Ultrasound Concave 2-D Ring Array for Retinal Stimulation.

Area of Science:

• Biomedical Engineering
• Ophthalmology
• Acoustics

Background:

• Retinopathies cause blindness in individuals with intact retinal neurons.
• Current treatments for vision loss due to retinopathies are limited.
• Ultrasound technology offers potential for non-invasive neural stimulation.

Purpose of the Study:

• To design and simulate a 2-D ring array ultrasound transducer for retinal visual stimulation.
• To evaluate the transducer's ability to achieve high-resolution wave patterns for potential vision restoration.

Main Methods:

• A concave 2-D ring array transducer was designed with specific parameters (20 MHz, 18 mm focal length, 1004 elements).
• Simulations were performed to analyze wave patterns at the focal distance.
• A scaled experiment at 2.5 MHz was conducted to validate simulation results.

Main Results:

• Simulated wave patterns achieved a full-width-at-half-maximum (FWHM) resolution of 0.147 mm.
• This resolution is close to the theoretical FWHM diffraction limit of 0.136 mm.
• Experimental results closely matched simulation predictions.

Conclusions:

• The designed ultrasound transducer shows potential for precise retinal stimulation.
• The achieved resolution is near the diffraction limit, suggesting feasibility for visual field restoration.
• Further development could lead to novel therapies for blindness caused by retinopathies.