A noninvasive, continuous monitoring device for measuring intraocular pressure without interference with vision or normal activity of the patient. A miniature, planar-faced pressure transducer is fixed in a protruding section of a compliant hydrogel ring which has been tooled to conform to the spherical surface of the sclera. The hydrogel ring is placed noninvasively under the eyelids within the conjunctival cul-de-sac, the transducer being located in the lower temperal quadrant. Applanation of the sclera against the planar surface of the transducer results as a consequence of pressure from the separated tissues. Intraocular pressure readings are based on the variations in resistance in the strain gage elements of the transducer caused by the applied stress to the transducer diaphragm. Data is transmitted through connecting wires to a telemetry unit which transmits the data to a receiver-transcriber console. The total system permits free, uninhibited movement by the patient during the monitoring process and provides a record of intraocular pressure as a function of time-of-day.

Devices and methods for providing electrochemical cells are disclosed which can be used in virtually any gaseous or liquid environment to make electrochemical determinations. The electrochemical cell comprises a microelectrode and a large reference electrode which are positioned a very short distance apart. The space between the microelectrode and the reference electrode is filled with a highly resistant material which has been treated (or otherwise provided) with an ionic substance. In use, the ionic substance associated with the resistive material acts as an immobilized ionic solution in much the same way as an electrolyte in a conventional electrochemical cell. However, the relative size and positioning of the microelectrode and the reference electrode overcame the problems of the prior art so that sensitive, accurate measurements can be obtained in both gas and liquid phase electrochemistry.

A tool for applying a membrane on a small upstanding post like device, which tool incorporates a housing with means for securing the membrane across the top of the post with additional means disposed opposite the post for holding the membrane against the post and urging it down the side of the post, the housing being closeable to serve as a shipping container and a calibration cell for the device to be membraned with means to secure the post captive with little or no chance of its falling into a non-sterile environment.

For use with the human eye, especially, there is provided a relatively narrow, split, flexible partial ring adapted to fit against the portion of the eyeball behind the upper and lower eyelids. The corneal opening is of an extent so that despite normal excursions of the cornea, the cornea does not substantially contact the ring. The split ring is formed of highly flexible material so as to permit a substantially universal fit and at the same time exert minimal effect on the physiological parameters being measured. A sensor or other device is located on a widened portion of the carrier in contact with the palpebral conjunctiva. A conductor or other transmission device may lead from the device through a projection, preferably integral with the ring, and extending beyond the eyelids. The device carrier is a split ring and relies upon its shape and self-resiliency in order to maintain its position within the eye.

A unique glucose sensor to determine the glucose level in patients, for example, for use in treating or diagnosing diabetes. The patient's eye is automatically scanned using a dual source of polarized radiation, each transmitting at a different wavelength at one side of the cornea of the patient. A sensor located at the other side of the cornea detects the optical rotation of the radiation that passed through the cornea. The level of glucose in the bloodstream of the patient is a function of the amount of the optical rotation of the radiation detected at the other side of the cornea of the patient. The result is transmitted to a remote receiver that is coupled to a readout device to thereby provide non-invasive glucose determinations of high specificity and reliability.