System for monitoring the position of a medical instrument with respect to a patient's body

Abstract

A system is disclosed for monitoring the position of a medical instrument with respect to a patient's body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient's body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field. A position detector in communication with the sensor output signal produces position data representative of the position of the remote unit with respect to the reference unit. An output display in communication with the position detector displays at least one of the prerecorded images responsive to the position data.

We claim:  
     
         1 . Apparatus for securing a reference unit to a patient's head, said apparatus comprising reference unit mounting means for mounting said reference unit to said apparatus, said reference unit for use in monitoring the position of a medical instrument with respect to said patient's head, and a nose bridge mounting element and two ear-mounting elements for attaching said reference unit to said patient's head.  
     
     
         2 . Apparatus as claimed in  claim 1 , wherein said reference unit mounting means includes means for releasably attaching said reference unit to said apparatus.  
     
     
         3 . Apparatus as claimed in  claim 1 , wherein each of said nose and ear mounting elements are disposed on a distal end of an elongated mounting arm.  
     
     
         4 . Apparatus as claimed in  claim 1 , wherein said apparatus further includes an elongated center member and two side members, each of said members being centrally attached to one another at first ends thereof, and said nose bridge mounting element being attached to said center member at a second end thereof and each of said ear mounting elements being attached to a respective side member at second ends thereof.  
     
     
         5 . Apparatus as claimed in  claim 3 , wherein each of said center and side members is made of a structurally resilient material and is capable of accommodating a plurality of sizes of patient heads.  
     
     
         6 . Apparatus as claimed in  claim 5 , wherein said structurally resilient material is plastic.  
     
     
         7 . Apparatus as claimed in  claim 1 , wherein said reference unit includes a field generator for generating a three dimensional position characteristic field.  
     
     
         8 . Apparatus as claimed in  claim 7 , wherein said reference unit further includes a reference sensor for generating a feedback reference signal.  
     
     
         9 . Apparatus as claimed in  claim 1 , wherein said reference unit includes an electromagnetic field generator for generating an electromagnetic field.  
     
     
         10 . Apparatus as claimed in  claim 1 , wherein said reference unit includes a field sensor for sensing a three dimensional position characteristic field and for producing a sensor output responsive to the presence of said sensed field.  
     
     
         11 . Apparatus as claimed in  claim 10 , wherein said reference unit further includes a reference sensor for generating an error detection signal.  
     
     
         12 . Apparatus as claimed in  claim 1 , wherein said reference unit includes an electromagnetic field sensor responsive to the presence of an electromagnetic field for producing a sensor output signal representative of said sensed electromagnetic field.  
     
     
         13 . Apparatus as claimed in  claim 1 , wherein said reference unit includes a signal transmitter for transmitting a reference signal to a signal receiver, said reference signal for use in detecting the position of said reference unit with respect to said signal receiver by comparing said signal to a second transmitted signal.  
     
     
         14 . Apparatus as claimed in  claim 11 , wherein said reference unit further includes a second signal transmitter for transmitting said second transmitted signal.  
     
     
         15 . Apparatus as claimed in  claim 1 , wherein said reference unit includes a signal receiver for receiving a reference signal from a signal transmitter, said reference signal for use in detecting the position of said reference unit with respect to said signal transmitter by comparing said signal to a second transmitted signal.  
     
     
         16 . Apparatus as claimed in  claim 15 , wherein said reference unit further includes a second signal receiver for receiving said second transmitted signal.  
     
     
         17 . Apparatus for monitoring the position of a medical instrument with respect to a patient's body, said apparatus including a reference unit removably attached to said medical instrument.  
     
     
         18 . Apparatus as claimed in  claim 17 , wherein said reference unit is removably insertable into said medical instrument.  
     
     
         19 . Apparatus as claimed in  claim 17 , wherein said medical instrument is an aspirating device.  
     
     
         20 . Apparatus as claimed in  claim 17 , wherein said reference unit includes a field generator for generating a three dimensional position characteristic field.  
     
     
         21 . Apparatus as claimed in  claim 17 , wherein said reference unit further includes a reference sensor for generating a feedback reference signal.  
     
     
         22 . Apparatus as claimed in  claim 17 , wherein said reference unit includes an electromagnetic field generator for generating an electromagnetic field.  
     
     
         23 . Apparatus as claimed in  claim 17 , wherein said reference unit includes a field sensor for sensing a three dimensional position characteristic field and for producing a sensor output responsive to the presence of said sensed field.  
     
     
         24 . Apparatus as claimed in  claim 17 , wherein said reference unit further includes a reference sensor for generating an error detection signal.  
     
     
         25 . Apparatus as claimed in  claim 17 , wherein said reference unit includes an electromagnetic field sensor responsive to the presence of an electromagnetic field for producing a sensor output signal representative of said sensed electromagnetic field.  
     
     
         26 . Apparatus as claimed in  claim 17 , wherein said reference unit includes a signal transmitter for transmitting a reference signal to a signal receiver, said reference signal for use in detecting the position of said reference unit with respect to said signal receiver by comparing said signal to a second transmitted signal.  
     
     
         27 . Apparatus as claimed in  claim 26 , wherein said reference unit further includes a second signal transmitter for transmitting said second transmitted signal.  
     
     
         28 . Apparatus as claimed in  claim 17 , wherein said reference unit includes a signal receiver for receiving a reference signal from a signal transmitter, said reference signal for use in detecting the position of said reference unit with respect to said signal transmitter by comparing said signal to a second transmitted signal.  
     
     
         29 . Apparatus as claimed in  claim 28 , wherein said reference unit further includes a second signal receiver for receiving said second transmitted signal.