Patent ID: 11957373
Assignee: SMITH & NEPHEW, INC.
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 6:
7. A mechanical resection system comprising:
a motor drive unit comprising a motor and a magnetic field sensor in operational relationship to a hub connector;
a resection control unit communicatively coupled to the motor and the magnetic field sensor;
a resection instrument comprising:
an outer hub coupled to the hub connector, and an outer tube with a cutting window;
an inner hub coupled to a drive shaft of the motor, and an inner tube with a cutting window rigidly coupled to the inner hub, the inner tube concentrically disposed within the outer tube;
a first magnet coupled to the outer hub; and
a second magnet coupled to the inner hub;

the resection control unit configured to:
cause rotation of the drive shaft of the motor, and thereby rotate the inner hub and the inner tube relative to the motor drive unit, the rotation responsive to activation of a switch;
sense, by way of the magnetic field sensor, a first magnetic field strength of the first magnet coupled to the outer hub, and determine a location of the cutting window through the outer tube based on the first magnetic field strength, wherein sensing the first magnetic field strength of the first magnet further comprises sensing a first magnitude with a first polarity;
sense, by way of the magnetic field sensor, a combined magnetic field strength of the first magnet and the second magnet, and determine a location of the cutting window through the inner tube based on the combined magnetic field strength, wherein sensing the combined magnetic field strength further comprises at least one selected from a group comprising: sensing a second magnitude higher than the first magnitude and with the first polarity; sensing a second magnitude lower than the first magnitude and with the first polarity; sensing a second magnitude with a second polarity opposite the first polarity; and
stop the rotation of the inner tube relative to the outer tube with the cutting window through the outer tube and the cutting window through the inner tube in a predetermined orientation, the stopping responsive to deactivation of the switch, and the predetermined orientation of the inner tube and output based on the combined magnetic field strength.