Apparatus and method for differentiating between tissue and mechanical obstruction in a surgical instrument

• US 9,962,157 B2
• Filed: 08/19/2014
• Issued: 05/08/2018
• Est. Priority Date: 09/18/2013
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Sapre, Parag
• Primary Examiner(s): Lopez, Michelle
• Application Number:
  US14/463,134
• Publication Number:
  US 20150076206A1
• Time in Patent Office: 1,358 Days
• Field of Search: 2271751
• CPC Class Codes: A61B 17/068 Surgical staplers , e.g. containing multiple staples or clampsstaplers containing only one staple A61B17/10; magazines or containers for staples A61B17/105; for performing anastomosis A61B17/115; staplers in general B25C5/00
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/00115 with audible or visual output with imaging means A61B90/37, A61B34/20
• CPC Class Codes: A61B 2017/00137 Details of operation mode
• CPC Class Codes: A61B 2017/00398 using powered actuators, e.g. stepper motors, solenoids
• CPC Class Codes: A61B 2017/0046 with a releasable handle; with handle and operating part separable for prosthetic joint-implanting tools A61F2/4603
• CPC Class Codes: A61B 2017/00473 Distal part, e.g. tip or head A61B2017/00464 takes precedence
• CPC Class Codes: A61B 2017/00734 battery operated
• CPC Class Codes: A61B 2090/0803 Counting the number of times an instrument is used
• CPC Class Codes: A61B 2090/0804 Counting number of instruments used; Instrument detectors
• CPC Class Codes: A61B 2090/0811 for the position of a particular part of an instrument with respect to the rest of the instrument, e.g. position of the anvil of a stapling instrument
• CPC Class Codes: A61B 90/03 Automatic limiting or abutting means, e.g. for safety

Abstract

A surgical instrument is provided. The surgical instrument includes: a handle assembly; a jaw assembly comprising a staple cartridge containing a plurality of staples and an anvil to form the plurality of staples upon firing; a drive assembly at least partially located within the handle and connected to the jaw assembly and the lockout mechanism; a motor disposed within the handle assembly and operatively coupled to the drive assembly; and a controller operatively coupled to the motor, the controller configured to control supply of electrical current to the motor and to monitor a current draw of the motor, wherein the controller is further configured to terminate the supply of electrical current to the motor in response to a rate of change of the current draw indicative of a mechanical limit of at least one of the jaw assembly, the drive assembly, or the motor.

Claims

1. A surgical instrument, comprising:

a handle assembly;

a jaw assembly comprising a staple cartridge containing a plurality of staples and an anvil to form the plurality of staples upon firing;

a drive assembly at least partially located within the handle assembly and connected to the jaw assembly and a lockout mechanism;

a motor disposed within the handle assembly and operatively coupled to the drive assembly; and

a controller operatively coupled to the motor, the controller configured to;

measure a plurality of current draw samples of a current draw of the motor;

determine a rate of change of the current draw;

store a first stability counter corresponding to current draw samples whose rate of change is within a first range of rate of change values; and

terminate a supply of electrical current to the motor based on the rate of change of the current draw being within the first range of rate of change values, and the first stability counter being above a predetermined stability threshold,

wherein the first range of rate of change values corresponds to a current draw indicative of a mechanical limit of at least one of the jaw assembly, the drive assembly, or the motor.

2. The surgical instrument according to claim 1, wherein the controller is further configured to determine whether the current draw is stable based on the rate of change of the current draw being within a second range of rate of change values.

3. The surgical instrument according to claim 2, wherein the controller is further configured to determine whether the current draw is unstable based on the rate of change of the current draw being within a third range of rate of change values.

4. The surgical instrument according to claim 3, wherein the controller is further configured to store a second stability counter of current draw samples within the second range.

5. The surgical instrument according to claim 4, wherein the controller determines whether the current draw is stable when the second stability counter is above a predetermined stability threshold.

6. The surgical instrument according to claim 5, wherein the first range is within the second range and the third range extends higher than the second range.

7. The surgical instrument according to claim 5, wherein the controller is further configured to store an event counter of current draw samples within the third range.

8. A surgical instrument, comprising:

a handle assembly;

a jaw assembly comprising a staple cartridge containing a plurality of staples and an anvil to form the plurality of staples upon firing;

a drive assembly at least partially located within the handle assembly and connected to the jaw assembly and a lockout mechanism;

a motor disposed within the handle assembly and operatively coupled to the drive assembly; and

a controller operatively coupled to the motor, the controller configured to;

measure a plurality of current draw samples of a current draw of the motor to determine a rate of change of the current draw,

store a first stability counter of current draw samples measured when the rate of change of the current draw is within a first range of rate of change values, and

determine whether the motor has reached a mechanical limit based on the rate of change of the current draw being within a first range of rate of change values indicative of the mechanical limit, and the first stability counter being above a predetermined stability threshold.

9. The surgical instrument according to claim 8, wherein the controller is further configured to determine whether the current draw is stable based on the rate of change of the current draw being within a second range of rate of change values.

10. The surgical instrument according to claim 9, wherein the controller is further configured to determine whether the current draw is unstable based on the rate of change of the current draw being within a third range of rate of change values.

11. The surgical instrument according to claim 10, wherein the controller is further configured to store a second stability counter of current draw samples within the second range.

12. The surgical instrument according to claim 11, wherein the controller determines whether the current draw is stable when the second stability counter is above a predetermined stability threshold.

13. The surgical instrument according to claim 12, wherein the first range is within the second range and the third range is higher than the second range.

14. The surgical instrument according to claim 12, wherein the controller is further configured to store an event counter of current draw samples within the third range.