Patent ID: 11957373
Assignee: SMITH & NEPHEW ASIA PACIFIC PTE. LIMITED
Field: Medical technology (Instruments)
Classification: CPC A | IPC A

Claim 0:
1. A method of operating a mechanical resection instrument coupled to a motor drive unit, the method comprising:
sensing a location of a cutting window through an outer tube of the mechanical resection instrument, the sensing based on a magnetic field strength of a first magnet coupled to an outer hub of the mechanical resection instrument, wherein sensing the magnetic field strength of the first magnet further comprises sensing a first magnitude with a first polarity;
sensing a location of a cutting window through an inner tube concentrically disposed within the outer tube, the sensing based on a combined magnetic field strength of the first magnet and a second magnet coupled to an inner hub of the mechanical resection instrument, the inner hub stationary relative to the inner tube, and the inner hub and the inner tube rotatable by the motor drive unit, 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
stopping, by the motor drive unit, a 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 based on the combined magnetic field strength.