Intraocular pressure measurement system including a sensor mounted in a contact lens

Abstract

An apparatus ( 180 ) for measuring intraocular pressure (IOP) comprises a contact lens ( 40 ) including an inner surface ( 42 ) contoured to a surface portion ( 34 ) of an eye ( 36 ) and a sensor ( 10 ) disposed in the contact lens. The sensor ( 10 ) comprises a contact surface ( 14 ) for making contact with the surface portion ( 34 ) of the eye ( 36 ). The contact surface ( 14 ) includes an outer non-compliant region ( 16 ) and an inner.compliant region ( 18 ) fabricated as an impedance element that varies in impedance as the inner compliant region changes shape. The sensor ( 10 ) further comprises a region of conductive material ( 38 ) electrically coupled to the impedance element of the compliant region ( 18 ) and responsive to an external signal for energizing the impedance element so that the IOP may be determined.

1 . An apparatus for measuring intraocular pressure of an eye, said apparatus comprising: 
 a contact lens including an inner surface contoured to a surface portion of the eye for engaging the surface portion; and    a sensor disposed in said inner surface of said contact lens, said sensor comprising: 
 a contact surface for making contact with the surface portion of the eye, said contact surface including an outer non-compliant region and an inner compliant region fabricated as an impedance element that varies in impedance as said inner compliant region changes shape; and  
 a region of conductive material electrically coupled to said impedance element of said compliant region and responsive to an external signal for energizing said impedance element so that the intraocular pressure may be determined.  
   
     
     
         2 - 4 . (canceled)  
     
     
         5 . The apparatus of  claim 1  wherein said compliant region comprises a diaphragm that functions as one plate of a capacitive element, said diaphragm being separated by a dielectric region from another plate of said capacitive element, said diaphragm flexing closer to said other plate as said contact surface is pressed against the surface portion of the eye to change the capacitance of said capacitive element in proportion to the intraocular pressure of the eye.  
     
     
         6 - 8 . (canceled)  
     
     
         9 . The apparatus of  claim 5  wherein said region of conductive material comprises an inductor coil that is electrically coupled to said capacitive element to form a resonant circuit, the external signal comprising an electromagnetic signal that varies in frequency to cause said resonant circuit to be energized and resonant at a frequency in proportion to the capacitance of said capacitive element so that the intraocular pressure may be determined.  
     
     
         10 . The apparatus of  claim 9  wherein said inductor coil is fabricated in said non-compliant region.  
     
     
         11 . The apparatus of  claim 9  wherein said inductor coil is fabricated on said inner compliant region.  
     
     
         12 . The apparatus of  claim 11  further comprising a second inductor coil formed underneath said diaphragm.  
     
     
         13 . The apparatus of  claim 9  wherein said inductor coil is formed by disposing conductive material in a predetermined pattern in a surface of said non-compliant region about said compliant region of said contact surface.  
     
     
         14 - 34 . (canceled)