Overview
This biomedical device spun out of my semester-long internship at the Biomedical Engineering and Technology Innovation Center, IIT Bombay in 2018 and was carried forward as my B.Tech project at the Symbiosis Institute of Technology in 2019 to develop and test the headgear-mounted device for reliable and rapid diagnosis of eye-related diseases such as glaucoma.
TEAM
Arvind Bhallamudi, Tapas Pandey, Rupesh Ghyar, Nitin Khedkar, Dr. Amit Kumar Tiwari
MY ROLE: Lead Design Engineer
Conducted research and led the medical device design, engineering, prototyping and fabrication, working with the team to patent, and test and validate the device in trials.
KEY SKILLS
Inventing a Glaucoma Screening Device
BIOMEDICAL ENGINEERING & TECHNOLOGY INNOVATION CENTER, IIT BOMBAY | 2018-2019
CHALLENGES
Discovering Patient Needs & Human-Centered Gaps
Over 80 million people are affected by glaucoma worldwide. In this condition, the system for absorbing the intraocular fluid from the eye becomes clogged. It causes intraocular pressure (IOP) to build up, damaging the optic nerve and leading to vision loss and blindness. While there is no cure for this condition, it can be controlled by frequent check-ups if detected early and managed. Gold standard devices like Schiøtz tonometer require the aid of experienced clinicians, and are often invasive, time-consuming, and cumbersome.
DESIGN
Mechanical Components and Assembly
The device developed in this work is based on literature that utilized a combination of indentation and applanation principle to measure IOP. It involves positioning the indenter such that it just touches the eyelid. Then it is moved forward (3mm) to gently flatten the cornea through the eyelid to obtain the reaction pressure from the eye. An LED provides a feedback alert when the IOP crosses the healthy threshold.
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A series of prototypes improved ergonomics, assembly fittings and reduced size to make it portable and lightweight. To place the screening module accurately above both eyes of the patient, an indenter positioning system was needed, where the screening module can be fixed and used.
Mechanism Design
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Initial Prototypes
Testing
PRODUCT DEVELOPMENT
A Novel Headgear System
For anatomically different facial structures and sizes, concepts of a headgear system to stabilize positioning the indenter and standardize measurements were sketched out. The 3-axis slider where the screening module can be fixed using screw knobs was the most feasible and flexible.
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A plot of stresses and displacement was generated for two of the key elements of the device – the indenter and the slots on the headgear frame. A nominal load of 1N was applied on the filleted edge of the slots from where the elastic band would be pulled. The maximum displacement is in the range of 10^(-3)mm which renders both parts safe to use.
The device was successfully validated by the BETIC team measuring the IOP in over 50 patients, which corresponded to the values obtained using Goldmann tonometer - the gold standard in measurement.
Concept Sketches
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CAD Assembly and Simulation
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How to Use
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Product Renders
IMPACT
An Accurate and Affordable Opthalmic Device
Positioned as an ophthalmic device for easy and rapid diagnosis of a disease that affects thousands each year. the design, engineering and findings of this study are published in Springer Nature: Design for Tomorrow: Volume III, winning a distinguished paper award, and an international patent published in the World Intellectual Property Organization.
