Patent Description:
The human eye in its simplest terms functions to provide vision by transmitting and refracting light through a clear outer portion called the cornea, and further focusing the image by way of the IOL onto the retina at the back of the eye. The quality of the focused image depends on many factors including the size, shape, and length of the eye, and the shape and transparency of the cornea and IOL. When trauma, age, or disease cause the IOL to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the IOL of the eye is medically known as a cataract. The treatment for this condition is surgical removal of the IOL and implantation of an artificial IOL ("IOL").

Many cataractous lenses are removed by a surgical technique called phacoemulsification. During this procedure, an opening is made in the anterior capsule of an eye and a phacoemulsification cutting tip is inserted into the diseased IOL and vibrated ultrasonically. The vibrating cutting tip liquifies or emulsifies the IOL so that the IOL may be aspirated out of the eye. The diseased IOL, once removed, is replaced with an IOL.

The IOL may be injected into the eye through a small incision, sometimes the same incision used to remove the diseased IOL. An IOL injector may be used to deliver an IOL into the eye. Reference is made to the documents <CIT>, <CIT> and <CIT> which have been cited as relating to the state of the art.

The scope of the invention is in accordance with the claims.

According to first aspect, the present disclosure relates to an IOL injector. The IOL injector has an injector body having a proximal end and a distal end. The injector body includes: a main injector body having a distal end and a proximal end; a nozzle coupled to the distal end of the main injector body; and a bore extending from the proximal end of the injector body to the distal end of the injector body. The IOL injector also has a plunger having a proximal portion and a distal portion, the plunger slideably disposed within the bore and adapted to advance an IOL along a longitudinal axis of the IOL injector. The IOL injector also has an automatic plunger advancement driver having: a cylinder concentrically disposed around the proximal portion of the plunger, the cylinder having a thread adapted to rotatably engage with a plunger thread in the proximal portion of the plunger; a torsion spring having stored rotational energy, the torsion spring concentrically disposed around the cylinder, wherein at least one end of the torsion spring is coupled to the cylinder such that in response to a release of the stored rotational energy, the cylinder is configured to rotate around the longitudinal axis and the plunger moves axially toward the distal end of the injector body.

According to a second aspect, the present disclosure relates to an IOL injector. The IOL injector has an injector body having a proximal end and a distal end. The injector body includes a main injector body having a distal end and a proximal end; a nozzle coupled to the distal end of the main injector body; and a bore extending from the proximal end of the injector body to the distal end of the injector body. The IOL injector also has a plunger having a proximal end and a distal end, the plunger slideably disposed within the bore and adapted to advance an IOL along a longitudinal axis of the IOL injector. The IOL injector also has a spring-assisted driving mechanism including one or more assistive springs having stored elastic energy, wherein the assistive springs are directly or indirectly coupled at a first end of the spring to the plunger and at a second end of the spring to the injector body, such that movement of the plunger toward the distal end of the injector body is assisted by release of elastic energy from the spring. The IOL injector also has a spring damping mechanism including one or more resistive springs directly or indirectly coupled at a first end of the spring to the plunger and at a second end of the spring to the injector body, such that elastic energy is stored in the resistive springs in response to axial movement of the plunger toward the distal end of the injector body.

The IOL injector has a braking mechanism configured to prevent axial movement of the plunger, including: a handle having a proximal end and a distal end and rotatably coupled to the injector body at a pivot point disposed between the proximal end and the distal end of the handle in response to a force applied to the handle; a brake release arm having a proximal end coupled to the handle and the distal end coupled to one or more brake pads adapted to apply a frictional braking force to the plunger in absence of a force applied to the handle; compression springs disposed between the injector body and the brake pads, the compression springs adapted to move the brake pads toward the plunger; wherein, in response to the force applied to the handle, the brake release arm compresses the compression springs and moves the brake pads away from the plunger thereby removing the frictional braking force from the plunger and allowing movement of the plunger in response to the release of the stored rotational energy of the torsion spring. The IOL injector has a hydraulic damping mechanism including: a proximal chamber having approximal end and a distal end; a distal chamber having a proximal end and a distal end; an orifice fluidically coupling the proximal chamber to the distal chamber; the proximal portion of the plunger having a proximal piston slideably disposed within the proximal chamber; and the distal portion of the plunger having a distal piston slideably disposed within the distal chamber; wherein: the proximal piston is movable from the proximal end of the proximal chamber to the distal end of the proximal chamber in response to movement of the threaded cylinder-engaging portion of the plunger; the orifice allows movement of a hydraulic fluid from the proximal chamber to the distal chamber in response to movement of the proximal piston; and the distal piston is movable from the proximal end of the distal chamber to the distal end of the distal chamber in response to movement of the fluid. The IOL injector has a braking mechanism configured to prevent axial movement of the plunger, including: a handle having a proximal end and a distal end and rotatably coupled to the injector body at a pivot point disposed between the proximal end and the distal end of the handle in response to a force applied to the handle; a hydraulic flow barrier having a first end coupled to the handle and a second end slideably disposed within the orifice and adapted to prevent movement of the fluid through the orifice from the proximal chamber to the distal chamber in absence of a force applied to the handle; and a hydraulic flow gate forming a passage adapted to allow movement of the fluid through the orifice when the hydraulic flow gate is disposed in the orifice; compression springs disposed between the handle and the orifice, the compression springs adapted to move the hydraulic flow gate out of the orifice; wherein: in response to application of a force to the handle, the hydraulic flow gate is moved into the orifice and allows movement of the fluid through the orifice from the proximal chamber to the distal chamber. The IOL injector may include an IOL disposed within a hollow portion of the nozzle, such that the axial movement of the plunger towards the distal end of the injector body causes the IOL to be ejected from the nozzle. The IOL injector may have a spring-assisted driving mechanism including one or more assistive spring-driven gears, having: a first spring having stored elastic energy coupled at a first end to a first gear rotatably coupled to the injector body and the first spring coupled at a second end to the injector body; a rack disposed on the plunger, the rack having teeth adapted to rotatably mesh with teeth of the first gear; wherein the first gear is adapted to rotate in response to release of the stored elastic energy from the first spring; and the plunger is adapted to move axially toward the distal end of the injector body in response to rotation of the first gear; the spring-assisted driving mechanism thereby assisting the axial movement of the plunger; and a spring damping mechanism having one or more damping spring-driven gears, having: a second spring coupled at a first end to a second gear rotatably coupled to the injector body and the second spring coupled at a second end to the injector body; wherein the second gear is adapted to rotate in response to axial movement of the plunger toward the distal end of the injector body; and the second spring is adapted to store elastic energy in response to the rotation of the second gear; the spring damping mechanism thereby providing resistance to the axial movement of the plunger. In some implementations of the IOL injector, in response to an application of an axial force by a user to the plunger to advance the plunger toward the distal end of the injector body, the rack engages the first gear and the first gear applies a force to assist further advancement of the plunger through the bore; and in response to further application of axial force by a user to the plunger to advance the plunger toward the distal end of the injector body, the rack engages the second gear and the second gear applies a force to resist further advancement of the plunger through the bore. The first spring and/or the second spring may be a tension spring. The first spring and/or the second spring may be a compression spring. The IOL injector may have an assistive tension spring coupled at a proximal end of the tension spring to the plunger and at a distal end of the tension spring to a sheath, wherein the tension spring is disposed within the sheath and a portion of the plunger is disposed within the tension spring; a damping compression spring coupled at a proximal end to the sheath and at a proximal end to at least one stop coupled to an inner wall of the injector body, wherein the disposed within the compression spring; wherein: the plunger moves axially toward the distal end of the injector body in response to release of elastic energy from the tension spring; and the compression spring is adapted to store elastic energy in response to movement of the plunger toward the distal end of the injector body. The IOL injector may have an assistive compression spring coupled at a proximal end of the assistive compression spring to the proximal end of the injector body and at a distal end of the assistive compression spring to the plunger; a resistive compression spring coupled at a distal end of the resistive compression spring to the distal end of the injector body; a first removable stop disposed within the bore at a proximal portion of the injector body; a second removable stop disposed within the bore at a distal portion of the injector body; wherein: in a first configuration, the first stop is adapted to contact the assistive compression spring, thereby maintaining the assistive compression spring in a compressed state having stored elastic energy; in a second configuration, the first stop is removed from the bore, and in response, the assistive compression spring is configured to expand and in response the plunger is configured to move axially toward the distal end of the injector body until the assistive compression spring contacts the second stop; in a third configuration, the second stop is also removed from the bore, and in response, the assistive compression spring is configured to expand and contact the resistive compression spring, and in response: the plunger is configured to move further axially toward the distal end of the injector body, and the resistive compression spring is configured to compress, wherein a compression of the resistive compression spring provides a resistive force in opposition to the movement of the plunger. In the second configuration, a plunger tip of the plunger may be configured to move to a location proximally adjacent to an IOL dwell position. In the third configuration, a plunger tip of the plunger may be configured to move to the distal end of the injector body.

For a more complete understanding of the present disclosure, reference is now made to the following description, taken in conjunction with the accompanying drawings, which are not to scale, and in which:.

For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the implementations illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described IOL injectors, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one implementation may be combined with the features, components, and/or steps described with respect to other implementations of the present disclosure.

Due to the sensitivity and delicacy of ocular tissues and structures, it is helpful for the user to be able to advance an IOL during implantation with acceptable peak speed and force. However, inherent to the mechanism of compressing and advancing the IOL into the eye, there is a large pressure release when the IOL is at the exit of the nozzle of the IOL injector. In some cases, this causes the IOL to be ejected with high velocity and in a less controllable manner. Pressure and force variations during injection reduce user control of the injector, which increases the risk of IOL sudden ejection. Therefore, injectors of the present disclose may help ensure that the mechanism and magnitude of force applied through user interaction is appropriate and repeatable. The injectors may also be intuitive to operate and able to be used by medical personnel over a wide spectrum of skills and techniques.

The present disclosure relates to systems, apparatuses, and methods for delivering an IOL into an eye.

<FIG> shows an example IOL <NUM>. The IOL <NUM> is a one-piece IOL that includes a optic <NUM>, a leading haptic <NUM>, and a trailing haptic <NUM>. Each of the haptics <NUM> and <NUM> has a freely extending end <NUM>.

In some implementations, the IOL <NUM> may be a one-piece IOL. That is, in some implementations, the IOL <NUM> may include an optic <NUM> and haptics <NUM> and <NUM>, as shown in <FIG>. In some implementations, the optic <NUM> and the haptics <NUM> and <NUM> may be integrally formed out of a single piece of material. In other implementations, the optic <NUM> may be formed out of one piece of material; the haptics <NUM> and <NUM> may be formed out of another piece of material; and the optic <NUM> and the haptics <NUM> and <NUM> may be coupled together prior to delivery into an eye. In some instances, the optic <NUM> and haptics <NUM> and <NUM> may be fixedly secured to each other prior to insertion into an IOL injector and delivered into an eye.

In other implementations, the IOL <NUM> may be a multi-piece IOL, as shown, for example in <FIG>. For example, in some implementations, the IOL <NUM> may include two or more separate components. <FIG> is an example IOL <NUM> that includes two removably attached components. As shown in <FIG>, the IOL <NUM> includes an optic <NUM> and a base <NUM> that includes haptics <NUM>. The base <NUM> may be a hollow base. The optic <NUM> and the base <NUM> are adapted to be coupled together into a unitary IOL and, thereafter, detached from each other into separate components, if desired. In some instances, one or more components of a multi-piece IOL, such as, for example the two-piece IOL <NUM> shown in <FIG>, are separately injectable into a patient's eye. Once in the eye, the components may be assembled into a complete IOL. For example, the two-piece IOL <NUM> shown in <FIG>, the optic <NUM> and the base <NUM> are separately injectable into an eye. Once injected, the optic <NUM> is adapted to be coupled to and to rest on the base <NUM>.

<FIG> and <FIG> are exemplary schematics of an IOL injector <NUM> that is actuated by manual user application of force. The IOL injector <NUM> includes an injector body <NUM>, a plunger <NUM> adapted to reciprocate through a bore formed in the injector body <NUM>, a folding device <NUM> and a nozzle <NUM> disposed at a distal end <NUM> of the injector body <NUM>.

The IOL injector <NUM> also includes a longitudinal axis <NUM>. The longitudinal axis <NUM> may extend along the plunger <NUM> and define a longitudinal axis of the plunger <NUM>.

The nozzle <NUM> defines a passage through which a folded IOL may be advanced and delivered into an eye via an opening at distal end <NUM>. A delivery channel <NUM> of the folding device <NUM> may be aligned with the bore and the passage through which the folded IOL may be advanced and delivered into an eye. The folding device <NUM> is shown schematically may be any folding device capable of folding an unfolded IOL <NUM> for delivery into an eye. The bore, the delivery channel <NUM> of the folding device <NUM>, and the passage through which the folded IOL may be advanced and delivered into an eye may combine and extend from proximal end <NUM> to distal end <NUM> of the injector body <NUM>. The plunger <NUM> is received within the bore and may be moveable therein such that the plunger <NUM> is slideable within the bore. Particularly, the plunger <NUM> may be slideable within the bore in order to advance an IOL, such as IOL <NUM>, within the delivery channel <NUM> of the folding device <NUM> and the passage of the nozzle <NUM> to allow delivery into the eye.

The folding device <NUM> may include a door <NUM> to provide access to the interior of the folding device <NUM>. The door <NUM> may include a hinge <NUM> such that the door <NUM> may be pivoted about the hinge <NUM> to open the folding device <NUM> and, for example, allow the installation of the IOL <NUM>. In other implementations, the folding device <NUM> may exclude a door for installing the IOL <NUM>. In such instances, the IOL <NUM> may be incorporated into the folding device <NUM> at the time of assembly of the folding device <NUM>. This, in such instances, the IOL injector <NUM> would be a preloaded IOL injector.

The injector body <NUM> may also include tabs <NUM> formed at the proximal end <NUM> of the injector body <NUM>. The tabs <NUM> may be manipulated by fingers of a user, such as an ophthalmologist, an ophthalmic surgical assistant or nurse, or other medical profession, to advance the plunger <NUM> through the bore. The plunger <NUM> may include a body portion <NUM>, a plunger rod <NUM> extending distally from the body portion <NUM>, and a plunger tip <NUM> formed at the distal end of the plunger rod <NUM> and adapted to contact the folded IOL disposed, for example, within the folding device <NUM> of the IOL injector <NUM>. As the plunger <NUM> is displaced distally within the bore in the direction of the arrow <NUM>, the plunger <NUM> engages and advances the folded IOL, such as IOL <NUM>, contained in the folding device <NUM>.

In some implementations described herein, various parts of the plunger <NUM> may be physically separated or decoupled from each other within the injector body <NUM> of the IOL injector <NUM>. For example, in some implementations, the body portion <NUM> may be physically separated or decoupled from the plunger rod <NUM>. In various implementations, where various parts of the plunger <NUM> are physically separated or decoupled from each other, additional components of the IOL injector <NUM> may actuate movement of one part of the plunger <NUM> in response to movement of another part of the plunger <NUM>, as will be apparent to persons of ordinary skill in the art upon reading of the present disclosure.

Occasionally, patients may require replacement of an IOL, and a procedure to replace an IOL may result in damage to the eye. With the use of a two-piece IOL, for example, a replacement procedure may involve replacement only of the optic, allowing the base to remain in place within the eye.

As explained above, in some implementations, the IOL <NUM> may be a two-piece IOL, as shown, for example, in <FIG>. The IOL <NUM> includes the base <NUM> and the optic <NUM> are separately injected into the patient's eye. Accordingly, for two-piece IOLs, the base <NUM> and the optic <NUM> may be contained in separate IOL injectors for insertion in the eye. In other implementations, the two components of a two-piece IOL may be inserted into an eye separately using a single IOL injector. For a single piece IOL (as shown, for example in <FIG>), the optic <NUM> and haptics <NUM> and <NUM> form a unitary IOL and is insertable into an eye as a single unit with the use of a single IOL injector.

Accordingly, in some implementations, a user may place a one-piece IOL into an IOL injector, for example, by loading an IOL into the IOL storage compartment of the IOL folding device of the IOL injector. In some implementations, the IOL may be manually folded into a compressed or folded configuration prior to installation into the IOL injector. The IOL may then be further compressed or folded by the folding device, or the IOL injector may lack a folding device and may simply include an IOL storage compartment in the place of the folding device.

In the case of a two-piece IOL, in some implementations, a user may load the base (which may be similar to base <NUM>) into an IOL storage compartment of an IOL injector, for example, via a door. The optic (which may be similar to optic <NUM>) may be introduced into the IOL storage compartment of separate IOL injector, for example, via a door. In some instances, the IOL storage compartment may be accessed through the door similar to door <NUM>. In some implementations, one or both of the base and the optic may be manually folded into a compressed or folded configuration prior to installation into an IOL injector.

In some implementations, the IOL may be pre-loaded into the storage compartment of an IOL injector, for example, during manufacturing or otherwise prior to distribution to an end user. Accordingly, for the one-piece IOL, the one-piece IOL may be pre-loaded into the storage compartment an IOL injector prior to receipt by the end user. For a two-piece IOL, the base may be pre-loaded into a storage compartment of one IOL injector, while the optic may be pre-loaded into the IOL storage compartment of another IOL injector. The term "pre-loaded" as used herein means that an IOL, either in a one-piece or multi-piece configuration (including, for example, a two-piece configuration) is loaded into the IOL injector not by a user, but, rather, the IOL is installed in the IOL injector before and is already contained within the IOL injector when the IOL injector is received by the user. The IOL injector(s) may be packaged within sterile packaging when received by a user.

As would be understood by persons of ordinary skill in the art, an IOL that is pre-loaded into an IOL injector has advantages over manual installation and folding of an IOL into the IOL injector that is performed by a user. For example, manual installation and folding of an IOL may allow more opportunity for errors, which have the potential to cause unnecessary secondary manipulation or correction during an already complex procedure. Manual installation and folding of an IOL may also introduce the possibility of contamination of the IOL, such as by human error or poor sterile technique. Contamination of the IOL may compromise the sterile environment for the patient and risk infection or other harm to the patient.

<FIG> shows a view of the distal end <NUM> of the IOL injector <NUM> with an IOL <NUM> located therein at a dwell position <NUM>. The dwell position <NUM> in <FIG> may correspond to a location in the nozzle <NUM> shown in <FIG>. As shown in <FIG>, the dwell position <NUM> of the IOL <NUM> may be defined as a location where a distal edge of an optic <NUM> of the IOL <NUM> substantially aligns with the demarcation <NUM>. A haptic <NUM> or a portion thereof may extend beyond the demarcation <NUM>.

In various implementations described herein and within the scope of the description as would be understood by persons of ordinary skill in the art, the IOL injectors of the present disclosure include one or more springs. In some implementations, the springs are configured to provide a mechanical force to drive or assist axial advancement of the plunger toward the distal end of the IOL injector. In some implementations, the springs are configured to provide a mechanical force in opposition to axial advancement of the plunger toward the distal end of the IOL injector, thereby providing a damping or resistive force to axial advancement of the plunger toward the distal end of the IOL injector body.

The term "spring" as used herein refers to an elastic object that stores mechanical energy. More specifically, a spring is a IOL injector that stores potential energy, specifically elastic potential energy, by straining the bonds between the atoms of an elastic material.

There are various types of springs, such as coil springs and torsion springs, that can be used in various implementations of the IOL injectors described herein and within the scope of the present disclosure.

For example, when a helical spring, otherwise known as a coil spring, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length. The term "resting position" as used herein refers to a spring having essentially no stored elastic energy. Coil springs are typically of two types: tension springs or compression springs. Tension or extension springs are designed to become longer under load. Their turns (loops) are typically touching in the unloaded position, and they may have a hook, eye or other means of attachment at each end. In contrast, compression springs are designed to become shorter when loaded. Their turns (loops) are typically not touching in the unloaded position, and they typically need no attachment points such as those used for tension springs.

A torsion spring is a spring that works by torsion or twisting; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a force (torque) in the opposite direction, proportional to the amount (angle) it is twisted.

Other types of springs that may be used in various implementations of the IOL injectors of the present disclosure include, but are not limited to constant springs, variable springs, variable stiffness springs, flat springs, machined springs, serpentine springs, cantilever springs, hollow tubing springs, volute springs, hairsprings, leaf springs, V-springs, Belleville springs, constant-force springs, mainsprings, negator springs, progressive rate coil springs, rubber bands, spring washers, and wave springs, among others identifiable by persons of ordinary skill in the art.

<FIG>, <FIG> and <FIG> show an example IOL injector <NUM> actuated by an automatic plunger advancement driver. In various implementations, the IOL injector <NUM> includes a injector body <NUM>, including a main injector body <NUM> having a distal end <NUM> and a proximal end <NUM> and a nozzle (not shown) coupled to the distal end <NUM> of the main injector body <NUM>. The injector body <NUM> defines a bore <NUM> extending from a proximal end <NUM> of the injector body <NUM> to a distal end (not shown) of the injector body <NUM>.

The IOL injector <NUM> has a plunger <NUM> adapted to reciprocate through the bore <NUM> formed in the injector body. The plunger <NUM> is received within the bore <NUM> and moveable therein such that the plunger <NUM> is slideable within the bore <NUM>. Particularly, the plunger <NUM> is slideable within bore <NUM> in order to advance an IOL, such as IOL <NUM>, within the injector body <NUM>.

As the plunger <NUM> is displaced distally within bore <NUM> in the direction of an arrow <NUM>, the plunger <NUM> engages and advances an IOL, such as IOL <NUM>, through the IOL injector <NUM> and out of the nozzle (not shown) into the eye.

The IOL injector <NUM> has a proximal portion of the plunger <NUM> concentrically disposed within a cylinder <NUM>. An internal wall <NUM> of the cylinder <NUM> has a cylinder thread <NUM>. A portion of the plunger <NUM> has a threaded cylinder-engaging portion <NUM> having a plunger thread <NUM>. The cylinder thread <NUM> is adapted to engage with the plunger thread <NUM> and allows axial movement of the plunger <NUM> in the direction of arrow <NUM> in response to rotation of the cylinder <NUM> in the direction of arrow <NUM>. The plunger <NUM> is rotationally fixed within the bore <NUM>, such that the plunger <NUM> does not rotate in the direction of the arrow <NUM>, but moves axially in the direction of arrow <NUM> in response to rotation of the cylinder <NUM> in the direction of arrow <NUM>.

The cylinder <NUM> is concentrically disposed with a torsion spring <NUM>. The torsion spring <NUM> contains stored potential rotational energy because the coiled windings of the torsion spring <NUM> are adapted to unwind in absence of a braking force applied to the driving mechanism that includes the torsion spring <NUM>. At least one end of the torsion spring <NUM> is coupled to the cylinder <NUM>. For example, the torsion spring may be coupled to the cylinder <NUM> at a distal end <NUM> and/or a proximal end <NUM> such that a release of the stored energy of the torsion spring <NUM> by unwinding, upon release of a braking force as described below, causes the cylinder <NUM> to rotate, for example in direction <NUM>. In some implementations, one end of the torsion spring may be coupled to the injector body <NUM>.

The IOL injector <NUM> has a braking mechanism adapted to prevent axial movement of the plunger <NUM>. In some implementations, for example as shown in <FIG>, the IOL injector <NUM> has a handle <NUM> rotatably coupled to the main injector body <NUM> at a pivot point <NUM> such that the handle <NUM> is adapted to rotate around the pivot point <NUM> in response to application of a force applied in the direction of an arrow <NUM>. The handle has a distal end <NUM> and a proximal end <NUM>. the proximal end <NUM> of the handle <NUM> is coupled to a proximal end <NUM> of a brake release arm <NUM> of the braking mechanism. A distal end <NUM> of the brake release arm <NUM> is coupled to one or more brake pads <NUM> adapted to contact the plunger <NUM> such that contact of the brake pads with the plunger provides a friction braking force in opposition of movement of the plunger <NUM>. The brake pads <NUM> are axially movably disposed within a brake pad pocket <NUM> having a space formed between the plunger <NUM> and an inner wall <NUM>. The inner wall <NUM> of the brake pad pocket <NUM> is tapered and is narrower a distal end <NUM> of the brake pad pocket <NUM> such that when the brake pads <NUM> are disposed at the distal end <NUM> of the brake pad pocket <NUM>, the brake pad <NUM> is held tightly between the inner wall <NUM> and the plunger <NUM>, providing transverse frictional braking force in the direction of arrow <NUM> toward the plunger <NUM>, thereby preventing axial movement of the plunger <NUM>.

In absence of application of force to the distal end <NUM> of the handle <NUM> in the direction of the arrow <NUM>, the brake pads <NUM> are held at the distal end <NUM> of the brake pad pocket <NUM> in response to axial force applied by one or more compression springs <NUM> coupled between a proximal end of the brake pad <NUM> and the main injector body <NUM>. Accordingly, decompression of the compression springs causes movement of the brake pads <NUM> in the direction of arrow <NUM> toward the distal end <NUM> of the braking pocket <NUM>. In response to application of force in the direction of arrow <NUM> to the distal end <NUM> of the handle <NUM>, the brake release arm <NUM> moves in the direction of arrow <NUM>, compressing the compression spring <NUM> and pulling the brake pads <NUM> toward a proximal end of the braking pocket <NUM>. The inner wall <NUM> at the proximal end of the braking pocket <NUM> tapers away from the plunger <NUM>, such that when the brake pads <NUM> move toward the proximal end of the braking pocket <NUM>, the brake pads <NUM> are not held tightly against the plunger <NUM>, and the transverse frictional braking force is removed from the plunger <NUM>.

Accordingly, is response to application of a force in direction <NUM> to the distal end <NUM> of the handle <NUM>, the compression springs <NUM> are compressed and the braking mechanism is released from the plunger <NUM>, allowing axial movement of the plunger <NUM> in the direction of the arrow <NUM> in response to release of the stored energy of the torsion spring <NUM> and rotation of the cylinder <NUM> in direction <NUM>.

The torsion spring <NUM> is used as the energy source to axially advance plunger <NUM>, which allows for single-handed use by a user. For example, the IOL injector <NUM> is adapted such that the user may hold the IOL injector <NUM> in a pencil grip and depress the distal end of the handle with an index finger. The automatic driving mechanism makes the IOL delivery process more consistent and predictable, while the braking mechanism mitigates against a risk of sudden IOL ejection.

The IOL injector <NUM> of <FIG>, <FIG>, <FIG> and <FIG> can further include an IOL disposed within the hollow portion of the nozzle. When the plunger advances towards the nozzle, the plunger pushes and ejects the IOL out of the nozzle into the eye.

In some implementations, the IOL injector having the automatic driving mechanism can include a hydraulic damping mechanism, for example as shown in an exemplary implementation in <FIG>. In some implementations, the exemplary hydraulic damping mechanism shown in <FIG> may function in a similar manner to the frictional braking mechanism described above and shown in <FIG>, but instead uses control of the flow rate of a hydraulic fluid to control the rate of advancement of the plunger <NUM>. The hydraulic damping mechanism includes a proximal chamber <NUM> having a proximal end <NUM> and a distal end <NUM> and a distal chamber <NUM> having a proximal end <NUM> and a distal end <NUM>. The plunger <NUM> includes a proximal portion <NUM> and a distal portion <NUM>. The proximal portion <NUM> includes a proximal piston <NUM> slidably disposed within the proximal chamber <NUM> and movable from the proximal end <NUM> of the proximal chamber <NUM> to the distal end <NUM> of the proximal chamber <NUM> in response to movement of the threaded cylinder-engaging portion <NUM> of the plunger <NUM> in the direction of arrow <NUM>. The distal end <NUM> of the proximal chamber <NUM> is coupled to an orifice <NUM> fluidically coupling the distal end <NUM> of the proximal chamber <NUM> to the proximal end <NUM> of the distal chamber <NUM> and allowing movement of a hydraulic fluid from the proximal chamber <NUM> to the distal chamber <NUM> in response to movement of the proximal piston <NUM>. The proximal end of the distal portion <NUM> of the plunger <NUM> includes a distal piston <NUM> slidably disposed within the distal chamber <NUM> and movable from the proximal end <NUM> of the distal chamber <NUM> to the distal end <NUM> of the distal chamber <NUM> in response to movement of the fluid.

The fluid may be a mineral oil or other fluid suitable for hydraulic movement as described herein.

In some implementations, an internal diameter of the orifice <NUM> may be from <NUM> to <NUM>.

In some implementations, the orifice may include a one-way valve, such that axial movement of the fluid is in the direction of arrow <NUM>, but not in a reverse axial direction.

In the exemplary implementation shown in <FIG>, the handle <NUM> is coupled between the pivot point <NUM> and the distal end <NUM> to a first end <NUM> of a hydraulic flow barrier <NUM>. A second end <NUM> of the hydraulic flow barrier <NUM> is slidably disposed within the orifice <NUM> such that in absence of a force applied to the handle <NUM> in the direction of arrow <NUM>, the hydraulic flow barrier <NUM> prevents movement of the fluid through the orifice from the proximal chamber <NUM> to the distal chamber <NUM>. The hydraulic flow barrier <NUM> includes a hydraulic flow gate <NUM> forming a passage adapted to allow movement of the fluid through the orifice <NUM> when the hydraulic flow gate <NUM> is disposed in the orifice. In absence of a force applied to the handle <NUM> in the direction of arrow <NUM>, compression springs <NUM> disposed between the handle <NUM> and the orifice <NUM> apply a force in opposition to the direction of the arrow <NUM> and move the hydraulic flow gate <NUM> out of the orifice <NUM>. In response to application of a force to the handle <NUM> in the direction of arrow <NUM>, the hydraulic flow gate <NUM> is moved into the orifice and allows movement of the fluid through the orifice from the proximal chamber <NUM> to the distal chamber <NUM>. Accordingly, in order to actuate axial movement of the plunger <NUM>, a user may depress the handle <NUM> by applying a force in the direction of arrow <NUM>, thereby positioning the hydraulic flow gate <NUM> within the orifice <NUM>, allowing movement of the fluid from the proximal chamber <NUM> to the distal chamber <NUM> in the direction of the arrow <NUM> in response to movement of the torsion spring <NUM> rotating the cylinder in the direction <NUM> and axially moving the proximal portion of the plunger coupled to the cylinder threads via the plunger threads in the direction <NUM>. The hydraulic damping mechanism thereby functions as a hydraulic brake. By depressing the handle <NUM> in the direction of the arrow <NUM>, the user may release the hydraulic brake and allow advancement of the plunger <NUM> in the direction <NUM>. Accordingly, the hydraulic damping mechanism allows a user to control the flow rate of the hydraulic fluid from the proximal chamber <NUM> to the distal chamber <NUM> and thereby control the transfer of rotational energy from the torsion spring <NUM> to axial movement of the plunger <NUM>.

Accordingly, in some implementations, such as the exemplary IOL injectors described above and shown in <FIG>, a driving force to axially move the plunger through the bore of the IOL injector towards the distal end of the IOL injector body to deliver an IOL to an eye may be provided by the release of stored energy from a spring such as a torsion spring. In some implementations, therefore, axial movement of the plunger may be automatically driven by release of stored energy from a spring. Accordingly, in some implementations, plunger advancement may occur in absence of an axial force applied to the plunger by a user. In addition, in some implementations, a braking mechanism may be included in the IOL injector, wherein a user may release application of a braking force on the plunger to allow release of the stored energy from the spring to drive axial movement of the plunger.

In other implementations, such as the exemplary IOL injectors described below and shown for example in <FIG>, a driving force to axially move the plunger through the bore of the IOL injector in a first axial direction toward the distal end of the IOL injector body to deliver an IOL to an eye may be provided by a first manual axial force applied to the plunger by a user and axial movement of the plunger may also be assisted by a second driving force provided by the release of stored energy from a spring. Accordingly, in various implementations, release of stored energy from the spring is adapted to assist axial movement of the plunger by transfer of the stored elastic energy from the spring into kinetic energy of axial movement of the plunger, herein referred to as a spring-assisted driving mechanism. For example, in some implementations, the release of the stored energy of the spring may be implemented by decompression of a compression spring. In other implementations, the release of stored energy of the spring may be implemented by contraction of a tension spring. In various implementations, springs that provide an assistive driving force to move the plunger toward the distal end of the IOL injector may be referred to as assistive springs. The spring-assisted driving mechanism may include one or more assistive springs. The assistive springs may be coupled at a first end of the spring directly or indirectly the plunger, and at a second end of the spring directly or indirectly to the injector body, such that release of the stored elastic energy from the assistive spring assists in driving axial movement of the plunger toward the distal end of the injector body. A non-limiting example described herein of an indirect coupling includes coupling of the spring to a gear, wherein the gear is rotatably coupled to the plunger having a rack adapted to mesh with the gear.

In addition, in some implementations, one or more springs may be included in an IOL injector in a spring damping mechanism adapted to provide a resistive force in an axial direction in opposition to axial movement of the plunger toward the distal end of the IOL injector body. For example, in some implementations, the resistive force may be implemented by compression of a compression spring. In other implementations, the resistive force may be implemented by stretching of a tension spring. Accordingly, in various implementations, the spring damping mechanism may be adapted to provide resistance to or damping of axial movement of the plunger by transferring the kinetic energy of plunger movement into stored elastic energy in the spring. In various implementations, springs that provide a resistive force in a second axial direction opposite to movement of the plunger toward the distal end of the IOL injector may be referred to as resistive springs or damping springs. The spring damping mechanism may include one or more resistive springs or damping springs. The damping springs may be coupled at a first end of the spring directly or indirectly the plunger, and at a second end of the spring directly or indirectly to the injector body, such that axial movement of the plunger toward the distal end of the injector body stores elastic energy in the damping spring. A non-limiting example described herein of an indirect coupling includes coupling of the spring to a gear, wherein the gear is rotatably coupled to the plunger having a rack adapted to mesh with the gear.

Accordingly, in various implementations, one or more assistive and/or resistive springs may be included in an IOL injector to provide a combination of assistive and/or resistive force to respectively assist in driving and/or dampening axial advancement of the plunger toward the distal end of the IOL injector body. In some implementations, the spring assisted driving force may include one or more spring driven gears. The term "spring driven gear" refers to a gear that is adapted to rotate in response to release of stored energy from a spring. Thus, in various implementations, a spring driven gear included in an IOL injector may be an assistive spring driven gear or a damping spring-driven gear. The term "assistive spring-driven gear" refers to a gear that assists in driving axial movement of the plunger toward the distal end of the injector body through release of stored energy from a spring, converting the released energy into rotational movement of the gear, wherein the gear is coupled to the plunger typically through meshing of teeth of the gear with teeth of a rack disposed on the plunger, and adapted to assist in driving axial movement of the plunger. In contrast, the term "damping spring-driven gear" refers to a gear that provides a force in opposition to axial movement of the plunger toward the distal end of the injector body by converting the kinetic energy of axial plunger movement into stored energy in the spring typically. through meshing of teeth of the gear with teeth of the rack disposed on the plunger.

For example, <FIG> is a schematic showing a view of an exemplary implementation of a spring-driven gear that may be used in various implementations in the IOL injector. <FIG> shows an IOL injector <NUM> having an injector body <NUM> defining a bore <NUM> and a plunger <NUM> adapted to reciprocate through the bore <NUM> and moveable therein such that the plunger <NUM> is slideable within the bore <NUM>. The plunger <NUM> includes a rack <NUM> disposed thereon including a plurality of teeth that are configured to mesh with teeth of the first gear <NUM> so that the plunger <NUM> is axially movable in response to rotation of the first gear <NUM>. The first gear <NUM> is fixedly coupled to a shaft <NUM> that is rotatably coupled to the injector body <NUM>. The first gear <NUM> is configured to rotate in the direction of an arrow <NUM> in response to contraction of a spring having stored elastic energy. For example, an exemplary spring shown in <FIG> is an elastic band such as a rubber band <NUM> wound up around the shaft <NUM> at a first end and coupled to the injector body <NUM> at a second end <NUM>. For example, as shown in <FIG>, release of the stored elastic energy in the rubber band <NUM>, by unwinding of the rubber band <NUM> around the shaft <NUM>, causes the first gear <NUM> to rotate in the direction of arrow <NUM>, and the plunger to move in response in the direction of the arrow <NUM> toward distal end <NUM> of the injector body. In contrast, movement of the plunger <NUM> in an axial direction opposite to the arrow <NUM> would cause the first gear <NUM> to rotate in the opposite direction to the arrow <NUM>, thereby winding up the rubber band <NUM> around the shaft <NUM> and thereby causing the kinetic energy of the plunger <NUM> movement to be stored as elastic energy in the rubber band <NUM>, wherein the rubber band would be providing a resistive force against axial movement of the plunger <NUM>. In some implementations, a spring-driven gear may be configured to sequentially function both as an assistive spring-driven gear and as a damping spring-driven gear.

<FIG> shows a cross-sectional view of an exemplary IOL injector <NUM> having an assistive spring driven gear and a damping spring driven gear. The IOL injector <NUM> includes an injector body <NUM> having a bore <NUM> defined by an interior wall <NUM> of the injector body <NUM>. The exemplary IOL injector <NUM> may have one or more assistive spring-driven gears adapted to transfer release of stored energy from a spring into axial movement of the plunger. For example, within the bore <NUM>, a first gear <NUM> is disposed on the interior wall <NUM> of the injector body <NUM> at a proximal end <NUM> of the injector body <NUM>. The first gear <NUM> may be an assistive spring-driven gear. Accordingly, for example, the first gear <NUM> may be coupled to a spring having stored elastic energy, wherein the first gear <NUM> is adapted to rotate in response to release of the stored elastic energy from the coupled spring. The IOL injector <NUM> has a plunger <NUM> movable within the bore <NUM> of the injector body <NUM> in a first direction indicated by arrow <NUM> toward the distal end <NUM> of the injector body <NUM> in response to an axial force applied to the proximal end <NUM> of the plunger <NUM>. The plunger <NUM> includes a rack <NUM> disposed thereon including a plurality of teeth that are configured to mesh with teeth of the first gear <NUM>, wherein the plunger <NUM> is axially movable in response to rotation of the first gear <NUM>.

Application of force by a user to the proximal end <NUM> of the plunger <NUM> to advance the plunger <NUM> through the bore <NUM> towards a distal end <NUM> of the injector body <NUM> may be assisted by release of the stored elastic energy from the spring coupled to the first gear <NUM>, thereby assisting advancement of the plunger <NUM> through the bore <NUM>.

In some implementations, the IOL injector may include a second spring-driven gear <NUM>.

In <FIG>, the first gear <NUM> and the second gear <NUM> are shown such that the axis of rotation of the first gear <NUM> and the second gear <NUM> are indicated by arrows <NUM> and <NUM>, respectively.

In some implementations, the second spring-driven gear <NUM> may be configured as a resistive spring-driven gear. Accordingly, in some implementations, the second gear <NUM> may be coupled to a spring having little or no stored elastic energy prior to engagement of the second gear <NUM> with the rack <NUM> of the plunger <NUM>. Upon continued application of axial force by the user to the plunger <NUM> in the direction of the arrow <NUM>, the rack <NUM> is configured to mesh with the teeth of the second gear <NUM> and cause the second gear to rotate. In response to rotation of the second gear <NUM>, elastic energy is stored in the spring coupled to the second gear <NUM>. The transfer of the kinetic energy of the plunger <NUM> movement into stored elastic energy by the second gear <NUM> provides a resistive force to axial movement of the plunger <NUM>.

In some implementations, the first and second gears <NUM>, <NUM> can be rotational spring driven gears. In some implementations, one or more of the gears can be replaced by helical springs, for example as described in the exemplary implementations shown in <FIG> below.

In some implementations, the second gear <NUM> can be replaced by a syringe-type damper adapted to provide frictional resistance against axial movement of the plunger <NUM>.

Accordingly, in some implementations, an IOL injector may include one or more spring-driven gears that provide an assistive axial force and/or a resistive axial force in relation to axial plunger movement. For example, in some implementations, as shown in <FIG>, the first gear <NUM> may be configured to provide a reduction in force required to be applied by a user to advance an IOL through the injector <NUM>. In some implementations, the second gear <NUM> may be configured to mitigate against a sudden drop in the force experienced by the user upon ejection of the IOL from the injector <NUM>. Therefore, in various implementations, one or more spring-driven gears included in an IOL injector may provide a consistent and smooth axial driving force to assist a user in advancing an IOL through the IOL injector, while the damping function decreases the risk of sudden ejection of the IOL, and provides higher reliability for the user.

Accordingly, in some implementations, upon application of an axial force by a user to the plunger to advance the plunger toward the distal end of the injector body, the rack engages the first gear and the first gear applies a force to assist further advancement of the plunger through the bore. In addition, in some implementations, upon application of further axial force by a user to the plunger to advance the plunger toward the distal end of the injector body, the rack engages the second gear and the second gear applies a force to resist further advancement of the plunger through the bore.

In some implementations, the first gear <NUM> and the second gear <NUM> may be respectively coupled to springs having different elastic or other mechanical properties. For example, in some implementations, the spring coupled to the first gear <NUM> may have a greater force of elastic energy release than the spring coupled to the second gear <NUM>. For example, the spring coupled to the first gear <NUM> may have, or have about, <NUM> times the force of the spring coupled to the second gear <NUM>. In some implementations, the spring coupled to the first gear <NUM> may have, or have about, <NUM>, <NUM>, <NUM>, or <NUM> times the force of the spring coupled to the second gear <NUM>.

<FIG> is a schematic showing a cross-sectional view of another exemplary IOL injector <NUM> having a helical spring assisted axial drive force. The exemplary IOL injector <NUM> includes an injector body <NUM> with a bore <NUM> defined by an interior wall <NUM>, and a distal end <NUM> and a proximal end <NUM>. At least one stop <NUM> is disposed on the distal end <NUM> of the interior wall <NUM>, each stop <NUM> having a pin <NUM> that projects into the bore <NUM>.

A first helical spring <NUM> is disposed within the interior wall <NUM> of the IOL injector <NUM>, and a second helical spring <NUM> disposed within the first helical spring <NUM>.

The IOL injector <NUM> includes a plunger <NUM> movable within the bore <NUM> in response to an axial force applied to the plunger <NUM> such that the plunger <NUM> is slideable within the bore <NUM>, the plunger <NUM> having a distal end <NUM> and a proximal end <NUM>. A user can apply axial force to the proximal end <NUM> of the plunger <NUM> to advance the plunger through the injector body <NUM>, as shown by direction <NUM>.

In an exemplary implementation shown in <FIG>, the plunger <NUM> is disposed within the second spring <NUM>, and the second spring is disposed within a sheath <NUM>. For example, the sheath <NUM> may be a cylinder sized to be disposed within the inner wall <NUM> of the injector body <NUM> and surrounding a portion of the plunger <NUM>. A portion of the bore <NUM> is defined within the sheath <NUM> allowing the plunger <NUM> to move slideably within the sheath <NUM>. A proximal end <NUM> of the second spring <NUM> is coupled to the plunger <NUM>. A distal end <NUM> of the second spring <NUM> is coupled to the sheath <NUM>. In some implementations, the second helical spring <NUM> may be an assistive spring. For example, the second helical spring <NUM> may be a tension spring having stored elastic energy that is released upon contraction of the tension spring. For example, as shown in <FIG>, when the second spring <NUM> is a tension spring, the plunger <NUM> is adapted to move in direction <NUM> in response to contraction of the second spring <NUM>.

The sheath is slideably movable in the bore <NUM> between the stops <NUM> in response to axial force applied to the plunger <NUM> in direction <NUM>. In particular, in some implementations, the sheath is slideably movable in the bore <NUM> between the stops <NUM> in upon full compression of the second spring <NUM> and in response to further axial force applied to the plunger <NUM> in direction <NUM>. Accordingly, the second spring <NUM> is coupled at the proximal end of the second spring to the plunger <NUM> and coupled indirectly at the distal end of the second spring <NUM> to the injector body <NUM>.

In some implementations, the first spring <NUM> may be a resistive spring. For example, in <FIG>, the sheath <NUM> is disposed within the first spring <NUM>. A proximal end <NUM> of the first spring <NUM> is coupled to the sheath <NUM>. A distal end <NUM> of the first spring <NUM> is coupled to the stops <NUM>. Accordingly, the first spring <NUM> is coupled indirectly at the proximal end of the first spring <NUM> to the plunger <NUM> and coupled indirectly at the distal end of the first spring <NUM> to the injector body <NUM>. In some implementations, for example, the first helical spring <NUM> may be a compression spring adapted to store elastic energy upon compression of the compression spring. For example, as shown in <FIG>, when the first spring <NUM> is a compression spring, the first spring is adapted to compress in response to axial movement of the plunger <NUM> in direction <NUM>. Accordingly, compression of the first spring provides a damping resistive force in the direction of arrow <NUM> against axial movement of the plunger in direction <NUM>. In particular, in some implementations, as shown in <FIG>, while the sheath <NUM> slideably moves through the bore <NUM> between the stops <NUM>, the first spring <NUM> may compress, providing a resistive damping force against axial movement of the sheath <NUM> and the plunger <NUM>.

Accordingly, the second helical spring <NUM> provides a reduction in the peak force necessary for the user to advance the IOL through the injector <NUM>. The first helical spring <NUM> may be configured to provide a damping force to reduce the probability of a sudden drop in the force experienced by the user upon ejection of the IOL from the injector <NUM>.

<FIG> are schematics of another example of an IOL injector that includes an assistive spring and a damping spring. The exemplary IOL injector <NUM> includes an injector body <NUM> having a bore <NUM> defined by an interior wall <NUM> of the injector body <NUM>. The injector body <NUM> has a distal end <NUM> and a proximal end <NUM>. A nozzle <NUM> is disposed at the distal end <NUM> of the injector body <NUM>.

The IOL injector <NUM> further includes a plunger <NUM>, having a distal end with a plunger tip <NUM> and a proximal end <NUM>. The plunger <NUM> is received within the bore <NUM> and is moveable therein such that the plunger <NUM> is slideable within the bore <NUM> in response to an axial force applied to the distal end <NUM>, as shown by direction <NUM>.

A first helical spring <NUM> is disposed within the bore <NUM> near the proximal end <NUM>. In some implementations, the first helical spring <NUM> is an assistive spring. For example, the first helical spring <NUM> may be a compression spring. In some implementations, in an initial configuration, the first helical spring is a compression spring that is compressed to, or to about, <NUM>-<NUM>% of its resting length in a resting position. For example, as shown in <FIG>, a distal end <NUM> of the first helical spring <NUM> is coupled to the plunger <NUM>. A proximal end <NUM> of the first helical spring <NUM> is coupled to the proximal end <NUM> of the injector body <NUM>. In some implementations, the proximal end <NUM> of the first helical spring <NUM> may be coupled to a proximal portion of the injector body <NUM>, for example at a location adjacent to the proximal end <NUM> of the injector body <NUM>. In some implementations, the distal end <NUM> of the first helical spring <NUM> is also coupled to a first contact tab <NUM> adapted to contact a first removable stop <NUM> disposed within the bore <NUM> when the IOL injector is in a first configuration. In other implementations, the first contact tab <NUM> may be absent and the distal end <NUM> of the first helical spring <NUM> may be adapted to contact the first removable stop <NUM> directly. In the first configuration, for example as shown in <FIG>, the first contact tab <NUM> is in contact with the first stop <NUM>, which maintains the first helical spring <NUM> in a relatively compressed state having stored elastic energy. As shown in <FIG>, in a second configuration, in response to removal of the first stop <NUM>, the first helical spring <NUM> is configured to expand, typically to, or to about, <NUM>% of the resting length of the first helical spring in its resting position, thereby assisting movement of the plunger in the direction of arrow <NUM>. The first helical spring <NUM> is adapted to expand until the first contact tab <NUM> contacts a second removable stop <NUM> disposed within the bore <NUM>. In some implementations, the plunger tip <NUM> may be proximally adjacent to an IOL dwell position <NUM> when the first contact tab <NUM> is in contact with the second removable stop <NUM>. In some implementations, the first contact tab <NUM> may be adapted to slide axially within a channel <NUM> disposed within the injector body <NUM>.

Accordingly, in some implementations, the first helical spring <NUM> provides an assistive force to the axial motion of the plunger in the direction <NUM> after the first stop is removed.

In some implementations, a second helical spring <NUM> may be disposed within the bore <NUM> near the distal end <NUM> of the injector body <NUM>. A distal end <NUM> of the second helical spring <NUM> is coupled to the injector body <NUM> adjacent to the distal end <NUM> of the injector body <NUM>, for example at a location adjacent to the distal end of the main injector body. A proximal end <NUM> of the second helical spring <NUM> is coupled to a second contact tab <NUM> adapted to contact the second removable stop <NUM>. In other implementations, the second contact tab <NUM> may be absent and the proximal end <NUM> of the first helical spring <NUM> may be adapted to contact the second removable stop <NUM> directly. In the second configuration, for example as shown in <FIG>, the second contact tab <NUM> may be in contact with the second stop <NUM>, which in some implementations may maintains the second helical spring <NUM> in a relatively uncompressed state, or resting position, having little or no stored elastic energy. In some implementations, the second contact tab <NUM> may be adapted to slide axially within the channel <NUM> disposed within the injector body <NUM>.

In a third configuration, the second removable stop <NUM> may be removed to allow the plunger <NUM> to be further advanced axially in the direction <NUM> such that the plunger tip <NUM> moves from a location proximally adjacent to the IOL dwell position <NUM> to the distal end <NUM> of the injector body <NUM>, thereby ejecting an IOL <NUM> into an eye. In the third configuration, when the second removable stop <NUM> is removed from the injector body <NUM>, the first contact tab <NUM> and the second contact tab <NUM> are adapted to contact each other as shown in <FIG>, or if the tabs are absent, the first helical spring and the second helical spring may contact each other. Accordingly, during axial movement of the plunger tip <NUM> from the location proximally adjacent to the IOL dwell position to the distal end <NUM> of the injector body <NUM>, the first helical spring <NUM> and the second helical spring <NUM> act against each other, with the first helical spring <NUM> extending its final approximately <NUM>% to full extension. At the same time, the second helical spring <NUM> is compressed from a relatively uncompressed state or resting position to a compressed state. In particular, when the plunger tip <NUM> is advancing the IOL out of the nozzle <NUM>, the second helical spring <NUM> is adapted to be near its maximum compression to ensure the user is now pushing against it to express the IOL at the nozzle exit. The damping force provided by the second helical spring has the advantage of decreasing the probability of sudden ejection of the IOL.

Claim 1:
An intraocular lens (IOL) injector, comprising:
an injector body (<NUM>) having a proximal end and a distal end including
a main injector body having a distal end and a proximal end;
a nozzle coupled to the distal end of the main injector body; and
a bore extending from the proximal end of the injector body to the distal end of the injector body; and
a plunger (<NUM>) having a proximal portion and a distal portion, the plunger slideably disposed within the bore and adapted to advance an IOL along a longitudinal axis of the IOL injector; characterised in that the injector is further provided with
an automatic plunger advancement driver having:
a cylinder (<NUM>) concentrically disposed around the proximal portion of the plunger, the cylinder having a thread adapted to rotatably engage with a plunger thread in the proximal portion of the plunger; and
a torsion spring (<NUM>) having stored rotational energy, the torsion spring concentrically disposed around the cylinder,
wherein at least one end of the torsion spring is coupled to the cylinder such that in response to a release of the stored rotational energy, the cylinder is configured to rotate around the longitudinal axis and the plunger moves axially toward the distal end of the injector body;
further comprising:
a hydraulic damping mechanism including:
a proximal chamber (<NUM>) having approximal end (<NUM>) and a distal end; (<NUM>);
a distal chamber (<NUM>) having a proximal end (<NUM>) and a distal end; (<NUM>);
an orifice (<NUM>) fluidically coupling the proximal chamber to the distal chamber; and
a braking mechanism configured to prevent axial movement of the plunger, including:
a handle (<NUM>) having a proximal end and a distal end and rotatably coupled to the injector body at a pivot point (<NUM>) disposed between the proximal end and the distal end of the handle in response to a force applied to the handle;
a hydraulic flow barrier (<NUM>) having a first end coupled to the handle and a second end slideably disposed within the orifice and adapted to prevent movement of the fluid through the orifice from the proximal chamber to the distal chamber in absence of a force applied to the handle.