METHOD FOR OPERATING A SURGICAL INSTRUMENT
A surgical instrument is configured to compensate for battery pack and drivetrain failures. One method includes generating a firing sequence, determining whether a subset of rechargeable battery cells is damaged during the firing sequence, and stepping-up an output voltage of the battery pack to complete the firing sequence in response to a determination that a subset of the rechargeable battery cells is damaged. Another method includes generating a mechanical output to motivate a drivetrain to transmit a motion to a jaw assembly of the surgical instrument, activating a safe mode in response to an acute failure of the drivetrain, and activating a bailout mode in response to a catastrophic failure of the drivetrain. Another method includes driving a drivetrain, sensing and recording vibration information from the drivetrain, generating an output signal based on the vibration information, and determining a status of the surgical instrument based on the output signal.
1 . A method of compensating for a battery pack failure in a powered surgical instrument, the method comprising:
generating, by an electric motor, a rotational motion to motivate a firing assembly to deploy staples into a captured tissue during a firing sequence;
determining, by a control circuit, whether a subset of rechargeable battery cells is damaged during the firing sequence based on a measurement performed by a battery-cell health indicator; and
stepping-up, by the control circuit coupled to a voltage converter, an output voltage of the battery pack to complete the firing sequence in response to a determination that a subset of the rechargeable battery cells is damaged.
2 . The method of claim 1 , further comprising storing, by the control circuit coupled to a memory, a damaged status of the power pack in the memory in response to a determination that a subset of the rechargeable battery cells is damaged.
3 . The method of claim 2 , further comprising clearing, by the control circuit, the damaged status after the damaged subset of the rechargeable battery cells is replaced with undamaged battery cells.
4 . The method of claim 1 , further comprising deactivating, by the control circuit, the surgical instrument after completion of the firing sequence in response to a determination that a subset of the rechargeable battery cells is damaged.
5 . A method of compensating for drivetrain failure in a powered surgical instrument, the method comprising:
generating, by an electric motor, a mechanical output to motivate a drivetrain to transmit a motion to a jaw assembly of the surgical instrument;
activating, by a control circuit, a safe mode in response to an acute failure of the drivetrain; and
activating, by the control circuit, a bailout mode in response to a catastrophic failure of the drivetrain.
6 . The method of claim 5 , further comprising modulating, by the control circuit, the mechanical output of the electric motor in response to the acute failure.
7 . The method of claim 6 , wherein modulating the mechanical output of the electric motor comprises slowing the mechanical output.
8 . The method of claim 5 , further comprising generating, by a power source, a motor input voltage.
9 . The method of claim 8 , further comprising modulating, by the control circuit, the motor input voltage in response to the acute failure.
10 . The method of claim 9 , wherein modulating the motor input voltage comprises delivering the motor input voltage in pulses.
11 . The method of claim 9 , wherein modulating the motor input voltage comprises reducing the motor input voltage.
12 . The method of claim 5 , further comprising disabling, by the control circuit, the electric motor in response to the catastrophic failure.
13 . The method of claim 8 , further comprising, employing, by the control circuit, a feedback element to provide bailout instructions in response to the catastrophic failure.
14 . A method of compensating for drivetrain failure in a powered surgical instrument, the method comprising:
driving, by an electric motor, a drivetrain comprising gear components to perform operations of the surgical instrument;
sensing, by a vibration sensor positioned relative to the drivetrain, vibration information from the drivetrain;
recording, by a processor coupled to a memory, the vibration information sensed by the vibration sensor;
generating, by the vibration sensor, an output signal based on the vibration information; and
determining a status of the surgical instrument based on the output signal.
15 . The method of claim 14 , further comprising:
filtering, by a filter, the output signal of the vibration sensor; and
generating, by the filter, a filtered signal based on the received output signal.
16 . The method of apparatus of claim 14 , further comprising generating, by the processor, a processed signal based on the filtered signal.
17 . The method claim 16 , further comprising comparing, by the processor, a predetermined threshold value to a corresponding value of the processed signal.
18 . The method of claim 17 , further comprising detecting, by the processor, a malfunction of the surgical instrument when the predetermined threshold value is equal to or less than the corresponding value of the processed signal.
19 . The method of claim 16 , further comprising generating the predetermined threshold value from a test output signal of the vibration sensor or a previously processed signal.
20 . The method of claim 19 , further comprising:
sensing, by the vibration sensor, test vibration information during a testing procedure of the surgical instrument; and
recording, by the memory, a test output signal based on the test vibration information sensed by the vibration sensor.