Abstract:
A method and apparatus for minimizing damage to an optical fiber used as part of a laser radiation delivery system are disclosed. The apparatus includes the use of a spacer positioned adjacent the tip of the fiber to minimize the impact on the fiber tip of debris and vapor generated by exposure of a tissue target to high energy radiation. The end of the apparatus is configured to vent debris and vapor from the end of the tip to reduce damage. The fiber tip may also be annealed to enhance its resistance to damage. The method includes the step of spacing the fiber tip at a predetermined distance from the tissue target during exposure of the tissue target to laser radiation, and may include venting the debris created away from the fiber end. The method may further include the step of providing an annealed fiber tip.
Abstract:
An apparatus is disclosed for attenuating the beam of a laser. The apparatus is particularly suited for situations where a low powered aiming beam is necessary to be coaxially aligned with a full power working beam. The apparatus includes a refractive element having a pair of spaced-apart, parallel faces. A mounting arrangement is provided for selectively moving the refractive element into and out of the path of the full power laser beam. The refractive element is mounted such that when it is moved into the path of the laser beam, the beam will be split into primary and secondary beams. The primary beam will exit the refractive element along a path displaced from the incoming beam. The power of this exiting primary beam can be captured through a beam dump. The secondary beam is a product of at least two internal reflections within the refractive element. The secondary beam is highly attenuated and travels along the same path as the incoming beam. The secondary beam may be used for aiming since the full power beam will travel along the same path as the attenuated beam after the refractive element is moved out of its path.
Abstract:
The subject invention relates to an apparatus for selectively intercepting and redirecting a beam from a laser. The apparatus is particularly suited for use in a photocoagulator having an argon laser and a dye laser which are rigidly mounted to a housing. A set of fixed optical elements are provided for directing the beam of the argon laser to the cavity of the dye laser to pump the dye laser. The subject apparatus selectively intercepts and redirects the argon laser beam from its initial path to the dye laser to an alternative path out of the photocoagulator. In this manner, the wavelengths available from the argon laser can also be utilized to perform surgery. The apparatus for selecting the argon beam includes a pivotally mounted frame which is easily aligned and can reliably maintain that alignment.
Abstract:
A fiber optic probe is disclosed for delivering laser radiation from a medical laser system to a treatment site. The probe includes a handpiece having an axial channel. The axial channel includes an intermediate mating region of reduced diameter. A tip piece having a fiber located therein is mounted on the front end of the handpiece. The input end of the fiber is mounted in a ferrule which is received in the reduced diameter mating region of the handpiece. A tail piece which includes an optical fiber is mounted at the rear end of the handpiece. The delivery end of the fiber in the tail piece is mounted in a ferrule and is also received in the mating region of the handpiece. The two ferrules are spring biased together to maximize coupling efficiency. The mating region is spaced from the front end of the handpiece so that the force on the mating region, caused by the torque imparted to the tip piece during use, is less than it would be if the mating region were located at the front end whereby the coupling efficiency is maintained. The handpiece is designed to be reused after sterilization in an autoclave.
Abstract:
A novel retinal photocoagulator is described, having a laser for generating a beam of laser radiation and a beam delivery system for delivering the laser beam to the surface of the retina. The delivery system includes a lens system for varying the spot size of the beam at the surface of the retina which is operable in two alternate modes over a given range of spot sizes, wherein one of the modes varies the size of the spot while maintaining the beam in a focused condition at the retina, and wherein the other mode varies the size of the spot at the retina by altering it focal point.
Abstract:
An access tube is used for accessing an anatomic space, such as a pericardial space between the parietal and visceral pericardia. The access tube is advanced against the parietal pericardium and an anchor structure thereon embedded into the parietal pericardium. The access tube can then be used to separate the parietal and visceral pericardia and enlarge the pericardial space. After such enlargement, a needle or other access device can be introduced through the access tube into the pericardial space to provide access for a wide variety of purposes, including aspiration, infusion, and guidewire placement.
Abstract:
A side firing fiber optic probe is disclosed. The delivery end of the probe is provided with an angled face oriented to totally internally reflect the treatment beam out of the side surface of the fiber in a direction transverse to the longitudinal axis thereof. The delivery end of the probe is further configured to reduce secondary reflections which occur as the light strikes the side surface of the fiber. This result can be achieved by modifying the shape of the cladding material which surrounds the fiber core. In one approach, the ratio of the diameters of the clad to the core is increased. Other specific cladding configurations for reducing reflections can be used. In a further alternative, the surface of a glass capillary which surrounds the fiber can be optically coupled to the fiber. Each of these approaches functions to reduce unwanted light leakage from the fiber. In another aspect of the probe design, a stainless steel shield is provided which functions to protect the capillary and the fiber against cavitation effects which occur during use.
Abstract:
An approach for sterilizing and reusing a fiber optic probe is disclosed. The fiber optic probe includes an input end having an axially projecting stem containing the input face of the fiber. Prior to sterilization, a cap member is mounted on the stem to prevent damage by the pressurized steam encountered in an autoclave. After being sterilized, the probe is brought to the operating theater. The sterilized probe is transferred to the sterile field while the stem and cap member are extended beyond the sterile field. The cap member is then removed and the input end of the probe is connected to the source of laser radiation. Using this approach, the probe can be sterilized without damage and reused without contaminating the sterile field.
Abstract:
A method and apparatus for minimizing damage to an optical fiber used as part of a laser radiation delivery system are disclosed. The apparatus includes the use of a spacer positioned adjacent the tip of the fiber to minimize the impact on the fiber tip of debris and vapor generated by exposure of a tissue target to high energy radiation. The end of the apparatus is configured to vent debris and vapor from the end of the tip to reduce damage. The fiber tip may also be annealed to enhance its resistance to damage. The buffer material may also be stripped from the delivery end of the fiber so that the inner diameter of the outer support can be narrowed. An epoxy resin is injected into the space between the uncoated fiber and the support to stabilize the fiber and prevent it from bending. The delivery end of the fiber can also be enlarged to shield the remainder of the fiber from debris and vapor.