Position sensing system

A method for sensing relative positions of first and second points within a patient's body, comprising the steps of:

• disposing within the patient's body a first transponder at the first point and a second transponder at the second point;
• communicating between the first and second transponders, the first transponder transmitting a signal and the second transponder receiving the signal therefrom;
• determining from the signal received a relative distance between the first and second transponders;
• transmitting from the second transponder data relating to the relative distance determined by the second transponder to an external source;
• receiving the data transmitted by the second transponder related to the relative distance data;
• and
• processing that data to determine the relative positions of the first and second points within the patient's body.

A method for sensing relative positions of first and second points, comprising the steps of:

• disposing a first transponder at the first point and a second transponder at the second point;
• radiating energy at a first frequency to the first and second transponders to enable operation thereof;
• transmitting a first set of instructions from a processing unit to the first transponder;
• transmitting a second set of instructions from the processing unit to the second transponder;
• storing the respective instruction sets in the first and second transponders for operation thereof, each according to its own internally stored instructions;
• communicating between the first and second transponders, the first transponder transmitting a signal and the second transponder receiving the signal therefrom;
• determining from the signal received a relative distance between the first and second transponders;
• transmitting data to the processing unit from the second transponder, the data including the relative distance determined by the second transponder;
• receiving the data by the processing unit;
• and
• processing the data relating to the relative positions between the first and second transponders.

A method for sensing relative positions of first and second points, comprising the steps of:

• disposing a first transponder at the first point and a second transponder at the second point;
• physically measuring the distance between the first and second points;
• communicating between the first and second transponders, the first transponder transmitting a signal and the second transponder receiving the signal therefrom;
• calibrating the signal received to the measured distance between the first and second transponders;
• repeating the above-recited sequence of steps at additional separation distances between the transponders over an approximate operable range to develop a lookup table of values in determining separation distance;
• beginning normal operation by positioning the transmitters at an unmeasured distance apart within the operable range;
• transmitting from the second transponder data relating to the relative distance determined by the second transponder to an processing unit.
• receiving the data transmitted by the second transponder related to the relative difference data;
• and
• processing that data to determine the relative positions.