POWERED SURGICAL STAPLING DEVICE
A surgical stapler which includes a tool assembly having a pair of opposing tissue engaging surfaces for deforming a plurality of surgical fasteners through and fastening tissue is disclosed. The surgical stapler includes a housing having a fixed handle and a movable handle mounted to said housing and selectively movable relative to said fixed handle from a first position to a second position to actuate the clamping of tissue. The stapler further includes a drive assembly including a motor, a power source and a coupling member. The motor engages the coupling member, wherein movement of the movable handle to the second position activates the motor, which advances a firing shaft and forces a firing piston into said tool assembly to deform the surgical fasteners through and fasten tissue.
1. Technical Field
The present disclosure relates to a surgical stapler for implanting mechanical surgical fasteners into the tissue of a patient, and, in particular, to a surgical stapler which is powered by a motor for firing surgical fasteners into tissue.
2. Background of Related Art
Current known devices can typically require 10-60 pounds of manual hand force to clamp tissue and deploy and form surgical fasteners in tissue which, over repeated use, can cause a surgeon's hand to become fatigued.
Gas powered pneumatic staplers which implant surgical fasteners into tissue are known in the art. Certain of these instruments utilize a pressurized gas supply which connects to a trigger mechanism by way of an intricate series of hoses and actuators. The trigger mechanism, when depressed, simply releases pressurized gas to implant a fastener into tissue.
Motor-powered surgical staplers are also known and are disclosed in U.S. Pat. No. 5,383,880 to Hooven and U.S. Pat. No. 6,716,233 to Whitman. The '880 and the '233 patents disclose powered surgical staplers including motors which activate staple firing mechanisms. In particular, the '880 patent discloses a powered stapler wherein the power of the motor is automatically controlled based on various types of sensor data (e.g., tissue thickness). The '233 patent teaches a powered stapler that is automatically controlled as a function of sensor data. However, both of these references only provide for limited user control of the stapling process. The '880 and '233 patents provide the user with the option of toggling a single switch and/or button to actuate the powered stapler which then automatically controls the motor and applies corresponding torque to the stapler's firing mechanisms. Consequently, in these references, the user only controls activation and deactivation of the device and the device does not provide any tactile feedback.
It would be desirable to provide a low cost motor powered stapler that provides the needed energy required to fire the instrument to form a series of surgical fasteners into and through tissue. It would also be desirable to provide an ergonomically advanced surgical stapler which reduces fatigue during repeated use and provides the surgeon with more tactile feedback during activation of the stapler. It would further be desirable to provide a powered stapler which provides the user with tactile feedback allowing to user to vary the force applied by the motor on the stapling and/or clamping mechanisms.
SUMMARYAccording to one aspect of the present disclosure, a surgical stapler having a tool assembly at its distal end is disclosed. The tool assembly includes a pair of opposing tissue engaging surfaces for deforming a plurality of surgical fasteners through and fastening tissue. The stapler also includes a housing having a fixed handle and a movable handle mounted to said housing and selectively movable relative to said fixed handle from a first position in spaced relation relative to said fixed handle to a second position closer to said fixed handle to actuate the clamping of tissue. The stapler further includes a drive assembly having a power source and a motor which engages a coupling member, the coupling member is operatively coupled to the movable handle, wherein movement of the movable handle to the second position activates the motor, which advances the coupling member which in turn advances a firing shaft and forces a firing piston into said tool assembly to deform the surgical fasteners through and fasten tissue, such that the rate at which the motor advances the coupling member is variably controlled in response to the force exerted on the movable handle during movement thereof to the second position.
According to another aspect of the present disclosure a surgical stapler is provided. The surgical stapler includes a housing, an elongated member attached to the housing, and a tool assembly attachable to the distal end of the elongated member, said tool assembly including an anvil assembly and a cartridge assembly each having an opposing tissue engaging surface, said cartridge assembly including a plurality of surgical fasteners. The stapler also includes a selectively activateable drive assembly including a power source and a motor which engages a coupling member, the coupling member is operatively coupled to the movable handle, wherein upon actuation the motor advances the coupling member which advances a firing shaft and forces a firing piston into said tool assembly to deform the surgical fasteners through and fasten tissue, such that the rate at which the motor advances the coupling member is variably controlled in response to the force exerted on the movable handle.
Various embodiments of the subject instrument are described herein with reference to the drawings wherein:
Referring initially to the embodiment disclosed in
The tool assembly 200 depicted in
Housing 12 includes a fixed handle 65 which is generally in the form of a pistol grip to enhance manipulation of the stapler 10 as needed during surgery. Stapler 10 also includes a movable handle 60 which is movable relative to fixed handle 65 (in the direction “A”) to actuate opposing tissue contacting surfaces 110 and 120 of tool assembly 100 to manipulate, grasp fasten and cut tissue. The proximal end of shaft 30 is integrally associated with, mounted to, or selectively attachable to housing 12. One or more actuating assemblies are incorporated within housing 12 and may include manual, robotic or computer operated systems. The actuating assembly may comprise that of a known open or endoscopic surgical stapler. Many types of mechanical actuators and handle mechanisms are known which are configurable to communicate with and actuate the functions of tool assembly 100. Mechanical actuators and handle mechanisms are disclosed in U.S. Pat. Nos. 5,318,221, 5,762,256 and 5,865,361, the disclosures of which are hereby incorporated by reference herein.
As best seen in
The drive assembly 20 includes a coupling member 90 operatively coupled to a shaft connector 92 which is coupled to the firing shaft 55, such that longitudinal movement of the coupling member 90 in the direction “D” is translated to the firing shaft 55. The coupling member 90 includes a ratchet track 94 having one or more teeth interfacing with a pawl 96 allowing for unidirectional motion. The pawl 96 is rotatively coupled to the movable handle 60 via a pin 98, such that when the movable handle 60 is pulled toward the handle 65, the pawl 98 engages one of the teeth of the ratchet track 94 and pushes the coupling member 90 in the distal direction “D.” The staple firing mechanism 70 is advanced by the distal movement of the coupling member 90 and firing shaft 55. The staple firing mechanism 70 engages the anvil assembly 113 and cartridge assembly 111 to clamp tissue therebetween. Further actuation of the staple firing mechanism deploys staples from the staple cartridge assembly 111 and deforms the staples against the anvil assembly 113.
The coupling member 90 includes a lumen defined therein having supporting walls 130 and 131. The supporting wall 130 along with the shaft connector 92 encloses a spring 32 or another compression mechanism. The spring 32 applies pressure onto supporting wall 130 which in turn pushes the coupling member 90 in the proximal direction “C.” The pressure on the coupling member 90 also moves apart the movable handle 60 away from the fixed handle 65, keeping the movable handle 60 in an unactuated position (e.g., first position).
The drive assembly 20 includes an electric DC motor 144 connected to a power source 142 (e.g., a battery). A variable resistor 140 and a switch 80 are connected in series with the DC motor 144 and the power source 142. The switch 80 is open when the movable handle 60 is in the first position and is closed when then movable handle 60 is pulled in the proximal direction into the second position actuating the coupling member 90. In particular, a contact 82 disposed on the movable handle 60 contacts a contact 81 disposed on the fixed handle 65. Once the contacts 81 and 82 are touching, the switch 80 is closed and the DC motor 144 is activated. It is envisioned that the switch 80 may be implemented via a variety of embodiments known to those skilled in the art, such as a push button switch being disposed on the fixed handle 65 and being activated by physical contact of the movable handle 60 as the movable handle 60 is actuated. As discussed above, the spring 132 biases the movable handle 60 away from the fixed handle 65 to maintain the switch 80 in an open position thereby preventing inadvertent activation of the DC motor 144. More specifically, the spring 132 biases the coupling member 90 by acting on a housing potion 12a and supporting wall 130.
The DC motor 144 is coupled to a unidirectional clutch 146 which interfaces with a pinion gear 148. Once the DC motor 144 is activated by pulling of the movable handle 60, the clutch 146 rotates in a clockwise direction rotating the gear 148 in the clockwise direction as well. The gear 148 interfaces with a rack surface 95 of the coupling member 90 and the rotational motion of the gear 148 translates the coupling member 90 in a longitudinal motion, advancing the coupling member 90 and the firing rod 55 in a distal direction “D.”
The rate at which the DC motor 144 rotates, and hence, the rate at which the firing shaft 55 is moved in the distal direction, is controlled via the variable resistor 140. In
The switch 80 is arranged to allow clamping of tissue before the motor 144 is actuated. This provides for user control of the initial grasping of the tissue with the end effector 100 and subsequent power-assisted firing of surgical fasteners 115. Those skilled in the art will appreciate that the disclosed variable resistor 140 may also be a rheostat.
Use of the surgical stapler 10 is as follows. The surgical stapler is positioned with the end effector 100 at the surgical site and the tissue engaging surfaces 110 and 120 are placed around tissue. The user thereafter initiates the stapling process by pulling on the movable handle 60 to bring the movable handle 60 toward the fixed handle 65 and clamp tissue. With further movement of movable handle 60, the switch 80 is closed. Simultaneously, the movable handle 60 moves the coupling member 90 in the distal direction along the direction “C” thereby moving the contact 143 along the potentiometer 141. The clamping force exerted by the pulling of the movable handle 60 is counterbalanced by the tissue being grasped and the spring 132. As the movable handle 60 moves the coupling member 90, the contact 143 moves along the potentiometer 141, adjusting the voltage supplied to the DC motor 144. The DC motor 144 rotates at the rate corresponding to the supplied voltage as varied by the variable resistor 140. In response thereto, the DC motor 144 actuates the pinion gear 148 via the unidirectional clutch 146. The rotational motion of the pinion gear 148, which interfaces with the rack surface 95, is translated into longitudinal motion of the coupling member 90 and the firing shaft 55. The firing shaft 55 forces the staple firing mechanism 70 and knife assembly 75 through tissue to sequentially fasten and separate the tissue. Consequently, the rates at which the opposing tissue contacting surfaces 110 and 120 are closed and the staples are fired are directly proportional to the pulling force on the movable handle 60. This provides the user with tactile feedback during the stapling process. Those skilled in the art will appreciate that a series of gears, shafts, screws or other mechanisms may be employed to convert the rotational energy of the drive assembly 20 to firing shaft 55 to actuate tool assembly 100. The drive assembly 20 desirably includes a switch for reversing the motor 144 for retracting the staple firing mechanism 70, and releasing the end effector 100 from tissue. A button may be provided on the housing 12 to actuate the switch.
Preferably, the presently disclosed staplers are designed for endoscopic use and are dimensioned to fit through a trocar or cannula for various endoscopic and laparoscopic procedures. As can be appreciated, the overall dimensions of the tool assembly and the elongated shaft are sized accordingly to fit through the trocar or cannula. Alternatively, the presently disclosed staplers may also be designed and/or used for open surgical procedures. The disclosed surgical staplers preferably are suitable for one-handed operation by the user.
The surgical stapler of
It will be understood that various modifications may be made to the embodiments shown herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
Claims
1. A surgical stapler including a tool assembly having a pair of opposing tissue engaging surfaces for deforming a plurality of surgical fasteners through and fastening tissue, the tool assembly being attached at a distal end of the surgical stapler, the surgical stapler comprising:
- a housing having a fixed handle;
- a movable handle mounted to said housing and selectively movable relative to said fixed handle from a first position in spaced relation relative to said fixed handle to a second position closer to said fixed handle to actuate the clamping of tissue;
- a drive assembly including a power source and a motor which engages a coupling member, the coupling member being operatively coupled to the movable handle, wherein movement of the movable handle to a third position activates the motor, the motor being arranged with the coupling member so that activation of the motor advances the coupling member which in turn advances a firing shaft to deploy and deform the surgical fasteners, the drive assembly including a controller, such that the rate at which the motor advances the coupling member is variably controlled in response to the force exerted on the movable handle during movement thereof to the third position.
2. A surgical stapler according to claim 1, wherein the coupling member advances the firing shaft to actuate said tool assembly to initially clamp tissue between opposing tissue engaging surfaces of said tool assembly.
3. A surgical stapler according to claim 1, wherein the drive assembly includes a variable resistor coupled in series with the motor and the power source.
4. A surgical stapler according to claim 3, wherein the variable resistor regulates amount of voltage supplied to the motor as a function of the force exerted on the movable handle during movement thereof to the second position.
5. A surgical stapler according to claim 4, wherein the drive assembly further includes a spring which compresses the coupling member to maintain the movable handle in the first position.
6. A surgical stapler according to claim 3, wherein the variable resistor is selected from the group consisting of a potentiometer and a rheostat.
7. A surgical stapler according to claim 1, wherein the drive assembly includes a switch coupled in series with the motor and the power source, wherein the switch is closed by moving the movable handle to the second position.
8. A surgical stapler, comprising:
- a housing;
- an elongated member attached to the housing;
- a tool assembly attachable to the distal end of the elongated member, said tool assembly including an anvil assembly and a cartridge assembly each having an opposing tissue engaging surface, said cartridge assembly including a plurality of surgical fasteners;
- a selectively activateable drive assembly including a power source and a motor which engages a coupling member, the coupling member is operatively coupled to the movable handle, wherein upon actuation the motor advances the coupling member which advances a firing shaft to deploy and deform the surgical fasteners, the selectively activateable drive assembly also including a controller configured to variably control the rate at which the motor advances the coupling member in response to the force exerted on the movable handle.
9. A surgical stapler according to claim 8, wherein the coupling member advances the firing shaft to actuate said tool assembly to initially clamp tissue between opposing tissue engaging surfaces of said tool assembly.
10. A surgical stapler according to claim 10, wherein the drive assembly includes a variable resistor coupled in series with the motor and the power source.
11. A surgical stapler according to claim 10, wherein the variable resistor regulates amount of voltage supplied to the motor as a function of the force exerted on the movable handle during movement thereof to the second position.
12. A surgical stapler according to claim 11, wherein the drive assembly further includes a spring which compresses the coupling member to allow for selective actuation of the drive assembly upon application of sufficient force.
13. A surgical stapler according to claim 11, wherein the variable resistor is selected from the group consisting of a potentiometer and a rheostat.
14. A surgical stapler according to claim 8, wherein the drive assembly includes a switch coupled in series with the motor and the power source, wherein the switch is closed by moving the movable handle to the second position.
Type: Application
Filed: Mar 15, 2007
Publication Date: Sep 18, 2008
Inventor: Stanislaw Marczyk (Stratford, CT)
Application Number: 11/724,744