GLAUCOMA DRAIN IMPLANT SYSTEM WITH PRESSURE SENSOR AND VALVE, AND EXTERNAL READING UNIT

Abstract

Glaucoma drainage implant system with intracular pressure sensor and microvalve, and external reading unit, including: (1) an ocular implant device including a main body attached to a cannula communicating through a microchannel passing therethrough with a sensor microchamber; the microchamber is in fluid communication with a microvalve regulating outlet passage of ocular liquid, the microvalve being covered by a plate in the main body, the implant device has also a flat coil energizing the sensor, microvalve and regulation microchip; and (2) an external reading unit receiving signals from the PIO sensor and displaying IOP pressure; the UEL includes an antenna and a main unit; where the antenna feeds by bursts of RF radio frequency energy to the implant sensor and when the sensor is energized, it returns a signal with information from the IOP, this signal being received by the antenna and sent to the main unit for processing.

Claims

1. Glaucoma drainage implant system with intracular pressure sensors and microvalve, and external reading unit comprising: (1) an ocular implant device comprising a main body attached to a cannula with an inlet port which communicates through a microchannel that passes through said cannula with a microchamber of the sensor on which at least one sensor is located; said microchamber is in fluid communication with a microvalve which regulates the passage of ocular liquid to an outlet port, where the microvalve is covered by a plate on said main body; the implant device has also a flat coil to energize the sensor and the microvalve and a microchip for regulation of a microvalve actuator and signal processing and modulation generated by the sensor; (2) an external reading unit, which acquires and processes signals from the PIO sensor(s) 5) and displays the PIO pressure data on a screen; the UEL mainly consists of two parts: an antenna and a main unit; wherein the antenna feeds by bursts of RF radio frequency energy to the implant sensor and when the sensor is energized, the sensor returns a signal with information from the IOP, this signal being received by said antenna and sent to the main unit for processing.

2. Glaucoma drainage implant system with intracular pressure sensor and microvalve, and external reading unit according to claim 1, wherein the plate of the implant device has at the opposite end of the cannula a fixation hole that allows the fixation of said implant to the sclera of the eye by suture.

Description

DESCRIPTION OF THE FIGURES

[0025] These and other features and details of the invention and the manner in which it can be embodied and practiced should be better understood by the detailed description of the examples not limited to the embodiments of the invention illustrated in the attached figures. Other variations, modifications, adaptations and/or additions can be made without falling outside the spirit and scope of the present invention.

[0026] FIG. 1: represents a perspective view from the upper side of the glaucoma drainage implant with a pressure sensor seen from the top of the microvalve where the cannula with the fluid inlet is observed on the left side of the valve, followed by the sensor and the flat coil, an external hole where the fluid is drained, a plate to extend the area of absorption by the conjunctiva that covers the microvalve, and on the plate at the opposite end to the inlet hole of the cannula, a hole to fix the implant to the sclera, the microchip is also observed for the microvalve actuator or signal processing and modulation.

[0027] FIG. 2: represents a side view of the pressure sensor glaucoma drainage implant.

[0028] FIG. 3: represents in the drawing above a top view of a variant of the glaucoma drainage implant with pressure sensor with the dimensions in millimeters and in the drawing below a side view of an enlarged profile of said variant of the glaucoma drainage implant with pressure sensor with dimensions in microns.

[0029] FIG. 4: represents in the drawing above a top view of a variant of the drainage implant for glaucoma with pressure sensor with the dimensions in millimeters and in the lower drawing a side view of said variant of the drainage implant for glaucoma with sensor pressure with dimensions in millimeters.

[0030] FIG. 5: represents 2 variants of the glaucoma drainage implant system with pressure sensor and valve, and external reading unit, the upper one showing the implant and the

DETAILED DESCRIPTION OF THE INVENTION

[0031] The present glaucoma drainage implant system with pressure sensor and external reading unit consists of the implant device (1) itself, which comprises a microvalve (2) that has a cannula (3) with the corresponding inlet port (4) thereof, where the eye fluid enters when said device (1) is permanently implanted in the eye. Following the cannula is a sensor (5), a flat coil (6), an outlet port (7) through which the ocular fluid drains to reduce intraocular pressure (IOP) in the anterior chamber of the eye, it also comprises a plate (8) to extend the area of absorption by the conjunctiva that covers the microvalve when the device is implanted in the eye; this plate has, at the end opposite the cannula, a fixing hole (9) that helps fixing the implant to the sclera by suture. The pressure sensor, in addition to providing the IOP measurement, serves to monitor the hydraulic resistance. This measure is used to guide the treatment of glaucoma.

[0032] The PIO sensor comprises a battery-free capacitive pressure sensor built into the implantable device to provide on-demand IOP measurement.

[0033] The microvalve (2) can have a microchip (12) for regulation of an actuator or signal processing and modulation.

[0034] The cannula has a microchannel (10) inside, which communicates a microchamber (11) for the sensor (5), the microvalve which is a flange valve and a hole for outlet to the plate (8). The low profile of the implant allows flexibility and compliance with the curvature of the eye.

[0035] The shunt reduces the IOP that drains aqueous humor from the anterior chamber of the eye into the subconjunctival space.

[0036] The microvalve used is a quasi-bistable microvalve as disclosed in U.S. Pat. No. 8,206,440 consisting of a diaphragm (or cantilever beam or other passive or active structure-mechanism to regulate flow) made of a conjugated polymer (or other material) that exhibits high deformability and biocompatibility and whose volume depends on the electrical potential applied by a pair of electrodes, where the sensor and valve actuator are coupled to the drain line, first to deform based on eyeball pressure and second in a buckling position to normally clog the drain line. The sensor is a membrane of conductive polymeric material with those same properties and whose ohmic resistance varies with the mechanical deformation produced by ocular or capacitive pressure or another transduction mechanism.

[0037] Preferred materials for implanting include Liquid Crystal Polymer (LCP) or any biocompatible material; in the construction of this implant, the following materials are required (not exclusive): [0038] Materials [0039] LCP sheets with copper [0040] Adhesives for LCP [0041] Gold [0042] Teflon

[0043] The present system also includes the External Reading Unit (UEL) (13):

[0044] ⋅ External Reading Unit (UEL): acquires and processes signals from the PIO sensor and displays the IOP pressure data to be reviewed by medical professionals and based on them make decisions about the patient's condition and initiate changes in medical therapy. The UEL is mainly made up of two parts:

[0045] i) Antenna

[0046] The antenna is used to interrogate the PIO sensor. The inventors have implemented a version of the antenna (2.25 cm external diameter, 5 mm internal diameter and 35 μm thick copper), in a rigid plastic housing (13). During the reading, the antenna is placed near the passive sensor between 5 mm and 10 mm distance (or other more remote and shorter distances), and the antenna feeds it by bursts of RF energy. When the sensor is energized, it returns a signal with pressure information. This signal is received by the antenna and sent to the main unit for processing. Other variants of energization such as energy harvesting itself are also included.

[0047] The antenna can be included within glasses (14) with data information storage units so that said data can then be processed by the external reading unit (13).

[0048] ii) Main unit

[0049] The main unit is the place where all the signals for the patient's electronic system are generated and processed. The custom circuitry generates bursts of RF energy through the antenna that powers the sensor, processes the sensor return signal, and visually displays the PIO pressure information.

[0050] The software in the UEL prompts and guides the patient to perform a pressure measurement.

[0051] Implant manufacture:

[0052] Firstly, the condition of the purchased raw materials is verified to ensure quality as required.

[0053] LCP sheets of different thicknesses, generally marketed for the manufacture of flexible printed circuit boards, are copper laminated on both sides. The first processing is to remove said copper from the laminates with ferric chloride solution according to conventional techniques.

[0054] Each sheet of LCP is subjected to some chemical process, followed by several steps of conductivity-controlled rinses of the final rinse solution to verify the complete removal of residues that may remain on the surface of the sheets. The sheet that contains the coil, which is made of copper, is subjected to another processing line, keeping the controls in the rinses.

[0055] The second step is the cutting of individual sheets according to the stack up design of various sheets. Said cut is made with a Cutter Plotter and adhesive mat to place a stack (stack-up) of “Dry Resist (DR)” paper and foil itself and thus achieve a proper hold of the foil to be cut against the cutting mat. After cutting, the stack-up is removed from the mat and then the resin with its corresponding remover.

[0056] The cut in the adhesive sheets of BS (Bonding Sheet) is performed directly on the cutting mat, since these are protected on both sides with PET laminates and do not require removal of adhesives.

[0057] Cutting on CuClad Adhesive Sheets is done the same way as LCP Sheets.

[0058] Two Gold electrodes deposited by the sputtering technique are used to manufacture the sensor. Furthermore, this technique is also used to obtain selective adhesiveness on certain surfaces of some sheets. To obtain deposited metal patterns, sheets are used in stencils aligned with the previously cut sheets.

[0059] Finally, in a previous step to a final thermocompression, a copper electrodeposition is carried out to increase the thickness of certain metal parts and to manufacture a connection path between the pads for the electrodes of the capacitor and the inductor.

[0060] The last step is thermocompression of all the individually pre-processed sheets.

[0061] For this, the sheets are sequentially placed on heating plates inside a hydraulic press, which have pins for the alignment of all the sheets.

OPERATION MODE

[0062] In one of the operating uses of the proposed system, the implant is implanted by means of surgery in a normal way and in another as a shunt or valves by opening channels in the sclera in the limbus for insertion of the implant cannula and sutures the fixing hole on the back side of the sclera.

[0063] The reading units are calibrated by standard tonometry (Goldmann) and control alarms can be set by health professionals.

[0064] The user can, whenever he wishes, read the reading unit in the eye at a short distance therefrom (or at a more remote distance by means of suitable telemetry mechanisms) and the eye pressure will be displayed on a screen. If the pressure is above or below the programmed maximum and minimum values, an alarm is activated that alerts the user to take into account on the next visit to the doctor.

[0065] Intraocular pressure values are stored and can be exported for future physician analysis during the patient visit.

[0066] The microvalve has an active control option where an actuator changes the hydraulic resistance of the microvalve and a microchip controls the actuator.