Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Fiber optic probe tip

Fiber optic probe tip description/claims

This application is a divisional of U.S. patent application Ser. No. 11/094,084 titled Fiber Optic Probe Tip filed on Mar. 30, 2005, which claims the benefit of U.S. provisional application No. 60/590,420 filed on Jul. 20, 2004.

The present invention generally relates to medical devices. More particularly, the invention relates to medical devices that deliver electromagnetic radiation to an area under treatment by means of an optical fiber.

Photodynamic therapy (“PDT”) has been used to treat various maladies and diseases. PDT often involves the use of a photosensitizing agent that is activated by electromagnetic radiation (e.g., light such as laser light). Therapeutic treatments of this type have been known for many years. For example, in some instances they have been applied to the treatment of localized cancer. There are photosensitizing drugs such as hematoporphyrin derivatives that have selective application to tumors. When activated by exposure to light, these drugs can cause cell necrosis. An example of this type of treatment is disclosed in U.S. Pat. No. 4,336,809.

PDT has also been used as a method for treating periodontal disease. When used with an appropriate photosensitizing compound, optical activation (e.g., by light or laser) irradiation is known to kill the type of bacteria that causes a number of oral or tooth-related diseases, including chronic periodontitis. This process is sometimes referred to as Photodynamic Disinfection (PDD).

The delivery of optical activation light in conjunction with PDT is often done with some type of optical fiber. As an example, U.S. Pat. No. 6,019,605 illustrates how an optical fiber is commonly used. In the patent, an optical fiber is inserted into the periodontal pocket near a tooth (see the '605 patent, FIG. 1, item 20). This type of fiber optic, light-delivery probe supplies light to a specific tissue area where treatment is needed. The way light is delivered or applied to the tissue depends on the optical characteristics and the shape of the tip at the very end of the fiber.

Whether or not optical fibers (or “fiber optic probes”) are used in connection with PDT or in other kinds of medical applications where light is provided to an area or a cavity within the human body, it is sometimes desirable to have lateral dispersion or diffusion of light from the end of the probe. Normally, the majority or nearly all of the light emitted out from an end of the fiber is emitted in a narrow cone shape that is directional and coaxial with the end of the fiber. Therefore, it will be delivered essentially as a “spot” on a tissue area that generally corresponds to or is only slightly larger than the diameter of the fiber. In order to diffuse or disperse the light over a larger area, there have been instances where fiber optic probes have been designed with a “bead” element that caps the terminal end of the fiber to roughly emulate the effect created by a Fresnel lens. While this type of design can disperse light laterally relative to the fiber, it suffers drawbacks in several respects.

First, probes of this type enlarge the outer diameter beyond the normal diameter of the optical fiber. Typical optical fibers may have a diameter in the range of 300-600 microns. These small diameters are desirable because they are relatively non-invasive when used in conjunction with medical procedures. The small diameter of fiber optic probes becomes particularly important if the probe is to be positioned into a periodontal cavity between tooth and gums. It is obvious, therefore, that an enlarged probe tip is undesirable when used in applications of this type. Second, this type of tip may be susceptible to breaking away from the fiber, unless very secure modes of attachment are used. Typically, it is not desirable to have any part of a probe tip break off in a periodontal cavity or any other place inside the human body where it is desirable to deliver light.

The present invention is an improvement that addresses these and/or other kinds of design drawbacks of conventional probes.

In one embodiment, present invention is an improved fiber optic probe or probe tip. It includes an optical fiber that has an outside diameter that is suitable for insertion into a periodontal pocket or other kind of cavity or region within the human body. The optical fiber typically has a tapered end and a terminal or filler material, that is preferably made from a different material relative to the material that makes up the optical fiber, is typically connected to the tapered end of the fiber. In a preferred embodiment, the terminal material has an outer diameter that is substantially the same as the outer diameter of the optical fiber. With this type of construction, when used as part of a fiber optic probe that transmits electromagnetic radiation (e.g. laser light) to a treatment area, the different optical properties of the fiber (e.g., the fiber taper), the fill material or both cause lateral dispersion of the light from the end of the probe. Moreover, by keeping a constant outer diameter during the transition from the optical fiber to the other material, the probe is able to disperse light while remaining less invasive.

It may be desirable to manufacture the probe with a polymer cladding that covers the transition region where the terminal material is connected to the tapered end of the fiber. Moreover, it may be desirable to include radiation or light-scattering elements within the terminal material. Titanium dioxide (TIO2) is suitable for use in this respect. Aluminum compounds may be equally suitable.

A better understanding of the invention will be had upon review of the follow detailed description, which is to be read in conjunction with the accompanying drawings.

In the drawings, like reference numerals and letters refer to like parts throughout the various views, unless indicated otherwise:

FIG. 1 is a pictorial view of a fiber optic probe tip constructed in accordance with a preferred embodiment of the invention;

• Provisional Patent
• Utility Patent

• What Is a Patent?
• What Is a Trademark or Servicemark?
• What Is a Copyright?
• Patent Laws