BACKGROUND

Minimally invasive surgical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. As a consequence, the average length of a hospital stay for standard surgery may be shortened significantly using minimally invasive surgical techniques. Also, patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.

A common form of minimally invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient's abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately one-half inch or less) incisions to provide entry ports for laparoscopic instruments.

Laparoscopic surgical instruments generally include an endoscope (e.g., laparoscope) for viewing the surgical field and tools for working at the surgical site. The working tools are typically similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube (also known as, e.g., an instrument shaft or a main shaft). The end effector can include, for example, a clamp, grasper, scissor, stapler, cautery tool, linear cutter, or needle holder.

To perform surgical procedures, the surgeon passes working tools through cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon views the procedure from a monitor that displays an image of the surgical site taken from the endoscope. Similar endoscopic techniques are employed in, for example, arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.

Minimally invasive telesurgical robotic systems are being developed to increase a surgeon's dexterity when working on an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location (outside the sterile field). In a telesurgery system, the surgeon is often provided with an image of the surgical site at a control console. While viewing a three dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the control console. Each of the master input devices controls the motion of a servo-mechanically actuated/articulated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors that perform various functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting tissue, or the like, in response to manipulation of the master input devices.

Manipulation and control of these end effectors is a particularly beneficial aspect of robotic surgical systems. For this reason, it is desirable to provide surgical tools that include mechanisms that provide three degrees of rotational movement of an end effector to mimic the natural action of a surgeon's wrist. Such mechanisms should be appropriately sized for use in a minimally invasive procedure and relatively simple in design to reduce possible points of failure. In addition, such mechanisms should provide an adequate range of motion to allow the end effector to be manipulated in a wide variety of positions.

Surgical clamping and cutting instruments (e.g., non-robotic linear clamping, stapling, and cutting devices, also known as surgical staplers; and electrosurgical vessel sealing devices) have been employed in many different surgical procedures. For example, a surgical stapler can be used to resect a cancerous or anomalous tissue from a gastro-intestinal tract. Many known surgical clamping and cutting devices, including known surgical staplers, have opposing jaws that clamp tissue and an articulated knife to cut the clamped tissue.

Surgical clamping and cutting instruments are often deployed into restrictive body cavities (e.g., through a cannula to inside the pelvis). Accordingly, it is desirable for the surgical clamping and cutting instrument to be both compact and maneuverable for best access to and visibility of the surgical site. Known surgical clamping and cutting instruments, however, may fail to be both compact and maneuverable. For example, known surgical staplers may lack maneuverability with respect to multiple degrees of freedom (e.g., Roll, Pitch, and Yaw) and associated desired ranges of motion. Typically, known surgical staplers have a smaller range of Pitch motion than desirable and no Yaw motion.

Additionally, surgical clamping and cutting instruments can sometimes fail to fully actuate (e.g., due to a hard obstacle blocking the knife path), potentially leaving a knife blade exposed. In such an event, it is desirable that the knife blade not be in a position that may represent a hazard with respect to removal of the surgical instrument from the surgical site. Known surgical clamping and cutting instruments, however, may fail to avoid the potential knife hazard and at the same time be compact and maneuverable.

Thus, there is believed to be a need for improved surgical clamping and cutting instruments and related methods. Such surgical clamping and cutting instruments should be compact and maneuverable, and employ a knife that does not represent a hazard with respect to removal of the surgical instrument from the surgical site when the surgical instrument fails to fully actuate.

BRIEF SUMMARY

Improved surgical clamping and cutting instruments (e.g., surgical staplers, and electrosurgical vessel sealing devices) and related methods are disclosed. Surgical clamping and cutting instruments described herein employ a proximal-to-distal knife movement, thereby orienting the knife to reduce the likelihood of unintentionally cutting tissue while removing the surgical instrument from the surgical site in the event that the surgical instrument fails to fully actuate. The surgical instruments described herein include first and second moving members that are moved toward the distal end at the same rate through a first distance to cut tissue and subsequently move relative to each other to facilitate stowing of the knife.

Thus, in one aspect, a method of articulating a knife in a surgical instrument is disclosed. The surgical instrument has a proximal end and a distal end. The method includes pivotally supporting the knife from a first member. The knife is configured to cut when the knife is moved toward the distal end. A rotation of the knife relative to the first member is blocked with the second member while moving the first member and a second member toward the distal end at the same rate. After moving the first and second members toward the distal end at the same rate, relative movement between the first and second members is generated to accomplish at least one of permitting rotation of the knife or inducing rotation of the knife.

In many embodiments, a lead screw is used to actuate the first and second members. For example, moving the first and second members towards the distal end at the same rate can include rotating a lead screw having a threaded portion operatively coupled with at least one of the first member or the second member. Generating relative movement between the first and second members can include rotating a lead screw having a threaded portion and a non-threaded portion. The threaded portion can be operatively coupled with one of the first and second members and the non-threaded portion can interface with the other of the first and second members such that rotation of the lead screw generates the relative motion between the first and second members.

Any suitable relative movement between the first and second members can be used. For example, generating relative movement between the first and second members can include moving the either one of the first member or the second member toward the distal end while preventing the other one of the first and second members from moving toward the distal end to reposition the second member relative to the first member to not block the rotation of the knife. As another example, generating relative movement between the first and second members can include moving the either one of the first member or the second member toward the proximal end while preventing the other one of the first and second members from moving toward the proximal end to reposition the second member relative to the first member to not block the rotation of the knife.

In many embodiments, the relative movement between the first and second members induces rotation of the knife relative to the first member. For example, the knife can include external gear teeth that mate with external gear teeth coupled with the second member so that the relative movement between the first and second members causes movement of the second member gear teeth relative to the knife gear teeth and corresponding rotation of the knife relative to the first member.

The knife can engage one or more features to selectively cause the knife to rotate into a desired position. For example, the method can include engaging the knife with a kick-down feature to cause the knife to rotate relative to the first member to stow a cutting edge of the knife below an upper surface of the housing. As another example, the method can include engaging the knife with a kick-down feature coupled to the second member thereby causing the knife to rotate relative to the first member to stow a cutting edge of the knife below the upper surface of the housing. As an additional example, the method can include engaging the knife with a kick-up feature to cause the knife to rotate into a cutting position during the movement of the first and second members towards the distal end at the same rate.

The method can further include additional acts performed using the surgical instrument. For example, the method can include deploying staples during the movement of the first and second members toward the distal end at the same rate.

In another aspect, a surgical instrument is disclosed. The surgical instrument includes an elongated shaft having a shaft distal end and a shaft proximal end, an end effector coupled to the shaft distal end and including two opposed jaws, a housing included in one of the jaws, a first member mounted in the housing and movable toward the housing distal end, a knife, and a second member. The second member is configured to move with the first member toward the housing distal end through a first distance. Relative movement between the first and second members occurs after the first and second members move through the first distance. The housing includes a housing proximal end, a housing distal end, an upper surface extending between the housing proximal and distal ends, a central cavity extending between the housing proximal and distal ends, and a longitudinal slot extending through the upper surface. The knife is pivotally coupled with the first member. The knife has a cutting edge configured to cut when the first member is moved toward the housing distal end. The cutting edge extends above the housing upper surface for at least a portion of the distal movement of the first member. The second member blocks a rotation of the knife relative to the first member while moving with the first member at the same rate toward the housing distal end and at least one of permits rotation of the knife after a relative movement between the first and second members or induces rotation of the knife during a relative movement between the first and second members.

In many embodiments, the surgical instrument includes a lead screw coupled with the housing for rotation relative to the housing. The lead screw is operatively coupled with at least one of the first member or the second member to drive the coupled member along at least a portion of the lead screw in response to rotation of the lead screw. For example, the lead screw can have a threaded portion and a non-threaded portion disposed distally of the threaded portion. Both the first and second members can be driven along the lead screw when the second member moves with the first member toward the housing distal end at the same rate. To generate the relative movement between the first and second members, one of the first and second members can be interfaced with the non-threaded portion and the other one of the first and second members can be interfaced with the threaded portion.

The surgical instrument can employ any suitable relative movement between the first and second members. For example, the first member or the second member can move toward the housing distal end when the second member moves relative to the first member. As another example, the first member or the second member can move toward the housing proximal end when the second member moves relative to the first member.

In many embodiments of the surgical instrument, the relative movement between the first and second members induces rotation of the knife relative to the first member. For example, the knife can include gear teeth that mate with gear teeth coupled with the second member so that the relative movement between the first and second members causes movement of the second member gear teeth relative to the knife gear teeth and corresponding rotation of the knife relative to the first member.

In many embodiments of the surgical instrument, the second member moves along with the first member until prevented from doing so. For example, the second member can be prevented from moving toward the housing distal end during a movement of the first member toward the housing distal end to reposition the second member to not block the rotation of the knife. In many embodiments, the second member is slidably mounted to the first member to move with the first member along the first distance and to not move toward the distal end during a movement of the first member toward the distal end.

The surgical instrument can include one or more features to selectively rotate the knife into a desired position. For example, the surgical instrument can include a kick-down feature coupled with the housing to cause the knife to rotate relative to the first member to stow the cutting edge of the knife below an upper surface of the housing. As another example, the surgical instrument can include a kick-down feature coupled to the second member to cause the knife to rotate relative to the first member to stow the cutting edge of the knife below an upper surface of the housing during the relative motion between the first and second members. As an additional example, the surgical instrument can include a kick-up feature coupled with the housing to cause the knife to rotate into a cutting position during the movement of the first and second members towards the distal end at the same rate.

The surgical instrument can include additional features providing additional functionality. For example, the housing can include a plurality of staple openings extending between the upper surface and the central cavity. A plurality of staples can be disposed in the staple openings, each of the staples being deployed during a movement of the first and second members toward the housing distal end at the same rate.

In another aspect, a demountably attachable cartridge of a surgical instrument is disclosed. The cartridge includes a housing demountably attachable to an end effector of the surgical instrument, a first member mounted in the housing and movable toward a distal end of the housing, a knife, and a second member. The second member is operable to move with the first member toward the distal end through a first distance. Relative movement between the first and second members occurs after the first and second members move through the first distance. The housing includes a proximal end, a distal end, an upper surface extending between the proximal and distal ends, a central cavity extending between the proximal and distal ends, and a longitudinal slot extending through the upper surface. The knife is pivotally coupled with the first member or the second member. The knife has a cutting edge configured to cut when moved toward the distal end. The cutting edge extends through the longitudinal slot for at least a portion of the movement of the first member along the lead screw. The second member blocks a rotation of the knife relative to the first member while moving with the first member. The second member at least one of permits rotation of the knife or induces rotation of the knife after a relative movement between the first and second members.

In many embodiments, the cartridge includes a lead screw coupled with the housing for rotation relative to the housing. The lead screw is operatively coupled with at least one of the first member or the second member to drive the coupled member along at least a portion of the lead screw in response to rotation of the lead screw. For example, the lead screw can have a threaded portion and a non-threaded portion disposed distally of the threaded portion. Both the first and second members can be driven along the lead screw when the second member moves with the first member toward the housing distal end at the same rate. To generate the relative movement between the first and second members, one of the first and second members can be interfaced with the non-threaded portion and the other one of the first and second members can be interfaced with the threaded portion.

In many embodiments of the cartridge, the lead screw has a threaded portion and a non-threaded portion disposed toward the distal end relative to the threaded portion. Both the first and second members are driven along the threaded portion when the second member moves with the first member toward the distal end at the same rate. One of the first and second members can interface with the threaded portion and the other one of the first and second members can interface with the non-threaded portion to generate the relative movement between the first and second members in response to a rotation of the lead screw.

The cartridge can employ any suitable relative movement between the first and second members. For example, the first member or the second member can move toward the housing distal end when the second member moves relative to the first member. As another example, the first member or the second member can move toward the housing proximal end when the second member moves relative to the first member.

In many embodiments of the cartridge, the relative movement between the first and second members induces rotation of the knife relative to the first member. For example, the knife can include gear teeth that mate with gear teeth coupled with the second member so that the relative movement between the first and second members causes movement of the second member gear teeth relative to the knife gear teeth and corresponding rotation of the knife relative to the first member.

In many embodiments of the cartridge, the second member moves along with the first member until prevented from doing so. For example, the second member can be prevented from moving toward the distal end during a movement of the first member toward the distal end to reposition the second member to not block the rotation of the knife. In many embodiments, the second member is slidably mounted to the first member to move with the first member along the first distance and to not move toward the distal end during a movement of the first member toward the distal end.

The cartridge can include one or more features to selectively rotate the knife into a desired position. For example, the cartridge can include a kick-down feature coupled with the housing to cause the knife to rotate relative to the first member to stow a cutting edge of the knife below an upper surface of the housing. As another example, the cartridge can include a kick-down feature coupled to the second member to cause the knife to rotate during a relative movement between the first and second members to stow a cutting edge of the knife below the upper surface of the housing. As an additional example, the cartridge can include a kick-up feature coupled with the housing to cause the knife to rotate into a cutting position during the movement of the second member with the first member toward the distal end at the same rate.

The cartridge can include additional features providing additional functionality. For example, the housing can include a plurality of staple openings extending between the upper surface and the central cavity. A plurality of staples can be disposed in the staple openings, each of the staples being deployed during a movement of the first and second members toward the distal end at the same rate.

For a fuller understanding of the nature and advantages of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the drawings and detailed description that follows.

