DE2424726A1 - Radiation - emitting probe for medical use - having rigid or flexible light conductor coated with tetrafluoro-ethylene polymer - Google Patents

Abstract

Radiation-emitting probe for medical use, esp. for coagulating blood vessle, has a rigid or flexible, e.g. a rod or fibre bundle, light conductor that consists of a dielectric material, e.g. glass, encapsulated glass or quartz glass, and is connected to a radiation source in the spectral region between long wave u.v. and short wave i.r., and a radiation-emitting face on the light conductor that consists of a thin, smooth, pref. transparent layer of a polymer, selected from PTFE, or a tetrafluoroethylene copolymer having similar properties to PTFE, specif. "Teflon FEP" and "Teflon PFA" e.g. non-stick properties, optical transparency, and heat resistance. The probe does not contaminate the tissues during coagulation. It provides a high radiation density. Good protection of the radiation emitting face of the dielectric material. Very low adhesion to tissues.

Description

Radiation coagulator The invention relates to a movable probe, which emits intense ultraviolet, visible or even infrared radiation, in order to use it for medical purposes to obliterate tissue and coagulate bleeding vessels.

Ls is known to coagulate with radiation either light sources to be used with reflector or focusing device, or rigid or flexible, to use light guides connected to a light source that are capable of high radiation output to be carried out. Such flexible light guides are in the Form of liquid light guides known in the DP2352670.7 and in the DP2406424.2 become. In the DP-os 2145921 there is also a special flexible light guide for Intense laser radiation indicated, with which one can coagulate and scleros. Rigid Light guides mostly consist of optically isolated or non-isolated (i.e. insulated against air) glass rods, in whose entrance surface the radiation of a Large is focused.

All these radiation coagulation probes have in common that coagulation must be made contactless, since the sensitive glass beam exit surfaces the rigid or flexible light guide does not come into contact with tissue, blood or may be contaminated by the vapors rising during coagulation. Such Dirt sticks to the glass surface and is heated up by the radiation and burn themselves into the exit surface, so that the optical transmission is rapid decreases. Another decisive disadvantage thus arises from the Coagulation, the minimum distance to be maintained (light guide exit surface - tissue) by that with the strong divergence dec exiting beam the power density at the location the coagulation has already decreased considerably. But it is precisely during coagulation bleeding vessels are often desirable, a maximum flow rate is available and during the coagulation with radiant heat through the blooming vessel mechanical pressure to close, thus preventing the flow of blood, the otherwise the supplied heat would quickly be removed again. Besides, it is for the coagulation of a bleeding vessel it is important that as much radiation as possible reaches the vessel stump, which is not the case in the case of contactless congulation is always possible because the pool of blood spread over the vessel stumps the radiation can absorb almost completely.

This can only be avoided if, during coagulation, the surface of the jet emerges of the rigid or flexible light guide presses directly onto the bleeding vessel.

The invention is therefore based on the object a Specify light coagulator with rigid or flexible light guide, which in the Coagulation can be brought into contact with the tissue without contaminating it and thus the maximum radiation power density at the light guide exit surface for to make the coagulation usable.

According to the invention, this object is achieved in that this mostly consists of Glass existing cylindrical end piece of the light guide with a thin, if possible transparent Teflon sleeve closed on one side, or a polymer, which consists only of the chemical elements C and F or C, F and O composed.

Such a polymer is commercially available under the name Teflon, Teflon FEP or TefLon PFA known. The Teflon layer can also be applied to the previously roughened beam exit surface of the light guide be sprayed on, but it is also possible, the cylindrical ones described in the DP2352670.7 and in the DP2406424.2 glass end pieces of the light guide with preformed Teflon sleeves closed on one side to be coated or to be shrunk on by thermal treatment. Dadurh surrenders the advantage that the outer surface of the cylindrical end pieces of the light guide is protected, and that the Teflon sleeves can be replaced from time to time. This technique is also suitable for a rigid light guide rod made of glass. at With the laser light guide described in DP-os 2145921, it is possible to use the Teflon window at a distance from the light exit surface, since the light beam only with very less Divergence emerges and therefore not at maximum power density Attention must be paid to the contact surface between the Teflon window and the fabric.

The use of the copolymers Teflon FEP or PFA as a coating in contrast to pure Teflon, offers the advantage for the light guide end faces the west-ntly higher transparency, whereby the optical scattering is hexabye and the light losses are minimal. However, pure Teflon and Teflon possess PFA the highest thermal resilience, and therefore offer advantages. The pure Teflon should be as little crystalline as possible because of the better transparency. The adhesive forces on the Teflon window are of course the least when it is polished as smoothly as possible is.

The advantages that can be achieved with the invention consist in particular in that the Teflon window pressed onto the fabric after the heating process kasln can be removed again without significant adhesion, which is related to the Teflon-coated frying pan is already known.

In contrast to the frying pan, the tissue here is not exposed to thermal Contact, but heated by radiation that passes through the Teflon layer, without heating them up. This type of heating is more direct and has the Advantage of better reproducibility. For the coagulation of bleeding vessels is the lack of adhesion between Teflon and fabric is crucial because the metallic electrics because of the adhesion between metal and fabric coagulated vessels on removal the cold tear open again.

In addition, the radiation coagulator, which is provided with a Teflon window, allows compared to already known radiation coagulators by mechanical pressure Prevent heat flow through the vessel, as the sensitive glass window is protected are and not Teflon itself because of the lack of adhesive forces. contaminated.

The spectral transmittance of Teflon and the Teflon copolymers (FEP, PFA) is so large in both UV and near IR that when using the common sources of radiation, such as the Wo-Halogen-Lampc, the Hg-high pressure lamp and xenon high pressure lamp as well as the Nd-YAG and argon laser, the thin Teflon window (d-5/10 mm) almost 80% of the radiation from these light sources lets through without itself to warm up. The remaining 202 are scattered in the Teflon and not absorbed. With the Teflon window pressed against the tissue, the radiation coagulation the same good coagulating effect as the electrocautery, which also with mechanical pressure arLitet, but has the disadvantage that the human body as a conductor for the high frequency current is needed, causing uncontrollable burns can be generated.

When using a divergent surface emitter, e.g.

of the Wo lamp, the beam power density is directly at the light guide exit surface the biggest. The thin Teflon window lying on the exit surface permits in connection with 'the mechanical pressure, this maximum power density for Generation of maximum temperature.

Another advantage arises from the fact that the refractive index of Teflon is significantly lower <n = 1.35) than that of all glasses, so that the Teflon sleeve pulled over a glass rod, the total reflection on the outer surface the glass rod does not interfere.

An embodiment of the invention is shown in the drawing and is described in more detail below. FIG. 1 shows a light coagulator with light source (1), a tungsten or high pressure lamp, reflector (2) and rigid Light guide rod (3), the æ.B. can consist of fused quartz, as well as one in the form of a sleeve closed on one side covered Teflon window (4), which adheres firmly to the light guide rod. This window (4) can be removed and shown separately in cross section (4a).

The groove (4b, is used to displace air when the window is pushed open on the light rod. Typical dimensions for the window 4) are: Length 0.5 - 5 cm,; Ennand diameter 2 - 10 mm, wall thickness of the cylinder surface approx. 1 mm, wall thickness the window area (41) 2/10 - 1 mm.

Fig. 2 shows a light coagulator with an Hg or Ze high pressure lamp (1 ') and a flexible liquid light guide (Teflon FEP tube (3'a) and Liquid (3'b)) as described in DP2406424.2, with a cylindri cal exit window (3'C) made of quartz glass or glass. On this exit window is again the Teflon window (411) in the form of a sleeve (4 ') closed on one side pulled over, in a similar way to Fig. 1. The Teflon sleeve (4l) can also be shrunk on in the heat, making it even more solid Seat has, but not so easily changed, cant. The same goes for in the event that the Teflon window is sprayed on.

Fig. 3 igt a light guide with a conical exit window made of glass (3 "c), onto which a tight-fitting Teflon sleeve (4") is also shrunk, is sprayed on or pressed on. The conical shape of the light guide end increases the Radiation power density at the contact point Teflon window (41 ") - fabric.

Claims (7)

Claims 1.) Radiation coagulator with a radiation source in the spectral Range from long-wave UV to short-wave IR with a rigid light guide rod dielectric material such as glass, coated glass or quartz glass or optically isolated Quartz glass or flexible light guide for the transmission of intense radiation in the form of liquid light guides, fiber bundles or monofiber light guides for laser radiation, characterized in that the beam exit surface of the rigid or flexible Light guide from a thin, as transparent and smooth layer as possible Polymers bc.stelat, which belongs to the group of Teflones (? Eflon, Teflon FEP, Teflon PFA) originates from or consists of a Teflon copolymer with a similarly high thermal Resilience, non-stick properties and optical transparency like Teflon. 2.) Radiation coagulator according to claim 1), characterized by that the Teflon window (41) has the shape of a unilaterally closed cylindrical The sleeve (4) has a seizure fit over the cylindrically shaped end piece of the light guide rod or the flexible light guide can be pushed on. 3.) Radiation coagulator according to claim 1 and 2, characterized in that that the one-sided closed Tefionhtjlse (4) is provided with a groove (1b) on the inside which makes it easier to change the windows. 4.) Radiation coagulator according to claim 1 and 2, characterized by dadurcl, that the Teflon sleeve (4) is shrunk onto the end piece of the light guide in the heat will. 5.) Radiation coagulator according to claim 1), characterized in that that the beam exit surface of the cylindrical light guide end piece and a part the adjacent jacket surface is coated with a sprayed-on Teflon film e; ind. 6.) Radiation coagulator according to claim 1), characterized gekennzeich1let, that the Teflon window (41) lies tightly on the end face of the light guide. 7.) Radiation coagulator according to claim 1), characterized in that that the Teflon sleeve (42 ') tapers conically towards the jet exit surface (41 ") and überc.r a likewise conical end piece (3 "c) of the Idchtleiters Snug fit is shrunk or sprayed on. Blank page