Intraocular Pressure Sensor with External Pressure Compensation

Abstract

An intraocular pressure sensor system has a first pressure sensor located in an anterior chamber of an eye and a remote pressure sensor located remotely from the first pressure sensor. The remote pressure sensor measures or approximates atmospheric pressure. A difference between readings from the first pressure sensor and the remote pressure sensor approximates intraocular pressure.

1 . A pressure-controlled glaucoma drainage device comprising:
 a first pressure sensor located in fluid communication with an anterior chamber of an eye;   a second pressure sensor located in fluid communication with a drainage location, the second pressure sensor measuring a pressure in the drainage location;   a tube fluidly coupling the anterior chamber to the drainage location, the tube having an internal valve that regulates fluid flow through the tube;   a remote pressure sensor located remotely from the first pressure sensor such that the remote pressure sensor measures or approximates atmospheric pressure;   wherein a difference between readings from the first pressure sensor and the remote pressure sensor approximates intraocular pressure, a difference between readings from the second pressure sensor and the remote pressure sensor approximates a drainage location pressure; and the valve is controlled based on the approximated intraocular pressure and the approximated drainage location pressure.   
     
     
         2 . The glaucoma drainage device of  claim 2  further comprising:
 a processor; 
 a power source coupled to the processor; and 
 a memory coupled to the processor. 
 
     
     
         3 . The glaucoma drainage device of  claim 2  wherein the processor writes values corresponding to intraocular pressure to the memory. 
     
     
         4 . The glaucoma drainage device of  claim 2  further comprising:
 a data transmission module coupled to the processor. 
 
     
     
         5 . The glaucoma drainage device of  claim 1  wherein the remote pressure sensor is located in a subconjunctival space of the eye. 
     
     
         6 . The glaucoma drainage device of  claim 1  further comprising:
 a barrier separating the first pressure sensor from the remote pressure sensor. 
 
     
     
         7 . The glaucoma drainage device of  claim 6  wherein the first pressure sensor, the second pressure sensor, the remote pressure sensor, the tube, the valve, and the barrier are integrated into a single package that is implantable into the eye. 
     
     
         8 . The glaucoma drainage device of  claim 1  further comprising:
 an end cap that fits onto an end of the tube, wherein the first pressure sensor is located at a first end of the end cap and the remote pressure sensor is located at a second end of the end cap. 
 
     
     
         9 . The glaucoma drainage device of  claim 1  wherein a substantially constant intraocular pressure is maintained in the eye by controlling the valve. 
     
     
         10 . The glaucoma drainage device of  claim 1  wherein a substantially constant intraocular pressure drop is maintained by controlling the valve. 
     
     
         11 . The glaucoma drainage device of  claim 2  wherein the processor writes values corresponding to the drainage location pressure to the memory. 
     
     
         12 . The glaucoma drainage device of  claim 1  wherein the valve is controlled such that a desired intraocular pressure and drainage location pressure are achieved. 
     
     
         13 . The glaucoma drainage device of  claim 1  wherein the drainage location is located under the conjunctiva or the sclera, and the valve is controlled such that a desired drainage location pressure is achieved. 
     
     
         14 . The glaucoma drainage device of  claim 1  further comprising:
 A speaker coupled to the processor, the speaker sounding a warning when an unsafe intraocular pressure exists. 
 
     
     
         15 . The glaucoma drainage device of  claim 1  wherein the first pressure sensor is in fluid communication with the tube on an anterior chamber side of the valve and the second pressure sensor is in fluid communication with the tube on a drainage location side of the valve. 
     
     
         16 . A pressure-controlled glaucoma drainage device comprising:
 a tube fluidly coupling an anterior chamber of an eye with a drainage location;   a valve located in the tube, the valve regulating fluid through the tube;   a first pressure sensor located in fluid communication with the tube on the anterior chamber side of the valve, the first pressure sensor for measuring a pressure in the anterior chamber of an eye;   a second pressure sensor located in fluid communication with the tube on the drainage location side of the valve, the second pressure sensor measuring a pressure in the drainage location;   a remote pressure sensor located remotely from the first pressure sensor such that the remote pressure sensor measures or approximates atmospheric pressure;   a processor;   a power source coupled to the processor;   a memory coupled to the processor; and   an integrated package suitable for implantation into the eye, the integrated package at least partially enclosing the tube, the valve, the first pressure sensor, and the second pressure sensor;   wherein a difference between readings from the first pressure sensor and the remote pressure sensor approximates intraocular pressure, a difference between readings from the second pressure sensor and the remote pressure sensor approximates a drainage location pressure; and the valve is controlled based on the approximated intraocular pressure and the approximated drainage location pressure.   
     
     
         17 . The glaucoma drainage device of  claim 16  wherein the drainage location is located under the conjunctiva or the sclera, and the valve is controlled to maintain a desired pressure in the drainage location. 
     
     
         18 . The glaucoma drainage device of  claim 16  wherein the valve is controlled to maintain a desired intraocular pressure. 
     
     
         19 . The glaucoma drainage device of  claim 16  wherein the drainage location is located under the conjunctiva or the sclera, and the valve is controlled to maintain a desired pressure in the drainage location and a desired intraocular pressure.