Eye probe for treatment with ultrasonic waves

A probe for treating an ocular pathology. The probe has a ring including a cone frustum having a first end suitable for supporting an ultrasound generator and a second end for coming into contact with an eye of a patient. The ultrasound generator includes a first base intended to come to face the first end, and a second base opposite the first base. The probe further includes a flow regulator for eliminating the bubbles contained in a coupling fluid flowing to the first base when filling the probe with the fluid.

FIELD OF THE INVENTION

The present invention relates to the general technical field of non-invasive treatment devices for an eye pathology by generation of focused or non-focused ultrasonic waves, of high or low intensity.

More particularly, the invention relates to a probe of a device for generating ultrasonic waves for treating an eye pathology, such as for example the treatment of a glaucoma.

BACKGROUND OF THE INVENTION

Glaucoma is an optical neuropathy, i.e. a degeneration of the optical nerve, this leading very often to an increase in the intraocular pressure (IOP).

When the aqueous humor is no longer discharged sufficiently rapidly, the latter accumulates, which induces an increase in the IOP. The increase in the IOP compresses the axones in the optical nerve and may also compromise the vascularization of the optical nerve. A high IOP for a long period may induce a total loss of vision.

The only therapeutic approach presently available for treating glaucoma consists of reducing the intraocular pressure:either by improving the draining of the aqueous humor through the trabeculum and the Schlemm channel of the eye,or by reducing the production of aqueous humor by the ciliary body of the eye.

From document WO 2009/103721 a device is known for reducing the production of aqueous humor based on the principle of cyclo-coagulation with focused ultrasonic waves of high intensity which consists of destroying a portion of the ciliary bodies in order to reduce the production of aqueous humor.

The device described in WO 2009/103721 allows the treatment of one or several sectors of the eye in one single act. This device comprises a probe consisting of a ring and of means for generating ultrasonic waves.

The ring has a proximal portion intended to be in contact with an eye of a patient, and a distal portion intended to receive the means for generating ultrasonic waves.

The means for generating ultrasonic waves has a concave profile. More specifically, the means for generating ultrasonic waves comprise six transducers with the form of a cylinder segment positioned on a cylindrical crown of axis A-A′.

In order to allow transmission of the ultrasonic waves towards the eye of the patient, the six transducers have to be immersed in a coupling liquid. The coupling liquid is generally conditioned in a flask of the dropwise type consisting:of a container containing the coupling liquid,of a drop dispenser mounted on the container, andof a plug for closing the dispenser.

Once the ring is positioned on the eye to be treated, the practitioner is therefore forced to fill the ring with coupling liquid by applying pressure on the container for expelling the coupling liquid through the dispenser.

In order to limit the period of the filling step, the practitioner generally applies a very strong pressure so that the liquid is expelled in the ring as a jet.

During the gradual filling of the ring, this jet induces turbulences with the liquid already contained in the ring, which causes the formation of air bubbles which may come and be accommodated between the eye and the means for generating ultrasonic waves.

As air is not very permeable to ultrasonic waves, the presence of an air bubble between the eye and the means for generating ultrasonic waves may be detrimental to the efficiency of the treatment.

An object of the present invention is to propose a solution to the problem described above.

SHORT DESCRIPTION OF THE INVENTION

For this purpose, the invention proposes a probe for treating an eye pathology comprising:a ring including a truncated cone having a first end adapted for supporting means for generating ultrasonic waves and a second end for coming into contact with an eye of a patient,means for generating ultrasonic waves including a first base intended to come to face the first end, and a second base opposed to the first base,
remarkable in that the probe further comprises a flow rate regulator for suppressing the bubbles contained in a coupling fluid flowing towards the first base during the filling of the probe with said fluid.

Thus, the probe according to the invention comprises a flow rate regulator between the second and first bases of the generation means. This flow rate regulator includes a conduit for supplying a coupling fluid for which the dimensions are adapted for preventing the propagation towards the first base, of the bubbles contained in the coupling fluid.

Advantageously, the dimensions of the fluid supply conduit are calculated so as to limit the risks of propagation of bubbles when the coupling fluid has a viscosity equal to that of water. This gives the possibility of guaranteeing that the function of suppressing the bubbles of the regulator are effective for any coupling fluid having a viscosity greater than or equal to that of water.

As indicated earlier, the air bubbles are detrimental to the propagation of the ultrasonic waves because of their strong acoustic resistance.

The flow rate regulator gives the possibility of reducing the risk of presence of these air bubbles between the eye of the patient and the means for generating ultrasonic waves, which guarantees the whole efficiency of the probe.

Preferred aspects but non-limiting aspects of the treatment probe according to the invention are the following:the ring may comprise a coaxial skirt with the truncated cone, and the means for generating ultrasonic waves may comprise a crown, the skirt extending outwards from the first end so as to surround the crown;the regulator may comprise an aperture defined between the skirt and the crown, said aperture extending over the whole height of the crown for allowing passing of the fluid between the second and first bases;the aperture may extend over the whole perimeter of the crown;the thickness of the aperture may be comprised between 0.1 mm and 5 mm, preferentially between 0.2 and 2 mm, and still more preferentially equal to 0.5 mm;the first base of the means for generating ultrasonic waves may comprise a hydrophilic treatment;the probe may also comprise a purger for the exhaust of the gases during the filling of the probe with the coupling fluid;the means for generating ultrasonic waves may comprise a crown having a central channel, the purger comprising at least one chimney coaxial with the central channel and extending outwards on the second base;the ring and the means for generating ultrasonic waves may be made in two distinct parts intended to be assembled, the probe comprising a guide for guiding the sliding of the means for generating ultrasonic waves relatively to the ring;the guide may consist in a groove laid out on the ring and a slider laid out on the means for generating ultrasonic waves;the probe may further comprise at least two suction nozzles on the second end, the nozzles being laid out so as to be localized in a temporal/nasal plane B-B′ of the eye when the probe is positioned on the eye;the means for generating ultrasonic waves may comprise a gripper extending on the second base;the ring and the means for generating ultrasonic waves may be made in two distinct parts intended to be assembled, the probe comprising blockers for immobilizing the ring relatively to the means for generating ultrasonic waves;the blockers may comprise a pair of elastic tabs with shape memory extending at the periphery of the second base, each tab including a bulge for cooperating by clipping with a bulge made on the ring so as to immobilize in translation the ring relatively to the means for generating ultrasonic waves;each bulge may have a V shape;the probe may further comprise at least one abutment for limiting the displacement of the tabs.

DETAILED DESCRIPTION OF THE INVENTION

Different examples of the probe according to the invention will now be described with reference to the figures. In these different figures, equivalent elements are designated by the same numerical reference.

With reference toFIGS. 1 to 4, an embodiment is illustrated of the probe for treating an eye pathology.

The probe comprises:a ring1,means for generating ultrasonic waves2.

The means for generating ultrasonic waves2are intended to cooperate with the ring1. More specifically, the ring1forms a housing for the means for generating ultrasonic waves2.

1. Presentation of the Probe

1.1. Means for Generating Ultrasonic Waves

The means for generating ultrasonic waves2give the possibility of generating ultrasonic energy. For example, the means for generating ultrasonic waves give the possibility of generating focused ultrasonic waves with high intensity.

They comprise a ring-shaped crown21with an axis A-A′ including:first and second opposed bases211,212orthogonal to the A-A′ axis,an external side wall213between the first and second bases, andan internal side wall214defining a central channel between the first and second bases211,212.

The first base211include at least one transducer215having a radiating element for generating ultrasonic waves.

The profile of the radiating element(s) may be adapted for allowing the orientation and the focusing of the ultrasonic waves in a given point. Alternatively, the transducer215may comprise reflector(s) for reflecting, orienting and focusing in a given point the ultrasonic waves generated by the radiating element(s).

In the embodiment illustrated inFIG. 3, six transducers215extend over the first base211of the crown21.

The transducers215are grouped in two pairs of three transducers separated by two inactive sectors217.

The inactive sectors217are localized on the crown21so as to extend in a temporal/nasal plane B-B′ of the eye4when the probe is set into place on the eye4, these sectors217corresponding to areas of the eye4including the majority of the nerve and vascular endings.

The ring1allows adequate and constant positioning of the means for generating ultrasonic waves2, both for the centering and for the distance relatively to the sclera of the means for generating ultrasonic waves2.

The ring1comprises a truncated cone (or cone frustum)11with an axis A-A′, and a peripheral skirt12coaxial with the truncated cone11.

The truncated cone11is opened at both of its ends. The large base111of the truncated cone11—a so called “first end” in the following—comprises a supporting cradle intended to receive the means for generating ultrasonic waves2. The small base112of the truncated cone11—a so called “second end” subsequently—is intended to come into contact with the eye4. The second end112may comprise an external annular flange able to be applied on the external surface of the eye4, this flange having a concave profile with a radius of curvature substantially equal to the radius of curvature of the eye4.

The skirt12comprises a ring-shaped wall123coaxial with the truncated cone11. The skirt12extends outwards from the first end111of the truncated cone11. More specifically, the skirt12comprises first and second open endings121,122:the first ending121being secured to the first end111, andthe second ending122being opposed to the second end112.

Advantageously, the skirt12has a shape mating the means for generating ultrasonic waves2. More specifically, the interior profile of the ring-shaped wall123is the conjugate of the outer profile of the crown21.

As illustrated inFIG. 4, the ring1forms a housing for the means for generating ultrasonic waves2:the truncated cone11extends under the crown21, facing the first base211, andthe skirt12encloses the crown21.

Preferably, the height (i.e. dimension along the A-A′ axis) of the ring-shaped wall123is greater than the height of the crown21so that the second ending122is localized at a non-zero distance from the second base212.

This gives the possibility of defining a sufficient space above the crown21so that it is totally immersed once the probe is filled with a coupling fluid.

1.3. Means for Generating a Depression

The probe may include means for generating a depression allowing the maintaining in position of the ring1on the eye4during the whole period of the treatment.

The means for generating a depression for example comprise two suction nozzles113extending along a diameter of the second end112.

Each nozzle113is connected to an external suction device (not shown) for generating a depression at the nozzles113when the probe is positioned on the eye4. This gives the possibility of securing the ring1on the eye4by suction cup effect.

In an embodiment, each nozzle113consists in an aperture opening onto the second end112so as to come into contact with the eye4of the patient. This gives the possibility of limiting the risks of a pressure drop of the suction (notably relatively to a nozzle with an oblong shape).

Preferably, the nozzles113are laid out so as to be localized in the temporal/nasal plane B-B′ of the eye4when the probe is applied on the eye4. This gives the possibility of improving the efficiency of the suction cup effect of the ring1on the eye4.

Indeed, the eye4has a substantially elliptical shape with a major radius contained in the temporal/nasal plane B-B′. By laying out the nozzles113so that they extend in the temporal/nasal plane B-B′ when the probe is set into place, an intimate contact is ensured between the nozzles113and the eye4, which improves the efficiency of the suction cup effect.

The means for generating a depression also comprise:a ring-shaped conduit for circulation of air, anda tubular access member124
allowing the connection of the nozzles113to the external suction device via a connection tubing.

The ring-shaped conduit for circulation of air extends at the periphery of the second end112. It allows the distribution of the depression generated at the nozzles113.

The access member124extends radially towards the outside of the ring-shaped wall123. Preferably, le access member124is laid out so as to be positioned in the temporal/nasal plane B-B′ of the eye4when the probe is set into place on the eye4. This gives the possibility of not bothering the practitioner with the connection tubing during the treatment.

As indicated earlier, the acoustic resistance of the air is very significant, the presence of an air bubble at a transducer215makes the latter inefficient. These air bubbles may be produced during the filling of the probe with the coupling fluid.

Within the scope of the present invention, this filling is applied by projecting the coupling fluid on the second base212of the crown21after having assembled the ring1with the means for generating ultrasonic waves2.

In order to avoid the risks of accumulation of air bubbles between the transducers215and the eye4, the probe comprises a flow rate regulator between the first and second_bases. The latter gives the possibility of preventing the circulation of air bubbles towards the first base211.

In this embodiment illustrated inFIG. 4, the flow regulator comprises a conduit for supplying a coupling fluid. This conduit for example consists in an aperture3between the ring-shaped wall123and the external side wall213. The dimensions of this aperture3are provided so as to retain the bubbles on the second base212.

This aperture also allows the passing of the coupling fluid poured on the second base212towards the truncated cone11. Advantageously, at least one of the dimensions of the aperture (and notably its thickness) is calculated so as to limit the propagation of bubbles towards the first base when the coupling fluid has a viscosity equal to that of water.

Thus, it is guaranteed that the retention function of the bubbles (on the second base) is fulfilled by the flow rate regulator with any type of coupling fluid which is more viscous than water.

Preferably, the distance between the skirt12and the crown21is constant in order to define a ring-shaped aperture3between the skirt12and the crown21.

The distance between the skirt12and the crown21may be comprised between 0.1 and 5 millimeters, preferentially between 0.5 and 2 millimeters. This allows the aperture3to filter the bubbles with a diameter greater than its thickness (i.e. dimension of the aperture according to a radius of the truncated cone) while guaranteeing sufficient cooperation between the ring1and the means for generating ultrasonic waves2.

Splines may be made in the annular wall123and/or in the external side wall213for facilitating the flow of the coupling fluid towards the truncated cone11during the filling of the probe. This gives the possibility of increasing the flow rate of the coupling fluid in order to avoid risks of overflow during the filling. The splines may extend over the whole or part of the height (i.e. the dimension along the A-A′ axis) of the crown21.

Even if the flow rate regulator allows retention of the majority of the bubbles contained in the coupling fluid during the filling, micro-bubbles may nevertheless circulate in the fluid flow flowing between the second and first bases212,211.

This is why the surface of the crown21may be treated for increasing its hydrophilic properties. For example, the transducer(s) may be covered with a layer of hydrophilic material. This gives the possibility of limiting the adhesion of air bubbles on the transducer(s)215.

The probe also comprises a purger for discharging the air contained in the ring1during the filling of the probe.

The purger includes a chimney218coaxial with the central channel. This chimney218extends at right angles from the internal side wall214.

The chimney218gives the possibility of preventing the flow of the coupling fluid through the central channel during the filling of the probe. Thus, it forces the fluid to flow through the aperture3forming a flow rate regulator.

Advantageously, the free end of the chimney218comprises a hole for allowing the air to escape. Indeed, during the filling of the probe, the coupling fluid gradually takes the place of the air contained in the ring1. The air tends to accumulate in the central channel of the crown21. The hole made in the chimney then allows this air to escape outwards from the probe.

The probe also comprises gripping means for facilitating its handling by the practitioner, and giving him/her an indication on the area where his/her fingers are positioned.

Preferably, the gripping means include:a first gripper positioned on the skirt12for allowing the practitioner to hold the ring1between his/her thumb and his/her forefinger, anda second gripper positioned on the crown21for allowing the practitioner to handle the means for generating ultrasonic waves2between his/her finger and his/her forefinger.

The first gripper for example consists in two pins125extending radially towards the outside of the ring-shaped wall123. Advantageously, the pins125may be laid out on the ring-shaped wall123so as to be positioned in an upper/lower plane C-C′ (orthogonal to the temporal/nasal plane B-B′) when the probe is set into place on the eye4. This allows the practitioner to be in an ergonomic position and be always placed at the head of the patient.

In order to improve the gripping of the ring1, each pin126may have a concave possibly striated surface. This gives the possibility of reducing the risk of an accidental sliding between the first gripper and the surgical glove of the practitioner (which may in certain cases be humid).

The second gripper may consist in free ends of two tabs219elastic and planar with shape memory. As illustrated inFIG. 4, these two tabs219are positioned facing each other along a diameter of the crown21, and extend and protrude at the periphery of the second base212, in the extension of the external side wall213.

A preformed dug imprint may be made at the end of each tab219in order to limit the risks of sliding of the surgical glove of the practitioner on the second gripper.

1.7. Guide in Translation

The probe also comprises a guide in translation for facilitating the assembly of the means for generating ultrasonic waves with the ring1.

This gives the possibility of guaranteeing an accurate and repeatable positioning of the means for generating ultrasonic waves2relatively to the ring11.

In the embodiment illustrated inFIG. 1, the guide in translation consists in:a groove126laid out on the ring1anda slider216laid out on the means for generating ultrasonic waves2.

The groove126is made on the inner face of the ring-shaped wall123. This groove126is adapted for receiving the slider216.

The slider216radially extends towards the outside of the external side wall213. The slider216may consist in a finger extending over one portion or over the totality of the height of the crown21.

The guide in translation gives the possibility of preventing the relative rotation of the means for generating ultrasonic waves2relatively to the ring1around the axis A-A′.

The use of a slider216intended to cooperate with a groove126gives the possibility of giving the practitioner an indication on the orientation of the means for generating ultrasonic waves2relatively to the ring1, the means for generating ultrasonic waves2not being only able to penetrate into the ring1along a single orientation.

1.8. Blocker in Translation

The probe may also comprise a blocker for attaching reversibly the means for generating ultrasonic waves2on the ring1.

The blocker gives the possibility of immobilizing (in translation) the means for generating ultrasonic waves2once the probe is assembled. It comprises:two bulges230on the means for generating ultrasonic waves2,two bulges130on the ring1.

Each bulge230is mounted on a respective elastic tab219and extends while radially protruding outwards on the whole width of the tab219.

Each bulge230is intended to cooperate with a respective bulge130made on the second ending122and radially extending inwards (i.e. in the direction of the A-A′ axis).

1.9. Down Holder

In order to limit the mechanical plays between the ring1and the means for generating ultrasonic waves2, the probe may also comprise a down holder for applying a down holding force on the means for generating ultrasonic waves2.

Advantageously, a component of this down holding force is parallel to the axis A-A′ and oriented towards the truncated cone11so as to flatten the ring21against the supporting cradle of the truncated cone11.

In the embodiment illustrated inFIGS. 1 to 4, a down holder is laid out on each bulge230. This down holder consists in an angle formed between a normal to the tab and the surface of the bulge230intended to come into contact with its associated bulge130.

The probe may also comprise a pair of associated abutments each to a respective tab219. These abutments have the function of limiting the travel of the tabs219.

This gives the possibility of reducing the risks of deterioration of the tabs219by applying a too large clamping force during the grasping of the means for generating ultrasonic waves2.

In the embodiment illustrated inFIG. 4, each abutment consists in a rigid blade231extending parallel to its associated tab219. The application of a clamping force on the tabs219induces their torsion towards the axis A-A′ until a limiting position where the tabs219will come into contact with the blades231. Beyond this limiting position, the displacement of the tabs219towards the axis A-A′ is prevented by the blades231.

In order to increase the rigidity of the blades231, each abutment may comprise a buttress232.

2. Use of the Probe

An example of the procedure for using the probe for treating the eye of a patient lying down on an operating table will now be described.

In a step of the procedure, the ring1and the means for generating ultrasonic waves2are connected to a control system. More specifically:the ring1is connected to a suction device of the control system by means of a connection tubing,the means for generating ultrasonic waves2are connected to a generator of the control system by means of an electric cable.

In another step, the practitioner grips the ring1by grasping the pins125between his/her thumb and his/her forefinger. He/she positions himself/herself at the front of the patient and lays the ring1on the eye4by putting the second end112in contact with the eye4.

The suction device is activated for generating a depression at the nozzles113so as to secure the ring1on the eye4by a suction effect.

If need be, and before activating the depression, the practitioner displaces the ring1for centering it on the eye4.

Once the ring1is centered on the eye4, the practitioner takes the means for generating ultrasonic waves2by clamping the ends of the elastic tabs219between his/her thumb and his/her forefinger. He/she positions the crown21above the skirt12.

The practitioner then aligns the slider216with the groove126by rotating the crown21around the axis A-A′. Once the slider216and the groove126are aligned, the practitioner slides the crown21inside the ring1so that the ring-shaped wall123surrounds the external side wall213.

During the relative displacement of the crown21relatively to the ring1, the bulges230will come into contact with the bulges130. The elastic tabs219deform until the bulges230have crossed the bulge130, and then reassume their rest positions.

The crown21is then blocked in the ring1by clipping by means of the bulges230and bulges130. The V shape of the bulges230induces the constant application of a force against the bulges130which tend to flatten the crown21against the cradle of the truncated cone11in order to ensure accurate positioning of the means for generating ultrasonic waves2.

Once the probe is assembled, the latter is filled with the coupling liquid. The practitioner positions the flask drop wise above the probe and pours the liquid onto the second base212.

The liquid spreads over the second base212and flows through the aperture3for filling the ring1. The chimney218prevents the liquid from penetrating into the central channel. The air bubbles with a diameter greater than the width of the aperture3(i.e. dimension of the aperture along a radius of the crown) are retained at the second base212.

Gradually during the filling of the ring1, the liquid gradually takes the place of the air which escapes through the hole of the chimney218via the central channel extending as far as the center of the first concave base211.

When the crown21is totally immersed, the practitioner interrupts the filling and activates the control device for applying the treatment.

By limiting the risks of the presence of an air bubble at a transducer, the probe described earlier guarantees to the practitioner good efficiency of the treatment.

The reader will have understood that many modifications may be provided to the invention described earlier without materially departing from the new teachings and advantages described here. Therefore, all the modifications of this type are intended to be incorporated inside the scope of the appended claims.