Multiple level thresholds to modify operation of powered surgical instruments

Abstract

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.

What is claimed is: 
     
         1 . A surgical cutting and stapling instrument comprising at least one processor and operatively associated memory, the instrument configured to:
 identify a parameter;   identify a value of an ultimate threshold for the parameter; and   identify a value of a marginal threshold for the parameter.   
     
     
         2 . The instrument of  claim 1 , wherein operations of the instrument are adjusted based on a determination that a measured value of the parameter exceeds the value of the ultimate threshold. 
     
     
         3 . The instrument of  claim 1 , wherein operations of the instrument are adjusted based on a determination that a measured value of the parameter exceeds the value of the marginal threshold. 
     
     
         4 . The instrument of  claim 1 , wherein a modified rate of change of the value of the parameter is calculated based on a determination that a predicted rate of change of the value of the parameter will result in a value that will exceed the value of the ultimate threshold. 
     
     
         5 . The instrument of  claim 4 , wherein operations of the instrument are adjusted based on the calculated modified rate of change of the parameter. 
     
     
         6 . The instrument of  claim 5 , wherein the adjustment is based on a stepped function. 
     
     
         7 . The instrument of  claim 5 , wherein the adjustment is based on a ramped function. 
     
     
         8 . The instrument of  claim 5 , wherein the value of the calculated rate of change comprises a set of values located between the value of the marginal threshold and the value of the ultimate threshold. 
     
     
         9 . The instrument of  claim 1 , wherein the value of the marginal threshold is approximately 75% of the value of the ultimate threshold. 
     
     
         10 . The instrument of  claim 1 , wherein the parameter comprises current drawn by a battery associated with the instrument. 
     
     
         11 . The instrument of  claim 1 , wherein the parameter comprises voltage of a battery associated with the instrument. 
     
     
         12 . The instrument of  claim 1 , wherein the parameter comprises speed of a knife fired by the instrument. 
     
     
         13 . The instrument of  claim 1 , wherein the parameter comprises a number of sterilization cycles associated with the surgical instrument. 
     
     
         14 . The instrument of  claim 1 , wherein the parameter comprises a measured behavior of a clinician during operation of the instrument. 
     
     
         15 . A surgical cutting and stapling instrument comprising at least one processor and operatively associated memory, the surgical instrument configured to:
 identify a first parameter;   identify a second parameter; and   identify a specified threshold, the specified threshold comprising one or more of:
 a value of an ultimate threshold for the first parameter; 
 a value of a marginal threshold for the first parameter; 
 a value of an ultimate threshold for the second parameter; and 
 a value of a marginal threshold for the second parameter. 
   
     
     
         16 . The instrument of  claim 15 , further configured to adjust operations upon a determination that a specified threshold has been exceeded. 
     
     
         17 . The instrument of  claim 15 , further configured to store an overlaying threshold, the overlaying threshold based on a mathematical relationship between, on one hand, the value of the first ultimate threshold or the value of the first marginal threshold, and, on the other hand, the value of the second ultimate threshold or the value of the second marginal threshold. 
     
     
         18 . The instrument of  claim 15  wherein the first parameter comprises speed of a motor of the instrument, and the second parameter comprises a number of sterilization cycles of the instrument. 
     
     
         19 . The instrument of  claim 15  wherein the first parameter comprises a speed of a knife deployed by the instrument, and the second parameter is a number of sterilization cycles of the instrument. 
     
     
         20 . The instrument of  claim 15 , wherein a third threshold is identified based on a determination that the instrument has exceeded a value of a specified threshold.