WO2011131972A1

WO2011131972A1 - Handle and surgical instrument

Info

Publication number: WO2011131972A1
Application number: PCT/GB2011/050758
Authority: WO
Inventors: Nicholas Robinson
Original assignee: Surgical Innovations Limited
Priority date: 2010-04-20
Filing date: 2011-04-18
Publication date: 2011-10-27
Also published as: GB201006539D0

Abstract

A handle for a surgical instrument which includes two protrusions set at different distances from the end of the handle. Depending on the hand size of a user, the user can select which protrusion to use. The handle reduces instrument inventory by allowing use of the same instrument handle by users with different hand sizes. A surgical instrument using the handle is also described. In one embodiment the handle comprises a housing defining a longitudinal axis. A first end of the housing is at one end of the longitudinal axis. The housing comprises a first protrusion positioned a first distance from the first end of the housing for use by a user having a first size of hand and a second protrusion positioned a second distance from the first end of the housing for use by a user having a second size of hand. Both the first protrusion and the second protrusion are configured to receive a digit of a user and to allow the digit to apply a force to the housing in the direction of the longitudinal axis towards the first end. The first distance is greater than the second distance. Depending on the user's size of hand they can select which of the first or second protrusions to use.

Description

HANDLE AND SURGICAL INSTRUMENT

The present application relates to handles for surgical instruments and a surgical instrument including such a handle. More particularly, the present invention relates to handles and surgical instruments for minimally invasive surgery.

Minimally invasive surgery is known. During such surgery, surgical instruments are inserted through small incisions, typically in the abdominal wall. Such instruments generally comprise an elongated shaft with an operative tip at a distal end. A handle is attached to the proximal end and is used to actuate the operative tip.

An example prior art minimally invasive surgical instrument is depicted in Figure 1.

Figure 1 depicts an endoclaw that may be used in wound closure procedures or other surgical procedures including fat clearance and surgical hernia mesh procedures. It comprises a handle 4 which defines a longitudinal axis. A plunger 6 is mounted within the handle 4 and extends from one end of the handle 4 along the longitudinal axis. At the other end of the longitudinal axis, an elongate shaft 8 extends distally leading to an operative tip 10. The handle 4 includes a protrusion 12 formed at its distal end. In use, the handle is held in one hand by a user. Typically, a user's thumb will engage the end of plunger 6 and one or more of the user's digits will engage the protrusion 12. The operative tip can then be operated by moving the plunger closer to the handle. This causes the operative tip 10 to extend from the elongate shaft 8. The ability of a user to control the endoclaw 2 of the prior art safely and easily depends on the size of the operator's hands. The user's hand must be able to cover the distance from the protrusion 12 to the end of the plunger 6 comfortably, when the plunger is at its maximum extension from the handle, as depicted in Figure 1. Other handles for surgical instruments designed for one handed use are also known. Such instruments generally include two parts that can be moved relative to each other. One group of instruments includes devices in which a sliding portion can be moved forwards and backwards along an axis. Examples include US-2005/0124912A (Griego et al), US- 4178810 (Takahashi) and US-6090129 (Ouchi) all include a finger grip with two spaced apart protrusions. One protrusion is configured to engage the finger of a user when the finger is moved in the forward direction. The other protrusion is configured to engage the finger of the user when the finger is moved in the backwards direction. A similar construction is used in US-5163942 (Rydell) which includes a thumb loop and two pairs of finger grips. In use, a user inserts a finger between the two sets of finger grips and can then move the slider in two directions to deploy and retract a grasping loop. The direction of movement determines which of the finger grips is engaged.

Anther group of instruments include a finger grip with two spaced apart protrusions to enable a user to use two fingers to move the finger grip, one engaging each protrusion. For example, US-5683413 (Miyagi) discusses a slider mounted on a rod. The rod has a ring at one end that can receive a user's thumb. A slider body is sandwiched between the user's middle finger and index finger and moved relative to the ring. US-4982727 (Sato) has a similar configuration to Miyagi, including a thumb ring and a slider which is sandwiched between first and middle fingers for relative movement of the thumb ring.

All these prior art handles are designed for a particular size of hand. Providing a variety of handles in different sizes to account for the differences in hand size of the user increases inventory and cost. It would therefore be desirable to provide a handle for a surgical instrument that can be used by users with different hand sizes.

According to the present invention, a handle for a surgical instrument is provided which includes two protrusions set at different distances from the end of the handle. Depending on the hand size of a user, the user can select which protrusion to use.

According to an aspect of the present invention there is provided a surgical instrument handle comprising a housing defining a longitudinal axis. A first end of the housing is at one end of the longitudinal axis. The housing comprises a first protrusion which is positioned a first distance from the first end of the housing for use by a user having a first size of hand. A second protrusion is positioned a second distance from the first end of the housing for use by a user having a second size of hand. Both the first protrusion and the second protrusion are configured to receive a digit of a user and to allow the digit to apply a force to the housing in the direction of the longitudinal axis towards the first end. The first distance is greater than the second distance.

According to the invention, because the first distance is greater than the second distance, the protrusions are positioned different distances from the end of the handle, enabling the handle to accommodate users with different hand sizes. The protrusions are configured so as to receive a digit and allow it to apply a force to the housing towards the first end, ensuring that the handle can be securely controlled during use. Unlike the devices of Griego et al, Takahasi, Rydell and Ouchi the protrusions are both configured to allow a user to apply a force in the same direction, allowing whichever protrusion is most comfortable to be selected by a user. Unlike the devices of Miyagi and Sato, the protrusions are positioned at distances for users with hands of different sizes, not so each protrusion can be engaged by two fingers of the same user simultaneously. Thus, the surgical instrument handle can be used comfortably by users with different hand sizes unlike prior art devices.

The protrusions may be formed integral with the housing or may be a separate part mounted on the housing.

In one embodiment, the handle further comprises a third protrusion opposite to the first protrusion in the direction perpendicular to the longitudinal axis and a fourth protrusion opposite to the second protrusion in the direction perpendicular to the longitudinal axis by providing pairs of protrusions opposite each other it enables two digits to engage the protrusions, improving ease of use and control.

The first distance is preferably 50-60mm, more preferably around 55mm and the second distance is preferably 75-85mm, more preferably around 79mm.

Preferably, the first protrusion and the second protrusion both define a curve with the housing at least on the side of the protrusion which is furthest away from the first end of the housing. This improves the comfort of the handle, because in use a user's digit can rest on the curve.

The handle may further comprise a sliding member, movable relative to the housing in the direction of the longitudinal axis. In use the sliding member can be moved relative to the housing by engaging either the first or the second protrusion with a finger of a user. The choice of first or second protrusion will depend on the hand size of the user. Preferably, the sliding member is a plunger mounted within the housing and partially extending from the first end of the housing.

The handle may further comprise a resilient member configured to exert a force on the sliding member. Preferably, the resilient member is contained with the housing and exerts a force in the direction of the longitudinal axis. This allows the user to move the sliding member in one direction relative to the housing by pressing it with their thumb while engaging one of the protrusions with a finger against the force of the resilient member. When the sliding member is released by the user the force of the resilient member then moves it in the other direction.

In one embodiment, a surgical instrument comprises a handle as defined above and a plunger mounted within the housing, movable relative to the housing in the direction of the longitudinal axis and partially extending from the first end of the housing. In this embodiment, the provision of two protrusions enables the user to select which is most comfortable for their hand size so that a digit engages one of the protrusions and another digit, for example a thumb, engages the plunger.

The handle may be used in a surgical instrument which further comprises an outer shaft extending from an opposite end of the housing to the first end along the longitudinal axis, wherein the outer shaft comprises a through bore; an inner shaft mounted in the through bore and connected to the plunger; and an operative tip connected to the inner shaft. The operative tip may be any tip suitable for use with a minimally invasive surgical instrument. This includes endoclaws and graspers. Some operative tips, such as endoclaws, are required only to be connected to the inner shaft. In further embodiments other operative tips, such as graspers, part of the operative tip may be connected to the outer shaft as well as the inner shaft.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figure 2 depicts a plan view of a first embodiment of the present invention;

Figure 3 depicts a section of the embodiment of Figure 2 along the longitudinal axis indicated by line AA in Figure 2;

Figure 4 depicts a plan view of the embodiment of Figure 2 showing the operative tip extended;

Figure 4a shows detail of the operative tip of Figure 4; and

Figure 5 depicts an exploded view of the construction of the embodiment of Figure 2. Figure 2 depicts an embodiment of a surgical instrument according to the present invention. The surgical instrument comprises a handle 12 which comprises a housing 14. The housing 14 defines a longitudinal axis 15. A first protrusion 16 and second protrusion 18 are formed at an end of the housing 14 opposite a first end 17 at one end of the longitudinal axis 15. An optional third protrusion 20 is formed opposite first protrusion 16 in the direction perpendicular to the longitudinal axis 15. A fourth protrusion 22 is formed opposite the third protrusion 18 in the direction perpendicular to the longitudinal axis 15.

A plunger 24 extends from the first end 17 of the handle. At an opposite end 26 of the housing 14 to end 17 along the longitudinal axis 15, an outer shaft 28 extends along the longitudinal axis 15. As can best be seen in the cross-sectional view of Figure 3 or the exploded view of Figure 5, the outer shaft 28 has an inner through bore in which an inner shaft 30 is mounted. At the distal end of the inner shaft 30, an operative tip 32 is provided.

Figure 2 depicts the surgical instrument when the plunger 24 is extended as far as possible from the first end 17 of the housing 14. This ensures that the distal tip 32 extends a minimal distance from the outer shaft 28. The internal construction of the various parts comprising the surgical instrument can be understood with reference to Figure 3 showing a cross-section view and Figure 5 showing an exploded view. The housing 14 is comprised of two injection moulded parts 34 and 36. The two parts are fixed together enclosing the plunger 24 so that the plunger 24 can move relative to housing 14. A resilient member, a spring 38 in this embodiment, is provided within the housing 14 to provide a force so that the plunger 24 is biased to extend out of the first end 17 of housing 14.

The outer shaft 28 is retained within the housing 14 and fixed relative to the housing. The inner shaft 30 with operative tip 32 is held within the outer shaft 28 and connected via a crimp member 40 to the end of the plunger. Thus, movement of the plunger 24 relative to the housing 14 causes the operative tip 32 to extend from the outer shaft 28.

Referring now to Figure 4 and 4a, the operative tip in this embodiment is an endoclaw. The endoclaw comprises a sharp distal tip 42 and a curved portion 44. The distal tip 42 is formed from a shape memory metal alloy, such as a nickel-titanium alloy, for example, nitinol, having superelastic properties. The metal is shape set so that, at body temperature, the curved portion 44 adopts the configuration shown in Figure 4a. In use, when the inner shaft 30 is advanced relative to the outer shaft, the curved portion 44 moves away from the pointed tip 42 as indicated by reference number 46. The superelastic properties mean that when the operative tip 32 is withdrawn into the outer shaft 28, the outer shaft 28 constrains the curved portion 44 to be close to the sharp tip 42, ensuring that the profile of the operative tip 32 is smaller than the outer diameter of the outer shaft 28.

In the present invention, the outer tube 28 is manufactured from stainless steel. The spring 18 is also manufactured from stainless steel. The operative tip 34 is integrally formed with the inner shaft 30 and this entire assembly is manufactured from a nickel-titanium alloy having shape memory and/or superelastic properties such as nitinol. The crimp member 40 is manufactured from stainless steel. The remaining parts, housing sections 34, 36 and plunger 24 are manufactured from polycarbonate. It will be appreciated that other materials can be used in other embodiments, dependent upon design decisions such as whether the tool is intended to be disposable or reusable and the material properties required. As can best be understood with reference to Figure 2, the first and third protrusions 16 are located a first distance from end 17 and a second and fourth protrusions 18, 22 are located a second distance from the first end 17. In this embodiment, the first distance is 55mm and the second distance is 79mm, both measured from the furthest point of the protrusion away from first end 17. In use, a user will typically place a thumb over plunger 24 and choose to engage their fingers with either first and third protrusions 16, 20 or second and fourth protrusions 18, 22, depending on the size of the hand. A user can thus operate the handle and instrument with a good degree of control.

During use, a user with a smaller hand may switch from the second and fourth protrusions (which are closer to the end 17) to the first and third protrusions, 16, 20 as the plunger 24 is pushed further into the housing 14.

Although the above described embodiment refers to the use of an endoclaw, it will be appreciated that the present invention can be applied to any surgical instrument handle which includes protrusions for engaging digits of a user. For example, it may be applied to other minimally invasive surgical instruments, such as graspers.

Claims

1. A surgical instrument handle, the surgical instrument handle comprising a housing defining a longitudinal axis, wherein a first end of the housing is at one end of the longitudinal axis and wherein the housing comprises:

a first protrusion positioned a first distance from the first end of the housing for use by a user having a first size of hand; and

a second protrusion positioned a second distance from the first end of the housing for use by a user having a second size of hand;

wherein both the first protrusion and the second protrusion are configured to receive a digit of a user and to allow the digit to apply a force to the housing in the direction of the longitudinal axis towards the first end; and wherein the first distance is greater than the second distance.

2. A surgical instrument handle according to claim 1, further comprising a third protrusion opposite to the first protrusion in the direction perpendicular to the longitudinal axis and a fourth protrusion opposite to the second protrusion in the direction

perpendicular to the longitudinal axis.

3. A surgical instrument handle according to any one of the preceding claims, wherein the first distance is between approximately 50mm and approximately 60mm and the second distance is between approximately 75mm and approximately 85mm.

4. A surgical instrument handle according to any one of the preceding claims, wherein the first protrusion and the second protrusion both define a curve with the housing at least on the side of the protrusion which is furthest away from the first end of the housing.

5. A surgical instrument handle according to any one of the preceding claims, further comprising:

a sliding member movable relative to the housing in the direction of the longitudinal axis.

6. A surgical instrument handle according to claim 5, wherein the sliding member is a plunger mounted within the housing and partially extending from the first end of the housing.

7. A surgical instrument handle according to claim 5 or 6, further comprising a resilient member configured to exert a force on the sliding member.

8. A surgical instrument comprising:

a surgical instrument handle according to claim 5, 6 or 7,

an outer shaft extending from an opposite end of the housing to the first end along the longitudinal axis, wherein the outer shaft comprises a through bore;

an inner shaft mounted in the through bore and connected to the sliding member; and

an operative tip connected to the inner shaft.