Surgical stapler having current mirror-based motor control

• US 10,076,326 B2
• Filed: 09/23/2015
• Issued: 09/18/2018
• Est. Priority Date: 09/23/2015
• Status: Active Grant

• Current Assignee: Cilag Gmbh International (Johnson & Johnson)
• Original Assignee: Ethicon, LLC (Johnson & Johnson)
• Inventors: Yates, David C., Shelton, IV, Frederick E.
• Primary Examiner(s): Smith, Scott A.
• Application Number:
  US14/862,455
• Publication Number:
  US 20170079650A1
• Time in Patent Office: 1,091 Days
• Field of Search: 227 19, 2271751, 2271752, 2271761, 2271801, 606139, 606213, 606219, 606143, 606151, 606153, 606 32, 606 33, 606133, 173 29, 173213, 173217, 173 2, 604 22, 604272, 600 34, 600 41, 600564, 600567, 600576, 323212, 323215, 323219
• CPC Class Codes: A61B 17/00 Surgical instruments, devices or methods, e.g. tourniquets A61B18/00 takes precedence; contraceptive devices, pessaries, or applicators therefor A61F6/00; eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 17/0469 Suturing instruments for use in minimally invasive surgery, e.g. endoscopic surgery
• CPC Class Codes: A61B 17/07207 the staples being applied sequentially
• CPC Class Codes: A61B 18/1445 at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• 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 2017/00486 Adaptors for coupling parts with incompatible geometries
• 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 2090/0811 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 2560/0204 of power management
• CPC Class Codes: G01R 19/00 Arrangements for measuring currents or voltages or for indicating presence or sign thereof G01R5/00 takes precedence; for measuring bioelectric currents or voltages A61B5/24
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H02P 7/18 by master control with auxiliary power
• CPC Class Codes: H02P 7/29 using pulse modulation
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A surgical stapler. The surgical stapler includes a drive system, an electric motor, a battery and a control system. The electric motor is mechanically coupled to the drive system. The battery is electrically couplable to the electric motor. The control system is electrically connected to the electric motor and includes an H-bridge circuit and a current mirror circuit. The H-bridge circuit includes a plurality of switching devices. The current mirror circuit is electrically connected to the H-bridge circuit. The control system is configured to control a force applied to the drive system based on a current measured at a node of the current mirror circuit. The node is electrically connected in parallel with the H-bridge circuit.

Claims

1. A surgical stapler, comprising:

a drive system;

an electric motor mechanically coupled to the drive system;

a battery electrically couplable to the electric motor; and

a control system electrically connected to the electric motor, the control system comprising;

an H-bridge circuit comprising a plurality of switching devices; and

a current mirror circuit electrically connected to the H-bridge circuit, wherein the control system is configured to control a force applied to the drive system based on a current measured at a node of the current mirror circuit, and wherein the node is electrically connected in parallel with the H-bridge circuit.

2. The surgical stapler of claim 1, wherein:

the H-bridge circuit comprises a high side and a low side; and

the current mirror circuit is electrically connected to the low side of the H-bridge circuit.

3. The surgical stapler of claim 2, wherein:

the low side of the H-bridge circuit comprises first and second legs; and

the current mirror circuit is electrically connected to one of the first and second legs of the H-bridge circuit.

4. The surgical stapler of claim 1, wherein the current mirror circuit comprises a three-transistor Wilson current mirror.

5. The surgical stapler of claim 1, wherein the control system further comprises a current sensor configured to measure the current.

6. The surgical stapler of claim 1, wherein:

the control system further comprises a second current mirror circuit electrically connected to the H-bridge circuit; and

the control system is further configured to control a second force applied to the drive system based on a second current measured at a node of the second current mirror circuit, wherein the node of the second current mirror circuit is electrically connected in parallel with the H-bridge circuit.

7. The surgical stapler of claim 6, wherein:

the H-bridge circuit comprises a high side and a low side; and

the current mirror circuit and the second current mirror circuit are each electrically connected to the low side of the H-bridge circuit.

8. The surgical stapler of claim 7, wherein:

the low side of the H-bridge circuit comprises first and second legs;

the current mirror circuit is electrically connected to the first leg of the H-bridge circuit; and

the second current mirror circuit is electrically connected to the second leg of the H-bridge circuit.

9. The surgical stapler of claim 6, wherein the control system further comprises a second current sensor, wherein the second current sensor is configured to measure the second current.

10. A surgical stapler, comprising:

a drive system;

an electric motor mechanically coupled to the drive system;

a battery electrically couplable to the electric motor; and

a control system electrically connected to the electrical motor, the control system comprising;

an H-bridge circuit comprising a plurality of switching devices;

a first current mirror circuit electrically connected to the H-bridge circuit; and

a second current mirror circuit electrically connected to the H-bridge circuit, wherein the control system is configured to;

control a first force applied to the drive system based on a first current measured at a node of the first current mirror circuit, wherein the node is electrically connected in parallel with the H-bridge circuit; and

control a second force applied to the drive system based on a second current measured at a node of the second current mirror circuit, wherein the node of the second current mirror circuit is electrically connected in parallel with the H-bridge circuit.

11. The surgical stapler of claim 10, wherein:

the H-bridge circuit comprises a high side and a low side; and

the first and second current mirror circuits are electrically coupled to the low side of the H-bridge circuit.

12. The surgical stapler of claim 11, wherein:

the low side of the H-bridge circuit comprises first and second legs;

the first current mirror circuit is electrically connected to the first leg of the H-bridge circuit; and

the second current mirror circuit is electrically connected to the second leg of the H-bridge circuit.

13. The surgical stapler of claim 10, wherein at least one of the first and second current mirror circuits is a three-transistor Wilson current mirror.

14. The surgical stapler of claim 10, wherein the control system further comprises:

a first current sensor configured to measure the first current; and

a second current sensor configured to measure the second current.

15. A surgical stapler, comprising:

a drive system;

an electric motor mechanically coupled to the drive system;

a battery electrically couplable to the electric motor; and

a control system electrically connected to the electric motor, the control system comprising;

a mirror bridge circuit, comprising;

an H-bridge circuit, the H-bridge circuit comprising;

a plurality of switching devices; and

a current mirror circuit electrically connected in series with the electric motor, wherein the control system is configured to control a force applied to the drive system based on a current measured at a node of the current mirror circuit, and wherein the node is external to the H-bridge circuit.

16. The surgical stapler of claim 15, wherein:

the H-bridge circuit comprises a high side and a low side; and

the low side of the H-bridge circuit comprises the current mirror circuit.

17. The surgical stapler of claim 16, wherein:

the low side of the H-bridge circuit comprises first and second legs; and

one of the first and second legs of the H-bridge circuit comprises the current mirror circuit.

18. The surgical stapler of claim 16, wherein:

the low side of the H-bridge circuit further comprises a second current mirror circuit; and

the control system is further configured to control a second force applied to the drive system based on a second current measured at a node of the second current mirror circuit, wherein the node of the second current mirror circuit is external to the H-bridge circuit.

19. The surgical stapler of claim 18, wherein at least one of the current mirror circuit and the second current mirror circuit is a four-transistor Wilson current mirror.

20. The surgical stapler of claim 18, wherein the control system further comprises:

a first current sensor configured to measure the current; and

a second current sensor configured to measure the second current.

21. A surgical stapler, comprising:

a drive system;

an electric motor mechanically coupled to the drive system;

a battery electrically couplable to the electric motor; and

a control system electrically connected to the electric motor, the control system comprising;

an H-bridge circuit comprising a plurality of switching devices; and

an electrical circuit electrically connected to the H-bridge circuit, wherein the control system is configured to control the electric motor based on a current measured in the electrical circuit.