Additive manufacturing for multimodal photoacoustic ophthalmoscopy

Abstract

Photoacoustic ophthalmoscopy in rodents is gaining research momentum, due to advancement in transducer shape and technology. Needle transducers emerged as most valuable tool for photoacoustic retinal imaging and have proven to be sensitive enough to resolve retinal vasculature in-vivo. Nevertheless, placement of the eye and screening of the retina remains challenging, since needle transducers must remain static during image acquisition, while the optical field of view is limited. Such restriction mandates movement of the mouse to rotate the eye and therefore the imaging area on the retina. The needle transducer needs to be temporarily detached during this process to avoid damage to the eye or the transducer. Re-attachment involves additional application of ultrasound gel and doesn’t guarantee ideal placement for optimized imaging performance. Additive manufacturing can help to tackle those challenges and allows to design novel rotational rodent holders for imaging. Hence, we present a fully 3D printable rotatable tip/tilt mouse platform with the eye in the center of rotation, combined with a printable needle transducer holder. Such system guarantees optimal placement of the needle transducer during imaging and rotation of the mouse eye, avoiding detachment of the transducer and effortless screening of the retina. The capabilities for retinal screening are demonstrated by a multimodal optical coherence photoacoustic ophthalmoscopy system employing two separated wavelengths, 1310 nm for optical coherence and 570 nm for photoacoustic ophthalmoscopy.