Contact Lens Strain Gauge Layout for Accurate Intraocular Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing eye pressure measurement technologies suffer from inaccuracies due to irregular corneal curvature variations among individuals, leading to deviations in intraocular pressure measurements.
Innovation Solution
An intraocular pressure sensing element comprising a lens with an annular strain gauge and multiple regional strain gauges, connected to a sensing processing circuit, measures stress data to generate accurate intraocular pressure distribution information by compensating for stress value differences across various regions of the eyeball.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single strain gauge is used to measure intraocular pressure, then the device complexity is reduced, but the measurement precision deteriorates due to inability to compensate for corneal curvature variations
Solution Approach 1:
The sensing element is divided into multiple strain gauges positioned at different locations (central region, intermediate region, and peripheral region) on the contact lens. Each strain gauge measures stress at its specific location, and the processing circuit combines these multiple measurements to calculate accurate intraocular pressure while compensating for corneal curvature variations.
Solution Approach 2:
Different regions of the contact lens are equipped with strain gauges having different characteristics or positions to capture local stress variations. The central strain gauge measures primary intraocular pressure, while peripheral strain gauges measure corneal curvature-related stresses, allowing localized measurements to be combined for improved overall accuracy.
2Measurement precision
If multiple strain gauges are arranged to compensate for corneal irregularities, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
Multiple strain gauge measurements are merged and processed by a processing circuit to calculate a single accurate intraocular pressure value. The circuit combines data from central and peripheral strain gauges, applying compensation algorithms to eliminate corneal curvature effects and produce a unified pressure measurement.
Solution Approach 2:
The contact lens sensing element serves multiple functions: it corrects vision (as a contact lens), measures intraocular pressure (through strain gauges), and compensates for corneal irregularities (through multiple measurement points). This multi-functionality reduces the need for separate diagnostic devices.
3Measurement precision
If strain gauges are positioned to capture regional stress differences, then the measurement precision improves, but the ease of manufacture deteriorates
Solution Approach 1:
The strain gauges are extracted as separate functional components that can be independently manufactured and then positioned on the contact lens. This allows for specialized fabrication of each strain gauge at optimal locations without complicating the overall lens manufacturing process.
Solution Approach 2:
Strain gauges are pre-positioned or pre-assembled on the contact lens during the manufacturing process at predetermined locations (central, intermediate, and peripheral regions). This preliminary positioning ensures accurate spatial relationships between gauges while simplifying the final assembly process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides accurate intraocular pressure measurements by using flexible capacitive pressure sensors and differential strain gauges, enhancing sensitivity and reducing errors caused by corneal irregularities, thereby enabling precise monitoring of intraocular pressure distribution.
Implementation Method 1
the sensing processing circuit is configured to measure the subject eyeball through the annular strain gauge to obtain first stress data
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An intraocular pressure sensing element (1, 1') and an intraocular pressure sensing method are provided. The intraocular pressure sensing element (1, 1') includes a lens (10), an annular strain gauge (12, 12'), regional strain gauges (14), and a sensing processing circuit (16). The lens (10) has a central region (A1) and a peripheral region (A2) surrounding the central region (A1). The annular strain gauge (12, 12') is disposed in the peripheral region (A2) and surrounds the central region (A1). The regional strain gauges (14) are arranged at predetermined positions in the peripheral region (A2), respectively. In response to the intraocular pressure sensing element (1, 1') being worn on a subject eyeball, the sensing processing circuit (16) measures the subject eyeball through the annular strain gauge (12, 12') to obtain first stress data, measures the subject eyeball through the regional strain gauges (14) to obtain second stress data corresponding to the plurality of predetermined positions, respectively, and generates intraocular pressure distribution information according to the first stress data and the second stress data.