Surgical instrument with improved stop/start control during a firing motion
A surgical instrument. The surgical instrument includes an elongated channel, an anvil pivotably connected to the elongated channel, a closure member mechanically coupled to the anvil, an electric motor mechanically coupled to the closure member, a motor controller electrically coupled to the electric motor and a control circuit electrically connected to the motor controller. The control circuit is configured to monitor a first predefined event, monitor a second predefined event, provide a stop signal to the motor controller to stop a closing motion of at least one of the elongated channel and the anvil after an occurrence of the first predefined event, and provide a start signal to the motor controller to start the closing motion of the at least one of the elongated channel and the anvil after an occurrence of a second predefined event.
1. A surgical instrument, comprising:
an elongated channel configured to support a staple cartridge;
an anvil pivotably connected to the elongated channel;
a knife mechanically coupled to the staple cartridge;
an electric motor mechanically coupled to the knife;
a motor controller electrically coupled to the electric motor; and
a control circuit electrically connected to the motor controller, wherein the control circuit is configured to:
monitor a first predefined event;
monitor a second predefined event;
provide a stop signal to the motor controller to stop an advancement of the knife upon an occurrence of the first predefined event; and
automatically provide a start signal to the motor controller to start the advancement of the knife upon an occurrence of the second predefined event.
2. The surgical instrument of claim 1 , wherein the occurrence of the first predefined event comprises at least one of the following:
an amplitude of a firing force signal exceeding a predetermined threshold;
a slope of a curve representative of the firing force signal exceeding a second predetermined threshold;
a slope of a line connecting successive peak values of the firing force signal exceeding a third predetermined threshold; and
a position of the knife is within a predetermined range of positions between a proximal end of the staple cartridge and a distal end of the staple cartridge and at least one of the following:
the amplitude of the firing force signal exceeding the predetermined threshold;
the slope of the curve representative of the firing force signal exceeding the second predetermined threshold; and
the slope of the line connecting successive peak values of the firing force signal exceeding the third predetermined threshold.
3. The surgical instrument of claim 2 , wherein the control circuit comprises:
a first sensor configured to measure the firing force signal;
a second sensor configured to measure the position of the knife; and
a controller electrically connected to the first and second sensors, wherein the controller is configured to:
generate the curve;
determine the slope of the curve;
determine the slope of the line connecting the successive peak values of the firing force signal; and
determine the position of the knife.
4. The surgical instrument of claim 3 , wherein:
the first sensor comprises a strain gauge; and
the second sensor comprises a Hall-effect sensor.
5. The surgical instrument of claim 2 , wherein the occurrence of the second predefined event comprises at least one of the following:
the knife being stopped for a period of time;
a slope of the curve falling below a fourth predetermined threshold; and
a slope of a line connecting successive valley values of the firing force signal falling below a fifth predetermined threshold.
6. The surgical instrument of claim 5 , wherein the period of time varies based on the position of the knife.
7. A surgical instrument, comprising:
an elongated channel configured to support a staple cartridge;
an anvil pivotably connected to the elongated channel;
a knife mechanically coupled to the staple cartridge;
an electric motor mechanically coupled to the knife; and
a controller configured to control the electric motor to:
stop an advancement of the knife upon the occurrence of a first predefined event; and
automatically restart the advancement of the knife upon an occurrence of a second predefined event.
8. The surgical instrument of claim 7 , wherein the occurrence of the first predefined event comprises at least one of the following:
an amplitude of a firing force signal exceeding a predetermined threshold;
a slope of a curve representative of the firing force signal exceeding a second predetermined threshold;
a slope of a line connecting successive peak values of the firing force signal exceeding a third predetermined threshold; and
a position of the knife is within a predetermined range of positions between a proximal end of the staple cartridge and a distal end of the staple cartridge and at least one of the following:
the amplitude of the firing force signal exceeding the predetermined threshold;
the slope of the curve representative of the firing force signal exceeding the second predetermined threshold; and
the slope of the line connecting successive peak values of the firing force signal exceeding the third predetermined threshold.
9. The surgical instrument of claim 8 , wherein the occurrence of the second predefined event comprises at least one of the following:
the knife being stopped for a period of time; and
the slope of the curve falling below a fourth predetermined threshold.
10. The surgical instrument of claim 9 , wherein the controller comprises:
a first sensor configured to measure the firing force signal;
a second sensor configured to measure the position of the knife; and
a second controller electrically connected to the first and second sensors.
11. The surgical instrument of claim 10 , wherein the first sensor comprises a strain gauge.
12. The surgical instrument of claim 10 , wherein the second sensor comprises a Hall-effect sensor.
13. A surgical instrument, comprising:
an elongated channel configured to support a staple cartridge;
an anvil pivotably connected to the elongated channel;
a knife operably coupled to the staple cartridge;
an electric motor operably coupled to the knife;
a motor controller electrically coupled to the electric motor; and
a control circuit electrically connected to the motor controller, wherein the control circuit is configured to:
monitor a first predefined event;
monitor a second predefined event;
provide a stop signal to the motor controller to stop an advancement of the knife upon the occurrence of the first predefined event; and
automatically provide a start signal to the motor controller to start the advancement of the knife upon the occurrence of the second predefined event.
14. A surgical instrument, comprising:
an elongated channel configured to support a staple cartridge;
an anvil pivotably connected to the elongated channel;
a knife operably coupled to the staple cartridge;
an electric motor operably coupled to the knife; and
a controller configured to control the electric motor to:
stop an advancement of the knife upon an occurrence of a first predefined event; and
automatically restart the advancement of the knife upon an occurence of a second predefined event.