Acoustic Resonance Tonometer

Period of Performance: 04/01/1994 - 09/30/1994


Phase 1 SBIR

Recipient Firm

Scion Scientific, Inc.
Cape Coral, FL 33991
Principal Investigator


The objective of the proposed work is to develop a non-invasive monitor for intraocular pressure (IOP). This device, based on acoustic resonance spectroscopy, would facilitate the measurement that is commonly used for glaucoma diagnosis and management and in addition could provide the first practical continuous measurement of IOP. A number of devices exist that accurately measure IOP. Contact devices risk corneal abrasion, reaction to topical anesthetics and spread of infection. Non-contact devices using air puffs for applanation are in widespread clinical use including home tonometry to a limited extent. There is a clear demonstrated need for a non-contact tonometer that can continuously read IOP and also provides safe and easy use by patients or technicians. The premise of this proposal is that the eye, when subjected to small vibrations, has inherent acoustic resonance frequencies that are a function of intraocular pressure. A measurement of these frequencies and their shifts with iOP will provide a demonstration of the feasibility of this approach. In phase I a prototype instrument will be constructed and its performance will be verified in bench model systems. Pre-clinical studies in animals will document the ability of the device to track IOP in vivo. A pilot clinical trial is anticipated in Phase II.