Afterloader with active force feedback

An apparatus for advancing and retracting a radioactive source into and out of the body of a patient comprising:

• a frame;
• an elongate lead adapted to support the radioactive source at an end thereof;
• means mounted to said frame for storing said elongate lead;
• drive means mounted to said frame for advancing said elongate lead along a path of travel into the patient;
• a force sensor for detecting the force required to advance said elongate lead into the patient and for generating an output signal proportional to said force;
• and
• circuit means responsive to the output signal of said force sensor for controlling advancement of said elongate lead into the patient in proportion to the output signal generated by said force sensor.

An apparatus for advancing a radioactive source along a tortuous path to a target site in the body of a patient comprising:

• a housing adapted to receive a proximal end of a catheter implanted in the patient along said tortuous path with a distal end of the catheter at or near the target site;
• an elongate lead having a proximal end and a distal end, said radioactive source being secured at the distal end of the lead;
• a radiation-proof safe coupled to said housing for storing at least the distal end of the lead when not advanced into the patient;
• drive means mounted to said housing and secured to the proximal end of the lead for selectively advancing the distal end of the lead from the safe and into the catheter via the housing, and for selectively retracting the distal end of the lead into the safe;
• a force sensor for detecting the magnitude of the force exerted by the drive means on the lead during advancement of the distal end thereof through the catheter and for generating an output signal indicative of said force;
• and
• feedback control means responsive to the magnitude of the exerted force detected by the force sensor for adjustment thereof to prevent buckling of the lead or puncture of the catheter when the distal end of the lead encounters obstructions or curves in the tortuous path during advancement thereof through the catheter.

A method of advancing a radioactive source along a tortuous path to a target site in the body of a patient, comprising:

• implanting a catheter in the patient along said tortuous path with a distal end of the catheter at or near the target site;
• storing at least the distal end of an elongate lead having said radioactive source secured at the distal end thereof in a radiation-proof safe when not advanced into the patient;
• selectively advancing the distal end of the lead from the safe and into the catheter;
• detecting the magnitude of the force exerted on the lead during advancement of the distal end thereof through the catheter;
• responding to feedback of the magnitude of the detected exerted force to adjust the exerted force to prevent buckling of the lead or puncture of the catheter when the distal end of the lead encounters obstructions or curves in the tortuous path during advancement thereof through the catheter;
• and
• selectively retracting the distal end of the lead into the safe after completing a procedure therewith.