Method of determining dullness of a surgical stapler knife
Thresholds can be assigned for one or more parameters in connection with the operation of a surgical device. An ultimate threshold can trigger a desired action, including cessation of operations or modification of operations, if the ultimate threshold is reached, or predicted to be reached. In addition, a marginal threshold can trigger a desired action, including improving operations such as slowing operations where the value of a parameter is measured to be between the values defined by a marginal threshold and an ultimate threshold. Multiple thresholds, based on multiple parameters, can be defined, further enabling calibrated usage, such as slowing operations based on exceeding both a marginal threshold based on number of sterilization cycles and exceeding a marginal threshold based on extent to which current draw exceeds a certain value.
1 . A method of determining an operability of a surgical stapler having a motor and an end effector with a knife, the method comprising:
capturing tissue with the end effector;
activating the motor and thereby advancing the knife through a medium separate from the tissue;
with the surgical stapler, monitoring a force required to advance the knife while advancing the knife through the medium; and
with the surgical stapler, comparing the force required to advance the knife to a force threshold to thereby determine a sharpness condition of the knife and a resulting operability of the surgical stapler to transect the captured tissue.
2 . The method of claim 1 , further comprising using a microcontroller of the surgical stapler to determine the operability of the surgical stapler.
3 . The method of claim 1 , further comprising monitoring an electric current to the motor to thereby monitor the force.
4 . The method of claim 1 , further comprising using a load cell to monitor the force.
5 . The method of claim 4 , wherein the load cell includes a strain gauge.
6 . The method of claim 1 , further comprising alerting an operator upon a determination that the force has exceeded the force threshold.
7 . The method of claim 6 , wherein alerting the operator includes providing a visual alert.
8 . The method of claim 6 , further comprising retracting the knife and subsequently advancing the knife a second time after alerting the operator.
9 . The method of claim 1 , further comprising ceasing further advancement of the knife upon a determination that the force exceeds the force threshold.
10 . The method of claim 9 , further comprising alerting an operator upon the determination that the force exceeds the force threshold.
11 . The method of claim 9 , further comprising advancing the knife after the cessation of the knife and upon an override command by an operator.
12 . The method of claim 1 , further comprising communicating to an operator via a display the determined operability of the surgical stapler.
13 . The method of claim 1 , further comprising estimating a number of cutting advancements of the knife until the force exceeds the force threshold, and storing the estimated number of cutting advancements in a memory of the surgical stapler.
14 . The method of claim 1 , further comprising controlling advancement of the knife based on the determined operability of the surgical stapler.
15 . A method of determining an operability of a surgical stapler, the method comprising:
engaging a cutting edge of the surgical stapler with a sharpness tester to thereby determine a force required to advance the cutting edge through at least a portion of the sharpness tester, wherein the force is determined by the sharpness tester; and
with the surgical stapler, comparing the force to a force threshold to thereby determine a sharpness condition of the cutting edge and a resulting operability of the surgical stapler to transect tissue.
16 . The method of claim 15 , wherein the force includes a first force, the method further comprising:
cutting tissue with the cutting edge after comparing the first force to the force threshold;
after cutting the tissue, reengaging the cutting edge with the sharpness tester to thereby determine a second force required to advance the cutting edge through at least a portion of the sharpness tester; and
comparing the second force to the force threshold to thereby determine the sharpness condition of the cutting edge.
17 . The method of claim 15 , further comprising alerting an operator regarding the determined sharpness condition.
18 . The method of claim 15 , further comprising alerting an operator that the cutting edge is unavailable to cut tissue upon determining that the force exceeds the force threshold.
19 . A method of determining an operability of a surgical stapler, the method comprising:
engaging a cutting edge of the surgical stapler with a load cell of a sharpness tester to thereby determine a force required to advance the cutting edge through at least a portion of the sharpness tester; and
comparing the force to a force threshold to thereby determine an estimated number of cutting cycles remaining in a lifespan of the cutting edge.
20 . The method of claim 19 , further comprising communicating the estimated number of cutting cycles of the cutting edge to an operator.