Patent Description:
During certain surgical procedures (e.g., ophthalmic procedures) a surgeon is required to manipulate (e.g., remove, cut, peel, etc.) certain tissues within a body part by using forceps, scissors, etc. Examples of such surgical procedures are internal limiting membrane (ILM) removal and epiretinal membrane (ERM) removal for treating different macular surface diseases. During such procedures, a surgeon inserts the tip of a surgical instrument, which, for example, functions as forceps, into a patient's eye globe and uses the forceps to grasp and peel the ILM/ERM. Certain designs are currently used for providing a surgical instrument with an actuation mechanism that allows a surgeon to close and open the jaws of the forceps or scissors, which are located at the tip of a surgical instrument. However, in certain cases, the existing actuation mechanisms may, among other things, require too much actuation force and be difficult to assemble. Reference is made to <CIT>, <CIT>, <CIT> and <CIT> which have been cited as relating to the state of the art. <CIT> relates to an instrument dispenser for single hand operation and provides an arrangement including an actuation sleeve, a ratcheting sleeve and a ridged sleeve for receiving a lance for supporting wound clamps at the surgical site.

Claim <NUM> defines the invention and further embodiments are listed in the dependent claims.

The present disclosure relates generally to a surgical instrument with an actuation mechanism including grooved actuation levers.

Particular embodiments disclosed herein provide a surgical instrument comprising a device having a proximal end and a functional end configured to be inserted into a body part, an assembly having a proximal end and a distal end, wherein the distal end of the assembly is coupled to the proximal end of the device, a shaft coupled to the proximal end of the assembly, the shaft having a shaft housing, a bearing positioned around the assembly, wherein the bearing is configured to slide over the assembly, a hub having a sleeve tube, wherein the sleeve tube is configured to partially house the device such that the functional end of the device at least partially extends beyond a distal end of the sleeve tube when the device is in a deactivated state, and a basket coupled to the hub. The basket comprises a plurality of levers, each grooved lever having a proximal end received by the shaft housing and a distal end coupled to a tip of the basket, wherein compressing one or more of the plurality of grooved levers moves the bearing and the hub relative
to the shaft and toward the functional end of the device, causing the sleeve tube to transition the device from the deactivated state to an activated state.

Particular embodiments of the present disclosure provide a surgical instrument with an actuation mechanism including grooved actuation levers.

<FIG> illustrates an example of a surgical instrument with a prior art actuation mechanism. As shown, surgical instrument <NUM> comprises a handle <NUM>, a basket <NUM> comprising a plurality of actuation levers <NUM>, a housing <NUM>, an actuation tube <NUM>, and a device, shown as forceps <NUM>, at the tip of the probe. Each actuation lever <NUM> comprising a first leg <NUM> and a second leg <NUM> joined at flexible juncture <NUM>. In other embodiments, the first leg <NUM> and second leg <NUM> may be separate pieces coupled together with a hinge. Each actuation lever <NUM> may be made from material such as shape memory material, titanium, stainless steel, suitable thermoplastic, etc. Actuation tube <NUM> may be any suitable medical grade tubing, such as titanium, stainless steel, or suitable polymer and is sized so that forceps <NUM> reciprocate easily within. Forceps <NUM> are generally made from stainless steel or titanium, but other materials may also be used.

Surgical instrument <NUM> is designed so that in use, when the plurality of actuation levers <NUM> are in their relaxed state, forceps <NUM> protrude or extend beyond the distal end of actuation tube <NUM>, which is coupled to a housing <NUM>. Squeezing one or more of the actuation levers <NUM> causes the respective actuation lever <NUM> to flex at juncture <NUM>, pushing housing <NUM> forward relative to handle <NUM>. The forward movement of housing <NUM> is transferred to actuation tube <NUM>, causing actuation tube <NUM> to slide forward over a distal portion of the jaws of forceps <NUM>, thereby activating forceps <NUM> by compressing together the jaws. By closing jaws of forceps <NUM>, the surgeon is able to, for example, grasp and peel a tissue (e.g., ILM) within a body part.

In the example of <FIG>, the actuation mechanism may, among other things, require too much actuation force and be too difficult to assemble. In addition, basket <NUM> is long and has a large diameter, which may make basket <NUM> too bulky. Accordingly, certain embodiments described herein relate to a surgical instrument with an actuation mechanism including grooved actuation levers. In particular embodiments, this may reduce the structural complexity of the actuation mechanism and allow for easier assembly.

<FIG> illustrates a perspective view of an example surgical instrument <NUM> in accordance with the teachings of the present disclosure. As shown in <FIG>, surgical instrument <NUM> comprises a rear cap <NUM>, a shaft housing <NUM>, a basket <NUM> comprising actuation levers ("levers") <NUM>, an adjustable hub ("hub") <NUM> coupled to a sleeve tube <NUM>, and device <NUM>.

Although in the example of <FIG>, device <NUM> is shown as forceps, generally device <NUM> may be any surgical device that is shaped to fit in sleeve tube <NUM> with a distal end that is referred to as a functional end (e.g., a movable or active end). For example, device <NUM> may be shaped as a needle with a functional end, which may comprise forceps, scissors, etc., with jaws or arms. The proximal end of device <NUM> is coupled to a coupling tube of a snapper assembly, as shown in <FIG>, <FIG>, <FIG>, etc..

As used herein, the term "proximal" refers to a location with respect to a device or portion of the device that, during normal use, is closest to the clinician using the device and farthest from the patient in connection with whom the device is used. Conversely, the term "distal" refers to a location with respect to the device or portion of the device that, during normal use, is farthest from the clinician using the device and closest to the patient in connection with whom the device is used.

Basket <NUM> couples to shaft housing <NUM> at its proximal end and to hub <NUM> at its distal end. Shaft housing <NUM> is part of a shaft that extends longitudinally within basket <NUM>. At its proximal end, the shaft couples to rear cap <NUM>. Basket <NUM> comprises levers <NUM>, each lever <NUM> including a first leg <NUM> and a second leg <NUM>, the second leg <NUM> comprising a grooved segment <NUM>. In certain aspects, the length of first leg <NUM> may be in the range of <NUM>-<NUM> millimeters (mms), the length of grooved segment <NUM> may be in the range of <NUM>-<NUM> mms, and the length of the second leg <NUM> may be in the range of <NUM>-<NUM> mms. Grooved segments <NUM> of levers <NUM> allow a user, such as a surgeon, to more easily grasp and actuate surgical instrument <NUM> as compared to the prior art basket design shown in <FIG>. The outer diameter of basket <NUM>, where the grooved segments <NUM> are, is smaller than the outer diameter of basket <NUM> where the distal ends of first legs <NUM> or the proximal ends of the un-grooved segments of the second legs <NUM> are. For example, the outer diameter of basket <NUM>, where the grooved segments <NUM> are, is <NUM> to <NUM> millimeters (mms) smaller than the outer diameter of basket <NUM> where the distal ends of first legs <NUM> or the proximal ends of the un-grooved segments of the second legs <NUM> are.

Each lever <NUM> also comprises three moving joints or junctures <NUM>, <NUM>, and <NUM>, which allow the lever to extend when it is compressed. More specifically, each lever <NUM> comprises a tail joint <NUM>, a main joint <NUM>, and a head joint <NUM>, which allow the lever to bend and extend. These joints allow basket <NUM> to be compressed thereby pushing hub <NUM> along with sleeve tube <NUM> forward relative to shaft housing <NUM>. In certain embodiments, each of tail joint <NUM>, main joint <NUM>, and head joint <NUM> may comprise a hinge.

Although not shown, the inner surface of hub <NUM> and the outer surface of the distal end of basket <NUM> may be threaded, thereby allowing hub <NUM> to be screwed on to the distal end of basket <NUM>. Hub <NUM> is adjustable meaning that, during the manufacturing process, screwing hub <NUM> clockwise or counterclockwise allows for adjusting how far the functional end of device <NUM> extends beyond the distal end of sleeve tube <NUM>. For example, a larger portion of the functional end of device <NUM> protrudes beyond sleeve tube <NUM> when hub <NUM> is fully rotated or screwed on to the distal end of basket <NUM>. By screwing hub <NUM> counterclockwise, however, hub <NUM> and sleeve tube <NUM> move in a distal direction relative to basket <NUM>, which causes the distal end of sleeve tube <NUM> to cover a larger portion of the functional end of device <NUM>, as compared to when hub <NUM> is fully screwed on to the distal end of basket <NUM>.

Surgical instrument <NUM> is designed so that in use, when levers <NUM> are in their relaxed or at-rest state (i.e., not compressed), the functional end of device <NUM> protrudes or extends beyond the distal end of sleeve tube <NUM>. In other words, sleeve tube <NUM> only partially covers the functional end of device <NUM>. When levers <NUM> are compressed, the distal end of basket <NUM> is pushed forward relative to shaft housing <NUM> and device <NUM>. The forward movement of the distal end of basket <NUM> is transferred to hub <NUM> and then sleeve tube <NUM>, causing sleeve tube <NUM> to slide forward and activate device <NUM>. Device <NUM> is activated as a result of the forward movement of sleeve tube <NUM>, which presses the jaws or arms of device <NUM> together. An activated device refers to a device whose jaws or arms are closed. Note that <FIG> illustrates levers <NUM> in their at-rest state while <FIG> illustrates a cross sectional view of surgical instrument <NUM> when levers <NUM> are compressed.

Levers <NUM> are made from flexible but resilient material to allow levers <NUM> to be compressed and then pushed back into their at-rest positions. In one example, levers <NUM> may be made from polyoxymethylene (POM). Note that in the example of <FIG>, surgical instrument <NUM> comprises <NUM> levers <NUM>. However, a fewer or larger number of levers <NUM> may be used in other embodiments. For example, surgical instrument <NUM> may have between <NUM>-<NUM> levers.

<FIG> illustrates a perspective view of hub <NUM> and basket <NUM> of surgical instrument <NUM> separately. As shown, hub <NUM> can be screwed on to a threaded tip or segment <NUM> of basket <NUM>. <FIG> also shows a coupling tube <NUM> of a snapper assembly that is positioned inside of basket <NUM>. Coupling tube <NUM> protrudes outside or beyond threaded segment <NUM>. The distal end of coupling tube <NUM> is configured to be coupled to a proximal end of a needle of device <NUM>. In some embodiments, the distal end of coupling tube <NUM> and the proximal end of the needle of device <NUM> are crimped together. <FIG> also shows a cap <NUM> that is configured to house hub <NUM>. Cap <NUM> is placed on hub <NUM> upon the completion of the manufacturing process, which includes the adjustment of hub <NUM>. <FIG> also shows the proximal end <NUM> of the shaft, described in further detail below. Proximal end <NUM> of the shaft is configured to be coupled to rear cap <NUM>.

<FIG> illustrates an exploded view of some of the components of surgical instrument <NUM>. As shown, basket <NUM> comprises an insert <NUM> at its proximal end, which is configured to be inserted into a cylindrical opening between the body of shaft <NUM> and shaft housing <NUM>. More specifically, insert <NUM>, in some embodiments, may be friction-locked into the opening. Shaft <NUM> comprises an extended cylindrical portion <NUM> that is configured to longitudinally extend within basket <NUM>. Shaft <NUM> comprises a hollow compartment to allow the proximal end of snapper assembly <NUM> to be inserted (or received) and snapped therein, as further described in relation to <FIG>.

Also shown is a bearing <NUM>, which is configured to be positioned at the distal end of cylindrical portion <NUM> of shaft <NUM>. As shown in <FIG>, bearing <NUM> is also configured to slide on snapper assembly <NUM> after snapper assembly <NUM> is snapped into the hollow compartment of shaft <NUM>. Bearing <NUM> is also configured to be housed by a bearing housing of basket <NUM>, as shown in <FIG> in more detail. When levers <NUM> are in their at-rest state, the proximal end <NUM> of bearing <NUM> and the distal end <NUM> of shaft <NUM> are in contact. However, when levers <NUM> are in their compressed state, bearing <NUM> slides forward relative to shaft <NUM> and snapper assembly <NUM> such that the proximal end <NUM> of bearing <NUM> and the distal end <NUM> of shaft <NUM> are no longer in contact. Bearing <NUM>'s inner surface is made of or comprises material that has a low friction coefficient with respect to the outer surface of the snapper assembly <NUM>. As a result, utilizing bearing <NUM> in the actuation mechanism described herein is advantageous because it allows for a smoother actuation, as bearing <NUM> is able to smoothly slide back and forth on snapper assembly <NUM>.

Snapper assembly <NUM> comprises a needle-shaped proximal end <NUM>, which, as described above, is configured to be inserted into the hollow compartment of shaft <NUM>. Snapper assembly <NUM> also comprises wings <NUM>, which are biased outwardly and configured to snap into the hollow compartment of shaft <NUM>. Once wings <NUM> snap into the hollow compartment, snapper assembly <NUM> does not move relative to shaft <NUM>. Different views of snapper assembly <NUM> are shown in <FIG>, which illustrate wings <NUM> more clearly. Snapper assembly <NUM> also comprises a cylindrical element <NUM> around which spring <NUM> is configured to be positioned. The distal end of spring <NUM> is positioned against barrier <NUM> of snapper assembly <NUM>. When basket <NUM> is compressed, the distal end of threaded segment <NUM> moves in a distal direction relative to shaft <NUM> and compresses spring <NUM> against barrier <NUM>. As a result, spring <NUM> becomes loaded or charged, thereby causing basket <NUM> to transition or snap back into its at-rest position when the user releases basket <NUM>.

Utilizing the basket design of basket <NUM> in the actuation mechanism described herein is advantageous because less actuation force is required to compress basket <NUM> and thereby activate the device (e.g., device <NUM>) used in conjunction with or as part of surgical instrument <NUM>. More specifically, the diameter of basket <NUM> (e.g., in the range of <NUM>-<NUM> mms) is smaller at or over the grooved segment <NUM> of basket <NUM> as compared to the diameter of basket <NUM>, of the prior art actuation mechanism, at junctures <NUM>. As a result, with the actuation mechanism described herein a lower amount of force is applied to spring <NUM> and, therefore, a lower amount of opposite spring force is experienced by the user when compressing basket <NUM>. Also, as described above, grooved segments <NUM> of levers <NUM> allow for a user to more easily grasp and compress basket <NUM>. In certain aspects, spring <NUM>'s spring constant is in the range of <NUM>-<NUM> Newton/millimeter (N/mm).

<FIG> illustrate different views of snapper assembly <NUM>. <FIG> illustrates a perspective view of snapper assembly <NUM>, which comprises wings 428a and 428b, barrier <NUM> and cylindrical element <NUM>. <FIG> illustrates a side view of snapper assembly <NUM>. <FIG> illustrates a cross sectional view of snapper assembly <NUM>.

<FIG> illustrates a cross sectional view of surgical instrument <NUM> when levers <NUM> are in their at-rest state. As shown, insert <NUM> is positioned within the cylindrical opening between the body of shaft <NUM> and shaft housing <NUM>. Also shown is snapper assembly <NUM>, which is snapped into a hollow compartment <NUM> of shaft <NUM>. As described above, wings 428a-428b are biased outwardly such that to insert snapper assembly <NUM> into hollow compartment <NUM>, wings 428a-428b would have to be pushed inwardly towards a longitudinal axis of snapper assembly <NUM>.

During the assembly process of surgical instrument <NUM>, needle-shaped proximal end <NUM> may be used as a guide to insert snapper assembly <NUM> into hollow compartment <NUM>. At a certain point, by pushing snapper assembly <NUM> far enough, wings 428a-428b snap into hollow compartment <NUM>. More specifically, once snapper assembly <NUM> is fully inserted into hollow compartment <NUM>, the tips of wings 428a-428b snap into the distal end of hollow compartment <NUM>, at which point the inner diameter of shaft <NUM> is larger. What allows the tips of wings 428a-428b to snap into the distal end of hollow compartment <NUM> is the difference in the inner diameter of shaft <NUM> at its different portions. For example, as shown, shaft <NUM> has a smaller inner diameter at portion <NUM> in comparison with the inner diameter of shaft <NUM> at the distal end of hollow compartment <NUM>. Once wings 428a-428b snap into hollow compartment <NUM>, snapper assembly <NUM> is locked in place and can no longer be separated from shaft <NUM> because the proximal end of portion <NUM> acts as a barrier against the tips of wings <NUM>-428b.

As shown, the distal end <NUM> of shaft <NUM> is in contact with the proximal end <NUM> of bearing <NUM> when levers <NUM> are in their at-rest state. Bearing <NUM> is positioned in an opening between bearing housing <NUM> and snapper assembly <NUM>. More specifically, the opening is provided between the inner surface of bearing housing <NUM>, which is cylindrically shaped, and the outer surface of snapper assembly <NUM>. As shown, the distal end of bearing <NUM> is in contact with the end of the opening, which refers to the proximal end of a slider segment <NUM> of bearing housing <NUM>. Slider segment <NUM> does not make contact with the body of snapper assembly <NUM> and moves relative to shaft <NUM> when levers <NUM> are compressed. Slider segment <NUM> is positioned at the distal end of bearing housing <NUM>. As described above, <FIG> illustrates levers <NUM> in their at-rest state, meaning that the device (e.g., device <NUM>) is in an inactivated state (e.g., the jaws of the forceps are open).

<FIG> illustrates a cross sectional view of surgical instrument <NUM> when levers <NUM> are in their compressed state. As shown, when levers <NUM> are compressed, the distal end of levers <NUM> move in a distal direction, meaning slider segment <NUM> moves in a distal direction, thereby pressing spring <NUM> against barrier <NUM>, which results in spring <NUM> exerting opposite spring force against slider segment <NUM>. As shown, bearing <NUM> has moved in a distal direction relative to shaft <NUM>, such that there is now some space between the proximal end <NUM> of bearing <NUM> and the distal end <NUM> of shaft <NUM>. As described above, because the inner surface of bearing <NUM> has a low friction coefficient with the outer surface of snapper assembly <NUM>, bearing <NUM> is able to smoothly slide over snapper assembly <NUM>, thereby resulting in a smooth actuation. When levers <NUM> are compressed, the hub and the sleeve tube (e.g., hub <NUM> and sleeve tube <NUM>) move toward the functional end of the device, causing the sleeve tube to transition the device from a deactivated state to an activated state (e.g., forceps jaws are closed). Note that, in the example of <FIG>, basket <NUM> is manufactured as a single component (e.g., through injection molding), although in some other embodiments, that need not be the case.

<FIG> illustrate different views of a hub <NUM>. <FIG> illustrates a cross-sectional view of hub <NUM>. As shown, hub <NUM> comprises a threaded opening <NUM>, which allows hub <NUM> to be screwed on to the threaded segment <NUM> of basket <NUM>. Hub <NUM> also comprises an opening <NUM> through which the position of the device can be adjusted. For example, during the assembly process of the surgical device, after hub <NUM> is coupled to basket <NUM>, the proximal end of device <NUM> may be inserted into the sleeve tube <NUM> in order to couple the proximal end of device <NUM> to coupling tube <NUM> of snapper assembly <NUM>. During this process, the proximal end of device <NUM> passes through opening <NUM> and is, therefore, accessible through the opening. As a result, the position of the device <NUM> may be adjusted using an instrument that is able to grab on to device <NUM> through opening <NUM>. For example, device <NUM> may be further pushed in to ensure that its proximal end is fully coupled to coupling tube <NUM> using such an instrument through opening <NUM>.

<FIG> illustrates a side view of hub <NUM> with a <NUM>-degree rotation about an axis parallel to sleeve tube <NUM>. As shown, hub <NUM> comprises two openings <NUM>, shown from the side.

Claim 1:
A surgical instrument (<NUM>), comprising:
a device (<NUM>) having a proximal end and a functional end configured to be inserted into a body part;
an assembly (<NUM>) having a proximal end and a distal end, wherein the distal end of the assembly is coupled to the proximal end of the device;
a shaft (<NUM>) coupled to the proximal end of the assembly (<NUM>), the shaft having a shaft housing (<NUM>);
a bearing (<NUM>) positioned around the assembly (<NUM>), wherein the bearing is configured to slide over the assembly (<NUM>);
a hub (<NUM>) having a sleeve tube (<NUM>), wherein the sleeve tube (<NUM>) is configured to partially house the device such that the functional end of the device at least partially extends beyond a distal end of the sleeve tube when the device is in a deactivated state; and
a basket (<NUM>) coupled to the hub (<NUM>), the basket comprising:
a plurality of grooved levers (<NUM>), each grooved lever (<NUM>) having a proximal end received by the shaft housing (<NUM>) and a distal end coupled to a tip of the basket, wherein compressing one or more of the plurality of grooved levers (<NUM>) moves the bearing (<NUM>) and the hub (<NUM>) relative to the shaft (<NUM>) and toward the functional end of the device, causing the sleeve tube (<NUM>) to transition the device (<NUM>) from the deactivated state to an activated state;
the basket (<NUM>) comprises a bearing housing (<NUM>); and
the bearing (<NUM>) is positioned in an opening (<NUM>) provided between the bearing housing and a body of the assembly;
characterized in that:
a proximal end (<NUM>) of the bearing (<NUM>) is in contact with a distal end of the shaft (<NUM>) when the plurality of grooved levers (<NUM>) are in an at-rest state;
the device is de-activated when the plurality of grooved levers (<NUM>) are in the at-rest state; and
the proximal end of the bearing is separated from the distal end of the shaft when the plurality of grooved levers (<NUM>) are compressed.