WO2012168590A1

WO2012168590A1 - Device for irradiating light for applying a light beam onto or into a body, in particular a human body

Info

Publication number: WO2012168590A1
Application number: PCT/FR2012/050288
Authority: WO
Inventors: Jean Rousseau; Jean-Christophe HORNEZ; Anne LERICHE; Michel Descamps; Francine Monchau
Original assignee: Centre Hospitalier Regional Universitaire De Lille; Universite De Valenciennes Et Du Hainaut Cambresis
Priority date: 2011-02-10
Filing date: 2012-02-09
Publication date: 2012-12-13
Also published as: FR2971414A1

Abstract

The invention relates to a device for irradiating light for applying a light beam, such as a laser beam, onto or into a body, in particular a human body, which can be particularly used in the field of laser therapy. The device includes a light source (2) and a means (1) for conveying the light beam. A portion of the conveying means is inserted into a guide (3) that is configured so as to be at least partially inserted into the body, and is provided with a longitudinal irradiation window (4). The conveying means includes a longitudinal emission portion (1c) configured so as to emit at least a portion of the light beam non-parallel to the longitudinal axis. The irradiation window is arranged directly opposite the emission portion such that at least a portion of the light beam is scattered directly through the window. The conveying means is at least partially adhered to the inside of the guide using a resin configured so as to allow at least a portion of the light beam to pass therethrough. The resin consists of a layer for hermetically sealing the window.

Description

LIGHT IRRADIATION DEVICE FOR APPLYING A LIGHT BEAM ON OR INTO A BODY, IN PARTICULAR A

The invention relates to a light irradiation device intended to allow the application of a light beam, such as a laser beam, on or in a body, in particular a human body.

Such a device finds an application particularly in the field of laser therapies, aiming at using the energy transported by a laser beam to interact on an organ or a biological tissue.

In particular, the device finds particular application in interstitial laser thermotherapy (LITT) or dynamic phototherapy (PDT), especially in the field of oncology.

The principle of interstitial thermotherapy is based on thermally destroying deep tumors with minimal impact on adjacent healthy structures.

The principle of dynamic phototherapy is based on the action on tumor neovascularization through the production of intracellular free radicals.

Both processes have demonstrated their effectiveness and are part of the therapeutic arsenal, especially in oncology.

Thus, devices are known for implementing such laser therapies, by inserting an applicator into the body to bring the laser beam into contact with the area to be treated. These devices make it possible to emit a laser beam from a laser source to which an optical fiber is connected, under control by MRI (magnetic resonance imaging).

However, the conformation of the area to be treated remains a difficult problem to solve. In particular, for large targets, it is necessary to use several fibers.

Imaging is used to assist preparation, fiber placement, intraoperative control of thermal evolution, and postoperative follow-up. It is indeed difficult to avoid a localized overdose when the area to be treated is important and requires a large amount of laser energy. Among these known devices, the device described in EP 0 514 258 provides for the insertion of an optical fiber into a guide at the tip of which is formed an opening through which the laser beam irradiates.

One of the problems posed by such a device is that it does not allow to irradiate a large area, the beam being very concentrated from the tip of the guide. The treatment technique is therefore delicate and long, with a risk of overdose due in particular to the dissipation of maximum energy at the tip.

The device described in US 2005/283144 also provides for the insertion of an optical fiber in a guide. At the end of this guide is reserved a housing for a set of mirrors for redirecting, radially or at an angle relative to the axis of the main beam, the beam emitted longitudinally by the fiber through an opening formed along walls of the guide. This housing, disposed beyond the end of the optical fiber, also receives a mechanism for changing the orientation of the mirrors.

Such a device thus attempts to allow irradiation of a larger area to be treated, radially or non-parallel to the main beam.

However, in addition to the fact that such a device is complex and expensive to produce and maintain, due in particular to the redirection mechanism of the main laser beam, the redirected beam or beams remain concentrated, with a maximum dissipation of energy at the level of these bundles redirected. The risk of overdose is therefore the same as that concerning beam emitting devices by the tip.

The object of the invention is therefore to provide a solution to the aforementioned problems and disadvantages among others.

The invention thus relates, in a first aspect, to a light irradiation device for applying a light beam on or in a body, in particular a human body.

The device comprises a light source capable of emitting a light beam, and a means of transporting the light beam. The transport means has a longitudinal axis, a first free end, and a second end opposite the first end and connected to the light source.

At least a portion of the transport means, comprising the first end, is inserted into a guide capable of being itself inserted at least partially into the body and provided with an irradiation window arranged longitudinally and able to pass a beam. luminous.

The transport means further comprises at least one emission portion extending longitudinally between the first and second ends and capable of emitting, in a non-parallel manner to the longitudinal axis, at least a portion of the light beam transported.

Moreover, the irradiation window is arranged directly opposite the emission portion, so that at least a portion of the light beam transported is diffused directly through said window in a manner that is not parallel to the transmission portion. longitudinal axis.

In a first variant, the window comprises at least two openings connected by a bridge.

In a second variant, possibly in combination with the first, the window is positioned at a distance of between 2.5 mm and 4.5 mm, preferably between 3 mm and 4 mm, from the free end of the guide.

In a third variant, possibly in combination with one or more of the preceding, the window has a length of between 8 mm and 25 mm, preferably between 10 mm and 20 mm.

In another variant, possibly in combination with one or more of the preceding, the window and / or the openings have a width between 1/4 and 1/3 of the outer diameter of the guide.

In another variant, possibly in combination with one or more of the previous ones, the window is hermetically closed by a closure layer capable of passing at least a portion of the light beam.

In another variant, possibly in combination with one or more of the preceding, the transport means is at least partially glued within the guide. In another variant, in combination with the two previous ones, the bonding is carried out with a resin able to pass at least a part of the light beam, so that this resin also constitutes the closing layer of the window.

In another variant, possibly in combination with one or more of the previous three, the material of the closure layer is a material that does not interfere with a magnetic resonance imaging method.

In another variant, possibly in combination with one or more of the previous four, the material of the closure layer resists sterilization.

In another variant, possibly in combination with one or more of the previous five, the material of the closure layer comprises diffusing particles capable of increasing the diffusion of the light beam.

These diffusing particles may comprise glass microbeads and / or microbeads made of synthetic material, for example of the PMMA type.

In one variant, the diameter of the microbeads is greater than 300 μηι, preferably between 300 μηι and 400 μηι.

In another variant, in combination with the preceding one, the concentration of the microbeads is greater than 500 g / l, preferably between 500 g / 1 and 1200 g / l.

In another variant, possibly in combination with one or more of the previous ones, the light source is a laser source.

In another variant, possibly in combination with one or more of the preceding, the transport means comprises at least one optical fiber, preferably a single optical fiber.

Preferably, this optical fiber is covered with a sheath, for example of polymer-type material, and is stripped of its sheath in its emission portion.

In another variant, possibly in combination with one or more of the preceding, the guide is ceramic, for example comprising alumina. In another variant, possibly in combination with one or more of the preceding, the guide has a length of between 10 cm and 30 cm, preferably of the order of 20 cm.

In another variant, possibly in combination with one or more of the preceding, the guide has an inner diameter of between 1.2 mm and 2 mm, preferably of the order of 1.6 mm.

In another variant, possibly in combination with one or more of the preceding, the guide has an outer diameter of between 3.2 mm and 4 mm, preferably of the order of 3.6 mm.

In another variant, possibly in combination with one or more of the preceding, the guide has at its free end a closed tip.

Alternatively, the guide has at its free end a beveled open tip.

In another variant, possibly in combination with one or more of the preceding, the guide is at least partially covered with a heat-shrinkable sheath, for example of polyolefin material.

Other features and advantages of the invention will appear more clearly and completely on reading the following description of the preferred embodiments and implementations, which are given by way of non-limiting examples and with reference in the following appended drawings:

FIG. 1 schematically represents a first example of the device of the invention,

FIG. 2 schematically represents a second example of a device of the invention,

FIG. 3 schematically represents the guide of the first exemplary device of the invention with closure of the irradiation opening.

The device of the invention is shown schematically in Figure 1, in a first example.

The device comprises a light source 2, which is preferably a laser source capable of emitting a laser beam, for example in a range of infrared wavelengths or near the infrared. To this laser source 2 is connected a transport means 1 of the laser beam emitted by the source 2, which has a longitudinal axis L. This transport means 1 is for example an optical fiber 1, connected to the laser source 2 by the intermediate of one of its ends lb.

This optical fiber 1 is inserted, by its free end opposite to the end 1b of connection to the laser source 2, in a guide 3 which makes it possible to stiffen the optical fiber 1 in view of its insertion for example in the body of a patient to treat.

The guide 3 is preferably ceramic, for example alumina or comprising alumina which has a very good biocompatibility and a very good mechanical strength.

This guide 3 takes the form of a hollow rod 3, whose free end 3a is in the form of closed tip.

Alternatively, the free end 3a of the guide 3 could be formed by an open bevel in the hollow rod 3.

Thus, the guide 3 can be inserted at least partially into the body of the patient to be treated by laser therapy.

In a preferred embodiment, the length of the guide 3 is between 10 cm and 30 cm, preferably of the order of 20 cm.

Also in a preferred embodiment, the outer diameter of the guide 3 is between 3.2 mm and 4 mm, preferably of the order of 3.6 mm, and its internal diameter is between 1.2 mm and 2 mm, preferably of 1 mm. 1.6 mm.

In order to secure the guide, to allow the practitioner to easily remove the guide 3 in its entirety from the body of the patient in case of breakage, it can be provided to cover it at least partially with a heat-shrinkable sheath. To do this, one can choose a biocompatible material such as polyolefin, which will preferably optimize the retractability as a function of temperature and duration of use.

The biocompatibility, both for the material of this heat-shrinkable sheath, and for the material of the guide 3 itself, can be evaluated by means of cytotoxic tests to demonstrate the biological safety of the materials used.

The optical fiber 1 is inserted in the guide 3 on a portion from its free end la.

Along the wall of the guide 3 is disposed longitudinally an irradiation window 4 capable of passing a laser beam.

This irradiation window 4 is arranged directly opposite a portion 1c of the optical fiber 1, called the transmission portion 1c, capable of transmitting all or part of the laser beam transported by the optical fiber 1.

The emission through the irradiation window 4 is therefore directly from the transmission portion 1c of the optical fiber 1, non-parallel to the longitudinal axis L of this optical fiber 1, for example radially, c ' that is to say along an emission axis perpendicular to the longitudinal axis L of the optical fiber 1.

When the optical fiber 1 is covered with a sheath, such as a sheath made of polymer-type material, it is possible to strip all or part of this sheath, in the transmission portion 1c, to increase the scattering of the beam laser.

This also has the effect of avoiding the formation of hot spots and making the diffusion of the laser beam more homogeneous.

In a preferred embodiment, the irradiation window 4 is disposed at a distance from the free end 3a of the guide 3, between 2.5 mm and 4.5 mm, preferably between 3 mm and 4 mm, and has a length of between 8 mm and 25 mm, preferably between 10 mm and 20 mm.

As can be seen more clearly in FIG. 3, corresponding to a three-dimensional view of the guide 3 of FIG. 1, the width of the window, measured along the outside diameter of the guide 3, represents 1/4 to 1 / 3 of this outer diameter of the guide 3.

As illustrated in the example shown schematically in Figure 2, the irradiation window 4 may be formed of several openings each separated from another or connected to another by a bridge. In the example shown in FIG. 2, the irradiation window 4 thus consists of two openings 4a, 4b separated by a point 4c, the assembly always vis-à-vis the emission portion of the optical fiber 1.

In order to isolate the interior of the guide 3 from the biological fluids, it is preferable to seal the window 4 by a closure layer 5, as illustrated in FIG.

For example, the irradiation window 4 may be closed by a layer in the form of a cover or cover 5.

The material of the closure layer must nevertheless be able to pass a light beam, such as a laser beam of near infrared wavelength.

It may be for example a PMMA type material, in particular when the closure is obtained by a cover 5.

The hermetic closure of the irradiation window 4 can also be obtained by injection of a resin into the guide, for example an epoxy resin or if I icon.

Such a resin also has the advantage of not disturbing the control by magnetic resonance imaging, in particular not to generate artifact in the images taken by MRI.

It is also preferable that the resin has good resistance to sterilization processes, hence good resistance to temperatures above 100 ° C.

This resin must also have a low viscosity to facilitate injection by the irradiation window 4, while having a high hardness after polymerization.

Furthermore, it is preferable to stick, at least in part, the optical fiber 1 inside the guide 3, to ensure that it does not move.

It is also possible to use a resin for gluing. Preferably, the resin used for the hermetic closure of the irradiation window 4, injected by this window 4 after insertion of the optical fiber 1 in the guide 3, is also used for bonding the optical fiber 1 inside the guide 3.

To further improve the diffusing properties of the closure layer 5, in particular cap 5 or resin 5, of the irradiation window 4, it is possible to provide to include in the material constituting this closure layer 5 diffusing particles.

For example, it is possible to include, in particular with the resin 5, microbeads particles of glass or synthetic material such as PMMA.

This advantageously makes it possible to increase the scattering of the laser beam through the irradiation window 4 and to reduce the hyperthermia problems, making the laser beam less directional.

In a preferred embodiment, the microbeads have a diameter greater than 300 μηι, preferably between 300 μηι and 400 μηι.

Also in a preferred embodiment, the microbeads are present in the material of the closure layer 5 in a concentration greater than 500 g / l, preferably between 500 g / 1 and 1200 g / l.

The whole of the description above is given by way of example and is not limiting of the invention.

In particular, the exact shape of the irradiation window 4, with one or more openings 4a, 4b does not necessarily correspond to a rectangular cut in the wall of the guide 3. Other longitudinal cuts may be envisaged, provided that they are arranged directly vis-à-vis the transmission portion 1 c of the transport means 1, and they allow a homogeneous and non-directional diffusion of the emitted beam.

Similarly, the length and the exact position of the emission portion 1 c are not limiting of the invention, provided that this emission portion extends longitudinally between the two ends 1 a and 1 b, directly in vis-à-vis the irradiation window 4.

Claims

1. Apparatus for light irradiation intended to allow the application of a light beam on or in a body, in particular a human body, comprising a light source (2) configured to emit a light beam, a transport means (1) of the light beam having a longitudinal axis (L), a first end (la) free and a second end (Ib) opposite said first end (la) and connected to the light source (2), at least a portion of the transport (1) comprising the first end (1a) being inserted in a guide (3) configured to be itself inserted at least partially into said body and provided with an irradiation window (4) arranged longitudinally and configured to leave passing a light beam, the transport means further comprising at least one transmitting portion (1c) extending longitudinally between the first and second ends (1a, 1b) configured to emit, non-parallel to the longitudinal axis (L), at least a portion of the light beam transported, the irradiation window (4) being disposed directly opposite said emission portion (1c), so at least a portion of the light beam transported is diffused directly through said window (4) non-parallel to the longitudinal axis (L), said device being characterized in that the transport means (1) is at least partially adhered to the inside of the guide (3), the bonding being carried out with a resin configured to pass at least a portion of the light beam, so that said resin also constitutes a hermetic closure layer (5) of the window ( 4).

2. Device according to claim 1, characterized in that the window (4) comprises at least two openings (4a, 4b) connected by a bridge (4c).

3. Device according to any one of claims 1 and 2, characterized in that the window (4) is positioned at a distance of between 2.5 mm and 4.5 mm, preferably between 3 mm and 4 mm, of the free end (3a) of the guide (3).

4. Device according to any one of claims 1 to 3, characterized in that the window (4) has a length of between 8 mm and 25 mm, preferably between 10 mm and 20 mm.

5. Device according to any one of claims 1 to 4, characterized in that the window (4) and / or the openings (4a, 4b) have a width between 1/4 and 1/3 of the outer diameter of the guide (3).

6. Device according to any one of claims 1 to 5, characterized in that the material of the closure layer is a material which does not interfere with a magnetic resonance imaging method.

7. Device according to any one of claims 1 to 6, characterized in that the material of the closure layer resists sterilization.

8. Device according to any one of claims 1 to 7, characterized in that the material of the closure layer comprises diffusing particles configured to increase the diffusion of the light beam.

9. Device according to claim 8, characterized in that the diffusing particles comprise glass microbeads and / or microbeads of synthetic material, for example of the PMMA type.

10. Device according to claim 9, characterized in that the diameter of the microbeads is greater than 300 μηι, preferably between 300 μηι and 400 μηι.

11. Device according to claim 10, characterized in that the concentration of the microbeads is greater than 500 g / 1, preferably between 500 g / 1 and 1200 g / 1.

12. Device according to any one of claims 1 to 11, characterized in that the light source (2) is a laser source (2).

13. Device according to any one of claims 1 to 12, characterized in that the transport means (1) comprises at least one optical fiber (1), preferably a single optical fiber (1).

14. Device according to claim 13, characterized in that the optical fiber (1) is covered with a sheath, preferably of polymer-type material, and in that said optical fiber is stripped of its said sheath in its portion d. issue.

15. Device according to any one of claims 1 to 14, characterized in that the guide (3) is ceramic, for example comprising alumina.

16. Device according to any one of claims 1 to 15, characterized in that the guide (3) has a length of between 10 cm and 30 cm, preferably of the order of 20 cm.

17. Device according to any one of claims 1 to 16, characterized in that the guide (3) has an inner diameter of between 1.2 mm and 2 mm, preferably of the order of 1.6 mm.

18. Device according to any one of claims 1 to 17, characterized in that the guide (3) has an outer diameter of between 3.2 mm and 4 mm, preferably of the order of 3.6 mm.

19. Device according to any one of claims 1 to 18, characterized in that the guide (3) has at its free end (3a) a closed tip.

20. Device according to any one of claims 1 to 18, characterized in that the guide (3) has at its free end (3a) a tapered open tip.

21. Device according to any one of claims 1 to 20, characterized in that the guide (3) is at least partially covered with a heat-shrinkable sheath, for example of polyolefin material.