DESC:FIELD OF THE INVENTION
The present invention relates generally to ophthalmic instruments, particularly to Phaco emulsification system. More particularly, the present invention relates to light weight orbital Phaco hand piece to provide efficient cutting in hard grade cataracts.

BACKGROUND OF THE INVENTION
The human eye is divided into anterior and posterior chambers by a normal transparent lens. The transparent lens focuses light onto the retina defined on the rear surface of the posterior chamber. The transparent lens of the eye may become cloudy for any of the reasons and leads to a decrease in vision. When this happens, sight is impaired leading to the removal of the cloudy lens material. A number of medically recognized techniques are utilized for cataract lens removal that include Phaco emulsification, mechanical cutting or destruction, laser treatments, and water jet treatments. The function of the lens is then performed with an intraocular lens (IOL) implant or by using thick glasses or contact lenses.

US3857387 relates to ultrasonic instrumentation for the removal of cataracts, in surgical operations. The ultrasonic instrumentation includes a hand-held instrument adapted to have a vibrating tool to reduce the volume of the cataract.

US20120065578 discloses ophthalmic surgical hand piece that has a horn and two transducers with two different modes (longitudinal and torsional) to produce two different needle motions.

US20090082716 relates to linear-to-torsional converter that changes the linear motion imparted by a phaco handpiece to torsional or rotational motion.

US20090005712 discloses method and system for controlling an ultrasonically driven handpiece employable in an ocular surgical procedure.

WO2011112582 relates to a phaco emulsification handpiece, comprising a needle and a micro electromechanical system (MEMS) device, wherein the needle is coupled with the MEMS device. The MEMS device is capable of generating movement of the needle in at least one direction, wherein at least one direction is selected from the group consisting of transversal, torsional, and longitudinal.

Further, conventional Phaco emulsification system includes a Phaco emulsification hand piece coupled to an irrigation source and an aspiration pump. The hand piece includes a distal tip that emits ultrasonic energy to emulsify the cataract lens within the patient's eye. However, contemporary hand piece uses an external line for irrigation which causes the hand piece to become less ergonomic.

Further, in a traditional Phaco emulsification system, the applied electric power has a signal frequency that causes crystal, horn and needle assembly in the system to vibrate at a mechanically resonant frequency. This causes the needle to vibrate in the longitudinal direction with a maximum range of motion, which many consider to be the state where the needle's cutting efficiency is at its maximum. There are also systems that enable the distal end of the needle to ultrasonically vibrate in a direction that is transverse of the longitudinal axis of the hand piece, in the x and y direction, which provides follow ability but less than optimum cutting efficiency. However, there are a couple of known drawbacks. First, at this frequency, maximum power is applied to the needle that results in maximum heat introduced into the eye, which can cause undesirable burning of eye tissue. Second, the longitudinal motion can cause the material being emulsified to repel away from the needle, which is disagreeable when the goal is to keep the material close to the needle to be aspirated. There are further systems that enable the distal end of the needle to alternate between one type of direction and another by alternating between two different pulses of energy applied to the hand piece, each pulse having different signal frequencies.

Also, traditional Phaco emulsification hand piece have 4 or more crystals to allow the needle to handle more loads for a hard cataract. Increasing the ultrasound power typically increases the excursion of the needle but not the frequency which usually remains stable. With increasing load, such as a very hard cataract, the frequency and excursion may not keep up.

Accordingly, there exists a need for Phaco emulsification system with light weight orbital Phaco hand piece to overcome the above-mentioned drawbacks.

OBJECTS OF THE INVENTION
One or more of the problems of the conventional prior art may be overcome by various embodiments of the system of the present invention.

It is the primary object of the present invention to provide a light weight Phaco hand piece for efficient cutting and removing of hard grade cataracts when compared to existing systems.

It is another object of the present invention, wherein the Phaco hand piece provides cutting motion in longitudinal and orbital directions simultaneously.

It is another object of the present invention, wherein the cutting motion in longitudinal and orbital directions is achieved mechanically by asymmetrically distributing the mass in horn of the hand piece.

It is another object of the present invention, wherein the asymmetrical distribution of the mass is achieved by a geometrical cut in the horn.

It is another object of the present invention, wherein the orbital motion is approximately 25% of the longitudinal motion.

It is another object of the present invention, wherein irrigation and aspiration lines run through the centre of the orbital Phaco hand piece coaxially to become less weight and to reduce the heat in Piezo ceramic stack enclosed in the hand piece.

It is another object of the present invention, wherein the orbital hand piece is more efficient than other hand pieces as it reduces the losses between joints in the Piezo ceramic stack.

It is another object of the present invention, wherein distal end of needle in the Phaco hand piece is enabled to move in both the longitudinal and orbital/transversal directions within a single pulse of energy or from power applied to the hand piece having a single effective operating frequency to achieve follow ability and efficient cutting.

SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention, there is provided a Phaco emulsification system, comprising of Phaco hand piece with its needle coupled to an irrigation source and an aspiration pump,
wherein the hand piece includes an irrigation port proximal to distal tip, which is coupled to the irrigation source via an irrigation line; and an aspiration port at the distal tip, which is coupled to the aspiration pump via an aspiration line,
wherein proximal end of the needle is coupled to a horn, which has its proximal end coupled to one or more sets of piezoelectric crystals,
wherein the horn is provided with a geometrical cut which is capable of generating cutting motion in both longitudinal oscillation and transversal oscillation simultaneously,
wherein said cutting motion in longitudinal and transversal directions simultaneously is achieved mechanically by asymmetrically distributing the mass in the horn, and
wherein the irrigation line and aspiration line runs through the center of the hand piece coaxially to become less weight and provide more efficient cooling to piezo ceramic stack, so that the endothelial cell damage is significantly reduced.

It is another aspect of the present invention, wherein the distal end of the needle in the Phaco hand piece is enabled to move in both the longitudinal and transversal directions within a single pulse of energy or from power applied to the hand piece having a single effective operating frequency to achieve follow ability and efficient cutting.

It is another aspect of the present invention, wherein the needle is ultrasonically vibrated by applying electric power to the piezoelectric crystals, which in turn, cause the horn to ultrasonically vibrate, which in turn, ultrasonically vibrates the needle.

It is another aspect of the present invention, wherein since the power is applied in pulses, where little or no power is applied in between the pulses, the total amount of power and heat applied to the needle is reduced thereby eliminating the undesirable burning of eye tissue.

It is another aspect of the present invention, wherein the transversal motion is approximately 25% of the longitudinal motion.

It is another aspect of the present invention, wherein the Phaco hand piece reduces the losses between joints in the Piezo ceramic stack and hence is more efficient than other hand pieces.

BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1: illustrates Phaco emulsification system according to present invention.
Figure 2: illustrates Phaco emulsification system with control panel and switching unit according to present invention.
Figure 3a: illustrates Phaco hand piece according to present invention.
Figure 3b: illustrates sectional view A-A of Figure 3a according to present invention.
Figure 4: illustrates detailed section C of Figure 3b according to present invention.
Figure 5: illustrates horn according to present invention.
Figure 6: illustrates Phaco hand piece according to present invention.
Figure 7: illustrates Phaco emulsification needle according to present invention.
Figure 8: illustrates switching unit of the Phaco emulsification system according to present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING FIGURES
The present invention as herein described relates to a Phaco emulsification system with light weight orbital Phaco hand piece. Advantageously, the Phaco hand piece is lighter and smaller than existing hand pieces because 90% of the metallic components are made from high grade Titanium alloy.

Referring to Figure 1, the Phaco emulsification system comprising of Phaco emulsification hand piece [1] coupled to an irrigation source [2] and an aspiration pump [3]. The hand piece [1] includes a distal tip [1a'] that emits ultrasonic energy to emulsify the cataract lens within the patient's eye. The hand piece [1] further includes an irrigation port [1b] proximal to the distal tip [1a'], which is coupled to the irrigation source [2] via an irrigation line [2a], and an aspiration port [1c] at the distal tip [1a'], which is coupled to the aspiration pump [3] via an aspiration line [3a]. Along with the emulsification, fluid from the irrigation source [2], which is typically an elevated bottle of saline solution, is irrigated into the eye via the irrigation line [2a] and the irrigation port [1b], and the irrigation fluid and emulsified cataract lens material are aspirated from the eye by the aspiration pump [3] via the aspiration port [1c] and the aspiration line [3a]. Figure 2 illustrates the Phaco emulsification system with control panel and switching unit.

Referring to Figures 3a, 3b, and 6, the Phaco hand piece [1] includes a needle [1a] that is operatively coupled to the aspiration pump [3], forming an aspiration line [3a]. The needle [1a] includes distal tip [1a'], a needle base [1a''] and a needle interface/adapter [1a'''] as shown in Figure 7, to couple the needle [1a] with the horn [1d]. The proximal end of the needle [1a] is coupled to the horn [1d], which has its proximal end coupled to one or more sets of piezoelectric crystals [1e]. The horn [1d], piezoelectric crystals [1e] and proximal portion of the needle [1a] are enclosed within a hand piece casing [1f] having the irrigation port [1b] coupled to the irrigation line [2a] defining an irrigation pathway [1g]. The Phaco hand piece further includes hypo tube [1h]; slotted bias [i]; rear mass [1j] and O ring [1k] positioned in the horn [1d] as shown in Figures 3b and 4. The irrigation line [2a] is coupled to the irrigation source [2]. In an aspect, the horn is typically an integrated metal, such as titanium. The irrigation and aspiration line [2a and 3a] runs through the center of the hand piece [1] coaxially to become less weight and provide more efficient cooling to the piezo ceramic stack, so that the endothelial cell damage is significantly reduced. The hand piece offers cutting motion in longitudinal and orbital/transversal directions simultaneously which is achieved mechanically by asymmetrically distributing the mass in the horn [1d], said horn [1d] is provided with a geometrical cut [1d'] as shown in Figure 5, which is capable of generating cutting of the human eye cataract by bi-directional motion that is by longitudinal oscillation and transversal oscillation simultaneously. The orbital motion is approximately 25% of the longitudinal motion. Further, the hand piece is more efficient than other hand pieces as it reduces the losses between joints in the Piezo ceramic stack. Also, the torqueing process during assembly of the Phaco hand piece ensures consistent and repeatable performance. Further, the Phaco hand piece includes a male threaded luer fitting [5] and female threaded luer fitting [6].

Figure 8 illustrates the switching unit with one or more switches [A, B, C, D] coupled to control vibrations, power during operation. The switching unit further includes a foot pedal [8] pivotally mounted to a base to provide control signals for hand piece operation.

For illustration:
In preparation for operation, a sleeve [4] is typically added to the distal end [1a'] of the hand piece [1], covering the proximal portion of the needle [1a] thus, exposing the distal tip of the needle, and the distal end of the irrigation pathway [1g], thereby extending the pathway and defining the irrigation port [1b] just before the distal tip of the needle. The needle and a portion of the sleeve are then inserted through the cornea of the eye to reach the cataract lens. During operation, the irrigation path, the eye's chamber and the aspiration line form a fluidic circuit, where irrigation fluid enters the eye's chamber via the irrigation path, and is then aspirated through the aspiration line [3a] along with other materials that the surgeon desires to aspirate out, such as the cataract lens. If, however, the materials, such as the cataract lens, are too hard and massive to be aspirated through the aspiration line [3a], then the distal end of the needle is ultrasonically vibrated and applied to the material to be emulsified into a size and state that can be successfully aspirated. The needle is ultrasonically vibrated by applying electric power to the piezoelectric crystals [1e], which in turn, cause the horn [1d] to ultrasonically vibrate, which in turn, ultrasonically vibrates the needle. The electric power is defined by a number of parameters that include signal frequency and amplitude, and if the power is applied in pulses, then parameters can further include pulse width, shape, size, duty cycle, and amplitude.

The ultrasound power used to emulsify the lens originates from the longitudinal movement of the needle, with the tip of the hand piece moving at a high frequency in an advancing and retreating motion. The ultrasound hand piece vibrates the needle at a particular frequency range between 28,000 to 40,000 HZ. The ultrasound mode can produce a repulsion effect, because the Phaco tip pushes the nucleus away with each stroke as it advances. As a result, the ultrasonic impact upon the lens fragments can be interrupted and efficacy compromised. Since the power is applied in pulses, where little or no power is applied in between the pulses, the total amount of power and heat applied to the needle is reduced thereby eliminating the undesirable burning of eye tissue. Since the longitudinal motion can cause the material being emulsified to repel away from the needle, which is disagreeable when the goal is to keep the material close to the needle to be aspirated, in the hand piece of the present invention, the power is applied to the hand piece to cause the needle to vibrate in the orbital direction. When the power is applied, the hand piece offers cutting motion in longitudinal and orbital/transversal directions simultaneously which is achieved mechanically by asymmetrically distributing the mass in the horn. The orbital motion is approximately 25% of the longitudinal motion.

The Phaco hand piece of the present invention can individually or collectively enable both orbital and longitudinal ultrasonic vibration in two aspects namely:
The structure of the hand piece including the needle and the horn.
The hand piece centre of mass relative to its longitudinal axis, and the structure of the hand piece at the nodes and anti-nodes of the hand piece.
,CLAIMS:WE CLAIM:
1. A Phaco emulsification system, comprising of Phaco hand piece [1] with its needle [1a] coupled to an irrigation source [2] and an aspiration pump [3],
wherein the hand piece [1] includes an irrigation port [1b] proximal to distal tip [1a'], which is coupled to the irrigation source [2] via an irrigation line [2a]; and an aspiration port [1c] at the distal tip [1a’], which is coupled to the aspiration pump [3] via an aspiration line [3a],
wherein proximal end of the needle [1a] is coupled to a horn [1d], which has its proximal end coupled to one or more sets of piezoelectric crystals [1e],
wherein the horn [1d] is provided with a geometrical cut [1d'] which is capable of generating cutting motion in both longitudinal oscillation and transversal oscillation simultaneously,
wherein said cutting motion in longitudinal and transversal directions simultaneously is achieved mechanically by asymmetrically distributing the mass in the horn [1d], and
wherein the irrigation line and aspiration line [2a and 3a] runs through the center of the hand piece [1] coaxially to become less weight and provide more efficient cooling to piezo ceramic stack, so that the endothelial cell damage is significantly reduced.

2. The Phaco emulsification system as claimed in claim 1, wherein the distal end [1a'] of the needle [1a] in the Phaco hand piece [1] is enabled to move in both the longitudinal and transversal directions within a single pulse of energy or from power applied to the hand piece having a single effective operating frequency to achieve follow ability and efficient cutting.

3. The Phaco emulsification system as claimed in claim 2, wherein the needle [1a] is ultrasonically vibrated by applying electric power to the piezoelectric crystals [1e], which in turn, cause the horn [1d] to ultrasonically vibrate, which in turn, ultrasonically vibrates the needle.

4. The Phaco emulsification system as claimed in claim 3, wherein since the power is applied in pulses, where little or no power is applied in between the pulses, the total amount of power and heat applied to the needle [1a] is reduced thereby eliminating the undesirable burning of eye tissue.

5. The Phaco emulsification system as claimed in claim 1, wherein the transversal motion is approximately 25% of the longitudinal motion.

6. The Phaco emulsification system as claimed in claim 1, wherein the Phaco hand piece [1] reduces the losses between joints in the Piezo ceramic stack and hence is more efficient than other hand pieces.