Multi-posture robotic optical coherence tomography for single-session standing, seated, and supine imaging

Abstract

Purpose : The automatic alignment capabilities of robotically-aligned optical coherence tomography (RAOCT) enable new patient imaging scenarios. Current systems have avoided imaging of reclined or supine subjects, however, due to potential safety hazards and the difficulty of accommodating large changes in head elevation without extensive mechanical modifications. Imaging of subjects in these postures is necessary to perform clinically-relevant eye imaging in routine healthcare environments, such as emergency departments and hospital wards.

Methods : We first improved the safety of our previously-reported RAOCT system through incorporation of spring-loaded contact sensors around the scanner’s objective lens that trigger below 10 N of force. This design both cushioned physical contact with the scanner and triggered an immediate robot safety stop, which mitigated the pinning hazard that exists for reclined or supine subjects who cannot retreat from the robot. We then extended our system to include a motorized vertical lift with 100 cm stroke for the robot’s base. The lift allowed us to dynamically configure the robot arm for head elevations between about 50 cm and 200 cm in under 30 seconds, instead of tediously remounting the robot, and select a robot elevation that optimized scanner maneuverability. We evaluated these improvements through IRB-approved retinal imaging of subjects with and without the ability to alter the robot base elevation. We operated the robot in semi-automatic mode in which the investigator cued the system to align and image each subject.

Results : Our system successfully performed imaging with and without the vertical lift (Fig. 1); however, the transition from standing to reclined or supine imaging was only possible with the lift (Fig. 2). Despite large variations in subject head orientation and posture, we obtained consistent OCT volumes. No safety events occurred during subject imaging.

Conclusions : RAOCT with dynamically adjustable robot base elevation allows imaging of standing, seated, reclined, and supine within a single imaging session. This capability enables RAOCT imaging of subjects in realistic postures for clinical environments.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

RAOCT imaging configurations (top) and foveal B-scans (bottom) acquired without vertical lift.

 

Multi-posture imaging configurations (top) and foveal B-scans (bottom) of subject from Fig. 1 acquired in a single session with vertical lift.