WO2014068495A2

WO2014068495A2 - Medical device for illuminating tissue

Info

Publication number: WO2014068495A2
Application number: PCT/IB2013/059774
Authority: WO
Inventors: Roland Bays
Original assignee: Medlight S.A.
Priority date: 2012-11-05
Filing date: 2013-10-30
Publication date: 2014-05-08
Also published as: WO2014068495A3

Abstract

The invention relates to a device for illuminating tissue, including an insertion catheter (6) inside of which a light diffuser can be arranged, which essentially consists of an optical fibre (3) comprising a diffusing distal end, the distal end (8) of the insertion catheter (6) consisting of a transparent or optically diffusing material; characterised in that the insertion catheter (6) is surrounded by an outer tube (10) which is mounted such as to slide along the insertion catheter (6). The invention also relates to a winder for a light diffuser as well as to various uses of the aforementioned device.

Description

MEDICAL DEVICE FOR ILLUMINATION OF FABRICS

Field of the invention

The invention relates to phototherapy and more particularly to the use of light diffusers that are introduced into biological tissues.

State of the art

There are currently many medical treatments based on the interaction of light with endogenous or exogenous photosensitive components present in biological tissues (thermotherapy, low intensity laser therapy (LLLT), dynamic phototherapy, etc.). The transmission of light to the tissue to be treated may be from the tissue surface or interstitial.

Interstitial illumination is often achieved by using a light diffuser inserted into the tissue. The light diffuser is an instrument constituted by an optical fiber (Fig.1) and a diffusing end. An optical connector couples the proximal end of the optical fiber to a light source. The optical fiber then guides the light to the diffusing distal end. The light is then emitted in a controlled manner, for example uniform, on the typically cylindrical surface, over a defined length, the so-called illumination length. There are today different models of interstitial light diffuser commercially available. The length of illumination is non-adjustable and is usually between a few millimeters and a few centimeters.

A stiffer catheter, terminated with a tip, can be used to facilitate the insertion of the light diffuser and its positioning in the tissue. Illumination is then made through the walls of this insertion catheter. If this is not possible, it is removed before illumination.

The insertion catheters currently used are either rigid and brittle cannulas, optically transparent (diffusing white ceramic for example), or metal needles that must be removed after insertion of the light diffuser, or flexible transparent needles reinforced by a metal mandrel. place to the inside of the needle. The mandrel is removed after positioning the catheter to make room for the light diffuser (eg Introduction Fiber Catheter, model iCAT, Medlight SA, Switzerland). In any case, by their very concept (permeable catheter and / or short catheter), these insertion catheters require the use of a sterile light diffuser. Sterilization of such an instrument is hardly possible in a clinical environment, the sterility condition makes multiple use of the light diffuser impossible for interstitial applications.

In the case of large tissues, several light diffusers are sometimes necessary (Fig.2), arranged in such a way as to obtain the distribution of the light intensity sufficient for the targeted treatment in the volume to be treated. The position and the illumination length of each light diffuser depend on the propagation properties of the light in the treated tissue as well as the geometry of the targeted area. A wide range of illumination lengths may sometimes be necessary to allow precise treatment. The determination of the lengths used and the positioning of each selected diffuser in the appropriate insertion catheter should be done carefully and can be a source of error.

With the equipment of the state of the art:

1. The insertion catheter and the light diffuser must be sterile.

The technology used in light diffusers does not allow sterilization in a hospital environment, the light diffuser is either single use or requires a return to the manufacturer for a validated reconditioning. Both solutions are associated with an unavoidable extra cost. Handling without risk of contamination of a thin and flexible sterile element, more than 1 meter long, is also a problem in a clinical setting. Its connection with a light source, non-sterile, must be done without risk of contamination. Calibration of the light diffuser, requiring the introduction of its diffusing end in a calibration unit, non-sterile, must also be performed without contact with the calibration unit. In both cases, this means a sterile barrier between the diffuser and the 2 non-sterile instruments. In addition, the person handling the sterile dispenser can not touch these non-sterile devices. The involvement of a third person is often necessary. 2. The illumination area is determined by the illumination length of the light diffuser.

This determination can usually be made accurately only when the insertion catheter has been placed in the volume to be treated. Depending on its position within this volume and by ultrasound image, the operator can determine the limits of the desired illumination area and thus the length of the necessary light diffuser. It is therefore only after placement of the insertion catheter that the light diffuser is selected and prepared (removed from its sterile packaging and calibrated). The luminous power required for the treatment, depending on the length of the diffuser illumination, must be selected at the light source according to the chosen diffuser.

For the treatment of a large volume requiring several light diffusers, the insertion catheters insertion and preparation of light diffusers can therefore be done only in succession and the correspondence between each insertion catheter and the length light diffuser chosen by the doctor must be guaranteed. These conditions strongly influence the processing time and its complexity.

The control of the illumination length is thus ensured by a distance measurement on an ultrasound image, followed by a choice of diffusion length of the appropriate light diffuser with limited available lengths and a certain tolerance on these values, followed by a positioning of the diffuser in the insertion catheter. This succession of operations does not guarantee a high accuracy and increases the risk of the occurrence of an error on the treatment length finally obtained.

Description of the invention

The invention relates to a device for interstitial illumination of tissue as defined in the claims.

The main advantage of the invention is a reduction in the cost of treatment in allowing the realization of an interstitial illumination system in which the most expensive part, the light diffuser, is multiple use. This is achieved by isolating the light diffuser from the sterile area and protecting it from the risk of aggression (mechanical, chemical, etc.) during its use and between uses. The proposed concept also allows the realization of an illumination device where the illumination length is adjustable during treatment, for example under ultrasound vision. This simplifies the procedure especially during multi focal interstitial processing and reduces sources of error.

In the present text, the term "rigid outer tube" should be understood to include an object whose rigidity is greater than that of the flexible catheter located inside said tube, so as to facilitate the insertion of the catheter into the tissue.

The invention will be better understood hereinafter, by presenting some embodiments and some figures.

Brief description of the figures

FIG. 1 represents a typically cylindrical light diffuser of the state of the art

Figure 2 shows an illumination of large target areas using several typically cylindrical light diffusers.

Figure 3 shows a flexible insertion catheter with an outer rigid tube, according to an embodiment of the invention.

Figure 4 shows a flexible insertion catheter according to the invention with an inner mandrel.

Figure 5 illustrates the preservation of a sterile area by the insertion catheter.

Figure 6 shows an insertion catheter according to the invention with control of the illumination length.

FIG. 7 represents an individual manipulation of insertion catheters according to the invention which are positioned side by side thanks to a flexible tube attached to the tube mobile rigid exterior.

Figure 8 shows the operating mode of a fiber optic catheter storage box.

Figure 9 illustrates various steps of using a catheter storage box according to the invention.

Figure 10 illustrates the flow mechanism of a catheter.

Figure 11 shows one embodiment of the catheter storage box.

Numerical references used in the figures

1. Cylindrical light diffuser

2. Optical connector.

3. Optical fiber.

4. Illumination length of the cylindrical light diffuser.

5. Area targeted typically a lesion.

6. Insertion catheter

7. Flexible tube.

8. Transparent flexible tube.

9. Rigid tip.

10. Outside tube, rigid, mobile

1 1. Chuck (rigid).

12. Light source.

13. Illumination length defined by the outer tube (10).

14. External flexible tube.

15. Circular box.

16. Calibration or control instrument.

17. Guiding the light diffuser.

According to a first embodiment, the invention relates to an interstitial illumination system in which the insertion catheter consists of a first flexible tube terminated by a transparent section, closed by a rigid tip (FIG. 3a). To allow insertion and positioning in the fabric of the first flexible tube, the latter is stiffened over a length corresponding at least to the insertion length by a second tube, external and movable relative to the first. When the insertion catheter is correctly positioned in the tissue, the diffusing end of the typically cylindrical light diffuser can be positioned in the transparent portion of the flexible tube and the rigid tube can be moved along the flexible tube to allow the light emitted by the cylindrical light diffuser to reach the tissues (Fig.3.b). With this concept of insertion catheter, it is possible to make an insertion catheter of any length and flexible. The only requirement is to have a rigid outer tube adapted to the insertion depth.

The use of a long insertion catheter makes it possible to consider the clinical use of cylindrical light diffusers in a non-sterile manner. The proposed insertion catheter, which is sterile, makes it possible to prevent contamination of the light diffuser by the tissue during treatment and also to protect the sterile area surrounding the operating field from contamination by the light diffuser (FIG. .5). Simply place the proximal end of the insertion catheter sufficiently far from the operative field after performing the insertion of the distal portion and thereby effect the introduction of the light valve into the insertion catheter outside. of the sterile area. During placement of the insertion catheter, its proximal end may be closed by a sealing cap to prevent any risk of contamination of its inner canal. An interface element between the insertion catheter and the light diffuser is also conceivable to facilitate the connection.

Another possibility to stiffen the flexible tube of an insertion catheter is to place a rigid mandrel inside the tube (Fig.4) This mandrel is removed after insertion to allow the positioning of the light diffuser. may be short in relation to the length of the insertion catheter, simply attach it to a flexible wire allowing it to be removed from the insertion catheter once insertion is complete.

The possibility of using non-sterile light diffusers makes it possible to envisage a multiple use of these latter. Indeed, compatible sterilization techniques with the technologies currently used for the production of light diffusers are generally not applicable in hospitals. If the sterility of the light diffusers is obligatory, their multiple use is not practicable in real clinical conditions. An insertion catheter as defined thus makes it possible to dispense with the sterility of the diffuser and thus introduces the possibility of its multiple use.

As previously indicated, the multiple use of the light diffuser is made possible by the proposed insertion catheter concept. To allow the application of this modality, however, it is also necessary to minimize the risk of damage to the multiple use light diffuser, both during the preparation of the procedure (calibration, verification, etc.) than during the treatment, storage (especially cleaning) and storage of the instrument between two procedures. To this end, the invention also relates to a package for meeting these safety requirements while allowing easy application of all the usual manipulations that must undergo a light diffuser during a standard interstitial therapy.

Advantageously, the light diffuser is wound inside a circular box. Both ends come out of the box (Fig.8.a). Changing the winding diameter of the part of the diffuser inside the box, allows to change the lengths of the ends of the light diffuser outside the box (Fig.8.b).

During transportation and storage, both ends of the light diffuser can be wound around the outer circumference of the circular box and immobilized (Fig.9.a). At the time of calibration, both ends can be detached and unwound (Fig.9.b). The proximal end corresponding to the optical connector may be attached to the light source. The distal end with the illumination area can be manipulated to perform the calibration. At the time of treatment, when the light diffuser is to be introduced into the insertion catheter, the length of the distal end of the light diffuser, outside the circular box, can be increased using the previously mentioned principle (Fig.9.c).

In a particular embodiment, the two ends of the light diffuser, in their storage position, are integrally protected in flexible protective sheaths or catheters, fixed at one of their ends to the storage box. At At the time of treatment, the distal end of the light diffuser may exit its protective tube to be inserted into the insertion catheter. The light diffuser is thus always protected.

In a particular embodiment, the perimeter of the circular box is close to the length of each of the ends of the light diffuser wound outside the circular box. So just a single round around the box to make the storage.

Light diffusers generally consist of an optical fiber whose radius of curvature must not exceed a lower limit. In a particular embodiment, a circular element with a radius of curvature satisfying this condition is placed inside the box (Fig.8.b), limiting the stroke of the light diffuser.

The change in length of the ends of the light diffuser outside the storage box, made possible by the change in winding diameter of the part of the catheter wound inside the circular box, can be obtained from different ways. A solution proposed in the context of the present invention is as follows. A section of the light diffuser, between the outer end of the housing and the coiled portion therein, is guided along the circumference of the circular housing (Fig.10). By moving a point (P) of this section following the guide member, it is possible to vary the length of the end of the light diffuser outside the housing.

In a particular embodiment, the guide is made by a groove on the upper surface of the side wall of the circular box (Fig. 11). This groove can be simply circular (Fig.1 1), following the circumference of the circular box. A spiral groove is also possible and allows movement greater than the circumference of the storage box. In both cases, the displacement of the point P can be done by the concentric rotation of a component relative to the box such as for example a circular disk that can also serve as a cover for the box.

The concept of a movable outer tube placed around the flexible tube of the insertion catheter not only stiffens the flexible tube during insertion of the catheter, but this outer tube can also be used as a light shield and thus change to will, by longitudinal displacement, the illumination length along the insertion catheter (Fig.6). With a light diffuser of a single illumination length, it is thus possible to determine different lengths of treatment. The displacement of the outer tube can be done after insertion of the insertion catheter, for example under ultrasound control. Such in situ adjustment is particularly appreciable in the case of a multifocal treatment in which it is necessary to apply a specific illumination length depending on the position of the insertion catheter in the lesion to be treated.

The outer movable tube may also be partially opaque, that is to say have windows transparent to light, of any shape and size. By translation and rotation of the tube, it is possible to position and orient the window or the illumination windows at will in the fabric. In a particular embodiment, the outer tube is a longitudinally split tube.

In a particular embodiment, the outer tube consists of two concentric tubes that are movable relative to each other and that are partially opaque. By translation or rotation of one of the two tubes relative to each other, it is possible to vary the characteristics of the screen they constitute for the light diffuser.

Of necessity, the stiffening tube has a slightly larger outer diameter than the outer diameter of the flexible tube of the insertion catheter. Its position is therefore visible in standard ultrasound whatever the ultrasound properties of the materials involved. If this tube is used as a screen, its positioning along the insertion catheter and thus the illumination length that it defines can be visualized. and adapted to the geometry of the targeted area by observing the ultrasound image.

The rigid outer tube can be attached to a second flexible outer tube. This second tube is used to move the rigid tube. This concept is particularly useful when multiple insertion catheters are placed side by side in a dense manner leaving little room for precise individual handling (Fig.7).

The transparent section of the insertion catheter may also be replaced by an optically diffusing tube section, that is, the wall of which strongly diffuses light with a negligible absorption rate. The tube section thus defined constitutes a cavity with optical properties similar to that of an optical integration sphere (also called Ulbricht sphere). A light beam emitted at a point in the cavity undergoes numerous reflections on the walls of the cavity before exiting, which has the effect, in the present situation, of averaging the possible and unintended fluctuations in space along the diffuser of the cavity. light. Similarly, the transmission of light through the diffusing wall has a weighting effect on such fluctuations. Overall the use of a diffusing tube instead of a transparent tube increases the uniformity of the illumination defined by the light diffuser and in particular reduces the effects of a local illumination peak determined for example by a damage. localized light diffuser occurred during its use. This increases the reliability of the illumination system, especially when multiple use of the light diffuser.

The proposed illumination system is particularly suitable for interstitial therapeutic applications of light. It can, however, also be advantageously used in non-interstitial applications (esophagus, bronchi, blood vessels, etc.).

The illumination system according to the invention allows the following procedure:

The doctor introduces the insertion catheter (s) and positions them, for example, under an ultrasound image, according to the planned treatment plan. The illumination length at each position can be adjusted by removing the rigid outer tube along each insertion catheter and verifying on the ultrasound image its position relative to the desired spatial treatment limit (edge of the target area, for example).

Independently, simultaneously, or in advance for an intervention or a series of interventions, the nurse or the technician responsible for the light source, without constraint of sterility, prepares an equivalent number of light diffusers all identical. All diffusers have the same illumination length corresponding to at least the maximum length of the treatment. The light diffusers are non-sterile, protected in their storage case. The end with the optical connector is unhooked from the housing and unwound for allow connection with the light source. The scattering end is detached from the housing and unrolled to allow its introduction into the calibration unit of the light source. Calibration is performed with all light diffusers. When a light diffuser is ready, its scattering end may be placed on a common interface medium waiting to be connected to an insertion catheter.

During or at the end of placement of the insertion catheters and / or adjustment of the illumination area, the proximal portion of each insertion catheter may be connected to the distal end of any one of the prepared light diffusers, without distinction, so without risk of confusion. With an appropriate connection system and sufficient insertion catheter length, it is possible to make such a connection at a large distance from the insertion point, without risk of contamination of the sterile area and also without risk of contamination. of the light diffuser.

When the connection is made, the diffusing portion of the light diffuser can be moved within the insertion catheter safely, without risk of contamination, from the insertion point by the fiber or fiber by the nearby tissues. from the insertion point. The movement of the diffuser is obtained by manipulation at the storage box, without direct manipulation of the light diffuser.

When all the light diffusers are correctly positioned in each insertion catheter, the actual treatment can take place. The light power is supplied to all light diffusers simultaneously in an identical time profile.

When the illumination session is over, the light diffusers are removed from the insertion catheters which can then be disconnected from the distal portion of the diffusers. The 2 ends of each light diffuser or their protective catheter are wound on the housing storage and fixed. No cleaning is necessary. The light diffusers are ready for another treatment.

Under certain conditions, in particular, for example, when either the power the illumination length variation required are too great, to the point of inducing a level of heat dissipation in the tissue by the unacceptable insertion catheter, light diffusers of different diffusion lengths may also be considered. Their number can be reduced, however, and operations simplified with the insertion catheter.

Claims

claims

1. Apparatus for tissue illumination comprising an insertion catheter (6) within which a light diffuser consisting essentially of an optical fiber (3) having a diffusing distal end, the distal end (8) ) the insertion catheter (6) being made of a transparent or optically diffusing material; characterized in that the insertion catheter (6) is surrounded by an outer tube (10) which is slidably mounted along the insertion catheter (6).

2. Device according to claim 1 wherein the insertion catheter is made of a rigid material.

3. Device according to claim 1 wherein the insertion catheter is made of a flexible material and comprising a rigid mandrel adapted to be positioned inside said catheter (6), prior to the insertion of said optical fiber ( 3).

4. Device according to claim 1 wherein the insertion catheter is made of a flexible material and wherein the outer tube (10) is made of a rigid material.

5. Device according to the preceding claim wherein the outer tube (10) at its proximal end is attached to a flexible tube (14).

6. Device according to claim 1 wherein the insertion catheter (6) is hermetically sealed at its distal end and its length is such that it allows to arrange the distal part of the device in a sterile area and manipulate the proximal portion in a non-sterile area, without risk of contamination.

7. Device according to any one of the preceding claims wherein the distal end of the outer tube (10) consists of an optically opaque material.

8. Device according to any one of the preceding claims wherein the distal end of the outer tube (10) consists of an optically opaque material, but having openings transparent to light.

9. Device according to claim 8 wherein the outer tube (10) consists of two concentric tubes movable relative to each other, opaque opaque and each having openings transparent to light.

A light diffuser reel as defined in any one of the preceding claims comprising a circular shaped cavity dimensioned to contain a wound light diffuser, the cavity further comprising an inlet port and an exit port disposed towards or around the circular cavity and oriented in opposite directions, so that when a pulling or compressive force is exerted on one or the other end of a diffuser disposed in the cavity and whose ends pass through the two orifices, the diameter of the coil of the diffuser changes, allowing the length of the end or the ends of the light diffuser to be modified outside the cavity.

1 1. The box of claim 10 including a mechanism for winding, respectively unrolling, a light diffuser which is disposed in the cavity.

12. Box according to claim 10 comprising two protective catheters coming out of said box. One of the catheters protects the proximal end of the light diffuser to the optical connector. The other catheter can connect directly to the insertion catheter and protect the distal portion of the light diffuser issuing from the cavity during storage as well as during all manipulations of the device.

13. Use of a device as defined in any one of claims 1 to 9 for interstitial medical applications.

14. Use of a device as defined in any one of claims 1 to 9 for non-interstitial medical applications (esophagus, bronchi, blood vessels, etc.).

15. Phototherapy treatment procedure using the device as described in claims 1 to 9 combined with the retractor of claim 10 or 11 or 12; characterized in that the length of the device is varied by winding, respectively unwinding, of the light diffuser.