a drive shaft contained within the guide member, the drive shaft having a longitudinal axis, a first end and a second end, the drive shaft being rotatable within the guide member while being fixable within the guide member along the longitudinal axis, the first end of the drive shaft having a first connector for receiving at least one drive source for transmitting torque to the drive shaft for causing rotation of the drive shaft relative to the guide member, and the second end having at least one instrument tip..Iaddend. .Iadd.55. The method of claim 54, further comprising: connecting the drive source to the drive shaft, wherein the drive source is a drive handle..Iaddend. .Iadd.56. The method of claim 54, further comprising: permanently attaching the drive shaft and the at least one instrument tip..Iaddend. .Iadd.57. The method of claim 54, further comprising: permanently attaching at least the drive shaft and the at least one drive source..Iaddend. .Iadd.58. The method of claim 54, further comprising: permanently attaching all of the drive shaft, the at least one instrument tip, and the drive source..Iaddend. .Iadd.59. The method of claim 54, further comprising: providing bushings between the drive shaft and the guide member to allow smooth operation of the drive shaft..Iaddend. .Iadd.60. The method of claim 54, further comprising: entering information regarding dimensions of the at least one instrument tip into the computer..Iaddend. .Iadd.61. The method of claim 54, further comprising: providing at least one of a tap, an awl, a shaped tool, or a screw driver as the at least one instrument tip..Iaddend. .Iadd.62. The method of claim 54, further comprising: displaying images with a monitor; connecting a reference arc to a patient; and triangulating a position of at least one of the tracking device or the reference arc with a digitizer..Iaddend. .Iadd.63. A method of configuring a trackable medical instrument for use with a surgical navigation system, comprising: providing an instrument tip having a distal end; configuring the instrument tip to couple to a drive shaft contained and rotatable within a guide member, wherein a tracking device is mountable to the guide member, wherein the drive shaft having a longitudinal axis has a shaft proximal end and a shaft distal end, wherein the shaft proximal end is adapted to receive a drive source and the shaft distal end is adapted to receive the instrument tip; and fixing the drive shaft in relation to the guide member in a direction of the longitudinal axis relative to the distal end, wherein a rotation of the mountable tracking device relative to the instrument tip enables the distal end of the surgical implement to be tracked by the surgical navigation system..Iaddend. .Iadd.64. The method of claim 63, wherein fixing the drive shaft in relation to the guide member in the direction of the longitudinal axis relative to the distal end maintains a constant distance between the tracking device and the distal end of the instrument tip..Iaddend. .Iadd.65. The method of claim 63, wherein fixing the guide member in the direction along the longitudinal axis relative to the distal end enables both orientation in three-dimensional space of the instrument tip and a depth the distal end of the instrument tip has been inserted into a body part to be tracked by the surgical navigation system..Iaddend. .Iadd.66. The method of claim 63, further comprising: rotatably coupling the instrument tip to the guide member..Iaddend. .Iadd.67. The method of claim 63, further comprising: integrally forming the instrument tip and the guide member..Iaddend. .Iadd.68. The method of claim 63, further comprising: mounting the tracking device to the guide member..Iaddend. .Iadd.69. The method of claim 63, further comprising: coupling the drive source to the instrument tip..Iaddend. .Iadd.70. The method of claim 69, further comprising: providing the driver source to be a handle for holding with a hand..Iaddend. .Iadd.71. The method of claim 69, wherein coupling the drive source to the instrument tip includes coupling the drive member to a proximal end of the instrument tip..Iaddend. |