Handheld Non-Contact Tonometer for Self-Operated IOP Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional tonometers are large, heavy, and limited to vertical use, requiring direct contact with the cornea, posing risks of infection and discomfort, and are not portable or user-friendly for self-operation, especially for pediatric and geriatric patients, and do not allow for continuous or remote monitoring of intraocular pressure.
Innovation Solution
A self-contained, hand-held, battery-operated tonometer with an internal air generator, electronic target display, automatic eye alignment detection, and corneal applanation detection, allowing operation in any position, with optional audio guidance and imaging for precise alignment and reduced discomfort, and capable of storing and transmitting IOP readings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional stationary tonometers are used, then measurement accuracy is maintained, but portability and ease of operation are severely limited
Solution Approach 1:
The tonometer is divided into separate functional modules: a handheld measurement unit with air generator and sensors, a separate display unit, and an optional data transmission module. This segmentation allows the measurement function to be portable while distributing system complexity across multiple components.
Solution Approach 2:
The patent replaces complex mechanical alignment and positioning systems with electronic sensors and software-based eye tracking. The air puff mechanism is controlled by electronic sensors that detect corneal applanation, eliminating the need for complex mechanical calibration systems.
2Measurement precision
If contact tonometry is used, then measurement precision is achieved, but risk of infection and corneal damage increases
Solution Approach 1:
The patent introduces air as an intermediary medium to transmit the measurement force to the cornea. The compressed air puff creates applanation of the cornea without physical contact, eliminating the transmission of infections while maintaining measurement precision through optical detection of corneal flattening.
Solution Approach 2:
The tonometer uses a compressed air system to deliver a controlled puff of air to the cornea. This pneumatic mechanism achieves corneal applanation without contact, and the air pressure is precisely controlled by electronic sensors to ensure accurate measurement while avoiding corneal damage.
3Reliability
If traditional tonometers are used, then reliable IOP measurement is obtained, but subject cooperation and positioning constraints are required
Solution Approach 1:
The tonometer incorporates dynamic eye tracking and alignment detection systems that automatically adjust to the subject's eye position. The device can operate in various orientations and automatically compensates for positioning variations, making it adaptable to pediatric, geriatric, and emergency settings while maintaining measurement reliability.
Solution Approach 2:
The device includes automated eye alignment detection and tracking functionality that eliminates the need for operator intervention in positioning. The system self-adjusts to the subject's eye location and maintains alignment automatically, reducing the need for subject cooperation and making the device suitable for uncooperative patients.
4Reliability
If multiple IOP measurements are taken at different positions, then comprehensive monitoring is achieved, but time consumption and subject burden increase
Solution Approach 1:
The tonometer enables continuous or repeated IOP measurements to be taken in quick succession due to its portable design and rapid measurement cycle. The device can be used at multiple positions during a single visit or across different visits, providing comprehensive monitoring data without requiring extended measurement sessions or multiple office visits.
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
Enables easy, safe, and comfortable intraocular pressure measurement by non-specialists, including self-operation, in various positions, with reduced anxiety and discomfort, and allows for remote monitoring and data transmission.
Implementation Method 1
contact-less tonometers which use a puff of air to achieve flattening or 'applanation' of the cornea and then compute the IOP as a function of the air pressure required for such corneal applanation
Implementation Method 2
compute the IOP as a function of the air pressure required for such corneal applanation
Data Source
AI summary
A portable non-contact tonometer (2) for measuring Intra-Ocular Pressure (IOP) of subject's eye is presented. Tonometer (2) is designed to be operated by the subject himself. It is housed in a hand-held case (4) which contains compressed air source (40), eye alignment detectors (12, 14), cornea applanation detector system (8, 10), a pressure sensor (32) and optical system for presenting gaze target (48). The animated gaze target (48) advantageously draws subject's attention to itself and keeps his eye (62) in alignment long enough for the measurement to take place, while optionally displaying system status and operating instructions. An audio annunciation system (16) guides the subject in the operation of the tonometer and prepares him for the actual procedure. The timing of the air puff is randomized to prevent subject's conditioning. The overall operation of the tonometer is controlled by a built-in microprocessor (50) system. A 3-D map of cornea is computed and a technique to compute the IOP derived from the difference of 3-D corneal maps before and during the air puff application is disclosed.