A hand tool has a pivot connection pivotally attaching a first arm to a second arm, with the pivot connection fixed relative to the first arm and movable to first and second positions relative to the second arm. A spring urges the pivot connection into the first position. When jaws on the front ends of the arms clamp tissue with force greater than a pre-set threshold, the spring force is overcome and the jaws may move linearly apart, allowing for more uniform clamping of the tissue. The first arm may have an arm spring extending between a front segment pivotally attached to a rear segment of the first arm.

BACKGROUND

The present disclosure relates to a hand-held tool for gripping and/or compressing an object.

Various designs of plyers-type hand-tools have been proposed for specific applications. Generally these tools have two pivotally attached arms with the arms acting as levers to increase the gripping or compression force applied by jaws at the front end of the arms. In the medical and surgical field, hemostats and surgical clamps are examples of these types of tools.

One specific, non-limiting example in the surgical field is removal of part of the liver (hepatic resection), which is often performed to remove a tumor. Blood loss is a serious complication associated with this procedure. Multiple surgical techniques and devices have been developed to minimize blood loss and improve outcomes in hepatic resection. The so-called clamp-crush technique is a preferred technique.

The clamp-crush technique generally involves crushing the liver parenchyma using a hemostatic clamp tool to expose small vessels and biliary radicals, which are then divided and sealed via radio frequency (RF) energy provided to the jaws of the tool. Various tools have been proposed for this purpose. However, challenges remain in providing a coaptive surgical sealing tool offering superior performance and efficiency in a simple and low-cost design.

SUMMARY

A hand tool has a pivot connection pivotally attaching a first arm to a second arm, with the pivot connection fixed relative to the first arm and movable to first and second positions relative to the second arm. A jaw spring urges the pivot connection into the first position. When jaws on the front ends of the arms clamp with force greater than a pre-set threshold, the spring force of the jaw spring is overcome and the jaws may move linearly apart, allowing for more uniform clamping. An arm spring in the first arm may limit the clamping force that may be applied to the clamped object.

In one aspect, there is disclosed A hand-held tool comprising: a first arm having a first jaw section and a first handle section; a second arm having a second jaw section and a second handle section; a pivot connection pivotally attaching the first arm to the second arm, wherein the pivot connection is fixed relative to the first arm and movable between first and second positions relative to the second arm; and a jaw spring urging the pivot connection into the first position.

In another aspect, there is disclosed A hand tool comprising; a first arm having a front section pivotally attached to a rear section via an arm hinge pin; an arm spring extending between the front section and to the rear section of the first arm; a jaw hinge pin pivotally connecting the front section of the first arm to a second arm, with the hinge pin at a fixed position on the first arm, and the hinge pin movable into first and second positions relative to the second arm; and a jaw spring urging the hinge pin towards the first position, and wherein the hinge pin is movable against the bias of the spring into the second position, wherein the front sections of the first and second arms may be spaced apart and substantially parallel to each other.

In another aspect, there is disclosed a hand tool comprising; a first arm having a front section pivotally attached to a rear section via an arm hinge pin; an arm spring extending between the front section and to the rear section of the first arm; a jaw hinge pin pivotally connecting the front section of the first arm to a second arm, wherein the hinge pin is at a fixed position on the first arm, and the hinge pin is movable into first and second positions relative to the second arm; a jaw spring urging the hinge pin towards the first position, and with the hinge pin movable against the bias of the spring into the second position wherein front sections of the first and second arms may be spaced apart and substantially parallel to each other; a first electrode on the front section of the first arm, and a second electrode on a front section of the second arm; wire leads on at least one of the first and second arms connecting to the first and second electrodes; and an irrigation line in or on at least one of the first and second arms connecting to front section of the first or second arms, and an aspiration line in or on at least one of the first and second arms connecting to the front section of the first or second arms.

Other features and advantages should be apparent from the following description of various embodiments, which illustrate, by way of example, the principles of the disclosure.

DETAILED DESCRIPTION

Disclosed is a hand tool for uses such as, for example, general manufacturing, assembly, and repair where grasping, clamping and/or holding is needed. The tool is sometimes described herein in the context of being a coaptive surgical sealing tool although it should be appreciated that this is just an example and that the tool is configured for use in a variety of situations.

As shown inFIGS. 1-3, a first embodiment of a hand tool20has a first arm22pivotally attached to a second arm52at a hinge joint44. The front section (forward of the hinge joint44) of the first arm22has a first jaw24and the front section of the second arm52similarly has a second jaw54. A grabbing element, such as a finger ring26, is provided at the back end of the back section28of each of the arms22and52. The second arm52includes an arm slot or opening56, with a reduced width hinge section30of the first arm22positioned within the slot56. Referring toFIG. 2, where the tool20is configured as a surgical tool, wire leads60and62may optionally be provided on or in one or both arms22and52to electrodes66and64on the arms22and52. The wire leads60and62may terminate at a connector on one or both of the arms, to allow energy such as RF (radio frequency) or microwave energy, to be supplied to the electrodes. In an embodiment the energy is at a frequency of at least 100 kHz. In another embodiment, microwave frequency is greater than 300 mHz.

As shown inFIG. 1, for applications such as surgery of the liver, the jaws24and54may be made long and slender, for example with a length from the hinge joint44to the front tip46of each jaw ranging from about 20 to 80 mm, or 30-40 mm, and with jaws having a maximum width and maximum height of about 1.5 to 5 mm. The jaws may taper outwardly in height and width from the front tip to the hinge joint44, with the width and height of each jaw1to 2.5 times greater at the hinge joint44than at the front tip46. The jaws24and54may also curve to one side, such as the left side in the example shown inFIG. 1. It should be appreciated that the aforementioned dimensions are just examples and that variations are within the scope of this disclosure.

Turning toFIG. 3, a spring arm40of a spring34may be attached to the first arm22. The spring34may have spaced apart upright clevis plates36on opposite sides of the second arm52, with a hinge pin42extending through the plates36and the second arm52to form the hinge joint44. The hinge pin42is movable via flexing of the spring34, from an up or open position shown inFIG. 3, to a down or closed position shown inFIG. 2. In the up position the hinge pin42is raised up and largely out of a recess32in the first arm22as shown inFIG. 3. In the down position the hinge pin42is largely within the recess32as shown inFIG. 2. As shown inFIG. 2, in the down position, the plane or axis of each jaw may be centrally aligned with the hinge pin42, with the jaws parallel to and in contact with each other. The hinge pin42defines an axis of rotation of the first arm22and the second arm52relative to one another wherein the axis of rotation can change position based on the position of the spring arm40.

Referring toFIG. 2, in use the jaws24and54are opened, moved to engage an object, such as a work piece, or tissue, and then closed. With nominal clamping pressure applied, in a surgical application the jaws may act as conventional hemostat or clamping jaws, as shown inFIG. 2. However, if greater clamping pressure is applied, the force acting to separate the jaws exceeds the force of the spring acting to hold the hinge pin42in the down position. As this occurs, the hinge pin42moves up (or away from the first arm22) towards the up position shown inFIG. 3. Correspondingly, the jaws move linearly away from each other rather than to the teen relative to one another. As a result, the jaws are able to clamp the work piece, or tissue, with more uniform clamping force. The linear separating movement of the jaws may be limited by a finger38on the first arm providing a hard stop position against the spring34. The linear separating movement of the jaws depends on the reaction force on the jaws (acting to separate the jaws). Depending on the geometry of the clamped object or tissue, the linear separating movement may be independent of the pivoting movement or angular position of the jaws.

With the jaws closing at an acute angle as shown inFIG. 2, the clamping force is greater closer to the hinge joint44and less at the tip46, so that the clamping force may vary significantly. With the tool20, however, after a pre-set clamping force is exceeded, the jaws move apart linearly, helping to provide a more uniform clamping force. As shown inFIG. 3, the jaws may remain substantially parallel as they move linearly apart. The pre-set clamping force is selected via the spring constant of the spring. Different embodiments of the tool20may have springs with different spring constants selected for use in different hand tool uses, or different surgical procedures. For a non-limiting example, the spring constant may be in the range of 2-8 Newtons/meter or 36 Newtons/meter.

In the configuration shown inFIGS. 1-3, the hinge pin42moves in an arc having a radius equal to the length of the spring arm40. Consequently, as the jaws move linearly relative each other, there is also a small front/back movement as well. Hence, with the jaws fully linearly open, and the hinge pin42in the full up position, the second jaw is positioned slightly behind the first jaw22, as shown inFIG. 3. Clearance to allow for this slight longitudinal shifting between the jaws may be provided via the leg slot56. The hinge pin42vertical range of travel may be about 2-10 or 3-7 mm.

Turning toFIGS. 4-6, in a second embodiment80, a first arm82is pivotally attached to a second arm84via a hinge pin86. Latch plates92may be used to latch the arms. As shown inFIG. 5, as applied to a surgical hand tool, electrical leads60and62along with an irrigation line or drip120and an aspiration or suction line or tube122may extend on or in either arm to electrodes96and100on first and second arms94and98. The tubes or lines120and/or122may be routed in a joggle around the hinge pin86. As shown inFIG. 6, the first arm82may be provided with separate front and back sections114and116, such as to allow for easier manufacture. The first arm82may be positioned within an arm slot90of the second arm84. Also as shown inFIG. 6, an insulator plate or layer130may be positioned between the arms94and98and the electrodes96and100. Irrigation and aspiration lines may also be provided on the tool20.

As shown inFIG. 7, the electrodes96and100may have angled complimentary surfaces102and104joining together at an edge106adjacent to the tip46. Aspiration and irrigation openings124and126connecting with the aspiration and irrigation lines may be provided in the electrodes96and100. As shown in dotted lines inFIG. 7, the aspiration openings124, if used, may also be located on a top and/or side surface of one or both jaws, in addition to, or instead of, locating the aspiration openings in the electrodes. The electrodes96and100may have complimentary shapes, so that the jaws mate uniformly when closed, with little or no space between them. The inner surfaces of one or more of the arms may be textured or can have any surface characteristic, such as serrations, that improves the gripping ability of the arms relative to tissue or other material. The serrations, if present, may also be shaped to bias any irrigation to flow toward a predetermined location of the arms, such as toward a front region.

In another embodiment, one or both arms may have a portion that is flexible or movable relative to another portion of the arm. For example, a tip region of one or both of the arms may pivot or rotate relative to a second region of the arm. The rotatable or pivotable portion may be spring-loaded toward a default position.

Turning toFIGS. 8 and 9, the hinge pin86on the second arm84may extend into a pin slot88in the first arm82. A jaw spring110may be attached to the first arm82with set screws112. The jaw spring110exerts upward force on the hinge pin86, holding the jaws together, as shown inFIG. 8.

Referring toFIG. 9, as with the tool20, when the jaws clamp onto an object with a force exceeding a pre-set amount, the force of the jaw spring110is overcome. The hinge pin86moves from the up position shown inFIG. 8, to the down position shown inFIG. 9, where the jaws are spaced apart and may be largely parallel to each other. The jaw spring110may be a spring wire. Other forms of springs such as coil compression springs, leaf springs and non-metal spring elements, such as resilient foam, rubber and plastic elements, may also be used.

As described, the pivot pin42or86provides a pivot point where the arms intersect, with the pivot point moving along a linear or curvilinear pathway up or down to accommodate the thickness of the clamped object. The spring moves the pivot pin. If the spring constant is too high, the pivot point will not move enough to keep the jaws parallel. Similarly, if the spring constant is too low, the spring will allow the pivot pin to move too easily, with the pivot pin moving too far to keep the jaws parallel. The spring constant may be selected based on the characteristics of the object to be clamped, or in surgical applications, the stiffness of the tissue to be operated on.

Relative to surgical uses, testing on calf liver revealed that 5 N of force was sufficient to fully collapse the calf liver, suggesting that a spring force on the order of 5 N may be suitable in some embodiments of the tool20. As shown inFIGS. 8 and 9, securing the jaw spring110in place with fasteners112allows the spring to be quickly and easily replaced. This allows the tool80to be adapted for different uses.

In addition to providing more even and uniform clamping force along the long jaws, the capability of providing parallel jaws, in surgical applications, also promotes an even seal along the long jaws. Substantially parallel jaws also tends to obviate any need for segmented RF tips on the jaws to allow different power or time settings along the jaw's length, and the associated added RF generator complexity and lead wires. In an embodiment, the jaws initially pivot or rotate relative to one another when initially opened and then transfer to parallel position and translate relative to one another without any pivoting after the arms have initially achieved a certain level of movement relative to one another.

Turning toFIGS. 10-12, a third hand tool150may be the same as the second tool configuration80shown inFIGS. 4-9, with the following changes. A first arm152is divided into a front segment154pivotally attached to a rear segment156via an arm hinge pin158. As shown inFIGS. 11 and 12, an arm spring160extends between the front segment154and the rear segment156. The arm spring160may be provided in the form of a spring wire, or as another type of spring similar to the alternative spring options discussed above for the jaw spring110. The arm spring160may be positioned within a spring slot162in the top surface of the front and rear segments.

As shown inFIG. 11, the central section of the arm spring160may be supported on a curved arch surface166extending over the hinge pin158, to reduce bending stresses on the arm spring160. The ends of the arm spring160may be positively attached to the front and rear segments via set screws, bonding, welding, etc. Alternatively, as shown inFIGS. 11 and 12, the arm spring160may be held in place via spring force, with the front end of the arm spring160captured under a bridge section164on the front segment, as shown inFIG. 12, and with the back end of the arm spring160captive within a slot in the rear segment156, as shown inFIG. 11. Capturing the arm spring160, rather than positively attaching the arm spring160to the segments allows the arm spring160to move slightly relative to the arm segments when the rear segment pivots relative to the front segment, which may simplify the hinge design.

An embodiment of arm spring160resists any deflection until the desired compression force limit is reached, so that the tool150would have a familiar feel and operation in the surgeon's hand. Such man arm spring160also then freely allows deflection when the desired compression force is exceeded, to as to precisely limit the compression force. Alternative spring configurations may be used to simulate such a spring. For example, laterally curved leaf springs, collapsing hollow tube springs, and similar alternatives may be used in place of a solid round wire to better achieve preferred handling characteristics of the tool150.

The arm spring160is pre-loaded or tensioned so that it exerts torque acting counterclockwise about the arm hinge pin158inFIG. 11. Consequently, the arm spring160holds the rear segment156in a straight or locked out position as shown inFIGS. 11 and 12. In ordinary use with nominal clamping force applied, the tool150operates in the same way as the tool80shown inFIGS. 4-6. However, if excessive force is applied, the arm spring160will bend, allowing the rear segment156of the first arm152to pivot about the arm hinge pin158downward towards the second arm180. Consequently, the clamping force applied by the jaws is automatically limited. As a result, inadvertent crushing of the clamped object is avoided. Damage to the long slender jaws caused by inadvertently clamping down on a hard object is also avoided. The arm spring160may be selected to have a spring constant which limits the clamping force to a desired maximum, for example 3-5 Newtons.

Referring back toFIGS. 10 and 11the rear arm segment154may have an upward curve, or an upward angle AA of 10-35 degrees, to provide clearance for pivoting movement of the rear arm segment when the compression force limit is exceeded. The second arm180may also curve away or extend at angle away from the first arm150for the same purpose. The pivoting design of the first arm152may optionally be used on the second arm180, or on both arms.

Also as shown inFIGS. 10 and 11, the arm hinge pin158may generally be located at a midpoint between the handle loop26and the jaw hinge pin86. Of course, the specific position of the arm hinge pin158may be shifted to the front or back of the first arm, depending on the tool application.

FIG. 13shows a fourth tool embodiment190having a first arm192and a second arm194which may be a mirror image of the first arm192. The arms192and194are connected by an X-linkage196. The front ends of the X-linkage may be pivotally pinned to the arms via front pins204, and the back ends of the X-linkage having slide pins200in slots202. The X-linkage196keeps the arms parallel, as the arms opened and closed.

FIG. 14shows a portion of the tool embodiment at the juncture between the handle portion300and the arms192and194. A flexure element formed of an elongated, cantilevered arm305is positioned at the juncture in a manner that interacts with the arms192and294in a manner that maintains the arms in a parallel position when the arms are clamping something, such as when clamping tissue. The arm305is mechanically coupled to a structure positioned between the arms of the handle portion300.

FIG. 15shows a perspective, enlarged portion of one of the arms192.FIG. 16shows a side view of the arm192. An electrode307removably attaches to the arm192along the length of the arm192. In an example embodiment, the electrode307includes one or more protrusions309that lockingly mate with complementary key-shaped openings311of the arm192. For example, the protrusions309can mate with the openings311in a slide and lock manner such that the protrusions are inserted into the openings311and then are slide along a key-shaped portion of the openings to lock therein. In another embodiment, the protrusions snap into and lockingly engage with the openings such as in a press fit manner. Other mechanisms for coupling and locking the electrode to the arms are within the scope of this disclosure. For example, the electrode may slide onto the arm such as in a front-loading manner such that the electrode slides into or onto the arm from the front of the device. In another embodiment, the protrusions are on the arm and the openings are on the electrode. A similar arrangement can be used for the other arm194.

In an embodiment, at least a portion of the device is disposable and another portion of the device is reusable. For example, as shown in the embodiment ofFIG. 17, the tool includes a disposable pair of removable arms or jaws313that removably mate with a handle portion300that is reusable. The arms313can removably mate with or otherwise removably couple to the handle portion300. This can occur using any of a variety of mechanisms, such as in a sliding tongue and groove mechanism wherein the arms slidingly engage and lock with the handle portion300.

As used here, unless otherwise stated, “in contact with” means elements actually or nominally touching each other, such as elements 1 or 2 mm apart. The term “linearly” is used here to distinguish from pivotal movement, and does not connote any geometrically precise linear characteristic. The term “joined”, “attached” or “connected to” means temporarily or permanently physically linked with, or integral with, as with different sections of a single integral element.

The elements described above may of course also be applied in other products having similar elements, movements or requirements. These include, for example door hinges, to create a weather tight seal, or as a hinge on a trunk or case, or a briefcase allowing for expansion when filled over capacity. The elements and principles described may also be applied to a gas or fluid tank cap to regulate or relieve pressure, or as a pouch sealer to equalize pressure on the seal.

Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.