Tip cover for appellation tonometer

Abstract

For calculating the intraocular pressure (IOP) of an eye, an applanation tonometer comprises an applanator formed of an optics array, a force transducer, an image sensor, and a processing circuit configured to calculate an intraocular pressure of the eye using one or more pairs of measured force and applanated area. The tonometer is provided with a disposable tip that covers the applanator, thereby providing a replaceable, sterile and transmissive interface between the tonometer's applanator and a patient's eye. Preferably, the applanating surface has a matte finish. The tonometer calculates the intraocular pressure using a predetermined relationship between interocular pressure and the slope of the line defined by data relating to the forces required to applanate the eye and the geometry of applanated portions of the eye. In a preferred embodiment, the data acquisition is synchronous. The tonometer may be of the type of a portable, hand-held device or a device affixed to and used in conjunction with a slit-lamp design. Also disclosed is a method and device for applying a disposable tip to the applanator.

What is claimed is:  
     
         1 . A disposable tip for a distal end of an applanator of a tonometer wherein the applanator includes a fiber optics array, the tip comprising a small sheet of thin light-transmitting but optically light-diffusing film adapted to be secured onto a distal end of the fiber optics array via an elastic member.  
     
     
         2 . A disposable tip as in  claim 1  wherein the elastic member is an O-ring.  
     
     
         3 . A disposable tip as in  claim 1  wherein the film is semi-transparent ethyl vinyl acetate having a matte surface on the side thereof distal from the tip of the applanator.  
     
     
         4 . A disposable tip for use with an applanation tonometer having a fiber optics array having first and second ends, the tip comprising a light-transmitting but optically diffusing material adapted to fit over the first end of the fiber optics array and to optically couple therewith, and 
 an attachment mechanism for detachably attaching the tip to the first end of the fiber optics array.    
     
     
         5 . The disposable tip of  claim 4 , wherein the material is formed at least in part of polyethylene fibers infused into a sheet.  
     
     
         6 . The disposable tip of  claim 4 , wherein the material is formed of semi-transparent ethylvinylacetate.  
     
     
         7 . The disposable tip of  claim 4 , wherein the attachment mechanism comprises an elastic ring for securing the material onto the first end of the fiber optics array.  
     
     
         8 . A disposable tip as in  claim 4 , wherein the first surface of the fiber optics array and the inner contacting surface of the tip are flat.  
     
     
         9 . A disposable tip for a distal end of an applanator of a tonometer wherein the applanator includes a fiber optics array, the tip comprising a small sheet of thin light-transmitting but optically light-diffusing film to be secured onto a distal end of the fiber optics array via a round member, the film being a semi-transparent material having a matte surface on the side thereof distal from the tip of the applanator.  
     
     
         10 . The disposable tip of  claim 9 , wherein the material is formed at least in part of polyethylene fibers infused into a sheet.  
     
     
         11 . The disposable tip of  claim 9 , wherein the material is formed of semi-transparent ethylvinylacetate.  
     
     
         12 . The disposable tip of  claim 9 , wherein the attachment mechanism comprises a ring for securing the material onto the first end of the fiber optics array.  
     
     
         13 . A disposable tip as in  claim 9 , wherein the first surface of the fiber optics array and the inner contacting surface of the tip are flat.  
     
     
         14 . A disposable tip for a distal end of an applanator of a tonometer wherein the applanator includes a fiber optics array, the tip comprising a small sheet of thin light-transmitting but optically light-diffusing film secured onto a distal end of the fiber optics array via a ring.  
     
     
         15 . A disposable tip as in  claim 14  wherein the film is a semi-transparent plastic material having a matte surface on the side thereof distal from the tip of the applanator.  
     
     
         16 . The disposable tip of  claim 14 , wherein the material is formed at least in part of polyethylene fibers infused into a sheet.  
     
     
         17 . The disposable tip of  claim 14 , wherein the material is formed of semi-transparent ethylvinylacetate.  
     
     
         18 . The disposable tip of  claim 14 , wherein the attachment mechanism comprises an elastic ring for securing the material onto the first end of the fiber optics array.  
     
     
         19 . A disposable tip as in  claim 14 , wherein the first surface of the fiber optics array and the inner contacting surface of the tip are flat.  
     
     
         20 . Apparatus for forming the disposable tip of  claim 1  for a distal end of an applanator of a tonometer comprising an assembly tool having a first upper cavity for receiving a thin light-diffusing film to result in a disposable tip, a second lower and smaller cavity into which an elastic member can be disposed, and a third lower or bottom cavity for receiving a distal end of an applanator, all for enabling the distal end of an applanator to be pushed into the assembly tool to cause the film to wrap around the distal end to thereby form the disposable tip and cause the elastic member to slide partway up the distal end to secure the film tip thereto.  
     
     
         21 . Apparatus for forming a disposable tip on a distal end of an applanator of a tonometer comprising an assembly tool having a first upper cavity for receiving a thin light-diffusing film to result in a disposable tip, a second lower and smaller cavity into which an elastic member can be disposed, and a third lower or bottom cavity for receiving a distal end of the applanator, all for enabling the distal end of the applanator to be pushed into the assembly tool to cause the film to wrap around the distal end to thereby form the disposable tip and cause the elastic member to slide partway up the distal end to secure the film tip thereto.