Patent Description:
Patient interfaces comprising an upper assembly and a lower assembly are known for example from <CIT> or <CIT>.

One aspect of the present disclosure regards a patient interface device for use with a laser surgery apparatus, the device including an upper assembly and a lower assembly attached to the upper assembly, wherein the upper assembly and the lower assembly define a volume of space. The lower assembly includes a portion that extends toward the volume of space and a suction enhancer that faces the portion and is positioned further from a centroid of the volume of space than the portion. The device further including a vacuum port formed in the lower assembly, wherein the vacuum port defines an opening that is in fluid communication with a vacuum source and the volume of space. In addition, at the vacuum port, the portion and the suction enhancer contact each other along a linear area.

A second aspect of the present disclosure regards patient interface system for use with a laser surgery apparatus, the device including an upper assembly and a lower assembly attached to the upper assembly, wherein the upper assembly and the lower assembly define a volume of space. The lower assembly includes a portion that extends toward the volume of space and a suction enhancer that faces the portion and is positioned further from a centroid of the volume of space than the portion. The system further including a vacuum port formed in the lower assembly, wherein the vacuum port defines an opening that is in fluid communication with a vacuum source and the volume of space. In addition, at the vacuum port, the portion and the suction enhancer contact each other along a linear area. The system further including a spherical-like object that engages the lower assembly and the portion so that an enclosed volume is defined between the spherical-like object, the portion and the lower assembly that contains a gas, wherein the vacuum port is in fluid communication with the enclosed volume and the vacuum source removes the gas from the enclosed volume.

A third aspect of the present disclosure regards a patient interface device for use with a laser surgery apparatus, the device including an upper assembly and a lower assembly attached to the upper assembly. The device including a spherical-like object that engages the lower assembly so that an enclosed volume is defined between the spherical-like object, the lower assembly and the upper assembly, wherein a first liquid substantially fills the enclosed volume. The device further including a channel that contains a second fluid that is exposed to ambient atmosphere. In <CIT> it is seen an example of prior art describing a self-adjusting interface device for use with laser surgery devices.

An embodiment of a patient interface device <NUM> for the use in the performance of ophthalmic laser surgery is shown in <FIG>. In particular, the patient interface device <NUM> includes a distal or bottom end <NUM>, which engages an eye <NUM>, and a proximal or top end <NUM>, which is disposed toward a laser apparatus (not shown). The device <NUM> has a ring shaped structure <NUM> that includes an outer structure <NUM><NUM>, an inner structure <NUM><NUM>, and a glass plate <NUM><NUM>. The outer structure <NUM> has an inner surface <NUM> and an outer surface <NUM>.

As shown in <FIG>, the device <NUM> is placed on an eye <NUM>. The relative size and position of the device <NUM> on the eye <NUM> is shown with respect to the lens <NUM><NUM>, iris <NUM><NUM>, sclera <NUM>, and cornea <NUM>.

A fluid reservoir <NUM> is formed by the bottom <NUM> of the glass plate <NUM><NUM> and the inner surface(s) of the ring structure(s). The components of the reservoir <NUM> are connected together in a manner that is fluid tight. The reservoir <NUM> is then held in place on the eye <NUM>, and rendered fluid tight with the eye <NUM>, while maintained on the eye <NUM> in the orientation shown in <FIG>, by suction that is applied to one or more vacuum chambers.

The reservoir <NUM>, when positioned on the eye <NUM> and after suction has been applied, can be filled with a fluid having a known index of refraction and thus the index of refraction can be set to match and/or approximate the index of refraction of the glass plate <NUM><NUM> to the index of refraction of the cornea <NUM>.

In operation, a vacuum is formed between device <NUM> and the surface of the eye <NUM> by a vacuum source (not shown) that is in communication with a suction entry port <NUM>. The vacuum formed can be so significant as to lift a portion <NUM> of the conjunctival membrane of the eye <NUM> into the suction entry port <NUM>. The lifted portion <NUM> clogs the suction entry port <NUM>, which in turn reduces the vacuum in the vacuum chamber. Such a reduction in vacuum in the vacuum chamber can have adverse effects. For example, proximal to the clog, fluid may drain from the reservoir and air may enter in via channel <NUM> causing undesirable bubbles to form in the reservoir, which may interfere with the laser beam. Besides the above mentioned draining of fluid, the fluid leaves channel <NUM> due to capillary action, water adhesion and water cohesion when channel <NUM> is in contact with an eyelid or cheek skin tissue.

An embodiment of a liquid holding interface device for use in the performance of ophthalmic laser surgery is shown in <FIG>. The device <NUM> includes an arm <NUM> that has an upper end <NUM> that connects to the laser device (not shown in the figures) and a lower end <NUM> that includes a ring <NUM>. The arm <NUM> and ring <NUM> are preferably made of a unitary material that is reusable and can be sterilized in a doctor's office, such as by use of an autoclave. However, the arm <NUM> and/or the ring <NUM> may be made of different materials that are disposable, not autoclaveable, and which are not unitary but may be fixedly and/or removably connected together, as well as combinations of such materials.

As shown in <FIG>, the upper end <NUM> engages a receiving element <NUM> of a device <NUM> that includes the laser device. In particular, the upper end <NUM> includes a male element <NUM> that is inserted into a slot <NUM> of the receiving element <NUM> by having its angled ends <NUM> inserted into complementary grooves <NUM> of receiving element <NUM>. The receiving element <NUM> includes a magnet <NUM>, attached to device <NUM> via screws <NUM>. The magnet <NUM> attractively engages magnet <NUM> of upper end <NUM>, wherein the magnet <NUM> is snugly fit within gap <NUM> so that a top end of the magnet <NUM> abuts a bottom end of magnet <NUM>. When snugly fit, the magnet <NUM> should snap into place. Once the magnet <NUM> is snapped into place, a lever <NUM> is rotated upwards counter-clockwise to a vertical position so as to lock the upper end <NUM> to the receiving element <NUM>.

The device <NUM> further has an upper assembly <NUM> of a liquid holding chamber <NUM>, wherein the upper assembly includes an adapter ring <NUM> for holding a glass or fused silica plate <NUM>. The plate <NUM> is attached to the adapter ring <NUM> via gluing, for example. The adapter ring <NUM> has a pair of oppositely positioned male extensions <NUM> that are designed to attach to and hold the adapter ring <NUM> in the ring <NUM>. Preferably, and by way of example, ramped surfaces <NUM> of the extensions <NUM> are inserted into corresponding slots <NUM> formed in the ring <NUM>. Note that in an alternative embodiment, the slots <NUM> can be removed and the adapter ring <NUM> can reach over the continuous ring <NUM> so as to engage the protruding lip of the ring <NUM>. Another alternative embodiment has the extensions positioned inside the ring which grip corresponding protrusions on the inside of the ring. Then, the adapter ring <NUM> is rotated so that the ramped surfaces <NUM> engage the underside of the lip <NUM> of the ring <NUM> so that a sufficient frictional attachment between the ring <NUM> and adapter ring <NUM> is achieved. Removal of the upper assembly <NUM> defined by plate <NUM> and ring <NUM> is accomplished by rotating the ring <NUM> in a direction opposite to the rotational direction that accomplished attachment. Note that the structure and function of the ring <NUM>, adapter ring <NUM> and plate <NUM> is similar to that described in <CIT>.

The device <NUM> further includes a lower assembly <NUM> of the liquid holding chamber <NUM>. As shown in <FIG>, a handle <NUM> is attached to the lower suction ring <NUM>, wherein the handle <NUM> allows a surgeon to position the suction ring <NUM> on the eye of a patient. As shown in <FIG>, the lower assembly <NUM> includes a top retainer <NUM> that includes a conical-shaped wall <NUM> that is integrally attached to an annular-like platform <NUM>. As shown in <FIG>, an exterior wall <NUM> is attached or integral with an outer surface of the wall <NUM>. An extending portion <NUM> of the wall <NUM>, an annular base <NUM> and a vertical wall <NUM> define a channel <NUM> to contain excess liquid that will be discussed later. Integrally attached to the bottom of the platform <NUM> is an inner annular wall <NUM> and an outer annular wall <NUM>. As shown in <FIG>, the outer annular wall <NUM> is continuous except where a cylindrical vacuum port <NUM> is formed. As shown in <FIG>, the vacuum port <NUM> is in fluid communication with a channel <NUM> and a vacuum source, schematically shown by box <NUM> of <FIG>. Thus, a vacuum is formed when vacuum source <NUM> removes air from the vacuum chamber of the lower assembly <NUM>.

As shown in <FIG>, a lower suction ring <NUM> is attached to the inner surface of the outer annular wall <NUM>. In particular, an annular top wall <NUM> of the low skirt <NUM> is integrally attached to the inner surface of the outer annular wall <NUM>. As shown in <FIG>, the lower suction ring <NUM> predominantly has an inverted J- shape for its cross-section, wherein the cross-section has a vertical extending top wall <NUM>, an inward extending annular surface <NUM> and an L-shaped end shaped portion <NUM> that wraps about and extends past the inner annular wall <NUM>. The surface <NUM> and portion <NUM> are integral with the facing surfaces of the platform <NUM> and the wall <NUM>, respectively.

As shown in <FIG>, in the area where the vacuum port <NUM> is formed, sections of the wall <NUM>, surface <NUM> and portion <NUM> are removed. In order to improve suction formed within the chamber a suction enhancer <NUM> is attached to a shoulder area <NUM> of the wall <NUM>. The suction enhancer <NUM> is in the form of a ring that circumscribes the wall <NUM> and is attached thereto by glue. Of course, in an alternative embodiment the suction enhancer <NUM> and the wall <NUM> are integral with one another. The suction enhancer <NUM> improves the vacuum within the chamber by providing a continuous port or multiple ports to mitigate suction loss via the conjuctive blocking of one or several ports. In addition, the suction enhancer prevents the very soft conjunctival membrane of the eye <NUM> from sticking and clogging the vacuum port <NUM>, and will keep the vacuum uniform throughout the vacuum chamber.

In operation, when the lower assembly <NUM> is positioned on the eye, the arm <NUM>, with ring <NUM> and upper assembly <NUM> attached thereto, is lowered. During this lowering, the ring <NUM> is inserted into a mating lip of housing <NUM>. Once inserted into the mating lip, rotation of lever <NUM> results in clamping attachment of the ring <NUM> to the housing <NUM>. This clamping attachment is understood upon viewing <FIG>, <FIG>. In particular, <FIG> shows that lever <NUM> has an oblong piece <NUM> attached at one end. The oblong piece <NUM> has a minimum width A and a maximum width B. While there is a <NUM>° angle between the maximum and minimum widths, other shapes of the piece <NUM> and orientations between the maximum and minimum widths are possible. In use the lever starts at <NUM> degrees from the vertical and is moved to the vertical position to lock. The angle is arbitrary, could be <NUM> degrees for instance. The oblong piece <NUM> is inserted into a slot <NUM> of the arm <NUM> that has a width that is substantially equal to the minimum width A. The lever <NUM> is rotated by <NUM> degrees as shown in <FIG> and <FIG> so that the minimum width A extends across the width of the slot <NUM>. Next, angled ends <NUM> of the piece <NUM> are inserted into complementary grooves <NUM> of the slot <NUM>. The lever <NUM> is pushed toward a closed end <NUM> of the slot <NUM>. As shown in <FIG>, the arm <NUM> has a longitudinal slit <NUM> that allows the ring <NUM> to be expanded. In particular, when lever <NUM> is rotated clockwise to a vertical position, the maximum width portion of piece <NUM> engages the grooves <NUM> resulting in the slit <NUM> to become wider and the diameter of the ring <NUM> to increase. So, when the ring <NUM> is inserted into the mating lip of the housing <NUM>, the lever <NUM> is rotated to a vertical clamping position, which results in the ring <NUM> to expand and contact the top retainer <NUM> in a clamping manner. As shown in <FIG>, barbs or protrusions <NUM> of the ring <NUM> engage and grab onto the surface of the top retainer <NUM>.

When the above described clamping of the ring <NUM> with top retainer <NUM> is combined with the constant downward force (approximately <NUM> to <NUM> ounces) of the arm <NUM>, the connection between the assembly <NUM> and the ring <NUM> is such that capillary action, adhesion and cohesion produce a small but continuous flow of water.

Note that if there was no lever mechanism so that the ring <NUM> engages the top retainer <NUM>, then the device would need to rely on the downward force alone to keep the ring <NUM> and the lower assembly <NUM> together. Such a configuration would not necessarily lock the ring <NUM> and lower assembly <NUM> together and so rocking between the parts could occur. Such rocking would result in unacceptable leaking of fluid. The use of the lever <NUM> solves this issue of not having a rigid coupling between the ring <NUM> and the lower assembly <NUM>. Furthermore, the generation of a rigid coupling does not cause any downward force, which could have resulted in a spike of intraocular pressure. With the above said, when a low pressure or partial vacuum is applied to the vacuum chamber via vacuum port <NUM>, the ring <NUM> is held in place on the eye. While only one vacuum port <NUM> is used, it is envisioned that multiple vacuum ports can be employed when one or multiple vacuum chambers are employed. In the case of multiple vacuum chambers, they can be separate from one another or they may be in fluid communication with each other, and thus a common vacuum source may be used to apply suction to these chambers and further provide that the amount of suction is equal across all vacuum chambers.

Note that when the lower assembly <NUM> is positioned on the eye, the free edge of the suction ring <NUM> engages the eye <NUM> in a manner similar to that shown in <FIG>. When the suction ring <NUM> engages the eye <NUM> and the vacuum is applied, a secure connection between the lower assembly <NUM> and the eye <NUM> is formed. The vacuum also depends on a seal formed between the bottom of the suction ring <NUM> and the eye <NUM>. In addition, a fluid tight seal is formed between the eye <NUM> and the lower assembly <NUM> is formed. As previously mentioned, a fluid tight seal is also formed between the assembly <NUM> and the ring <NUM>. With the formation of the fluid tight seals mentioned previously, a liquid holding chamber <NUM> is defined by volume bounded by the outer surface of the eye <NUM>, the upper assembly <NUM> (including glass plate <NUM>) and the lower assembly <NUM>. As shown in <FIG>, a fluid port <NUM> for adding and removing fluid from the chamber <NUM> is formed from the upper assembly <NUM> and is in fluid communication with a channel <NUM> and a fluid source, schematically shown by box <NUM> of <FIG>. Note that the fluid port <NUM> may further contain or have associated therewith valves, tubing and suitable fluid deliver components to add, hold and remove fluid from the chamber <NUM>. In addition, a thin annular gap between glass plate <NUM> and adapter ring <NUM> exists to allow air and bubbles expelled during the filling of the liquid holding chamber <NUM> to escape and to avoid obscuration of the therapeutic laser beam by entrapped bubbles.

Note that the fluid can be a fluid of a known index of refraction and thus the index of refraction can be set to match and/or approximate the index of refraction of the lens of the eye <NUM>. Thus, the chamber is preferably filled with a balanced salt solution ("BSS") or saline solution that has been degassed. Moreover, although the preferred embodiment of the present invention is to match or as closely as possible approximate the index of refractions of the device to that of the eye, in other applications having known and predetermined difference may be advantageous. Thus, the reservoir may be filled with a particular index matching fluid having a predetermined and known index of refraction, such as those that are obtainable from NYE and.

Besides the chamber <NUM>, the previously described exterior wall <NUM> shown in <FIG>, <FIG> and <FIG> contains a fluid. As shown in <FIG>, the fluid <NUM> is contained in the channel <NUM>. Note that the fluid <NUM> appears in channel <NUM> when the fluid overflows the top edge <NUM> during the filling of the main chamber via ports
<NUM>/<NUM>. The function of the exterior wall <NUM> is as follows: without a wall <NUM>, fluid in the fluid chamber <NUM> would flow over the top edge <NUM> and from the channel <NUM> via capillary action, water adhesion and cohesion when skin, eyelid or cheek, touches the top edge <NUM> or upper assembly <NUM>. When the fluid drains, a "bubble" appears under the window. It's not really a bubble, there is just not enough water to then contact the underside of the glass plate. The barrier ring keeps the skin away from the interfaces <NUM>, <NUM> between the horizontal contact surface at the top edge <NUM> and the matching horizontal surface under the ring <NUM>. At this interface there are molecular size level gaps that are sufficiently large to allow fluid to escape via capillary action in a manner described elsewhere. Now with the wall <NUM>, top edge <NUM> and base <NUM> in place, the fluid is filled into the main chamber <NUM> via channel <NUM>. The fluid will at times drain from channel <NUM>, not always but when it does, the fluid only drains from channel <NUM> and the flow will not continue once this fluid volume is gone. The fluid in chamber <NUM> remains. The flow is stopped by the higher edge, the high surface tension at the corners of surface <NUM>, the weight and cohesion of the water in chamber <NUM>.

Besides aiding in the containment of fluid <NUM>, the wall <NUM> performs another function. In particular, the vertical wall <NUM> portion of wall <NUM> is sufficiently raised so that it will prevent eyebrows or other facial skin tissues from contacting and draining fluid out of channel <NUM> and fluid chamber <NUM> via capillary forces.

Disconnection between the assembly <NUM> and ring <NUM> is
accomplished by lowering the lever <NUM> and manually removing the two elements from one another. In particular, upon completion of the procedure the vacuum is released, the lever <NUM> is lowered, and the arm <NUM> is pulled up away from the suction ring <NUM>. Next, the suction ring <NUM> is removed from the eye <NUM> by a surgeon using handle <NUM> ,.

Claim 1:
A patient interface device for use with a laser surgery apparatus, the device comprising:
an upper assembly (<NUM>) comprising a glass or fused silica plate (<NUM>);
a lower assembly (<NUM>) attached to the upper assembly (<NUM>);
wherein
the lower assembly (<NUM>) and upper assembly (<NUM>) define a liquid holding chamber (<NUM>) configured for engagement with an outer surface of an eye, and the lower assembly comprises
a channel (<NUM>) exposed to ambient atmosphere and configured to hold a fluid, and
wherein the channel (<NUM>) is defined by an extending portion (<NUM>) of a first wall (<NUM>), an annular base (<NUM>) and a second wall (<NUM>), and
the channel (<NUM>) and the liquid holding chamber (<NUM>) are in fluid communication.