Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
  • A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
  • A61B3/16—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for measuring intraocular pressure, e.g. tonometers

Definitions

• the present invention relates to a tonometer cone.
• the tonometer is an instrument used in ophthalmology to determine the intraocular pressure of an eye of the patient, for example in order to determine whether a glaucoma is present.
• the Goldmann applanation tonometer In the sector, the most widespread and most precise instrument is the Goldmann applanation tonometer. It is composed of a body, which contains mechanisms within it that are similar to those of a precision scales, and an upper portion, which is constituted by a thin metallic bracket at the end of which a cone is positioned which the ophthalmologist brings into contact with the eye of the patient.
• the value of the intraocular pressure is obtained as a function of the resistance offered by the ocular surface.
• the cone touches the apex of the cornea and, therefore, at each measurement it needs to be disinfected or, if it is a single-use cone, replaced.
• Reusable cones need to be carefully disinfected before every use, washed with running water, dried with a clean cloth and, after use, they need to be re-sterilized to prevent the transmission of pathogens from one patient to another through the lacrimal film.
• the latter are cones that are provided in two or in three separate parts, of which only the part that comes into contact with the eye of the patient during the examination is single-use.
• the two parts can be constituted by a tip, the part that comes into contact with the eye, and by a main body to be inserted into the tip.
• Some types of single-use cones available on the market are completely transparent, to the disadvantage of the image obtained, which is not completely clear owing to the dispersion inside the cone of light rays coming from outside.
• cones are provided with the central part tinted, or with the side surfaces tinted with a dark color.
• the cone is single- use and made of plastic material by co-molding a substantially transparent part and an opaque dark part.
• the first part is preferably made of polymethyl methacrylate (PMMA) or of polymethyl acrylate (PMA), and the second part is preferably made of thermoplastic elastomer.
• such cone has a first substantially cylindrical portion which constitutes the tip of the cone which comes into contact with the eye of the patient, a second conical portion which is adjacent to the first portion and the smaller-diameter end of which is substantially the continuation of the end of the first portion, opposite to the other end which comes into contact with the eye, and a third substantially cylindrical portion placed adjacent to the second portion so that one end of the third portion is substantially the continuation of the larger-diameter end of the second portion.
• Such cone can be easily gripped by the operator, by grasping it at the second or at the third portion.
• the aim of the present invention is to provide a tonometer cone that is capable of improving the prior art in one or more of the above mentioned aspects.
• an object of the invention is to provide a single-use tonometer cone, with high visual quality, in order to obtain an evaluation as correct as possible of the intraocular pressure of the patient, while limiting production rejects and therefore keeping costs down with respect to conventional cones.
• Another object of the invention is to provide a tonometer cone that is not only precise and capable of being provided simply and at low cost, but which is also safe for both doctor and patient from the point of view of hygiene and of its sterilization.
• a further object of the present invention is to overcome the drawbacks of the prior art in an alternative manner to any existing solutions.
• Another object of the invention is to provide a tonometer cone that is highly reliable, easy to implement and at low cost.
• FIG. 1 is a perspective view of the tonometer cone according to the invention.
• FIG. 2 is a cross-sectional side view of the tonometer cone according to the invention.
• FIG. 3 is a perspective view of the internal part of the tonometer cone according to the invention.
• the tonometer cone generally designated by the reference numeral 10, comprises an internal part 11 , which is substantially transparent and longitudinally extended, with an end portion 12 which is adapted to make contact with an eye of the patient, and an intermediate portion 14 which is substantially frustum-shaped or cylindrical (frustum-shaped in the example shown).
• the cone 10 also comprises a covering 13 which is complementary to the intermediate portion 14 and is to be fitted thereon.
• the covering 13 is made of a material with antibacterial properties.
• the internal part 11 comprises in succession:
• the intermediate portion 14 which is frustum-shaped (or cylindrical in a possible variation) and at least partially hollow,
• the end portion 12 if frustum-shaped as in the example shown, has an end, which comes into contact with the eye, of smaller diameter than the end that is adjacent to the intermediate portion 14.
• the internal part 11 is preferably made of thermoplastic material, preferably PMMA (polymethylmethacrylate), or alternatively ABS (acrylonitrile butadiene styrene) and the like.
• PMMA polymethylmethacrylate
• ABS acrylonitrile butadiene styrene
• the covering 13 is tinted, preferably with a dark color, and is adapted to coat the intermediate portion 15, and therefore has a complementary hollow frustum shape and is provided by molding plastic material with antibacterial properties.
• thermoplastic elastomeric material TPE
• MARFRAN.MED® is a TPE compound known in the medical and pharmaceutical sector.
• MARFRAN.MED® is a family of thermoplastic compounds based on SEBS (styrene-ethyl-butyl-styrene) in which usnic acid, an antibiotic of plant origin extracted from some species of lichen, is embedded in the matrix.
• the end portion 12 With its diameter creates a slight shoulder for the covering 13, thus preventing the separation thereof on the internal part
• the covering element 13 is inserted at the portion 12, and, owing to the presence of the shoulder, is snap-coupled to it by elastic deformation.
• the intermediate portion 14 has a greater diameter away from the end portion 12, and at the opposite end from the latter it has a circular protrusion 16.
• the invention also relates to an applanation tonometer cone, which comprises:
• - a substantially transparent and longitudinally extended internal part, with an end portion adapted to make contact with an eye of the patient, and a substantially frustum-shaped or cylindrical intermediate portion,
• the covering is again tinted and preferably dark in color.
• the internal part is obtained by hot-runner injection of plastic material in the cavity of a mold, which makes it possible to bring the material to the mold in liquid form.
• the injector used is relatively small, is controlled by an injection molding machine, and is capable of opening and closing at the appropriate time in order to control the introduction of thermoplastic material. This solution makes it possible to eliminate much of the filling sprues, with considerable saving of waste material.
• the apparatus should be preferably provided with occlusion pins, which advantageously ensure: the absence of cold material from the previous molding, constant and balanced filling (where the mold has multiple cavities, this makes it possible to deposit the same quantity of product in all the impressions), an injection point clean and free from filaments, shorter mold filling times (therefore also a shorter production cycle), and lower injection pressures with consequent longer lifetime of the mold.
• the tonometer cone according to the invention is single-use and is offered in single packages or in blister packs. To use it, the cone is freed from the package and applied by the operator to the tonometer. In this step of manipulation, the antibacterial material of the covering 13 prevents the transfer of contagious bacteria between patients and operators.
• the external covering being made of plastic material that is dark in color and has antibacterial properties, is capable not only of protecting the internal part from any light beams coming from outside, in order to obtain a clear image, but also of protecting the patient from contamination events that could occur after the extraction of the cone from the sterile package.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Medical Informatics (AREA)
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Citations (5)

• 2017
  • 2017-10-16 IT IT102017000116091A patent/IT201700116091A1/it unknown
• 2018
  • 2018-10-15 WO PCT/EP2018/078079 patent/WO2019076815A1/en active Application Filing

Patent Citations (5)

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