Measurement Device for Corneal Static Biomechanical Properties Based on Negative Pressure Adhesion

Accurate measurement of corneal biomechanics plays a critical role in ophthalmic activities such as refractive surgery planning, keratoconus detection and glaucoma diagnosis. The current invasive measurement techniques and dynamic elastography methods are inherently limited by their inability to assess corneal static biomechanical properties in vivo. In this article, we describe a non-invasive corneal static biomechanical measurement system integrating negative pressure expansion measurement and control with spectral domain optical coherence tomography (SD-OCT) imaging. This system enables precise steady-state negative pressure regulation from 0 to 60 kPa, inducing controllable corneal deformation ranging from 0 to 600 μm. The system provides 0-60 kPa precision steady-state negative pressure regulation to induce 0-600 μm controlled corneal deformation, while synchronizing with SD-OCT for real-time deformation monitoring. The system acquires the static stress-strain relationship of the cornea through its steady-state inflation response and corresponding biomechanical analysis model, enabling non-invasive measurement of corneal static Young’s modulus. Our system measured the Young’s modulus of the artificial cornea as 2.33 ± 0.02 MPa, which is highly consistent with the value obtained from uniaxial compression testing (2.33 ± 0.02 MPa). This non-invasive measurement system overcomes the invasive limitations of traditional inflation tests and provides a novel clinical tool for corneal biomechanical assessment.