Microprocessor Tonometer Estimating Ocular Perfusion Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for estimating ocular perfusion pressure, such as using brachial blood pressure estimates, are unreliable due to assumptions about arterial health, lacking direct measurement capabilities for central retinal artery pressure.
Innovation Solution
A microprocessor-controlled tonometer measures diastolic IOP, systolic IOP, and ocular pulse amplitude to estimate ocular perfusion pressure, using look-up tables and calculations to differentiate between normal and abnormal measurements, providing direct and accurate estimates of central retinal artery pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If brachial blood pressure is used to estimate central retinal artery pressure, then the estimation can be obtained, but the reliability is poor due to assumptions about arterial health
Solution Approach 1:
The patent uses intraocular pressure measurements as an intermediary to indirectly assess central retinal artery pressure. By measuring IOP at different applanation volumes and using the relationship between IOP and arterial pressure, the system provides a more reliable estimate without directly measuring arterial pressure. This intermediary approach resolves the contradiction by maintaining estimation capability while improving reliability through a different measurement pathway.
2Measurement precision
If a microprocessor-controlled tonometer is used to measure diastolic IOP, systolic IOP, and ocular pulse amplitude, then direct and accurate estimates of central retinal artery pressure can be obtained, but the device complexity increases
Solution Approach 1:
The tonometer is designed to perform multiple functions: measuring intraocular pressure, detecting ocular pulse amplitude, and estimating central retinal artery pressure. By integrating these functions into a single device, the patent achieves high measurement precision while managing device complexity through multi-functionality rather than separate specialized instruments.
Solution Approach 2:
The microprocessor automatically performs calculations to estimate central retinal artery pressure from the measured IOP and pulse amplitude data. The system self-processes the raw measurements through programmed algorithms and look-up tables, reducing the need for manual calculation and minimizing operational complexity despite the advanced measurement capabilities.
3Measurement precision
If look-up tables and automated calculations are implemented to differentiate normal and abnormal measurements, then diagnostic accuracy is improved, but the processing time and computational requirements increase
Solution Approach 1:
Look-up tables are pre-computed and stored in the device memory, containing the relationship between measured parameters and diagnostic conclusions. During operation, the microprocessor performs rapid table lookups rather than complex real-time calculations, significantly reducing processing time while maintaining high diagnostic accuracy. This preliminary preparation resolves the contradiction between accuracy and processing speed.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method of estimating mean central retinal artery pressure (MCRAP) by using a microprocessor controlled tonometer (10), the method comprising; using the tonometer (10) to determine a mean intraocular pressure [MIOP] including a diastolic value and a systolic value having an ocular pulse amplitude [OPA] using the microprocessor (20) to calculate a ratio between OPA and MIOP; using the microprocessor (20) to derive a multiplier from the ratio; and using the microprocessor (20) to multiply MIOP by the derived multiplier to produce an estimate ofmean central artery pressure [MCRAP].