Abstract: The invention is directed to an implantable device to enable delivery of drugs to the retina. The device minimizes stress to the retina by virtue of its softness and smooth shape that conform to the retina. Drugs are delivered by osmosis or by the device dissolving. It may be connected to an externally mounted pump and drug reservoir that control the amount of drug. It contains one or more holes that are positioned to deliver drugs to the desired location. Drugs may stimulate the retina to enable vision in blind patients. Drugs may be injected directly inside the eye by a trans-scleral pump and valve drug delivery device.

Abstract: A method and apparatus for adjusting a visual image provided to a patient. In one embodiment, an image may be presented to the patient to obtain the patient's subjective perception of the image, and the patient may either manipulate the image to obtain a desired adjustment, or guide a clinician performing the adjustment. In another embodiment, the clinician may make objective observations of, for example, the position of an electrode array on the patient's retina, and make adjustments accordingly. The adjustment may be a spatial adjustment comprising a re-mapping performed to decreases image distortion resulting from differences in the patient's perception of stimulation of different areas of the retina. Such distortion may result from differences between the patient's perception of stimulation falling within the macula, and stimulation falling within the periphery surrounding the macula. The adjustment may also compensate for translations or rotations of the electrode array on the retina.

Abstract: A method and apparatus for adjusting a visual image provided to a patient. In one embodiment, an image may be presented to the patient to obtain the patient's subjective perception of the image, and the patient may either manipulate the image to obtain a desired adjustment, or guide a clinician performing the adjustment. In another embodiment, the clinician may make objective observations of, for example, the position of an electrode array on the patient's retina, and make adjustments accordingly. The adjustment may be a spatial adjustment comprising a re-mapping performed to decreases image distortion resulting from differences in the patient's perception of stimulation of different areas of the retina. Such distortion may result from differences between the patient's perception of stimulation falling within the macula, and stimulation falling within the periphery surrounding the macula. The adjustment may also compensate for translations or rotations of the electrode array on the retina.

Abstract: The invention is directed to an implantable device to enable delivery of drugs to the retina. The device minimizes stress to the retina by virtue of its softness and smooth shape that conform to the retina. Drugs are delivered by osmosis or by the device dissolving. It may be connected to an externally mounted pump and drug reservoir that control the amount of drug. It contains one or more holes that are positioned to deliver drugs to the desired location. Drugs may stimulate the retina to enable vision in blind patients. Drugs may be injected directly inside the eye by a trans-scleral pump and valve drug delivery device.

Abstract: We describe and claim a delay locked loop harmonic detector and associated method. A delay locked loop includes a detection circuit to generate a detection signal responsive to an input clock and a control circuit to synchronize the delay locked loop to a fundamental of the input clock responsive to the detection signal. A method includes detecting harmonic synchronization in a delay locked loop responsive to an input clock and locking the delay locked loop to a fundamental of the input clock responsive to the detecting.

Abstract: The invention is directed to a method of bonding a hermetically sealed electronics package to an electrode or a flexible circuit and the resulting electronics package, that is suitable for implantation in living tissue, such as for a retinal or cortical electrode array to enable restoration of sight to certain non-sighted individuals. The hermetically sealed electronics package is directly bonded to the flex circuit or electrode by electroplating a biocompatible material, such as platinum or gold, effectively forming a plated rivet-shaped connection, which bonds the flex circuit to the electronics package. The resulting electronic device is biocompatible and is suitable for long-term implantation in living tissue.

Abstract: This invention is for directly modulating a beam of photons onto the retinas of patients who have extreme vision impairment or blindness. Its purpose is to supply enough imaging energy to retinal prosthetics implanted in the eye which operate essentially by having light (external to the eye) activating photoreceptors, or photoelectrical material. The invention provides sufficient light amplification and does it logarithmically. While it has sufficient output light power, the output light level still remains at a safe level. Most preferred embodiments of this invention provide balanced biphasic stimulation with no net charge injection into the eye. Both optical and electronic magnification for the image, as for example, using an optical zoom lens, is incorporated. Otherwise, it would not be feasible to zoom in on items of particular interest or necessity. Without proper adjustment, improper threshold amplitudes would obtain, as well as uncomfortable maximum thresholds.

Abstract: The invention is directed to a method of bonding a hermetically sealed electronics package to an electrode or a flexible circuit and the resulting electronics package, that is suitable for implantation in living tissue, such as for a retinal or cortical electrode array to enable restoration of sight to certain non-sighted individuals. The hermetically sealed electronics package is directly bonded to the flex circuit or electrode by electroplating a biocompatible material, such as platinum or gold, effectively forming a plated rivet-shaped connection, which bonds the flex circuit to the electronics package. The resulting electronic device is biocompatible and is suitable for long-term implantation in living tissue.

Abstract: A method and apparatus suitable for forming hermetic electrical feedthroughs in a ceramic sheet having a thickness of ?40 mils. More particularly, the method yields an apparatus including a hermetic electrical feedthrough which is both biocompatible and electrochemically stable and suitable for implantation in a patient's body. The method involves: (a) providing an unfired, ceramic sheet having a thickness of ?40 mils and preferably comprising ?99% aluminum oxide; (b) forming multiple blind holes in said sheet; (c) inserting solid wires, preferably of platinum, in said holes; (d) firing the assembly of sheet and wires to a temperature sufficient to sinter the sheet material but insufficient to melt the wires; and (e) removing sufficient material from the sheet lower surface so that the lower ends of said wires are flush with the finished sheet lower surface.

Abstract: The present invention is a method of improving the persistence of electrical neural stimulation, and specifically a method of improving the persistence of an image supplied to a retina, or visual cortex, through a visual prosthesis. A continuously stimulated retina, or other neural tissue, will desensitize after a time period in the range of 20 to 150 seconds. However, an interruption of the stimulation on the order of a few milliseconds will restore the retinal sensitivity without the user perceiving the interruption, or with the user barely perceiving the interruption.

Abstract: The present invention is an implantable electrode array having electrodes with variable pitch and variable size. Electrode arrays of the prior art provide electrodes with a common spacing and size. However, this is not how the human body is arranged. As an example, the retina has closely spaced retinal receptors near the fovea. Those receptors are spaced farther apart, farther away from the fovea. Further, the amount of electrical current required to stimulate the perception of light increases with distance from the fovea. Hence, larger electrodes are required to transfer the necessary current farther away from the fovea.

Abstract: The invention is a retinal implant device to stimulate a retina of an eye thereby producing a specific effect in an eye, such as vision or drug treatment of a chronic condition. The retinal device is made of a retinal implant that is positioned subretinally and that contains a multitude of stimulation sites that are in contact with the retina. A connection carries the stimulating electrical signal or drug. The connection passes transretinally through the retina and into the vitreous cavity of the eye, thereby minimizing damage to the nutrient-rich choroid. The lead is attached to a source of drugs or electrical energy, which is located outside the eye. The lead passes through the sclera at a point near the front of the eye to avoid damage to the retina.

Abstract: The invention is a retinal prosthesis with an improved configuration mounting necessary components within and surrounding the eye. The present invention better allows for the implantation of electronics within the delicate eye structure. The invention further limits the necessary width of a thin film conductor passing through the sclera by use of a multiplexer external to the sclera and a demultiplexer internal to the sclera.

Abstract: The invention is a retinal prosthesis with an inductive coil mounted to the side of the eye by means of a strap around the eye. This allows for close coupling to an external coil and movement of the entire implanted portion with movement of the eye ball.

Abstract: The invention is a method of automatically adjusting an electrode array to the neural characteristics of an individual patient. By recording neural response to a predetermined input stimulus, one can alter that input stimulus to the needs of an individual patient. A minimum input stimulus is applied to a patient, followed by recording neural response in the vicinity of the input stimulus. By alternating stimulation and recording at gradually increasing levels, one can determine the minimum input that creates a neural response, thereby identifying the threshold stimulation level. One can further determine a maximum level by increasing stimulus until a predetermined maximum neural response is obtained.

Abstract: The present invention is a system for mapping a high resolution image to a lower resolution electrode array and, by applying varying stimulus to neighboring electrodes, creating a perceived image greater in resolution than the electrode array. The invention is applicable to a wide range of neural stimulation devices including artificial vision and artificial hearing. By applying a sub-threshold stimulus to two neighboring electrodes where the sum of the stimuli is above the threshold of perception, a perception is created in neural tissue between the two electrodes. By adjusting the stimulus on neighboring electrodes, the location of stimulation can be altered. Further, noise can be applied to the stimulating electrode or its neighboring electrodes to reduce the threshold of stimulation.

Abstract: The present invention is a micro-machined electrode for neural-electronic interfaces which can achieve a ten times lower impedance and higher charge injection limit for a given material and planar area.

Abstract: Polymer materials are useful as electrode array bodies for neural stimulation. They are particularly useful for retinal stimulation to create artificial vision, cochlear stimulation to create artificial hearing, or cortical stimulation many purposes. The pressure applied against the retina, or other neural tissue, by an electrode array is critical. Too little pressure causes increased electrical resistance, along with electric field dispersion. Too much pressure may block blood flow. Common flexible circuit fabrication techniques generally require that a flexible circuit electrode array be made flat. Since neural tissue is almost never flat, a flat array will necessarily apply uneven pressure. Further, the edges of a flexible circuit polymer array may be sharp and cut the delicate neural tissue. By applying the right amount of heat to a completed array, a curve can be induced.

Abstract: An implantable electrode and method for manufacturing the electrode wherein the electrode has a strong, adherent surface coating of iridium oxide or titanium nitride on a platinum surface, which demonstrates an increase in surface area of at least five times when compared to smooth platinum of the same geometry. The iridium oxide coating may be formed on platinum by a physical deposition process, such as sputtering. The process of electroplating the iridium oxide surface coating is accomplished by voltage control processes. A gradient coating of iridium oxide ranging in composition from essentially pure platinum to essentially pure iridium oxide is produced by sputtering.

Abstract: The present invention is a surgical tool for implanting an electrode array and its connected cable within an orbital socket. The insertion tool is used to aid the surgeon in pulling the electrode wire and array through the scull, four-rectus muscles of the eye, and the sclera. The insertion tool consists of a medical grade ABS material that is commonly used in various medical products.