CN117835942A - Adjustable stiffener for surgical instrument - Google Patents

Abstract

The present disclosure relates generally to surgical instruments having variable stiffness, and more particularly to surgical instruments having variable stiffness for ophthalmic surgery. In certain embodiments, a surgical instrument includes a base unit, a probe, a stiffener, and an actuation mechanism. The stiffener is formed from a hollow tubular member that substantially surrounds at least a portion of the length of the probe. The actuation mechanism is configured to actuate the stiffener along the length of the probe and adjust the stiffness of the probe, thereby providing the user with better control over the surgical instrument. The actuating mechanism comprises: a stiffener biasing apparatus configured to apply a first biasing force to the stiffener in a distal direction, and in some embodiments includes a control member configured to lock the stiffener in position along the length of the probe.

Description

Adjustable stiffener for surgical instrument

Background

Technical Field

Embodiments of the present disclosure relate generally to small gauge instruments for use in surgery, and more particularly to small gauge instruments for use in ophthalmic surgery.

Description of related Art

Efforts are continually being made to minimize the invasiveness of surgical procedures, such as ophthalmic surgery, so that small gauge surgical instruments (known as microsurgical instruments) for micro-incision technology are being developed. Small gauge vitrectomy, also known as Minimally Invasive Vitrectomy (MIVS), is a typical example of one such type of surgical procedure that uses small gauge instruments. Examples of common ocular conditions that can be treated by minimally invasive vitrectomy include retinal detachment, macular hole, pre-macular fibrosis, and vitreous hemorrhage. Benefits associated with modern MIVS compared to more invasive vitrectomy include greater pathology, greater fluid stability, increased patient comfort, less conjunctival scarring, less post-operative inflammation, and earlier vision recovery, among others. Therefore, the indications of MIVS and other micro-incision techniques have expanded in recent years.

While micro-incision technology has the benefits described above and is widely accepted, many challenges remain in using small gauge surgical instruments, particularly in the ophthalmic field. One problem of general concern to surgeons is instrument stiffness. The smaller diameter of these micro-incision instruments (e.g., vitrectomy probes) results in reduced stiffness, making it difficult for the surgeon to control the instrument in certain ophthalmic surgical procedures. For example, with small gauge ophthalmic surgical instruments, the instrument tip may move in an unintended direction at the limit of the eye, making delicate procedures such as peeling the membrane from the retinal surface extremely difficult.

Accordingly, there is a need in the art for improved methods and apparatus for minimally invasive ophthalmic surgery.

Disclosure of Invention

The present disclosure relates generally to surgical instruments, and more particularly to microsurgical instruments for ophthalmic surgery.

In certain embodiments, a surgical instrument is provided that includes a base unit and a probe. The base unit is configured to be held by a user. The probe is disposed through a base unit opening in a distal end of the base unit, and the probe has a length parallel to a probe longitudinal axis of the probe. The surgical instrument further includes a stiffener extending through the base unit opening in the base unit and an actuation mechanism configured to actuate the stiffener along the length of the probe in the distal direction. The stiffener is formed from a hollow tubular member surrounding at least a portion of the probe and slidably coupled thereto. The actuation mechanism includes a stiffener biasing apparatus configured to apply a first biasing force to the stiffener in a distal direction. In some embodiments, the actuation mechanism further comprises a control member configured to lock the stiffener in place.

Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

Fig. 1A illustrates a perspective view of a vitrectomy probe having a dynamically adjustable stiffening sleeve, in accordance with certain embodiments of the present disclosure.

Fig. 1B illustrates a perspective view of a vitrectomy probe having a dynamically adjustable stiffening sleeve and control member, in accordance with certain embodiments of the present disclosure.

Fig. 2 illustrates a schematic cross-sectional side view of the vitrectomy probe of fig. 1A, in accordance with certain embodiments of the present disclosure.

Fig. 3A illustrates a perspective view of an illumination probe having a dynamically adjustable stiffening sleeve, in accordance with certain embodiments of the present disclosure.

Fig. 3B illustrates a schematic cross-sectional side view of the illumination probe of fig. 3A, in accordance with certain embodiments of the present disclosure.

Fig. 4A-4B illustrate schematic cross-sectional side views of the vitrectomy probe of fig. 1B, in accordance with certain embodiments of the present disclosure.

Fig. 4C illustrates a perspective view of a control member of the vitrectomy probe of fig. 1B, in accordance with certain embodiments of the present disclosure.

Fig. 4D illustrates a perspective view of a disconnect of the vitrectomy probe of fig. 1B, in accordance with certain embodiments of the present disclosure.

Fig. 4E illustrates a schematic cross-sectional side view of another exemplary instrument in accordance with certain embodiments of the present disclosure.

Fig. 4F illustrates a perspective view of a disconnect of the vitrectomy probe of fig. 4E, in accordance with certain embodiments of the present disclosure.

Fig. 5A-5H illustrate perspective views of various disconnects according to certain embodiments of the present disclosure.

Fig. 6A illustrates a perspective view of another exemplary control member in accordance with certain embodiments of the present disclosure.

Fig. 6B-6C illustrate schematic front cross-sectional views of another exemplary instrument according to certain embodiments of the present disclosure.

Fig. 7A illustrates a perspective view of another exemplary instrument in accordance with certain embodiments of the present disclosure. Fig. 7B-7C illustrate schematic front cross-sectional views of the instrument of fig. 7A, in accordance with certain embodiments of the present disclosure.

Fig. 8 illustrates a schematic front cross-sectional view of another exemplary instrument in accordance with certain embodiments of the present disclosure.

Fig. 9A illustrates a cross-sectional view of another exemplary instrument in accordance with certain embodiments of the present disclosure.

Fig. 9B illustrates a perspective view of a control member of the instrument of fig. 9A, in accordance with certain embodiments of the present disclosure.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of certain embodiments may be beneficially incorporated in other embodiments without further recitation.

Detailed Description

In the following description, details are set forth by way of example in order to facilitate an understanding of the disclosed subject matter. However, it will be apparent to those of ordinary skill in the art that the disclosed implementations are exemplary and not exhaustive of all possible implementations. Thus, it should be understood that reference to the described examples is not intended to limit the scope of the present disclosure. Any alterations and further modifications in the described devices, instruments, methods, and any further applications of the principles of the disclosure are generally contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that features, components, and/or steps described with respect to one embodiment may be combined with features, components, and/or steps described with respect to other embodiments of the present disclosure.

Note that as described herein, the distal end, distal section or distal portion of a component refers to an end, section or portion that is closer to the patient's body during use of the component. In another aspect, the proximal end, proximal section or proximal portion of a component refers to the end, section or portion that is farther from the patient's body. An intermediate section or portion of a component refers to a section or portion that is positioned between a distal section or portion and a proximal end or portion.

As used herein, the term "about" may refer to a +/-10% change from nominal. It is to be understood that such variations may be included in any of the values provided herein.

The present disclosure relates generally to surgical instruments (such as microsurgical instruments) having variable stiffness, and more particularly to microsurgical instruments (e.g., vitrectomy probes, illumination probes, etc.) having variable stiffness for ophthalmic surgery. In certain embodiments, a microsurgical instrument includes a probe and a stiffener. The stiffener may be formed from a hollow tubular member that substantially surrounds at least a portion of the length of the probe. Actuation of the stiffener along the length of the probe adjusts the stiffness of the probe, thereby providing the user with better control over the microsurgical instrument. The stiffener may include a decoupler and, in some embodiments, may be locked or held at different positions along the length of the probe by the interaction of the decoupler and the control member. In some embodiments, the decoupler may decouple the stiffener from the biasing spring without the control member. In some embodiments, the use of a stiffener locking mechanism may allow a user to set and "lock" the stiffness of the microsurgical instrument to a desired level.

Fig. 1A illustrates a perspective view of a vitrectomy probe 100 with a dynamically adjustable stiffening sleeve 132, in accordance with certain embodiments. As depicted in fig. 1A, the instrument 100 includes a probe 110 or needle (hereinafter "probe") and a base unit 120. The probe 110 includes a proximal portion 112 and a distal portion 114 that terminates distally at a distal end 116. In some embodiments, the proximal portion 112 extends through a majority of an interior chamber of the base unit 120 (e.g., interior chamber 124 in fig. 2, 4A, and 4B).

In one example, the probe 110 is an elongate cutting member of a vitrectomy probe. For example, the probe 110 may be aspiration or non-aspiration, and may be inserted into a cannula to perform a vitrectomy. The probe 110 may include a hollow tube having a diameter of, for example, less than about 20 gauges. For example, the diameter of the probe 110 is less than about 23 gauges, e.g., the diameter of the probe is less than about 25 gauges. In some embodiments, the probe 110 has a diameter of about 27 gauges. In further examples, the probe 110 may include an illumination device (e.g., as seen in fig. 3A-3B), a laser guide, a suction device, forceps, scissors, a retractor, or other suitable device disposed therein or coupled thereto.

Typically, the probe 110 is formed of a material suitable for minimally invasive surgery (e.g., vitreoretinal surgery or other surgical procedures involving removal of the vitreous body in the eye). For example, the probe 110 is formed of surgical grade stainless steel, aluminum, or titanium.

The probe 110 is disposed partially and longitudinally through the distal end 121 of the base unit 120 adjacent the proximal portion 112 of the probe 110, and may be directly or indirectly attached thereto within the interior chamber 124 of the base unit 120. In certain embodiments, the base unit 120 is a handpiece having an outer surface 122 configured to be held by a user (e.g., a surgeon). For example, the base unit 120 may be contoured to substantially fit the hand of the user. In some embodiments, the outer surface 122 may have a texture or have one or more gripping features formed thereon, such as one or more grooves and/or ridges.

In some embodiments, the base unit 120 may house at least a portion of a drive mechanism operable to reciprocate the probe 110 within and relative to the base unit 120. In one example, the drive mechanism may be a pneumatic drive mechanism that includes a diaphragm. The base unit 120 may also provide one or more ports 123 at its proximal end 125 for one or more supply lines to be routed into the interior chamber 124. For example, one or more ports 123 may provide a connection between the base unit 120 and a vacuum source for suction. In another example, one or more ports 123 provide a connection to a pneumatic, hydraulic, or electrical source to operate a drive mechanism, lighting device, laser, or other suitable device within or coupled to the base unit 120.

The instrument 100 further includes a stiffener 132 slidably coupled to and substantially surrounding at least a portion of the probe 110. The stiffener 132 is adjustable relative to the probe 110 such that a user can position the stiffener 132 (e.g., the distal end 131 of the stiffener 132) at different points along the length L of the probe 110 outside the base unit 120.

In some embodiments, the stiffener 132 is a generally cylindrical hollow tube that substantially surrounds the probe 110 at or near the proximal portion 112. Similar to probe 110, stiffener 132 is formed from a material suitable for minimally invasive surgery (e.g., vitreoretinal surgery and other surgical procedures). In some embodiments, the stiffener 132 is formed from a metallic material (e.g., surgical grade stainless steel, aluminum, or titanium). In other embodiments, the stiffener 132 is formed from a composite material (e.g., a polymer composite or a ceramic composite).

As seen in fig. 2 and 4A-4B, the lumen 135 of the stiffener 132 is sized to accommodate the outer diameter of the probe 110 while also allowing the stiffener 132 to easily move along the probe 110. Accordingly, the inner diameter or width of the stiffener 132 is larger than the outer diameter of the probe 110 and a slip fit can be achieved. In one embodiment, the radial clearance between the stiffener 132 and the probe 110 is between about 0.00020 inches and about 0.00060 inches, for example between about 0.00025 inches and about 0.00050 inches. For example, the radial clearance between the stiffener 132 and the probe 110 is between about 0.00030 inches and about 0.00040 inches, such as about 0.00035 inches. Further, the internal dimensions of the stiffener 132 may be uniform from the distal end 131 to the proximal end 133 to enable the probe 110 to be uniformly stabilized throughout the lumen of the stiffener 132.

Together with the probe 110, a stiffener 132 is disposed through the base unit opening 117 of the distal end 121 of the base unit 120 and has a proximal end 133 disposed in the interior chamber 124 of the base unit 120. As shown, the stiffener 132 includes an annular flange (e.g., flange 136) that positions the proximal end 133 of the stiffener within the inner chamber 124. In other embodiments, the flange 136 is disposed more axially along the length of the stiffener 132. Flange 136 is configured to prevent stiffener 132 from sliding completely through base unit opening 117 and out of base unit 120. Thus, flange 136 acts as an anchor in one capacity. The flange 136 provides a coupling surface between the stiffener 132 and the decoupler 134, which is further coupled to a stiffener biasing device 139 (e.g., a spring such as a compression spring). In some embodiments, the stiffener 132 may include a reduced diameter nose 143. The reduced diameter nose 143 can extend further into the cannula into the patient's eye.

The stiffener biasing apparatus 139 applies a biasing force to the decoupler 134, and thus to the stiffener 132, in a distal direction (e.g., toward the distal end 121) to bias the stiffener 132 toward the extended position. Thus, without applying a force in the opposite proximal direction (e.g., toward proximal end 125 in fig. 1B), stiffener 132 is always disposed in the extended position. During use, the probe 110 may be inserted into an insertion cannula having a center (hub) (e.g., including a valve) at a desired depth. When the distal end 131 of the stiffener 132 reaches the center of the insertion cannula, the user may further press the instrument 100 toward the center to drive the probe 110 deeper therein. Applying a force to the center greater than the force provided by the stiffener biasing means 139 will cause the stiffener 132 to retract into the base unit 120 (as shown in fig. 4B), allowing a greater portion of the probe 110 to enter the eye.

In certain embodiments, when the stiffener 132 is in the extended position, the stiffener 132 is sized to have an axial length sufficient to provide the probe 110 with the desired stiffness and stability while a portion thereof remains in the inner chamber 124. For example, the axial length of the stiffener 132 may be between about 0.25 inches and about 1.75 inches, such as between about 0.30 inches and about 1.50 inches. For example, the axial length of the stiffener 132 may be between about 0.50 inches and about 1.25 inches.

In certain embodiments, the stiffener 132 has a uniform outer diameter from the distal end 131 to the proximal end 133. Having a uniform outer diameter allows a majority of the length of the stiffener 132 to reciprocate through the base unit opening 117 without creating an air gap therebetween. However, other shapes and configurations of the stiffener 132 are also contemplated. For example, in some embodiments, the stiffener 132 comprises a square, rectangular, or polygonal tube. In further embodiments, the stiffener 132 may have a non-uniform outer diameter. For example, the outer diameter of the stiffener 132 may have one or more dimensions that follow a gradual or gradual increase.

In some embodiments, the actuation mechanism may include a biasing device 139, a decoupler 134, and an annular flange 136 integral with or attached to the stiffener 132 such that the biasing device is configured to apply a biasing force to the annular flange 136 of the stiffener 132 in a distal direction through the decoupler 134. In some embodiments, the decoupler 134 and the enhancer 132 are separate components biased toward one another by, for example, a biasing device 139 (such as a spring). The decoupler 134 may contact the annular flange 136 due to the biasing device 139 biasing the decoupler 134 toward the annular flange 136 and/or due to an external force on the stiffener 132 pushing the annular flange 136 (which may be integral with or attached to the stiffener 132) toward the decoupler 134. In some embodiments, the decoupler 134 and the annular flange 136 may additionally not be attached to one another to allow relative movement between the decoupler 134 and the annular flange 136.

Fig. 1B illustrates a perspective view of a vitrectomy probe having a dynamically adjustable stiffening sleeve and control member 138. In certain embodiments, the position of the stiffener 132 is locked in place using a control member 138, as described below with respect to fig. 4A-4C. Accordingly, the user may selectively adjust the stiffness level of the probe 110 by repositioning the stiffener 132 relative to the distal end 116, thereby manipulating the amount of support provided to the probe 110 and stabilizing the instrument 100 during use thereof.

In some embodiments, the stiffener 132 includes a keying feature 140 configured to operatively engage a base unit opening (e.g., base unit opening 117 in fig. 4A) located at the distal end 121 of the base unit 120 to prevent rotation of the stiffener 132, as further described in fig. 4A. As shown, the keying feature 140 is a protrusion of the stiffener 132 having a rectangular cross-section, but may be other shapes, such as semi-circular or triangular, in other embodiments. Note that while fig. 1B shows keying features 140, in some embodiments (e.g., as seen in fig. 1A), the keying features 140 are not used.

Fig. 3A illustrates a perspective view of an illumination probe 1000 with a dynamically adjustable stiffening sleeve 1032 in accordance with certain embodiments of the present disclosure. Fig. 3B shows a schematic cross-sectional side view of the illumination probe 1000 of fig. 3A. Illumination probe 1000 may include a cannula 1010 surrounding an optical fiber 1800 that directs light to, for example, the interior of an eye. The dynamically adjustable stiffening sleeve 1032 may include an annular flange 1836 that engages a control member biasing device (e.g., a spring 1849). When the reinforcing sleeve 1032 is biased toward the handle portion 1850 (e.g., when the reinforcing sleeve encounters an opposing structure such as a trocar cannula), the reinforcing sleeve 1032 may enter the nose 1810 and the interior of the handle portion 1850. In some embodiments, reinforcing sleeve 1032 may include a reduced diameter nose 1843. The reduced diameter nose can extend further into the cannula into the patient's eye. In some embodiments, the dynamically adjustable stiffening sleeve 1032 may include a biasing device 1849, a decoupler 1834, and an annular flange 1836 integral with or attached to the stiffener 1032 such that the biasing device is configured to apply a biasing force to the annular flange 1836 of the stiffener 1032 in a distal direction through the decoupler 1834. In some embodiments, the decoupler 1834 and the enhancer 1032 are separate components biased toward one another by, for example, a biasing device 1849 (such as a spring). The break-away device 1834 may contact the annular flange 1836 as the biasing device 1849 biases the break-away device 1834 towards the annular flange 1836 and/or urges the annular flange 1836 (which may be integral with or attached to the stiffener 1032) towards the break-away device 1834 as a result of external forces on the stiffener 1032. In some embodiments, the decoupler 1834 and the annular flange 1836 may otherwise not be attached to one another to allow relative movement between the decoupler 1834 and the annular flange 1836.

In some embodiments, when illumination probe 1000 is withdrawn, spring 1849 may bias against the decoupler 1834 and annular flange 1836 to restore reinforcing sleeve 1032 to its extended position (and the reinforcing sleeve is no longer biased against the opposing structure). In some embodiments, the spring may be fixed against the plug 1830. In some embodiments, the spring 1849 may not be attached to the disconnect 1834 or the plug 1830. In some embodiments, a spring 1849 may be attached to the disconnect 1834 and/or the plug 1830. As further seen in fig. 3B, in some embodiments, the coupler 1833 may couple optical fibers (one fiber 1800 extending outside of the handle 1850 and one fiber extending to the tip). In some embodiments, the optical fiber may be continuous from the exterior of the handle up to the tip (without the use of coupler 1833).

Fig. 4A and 4B illustrate schematic cross-sectional views of the instrument 100 with the stiffener 132 positioned at different points along the length L of the probe 110. Thus, for clarity, fig. 4A and 4B are described herein with fig. 1B. When the stiffener 132 is positioned at different points along the length L, the keying feature 140 operatively engages the base unit opening 117 and prevents rotation of the stiffener 132. This advantageously ensures that the opening of the disconnect 134 (referred to as the disconnect opening) does not rotate. The dashed line between the cylindrical body of the stiffener and the keying feature 140 is shown in fig. 4A and 4B and subsequent figures that include the stiffener 132 to emphasize that the keying feature 140 protrudes from the remainder of the stiffener 132.

In some embodiments, the stiffener biasing apparatus 139 applies a biasing force to the decoupler 134, and thus to the stiffener 132, in a distal direction (e.g., toward the distal end 121) to bias the stiffener 132 toward the extended position along the length L of the probe 110, as shown in fig. 4A. During use, the probe 110 may be inserted into an insertion cannula having a center (e.g., including a valve) at a desired depth along a user-selected length L. When the distal end 131 of the stiffener 132 reaches the center of the insertion cannula, the user may further press the instrument 100 toward the center to drive the probe 110 deeper therein. Applying a force to the center greater than the force provided by the stiffener biasing means 139 will cause the stiffener 132 to retract into the base unit 120 (as shown in fig. 4B), allowing a greater portion of the probe 110 to enter the eye. Once retracted, the stiffener 132 may be locked in the retracted position by the control member 138.

As shown in fig. 4B, the position of the stiffener 132 may be locked or maintained by the interaction of the control member 138 and the decoupler 134. For example, the surgeon may press the control member 138 radially inward toward the disconnect 134, causing the control member 138 and the disconnect 134 to engage to lock the stiffener 132 in place. More specifically, the control member 138 operatively engages the disconnect 134 through an opening 150 in the disconnect 134. The control member 138 may be a button, knob, switch, toggle switch, or any other suitable device capable of being actuated by a user. As shown, the disconnect opening 150 is a through-hole.

As depicted in fig. 4A and 4B, the control member 138 includes a head 142, a protrusion (e.g., a shaft 144), and a flange 146, wherein the head 142 and the shaft 144 are disposed at opposite ends of the control member 138, and the flange 146 is located between the head and the shaft. The control member 138 is partially disposed within a cutout 128 (e.g., a channel or opening) formed in the base unit 120. The cutout 128 includes a multi-sized passage 141 configured to receive features of the control member 138. For example, the head 142 is disposed in the first passage 141A, the flange 146 is disposed in the second passage 141B, and the shaft 144 is at least partially disposed in the third passage 141C. Flange 146 operatively engages second passage 141B to guide control member 138 through cutout 128 and ensure that control member 138 remains coupled to base unit 120. The cutout 128 extends substantially perpendicular to a longitudinal axis 170 of the probe 110 (referred to as a probe longitudinal axis) and enables bi-directional pushing of the control member 138 along a control member vertical axis 172. The vertical axis 172 may be referred to as and is relative to a longitudinal axis of the control member (e.g., control member longitudinal axis) that is different than the probe longitudinal axis of the probe 110.

As shown, a control member biasing device 149 (e.g., a spring) is disposed in the second passage 141B to bias the control member 138 in a radially outward direction along the vertical axis 172. The control member biasing device 149 applies a control member biasing force to the control member 138 in a direction substantially parallel to the vertical axis 172 and radially outward from the disconnect 134 to bias the control member 138 toward the extended position as shown in fig. 4A. Thus, the control member 138 is constantly disposed in the extended position without applying a force in the opposite direction to retract the control member 138 as shown in fig. 4B. Further, the control member biasing device 149, the passage 141 and the head 142 of the control member 138 are sized and configured to ensure that the shaft 144 never contacts the stiffener biasing device 139 when the control member 138 is retracted.

During use, the stiffener 132 and the decoupler 134 are positioned at a retracted point along the length L of the probe 110, as shown in fig. 4B. The head 142 of the control member 138 is depressed by, for example, a surgeon, and the shaft 144 operatively engages the disconnect opening 150 in the disconnect 134, and thus the reinforcement 132. Accordingly, pressing the control member 138 into the decoupler opening 150 holds the stiffener 132 in the retracted position, advantageously inhibiting force from the stiffener biasing apparatus 139 when the control member 138 is depressed. The release control member 138 urges the control member 138 toward the extended position and is thus operatively disengaged from the disconnect 134. The force from the stiffener biasing apparatus 139 returns the stiffener 132 to the extended position shown in figure 4A.

In general, the control member 138 may be formed of a metallic material or a composite material. In some embodiments, the control member 138 is formed of stainless steel, aluminum, or titanium. In other embodiments, the control member 138 is formed from a polymer composite or a ceramic composite. The control member 138 is further discussed in fig. 4C.

The configuration of the booster 132, the decoupler 134, the control member 138, and the biasing devices 139 and 149 are merely exemplary and therefore should not be considered limiting. Additional embodiments and configurations for different actuation mechanisms are described further below.

As shown in fig. 4A, a nut 180 couples the stiffener 132 to the decoupler 134. In other embodiments, the decoupler 134 is a direct extension of the stiffener 132. That is, the disconnect 134 and the enhancer 132 are a single integral component. In other embodiments (e.g., as seen in fig. 2), the decoupler 134 and the enhancer 132 are separate components biased toward one another by, for example, biasing means 139. In some embodiments, the decoupler 134 and the stiffener 132 are coupled to one another by one or more coupling mechanisms and/or adhesives. In other embodiments, the decoupler 134 and the enhancer 132 may be snap-fit together.

Fig. 4C shows a perspective view of the control member 138. As shown, the head 142 of the control member 138 is oval in shape and the shaft 144 and flange 146 are circular in shape, but each may be a different shape, such as oval, circular, triangular, or rectangular. The radially inward end 148 of the control member 138 (e.g., the end closer to the disconnect 134) optionally includes a rounded corner 151 or chamfer to facilitate insertion of the shaft 144 into a disconnect opening 150 of the disconnect 134.

Fig. 4D shows a perspective view of the disconnect 134. The disconnect 134 is a generally cylindrical hollow tube having a cap 154 and a transition (e.g., rounded corners 158) between the tube and the cap 154. As shown in fig. 4A, the distal end 131 of the stiffener 132 may be inserted through an opening 156 in the cap 154, and the cap 154 is configured to be coupled to the flange 136 of the stiffener 132. Thus, the decoupler 134 and the enhancer 132 move integrally. The decoupler opening 150 in the decoupler 134 optionally includes a fillet 151 or chamfer to facilitate insertion of the shaft 144 of the control member 138.

Fig. 4E illustrates a schematic cross-sectional side view of another exemplary instrument 200 in accordance with certain embodiments described herein. Instrument 200 is substantially similar to instrument 100, except for the structure of multi-opening disconnect 234. The decoupler 234 is generally similar to the decoupler 134 except that the decoupler 234 includes a plurality of decoupler openings 250. The plurality of disconnect openings 250 are positioned in a straight line along the length of the disconnects 134, as shown in fig. 4F. The control member 138 may operatively engage any of the decoupler openings 250 as described with respect to fig. 4B with respect to the decoupler opening 150. Thus, the position of the stiffener 132 is adjustable relative to the probe 110 such that a user can advantageously lock the position of the stiffener 132 (e.g., the distal end 131 of the stiffener 132) in place at different points along the length L of the probe 110.

In some embodiments, the position of the stiffener 132 is adjustable to a distance of about 15mm (millimeters) along the length L of the probe 110, such as a distance of about 10mm along the length L of the probe 110. For example, the stiffener 132 may be adjustable to a distance of about 5mm along the length L of the probe 110.

Fig. 4F shows a perspective view of the decoupler 234. As shown, the decoupler openings 250 form a straight line along the length of the decoupler 234 such that each opening (e.g., decoupler opening 250A) corresponds to a different stiffener position along the length L of the probe 110 as discussed with respect to fig. 4E. The disconnect opening 250 of the disconnect 234 is otherwise similar to the disconnect opening 150 of the disconnect 134. As shown, the disconnect 234 has four disconnect openings 250, but other embodiments may have more or fewer disconnect openings 250.

As previously discussed, in the embodiment of fig. 1A-4D, depressing the control member 138 of the instrument 100 locks the decoupler 134 and the enhancer 132 in place and releasing the control member 138 returns the enhancer 132 and the decoupler 134 to the extended position. In such embodiments, a user (e.g., a surgeon) needs to hold down on the control member 138 in order to lock the stiffener 132 in place, otherwise the stiffener 132 is released. However, it may be advantageous to allow a user to lock the stiffener 132 in place without requiring the user to continuously press or hold the control member 138. Fig. 5A-5H illustrate various examples of disconnects that may be used in conjunction with the various example instruments shown in fig. 6A-8 to allow a user to lock the stiffener in place without having to hold the control member.

Fig. 5A-5H illustrate perspective views of different disconnects 334. The decoupler 334 is generally similar to decouplers 134 and 234 of fig. 4D and 4F, respectively, except that a different type or shape of decoupler opening 350 is included.

Fig. 5A shows a disconnect 334A that includes a disconnect opening 350A having a circular cutout 360 and a recess 362A. The circular cutout 360 is substantially similar to the decoupler opening 150 in fig. 4D. The groove 362A extends outwardly from the circular cutout 360 in a direction perpendicular to the probe longitudinal axis 170 in fig. 4A. The recess 362A is used to operatively engage a control member (e.g., control member 438 in fig. 6A) and lock the decoupler 334A in place as described with respect to fig. 6A-6C. This advantageously allows the user to set the position of the stiffener (e.g., stiffener 432 in fig. 6B) without continuously depressing the control member.

Fig. 5B shows a decoupler 334B that includes a plurality of decoupler openings 350B positioned in a straight line along the length of the decoupler 334B. The decoupler openings 350B are each substantially similar to the decoupler opening 350A of fig. 5A.

Fig. 5C shows a decoupler 334C that includes a channel-shaped decoupler opening 350C positioned along a straight line along the length of the decoupler 334C. The disconnect opening 350C includes a disconnect channel 364 and a number of grooves 362A extending along the length of the disconnect 334C. The groove 362A extends outwardly from the disconnect channel 364 in a vertical direction (similar to the groove of fig. 5A) and is positioned at several locations along the length of the disconnect 334C.

The decoupler opening 350C allows the control member to be depressed and the shaft of the control member (e.g., shaft 444 and control member 438 in fig. 6A) to be inserted anywhere along the decoupler channel 364. The decoupler opening 250C advantageously allows a user to less precisely engage the decoupler 334C with the control member. The groove 362A is used to operatively engage the control member at different locations along the disconnect channel 364 and lock the disconnect 334C in place, as described with respect to fig. 5A.

Fig. 5D shows a disconnect 334D that includes a disconnect opening 350D. The decoupler opening 350D is generally similar to the decoupler opening 350C of fig. 5C, except that the decoupler channel 364 includes a channel inlet 365 at the proximal end (e.g., toward the proximal end 125 in fig. 1B). The passage inlet 365 is a notch in the disconnect 334D.

Note that while the decoupler openings 350C and 350D may be used in conjunction with a control member (e.g., control members 138, 438, etc.) configured to be depressed using a biasing device, the decoupler openings 350C and 350D also allow for embodiments in which the control member (e.g., control member 638 of fig. 8) is always positioned in a depressed state such that the tip of the shaft or a notch of the shaft (e.g., notch 645 described below) is always aligned with and/or surrounded by an inner wall (e.g., in the depth direction) of the decoupler opening 350D or 350C. For example, in the case of the decoupler opening 350C, the end (or notch) of the shaft may be disposed in the decoupler opening 350C at all times, including when the stiffener is in the extended position and when the stiffener is in the retracted position. In the example of the disconnect opening 350D, the shaft may slide through the passage inlet 365 when the disconnect 334D is retracted, even though the control member is not positioned above the disconnect 334D when the stiffener is in the extended position (e.g., because the disconnect 334D may not be long enough).

Fig. 5E-5H show the disconnects 334E-H, respectively. The decoupler openings 350E-H of fig. 5E-5H are generally similar to the decoupler openings 350A-D of fig. 5A-5D, respectively, except for the grooves. The grooves 362B of the disconnects 334E-H differ from the grooves 362A in fig. 5A-5D in that each of the grooves 362B includes a leg 366 and is generally dog-leg or L-shaped pattern. When the disconnects 334E-H are positioned in an instrument (e.g., instrument 400 in fig. 6B and 6C), the leg 366 of the dog leg extends parallel to the probe longitudinal axis 170 and toward the proximal end of the base unit 120 (e.g., toward the proximal end 125 in fig. 1B). Leg 366 is used to operatively engage a control member (e.g., control member 438 in fig. 6A) and lock disconnects 334E-H in place when the control member is located in one of the grooves 362B. Leg 366 ensures that disconnects 334E-H do not rotate when locked in place, as described with respect to fig. 6B and 6C.

The disconnects 334A-H described with respect to fig. 5A-5H may be used in a number of different instruments. Fig. 6A-6C illustrate how the stiffener 432 may be rotated to engage the control member 438 using the grooves 362A and 362B shown in fig. 5A-5H. Fig. 7A-8 illustrate how the control member 438 may slide to engage the grooves 362A and 362B.

Fig. 6A-6C illustrate different features and views of another exemplary instrument 400 that is generally similar to the exemplary instrument 100 of fig. 1-4B. The instrument 400 includes a control member 438, an enhancer 432, and a decoupler 334A from fig. 5A. The control member 438 is generally similar to the control member 138, except having a recess, and is described with respect to fig. 6A. The stiffener 432 is substantially similar to the stiffener 132 except that the stiffener 432 does not include the keying feature 140. Thus, the stiffener 432 and the decoupler 334A are free to rotate together about a probe longitudinal axis of the probe 110 (e.g., the probe longitudinal axis 170 shown in fig. 4A).

Fig. 6A illustrates a perspective view of the control member 438. As shown, the control member 438 includes a head 142, a flange 146, and a shaft 444. Shaft 444 is substantially similar to shaft 144 in fig. 4C, except that shaft 444 includes a notch 445 proximate to radially inward end 148 of control member 438. The notch 445 operatively engages the groove 362A in the decoupler 334A as described with respect to fig. 6B and 6C.

Fig. 6B and 6C illustrate schematic cross-sectional views of an exemplary instrument 400 from a point of view at a distal end of the instrument 400. The enhancer biasing device 139 is omitted to better illustrate the locking mechanism of the control member 438 and the decoupler 334A. As previously discussed, the stiffener 432 and the decoupler 334A are free to rotate together about the probe longitudinal axis 170. As shown in fig. 6B, the control member 438 is depressed and the shaft 444 of the control member 438 is inserted into the circular cutout 360 of the decoupler opening 350A such that the notch 445 is aligned with the groove 362A in the decoupler 334A. As shown in fig. 6C, the stiffener 432, and thus the decoupler 334A, rotates clockwise 476 and the notch 445 operatively engages the groove 362A. The stiffener 432 may be manually rotated by the surgeon relative to the probe 110 or base unit 120 of the instrument 100. For example, the notch 445 fits within the groove 362A and overhangs the decoupler 334A, thereby guiding the notch 445 into the groove 362A as the stiffener 432 and decoupler 334A rotate. The control member 438 is then released and the control member biasing device 149 urges the control member 438 in a direction radially outward from the disconnect 334A such that the notch 445 urges against the disconnect 334A and the control member 438 locks the disconnect 334A and thereby the reinforcement 432 in place. To release the disconnect 334A, the surgeon may rotate the stiffener 432 counterclockwise, thereby moving the notch 445 out of the recess 362A. The control member 438 is released and the stiffener biasing apparatus 139 urges the stiffener to the extended position shown in fig. 4A.

In other embodiments not shown, a disconnect (e.g., disconnect 334E in fig. 5E) has a recess 362B with legs 366. Once the notch 445 operatively engages the recess 362B and the decoupler 334E rotates clockwise 476 as far as possible, the decoupler is pushed by the stiffener biasing apparatus 139 in a distal direction (e.g., toward the distal end 121 in fig. 1B) and the notch 445 operatively engages the leg 366 of the recess 362B, advantageously preventing rotation and also locking the decoupler 334E and the stiffener 432 in place. To release the decoupler 334E, the booster 432 is pushed in a proximal direction (e.g., toward the proximal end 125 in fig. 1B) and rotated counterclockwise against the force of the booster biasing device 139. This moves the notch 445 out of the leg 366 and the groove 362B. The control member 438 is released and the stiffener biasing apparatus 139 urges the stiffener to the extended position shown in fig. 4A.

Fig. 7A illustrates a perspective view of an exemplary instrument 500 according to certain embodiments described herein. Instrument 500 is generally similar to instruments 100 and 400 in fig. 1B and 6B-6C, respectively, except as discussed herein. In particular, the instrument 500 uses the control member 438 to push and slide radially inward toward a disconnect (e.g., the disconnect 334A in fig. 7B) to lock the disconnect and the stiffener 132 in place. The instrument 500 includes a base unit 520 having a cutout 528 and an outer surface 522. The cutout may be referred to as a base unit channel that is different from the decoupler channel of the decoupler. The control member 438 is partially disposed within the cutout 528. The base unit 520 and the outer surface 522 are substantially similar to the base unit 120 and the outer surface 522 of fig. 1B, except for differences from the cutout 528. The base unit 520 includes a distal end 521 and a proximal end 525.

Fig. 7B and 7C illustrate schematic cross-sectional views of instrument 500. The instrument 500 uses the stiffener 132 described with respect to fig. 1A-4B. As previously discussed in fig. 4A and 4B, the keying feature 140 constrains the stiffener 132 to rotate about the probe longitudinal axis 170. Thus, rotation of the decoupler 334A is constrained. The enhancer biasing device 139 is omitted to better illustrate the locking mechanism of the control member 438 and the decoupler 334A.

The cutout 528 is configured to allow the control member 438 to be urged bi-directionally along the vertical axis 172, similar to that described previously with respect to fig. 4A and 4B. The cutout 528 is further configured to allow the control member 438 to slide about the probe longitudinal axis 170. As shown in fig. 7B, the control member 438 is depressed along the vertical axis 172 and the shaft 444 of the control member 438 is inserted into the circular cutout 360 of the disconnect 334A such that the notch 445 is aligned with the groove 362A in the disconnect 334A. As shown in fig. 7C, the control member 438 and the notch 445 slide about the probe longitudinal axis 170 and the notch 445 operatively engages the groove 362A. The control member 438 locks the decoupler 334A and the enhancer 432 in place similar to that described with respect to fig. 6B and 6C. To release the disconnect 334A, the control member 438 is slid in the opposite direction to move the notch 445 out of the groove 362A. The control member 438 is released and the stiffener 132 is pushed by the stiffener biasing apparatus 139 to the extended position shown in fig. 4A.

As described above, while the foregoing fig. 1A-4F and 6A-7C discuss depressing a control member to insert a shaft into an opening of a disconnect, in certain other embodiments (shown in fig. 8), the shaft of the control member may be slid or positioned within a channel-shaped disconnect opening of a disconnect shown in fig. 5C, 5D, 5G, or 5H without depressing the control member. In such an embodiment, to lock the stiffener in place, the user may slide the control member, for example, about the probe longitudinal axis 170, as further described with respect to fig. 8.

Fig. 8 illustrates a schematic cross-sectional view of an exemplary instrument 600. This cross-sectional view is substantially similar to the cross-sectional views of fig. 7B and 7C. Instrument 600 is generally similar to instrument 500 in fig. 7B and 7C, except as discussed herein. In particular, the instrument 600 is slid using the control member 638 to lock the stiffener 132 in place. The control member 638 includes a head 642, a flange 646, and a shaft 644. The shaft 644 includes a notch 645. The enhancer biasing device 139 is omitted to better illustrate the locking mechanism of the control member 638 and the decoupler 334D (or decoupler 334H).

The instrument 600 includes a base unit 620 having a cutout 628. The cutout 628 may be referred to as a base unit channel that is different from the disconnect channel of the disconnect. The cutout 628 includes a multi-sized passageway 641 similar to the passageway 141 discussed in fig. 4A and 4B, except that the second passageway 641B conforms to the flange 646 of the control member 638. The flange 646 operatively engages the second passage 641B, which guides the flange 646, and thus the control member 638, through the incision 628 about the probe longitudinal axis 170 when the control member 638 is slidably actuated by a user. Thus, the second passageway 641B is configured as a guide channel to guide the control member 638 when actuated by a user, and may be referred to as a guide channel. As shown, the second passageway 641B is a curved channel that curves about the probe longitudinal axis 170.

As previously discussed in fig. 5D, the disconnect 334D includes a disconnect channel 364 and a channel inlet 365. The stiffener 132 runs along the length L of the probe 110. As the stiffener 132 advances toward the proximal end 525 of the base unit 620, the channel inlet 365 and the decoupler channel 364 of the decoupler 334D operatively engage the notch 645 of the control member 638. As shown, when the shaft 644 and the recess 645 are aligned with one of the grooves 362A, the control member 638 can slide about the probe longitudinal axis 170 and into one of the grooves 362A such that the recess 645 operatively engages the groove. Thus, the control member 638 locks the decoupler 334D and the enhancer 132 in place, similar to that described with respect to fig. 7B and 7C. To release the decoupler 334D, the control member 638 is slid in the opposite direction to move the notch 645 out of the recess 362A and the stiffener 132 is urged to the extended position as shown in fig. 4A by the stiffener biasing apparatus 139.

In certain embodiments, the slide-only locking mechanism of instrument 600 is compatible with disconnects 334C and 334G of fig. 5C and 5G, respectively. For example, with respect to the decoupler 334C, the shaft 444 of the control member 438 is always disposed in the decoupler channel 364 as the stiffener 132 travels along the length L of the probe 110. When the disconnect 334C is locked in place, the notch 445 of the control member 438 operatively engages one of the grooves 362A of the disconnect 334C, as previously described with respect to the disconnect 334D. The disconnect 334G may be used in a similar manner. In such embodiments, a stiffener without a keying feature (e.g., stiffener 432) may be used because the control member is always disposed within the opening of the disconnect.

In another embodiment, the cutout 628 includes a track with a substantially planar surface perpendicular to the probe longitudinal axis 170 and the vertical axis 172 on which a user can slidably and dynamically actuate the control member. The planar surface of the track provides a planar surface for a control member (e.g., control member 638) to traverse. In such an embodiment, the second channel 641B is a linear channel that is straight along the track.

Fig. 9A illustrates a perspective view of an exemplary instrument 700 according to certain embodiments described herein. Although instrument 700 is generally similar to instrument 100 in fig. 4A, the configuration of instrument 700 may be applied to any of the instruments discussed herein.

As shown, the instrument 700 includes a probe 710 and a base unit 720 having a distal end 721. The base unit 720 includes an interior chamber 724 and a base unit opening 717. The stiffener 732 surrounds the probe 710. The stiffener 732 and probe 710 are disposed in the interior chamber 724 and pass through a base unit opening 717 of the distal end 721 of the base unit 720. The stiffener 732 includes a keying feature 740 that operatively engages the base unit opening 717 to prevent rotation of the stiffener 732.

A cutout 728 is formed in the base unit 720, and a control member 738 is partially disposed in the cutout 728. The control member 738 includes a control member biasing device 749. The control member biasing device 749 includes several extensions as described with respect to fig. 9B. The cutout 728 includes multi-sized passages 741 configured to receive the control member 738 and the control member biasing device 749. For example, the passageway 741B is formed to accommodate deflection of the control member biasing device 749 when the control member 738 is depressed radially inward toward the disconnect 734. Passages 741A and 741C are similarly formed to receive other portions of control member 738.

The decoupler 734 is coupled to the enhancer 732 and the biasing device 739 applies a biasing force to the decoupler 134. The biasing force urges the decoupler 734 and the enhancer 732 in a distal direction (e.g., toward the distal end 721) to the extended position shown in fig. 9A. When the enhancer 732 and the decoupler 734 are retracted in a direction opposite the distal direction (e.g., proximal direction), the control member 738 can be depressed to engage the decoupler 734 and lock the enhancer 732 in place, as similarly described in fig. 4A and 4B.

Fig. 9B shows a perspective view of the control member 738. As shown, the control member 738 includes a head 742 and a shaft 744 disposed at opposite ends of the control member 738. A flange 746 is disposed between head 742 and shaft 744. The flange 746 includes several extensions 747 that include control member biasing means 749. The extension 747 extends in a direction toward the shaft 744 and radially outward from the shaft. Thus, as shown, the control member biasing device 749 and the control member 738 are a single, integral component, advantageously reducing the overall components in the instrument 700. In certain embodiments, the extension 747 is made of a flexible but rigid material (e.g., polypropylene, polycarbonate, acrylonitrile butadiene styrene, etc.). When the control member 738 is depressed, the extension 747 contacts the passageway 741B, and when the shaft 744 travels toward the decoupler 734, the force depressing the control member 738 deforms the extension 747. When the force is removed, the extensions 747 return to their undeformed shape. Thus, the extension 747 acts as a spring.

In summary, embodiments of the present disclosure include structures and mechanisms for adjusting the stiffness of microsurgical instruments, such as small gauge instruments for minimally invasive ophthalmic surgery. The above-described instruments include embodiments in which a user (e.g., a surgeon) may adjust the stiffness of the instrument during its use. Thus, the described embodiments enable a surgeon to access a wider range of tissues using a single instrument, thereby expanding the applicability of smaller gauge instruments to a wider range of indications.

Certain embodiments described herein enable a surgeon to dynamically adjust the stiffness and length of a vitrectomy probe to access all areas of the vitreous cavity during a single procedure. The adjustment of the probe may be performed before the probe is inserted into the eye or after the probe has been inserted into the eye. Thus, the described embodiments may be used to facilitate access to the posterior segment of the eye during vitrectomy while retaining the benefits of smaller gauge probes, such as increased patient comfort, reduced conjunctival scarring, reduced post-operative inflammation, and faster healing time. While vitreous surgery is discussed as an example of a surgical procedure that may benefit from the embodiments, the advantages of having an adjustable stiffness instrument may also benefit other surgical procedures.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Additional considerations

The previous description is provided to enable any person skilled in the art to practice the various embodiments described herein. The examples described herein do not limit the scope, applicability, or embodiments set forth in the claims. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. For example, changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, replace, or add various procedures or components as appropriate. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method practiced using any number of the aspects set forth herein. In addition, the scope of the present disclosure is intended to cover an apparatus or method that is practiced with other structures, functions, or structures and functions in addition to or other than the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims.

As used herein, a phrase with respect to "at least one" in a list of items refers to any combination of those items, including individual members. For example, "at least one of a, b, or c" is intended to encompass a, b, c, a-b, a-c, b-c, and a-b-c as well as any combination of multiples of the same element (e.g., a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b-b, b-b-c, c-c, and c-c-c, or any other order of a, b, and c).

The following claims are not intended to be limited to the embodiments shown herein but are to be accorded the full scope consistent with the language of the claims. In the claims, reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more". The term "some" means one or more unless specifically stated otherwise. In accordance with the 35u.s.c. ≡112 (f) specification, the elements of any claim will not be explained unless the elements are explicitly recited using the phrase "means for … …" or, in the case of method claims, using the phrase "step for … …". All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.

Claims (15)

1. A surgical instrument, comprising:

a base unit configured to be held by a user;

a probe disposed through a base unit opening in a distal end of the base unit, the probe having a length parallel to a probe longitudinal axis of the probe;

a stiffener disposed through a base unit opening in the base unit, the stiffener formed from a hollow tubular member slidably coupled to and surrounding at least a portion of the probe; and

an actuation mechanism configured to extend the stiffener along a length of the probe in a distal direction, wherein the actuation mechanism comprises:

the first biasing means may be provided in the form of a first biasing means,

disconnector

An annular flange integral with or attached to the stiffener,

wherein the first biasing device is configured to apply a first biasing force to the annular flange of the stiffener in the distal direction through the disconnect.

2. The surgical instrument of claim 1, further comprising:

a control member configured to lock the stiffener in place;

Wherein the disconnect is configured to interact with the control member.

3. The surgical instrument of claim 2, wherein the disconnect comprises a disconnect opening.

4. A surgical instrument according to claim 3, wherein the decoupler opening comprises one or more through holes or decoupler channels.

5. The surgical instrument of claim 4, wherein the control member includes a protrusion configured to operatively engage a decoupler opening of the decoupler to lock the stiffener in place, the control member and the protrusion having a control member longitudinal axis that is perpendicular to a probe longitudinal axis of the probe.

6. The surgical instrument of claim 5, wherein the control member is partially disposed within a base unit channel formed in the base unit and the base unit channel is formed along the control member longitudinal axis.

7. The surgical instrument of claim 6, wherein pushing the control member along the base unit channel operatively engages the one or more through holes of the disconnect.

8. The surgical instrument of claim 6, wherein the control member further comprises a control member biasing device, and wherein the control member biasing device:

Is disposed in a base unit channel formed in the base unit, and

is configured to apply a control member biasing force to the control member in a direction radially outward from the decoupler.

9. The surgical instrument of claim 8, wherein,

the control member further comprises a flange which,

the control member biasing means is a spring, and

the control member biasing force is applied to a flange of the control member.

10. The surgical instrument of claim 6, wherein the decoupler opening of the decoupler further comprises a groove extending in a direction perpendicular to the probe longitudinal axis of the probe.

11. The surgical instrument of claim 10, wherein the protrusion of the control member comprises a shaft having a notch configured to operatively engage a decoupler opening of the decoupler.

12. The surgical instrument of claim 11, wherein,

the disconnect is configured to move about a probe longitudinal axis of the probe when rotated about the probe longitudinal axis,

the recess of the control member is configured to operatively engage the recess of the disconnect when the stiffener is rotated in a first direction, and

The recess of the control member is configured to operatively disengage the groove of the disconnect when the stiffener is rotated in a second direction.

13. The surgical instrument of claim 11, wherein,

the control member is partially disposed within a guide channel formed in the base unit, and the guide channel is formed about a probe longitudinal axis of the probe,

the control member is configured to move about the probe longitudinal axis when slid along the guide channel,

the recess of the control member is configured to operatively engage the recess of the disconnect when the control member slides in a first direction, and

the recess of the control member is configured to operatively disengage the groove of the disconnect when the control member is slid in a second direction.

14. The surgical instrument of claim 13, wherein the guide channel is a linear channel or a curved channel.

15. The surgical instrument of claim 1, wherein,

the stiffener further includes a keying feature; and is also provided with

The base unit opening in the distal end of the base unit is configured to operatively engage the keying feature to prevent rotation of the stiffener.