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Development of noninvasive tonometer using resonance phenomenon
M Nakai1, T Nagaoka, I Yoshizawa
1School of Science & Engineering, Waseda University, Tokyo, Japan.
Summary
This study introduces a novel tonometer applied over the eyelid to measure ocular pressure. This non-invasive method offers a comfortable and safe alternative to current ocular pressure measurement techniques.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Medical Devices
Background:
- Tonometers are essential for measuring intraocular pressure (IOP).
- Current tonometry methods (air-puff, direct contact) can cause patient distress or injury.
- A need exists for a more comfortable and safer IOP measurement technique.
Purpose of the Study:
- To develop and evaluate an improved tonometer for measuring ocular pressure.
- To provide a non-invasive and patient-friendly method for IOP assessment.
Main Methods:
- A novel tonometer utilizing a bimorph transducer was developed.
- The tonometer sensor is applied over the patient's closed eyelid.
- Vibrations induced by the transducer alter current flow, which correlates with ocular pressure.
Main Results:
- The new tonometer is non-invasive, applied over the closed eyelid.
- The device is lightweight (28.7g) and uses a bimorph transducer.
- Patients reported no pain and were unaware of sensor vibrations during measurement.
Conclusions:
- The developed tonometer offers a safe, comfortable, and potentially accurate method for measuring ocular pressure.
- This innovation addresses the limitations of existing tonometry, improving patient experience.
- Further research may validate this technique as a standard for IOP measurement.
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