Finding an Initial Probe Pose in Teleoperated Robotic Echocardiography Via 2D LiDAR-Based 3D Reconstruction
Mariadas Capsran Roshan, Edgar Mauricio Hidalgo Florez, Mats Isaksson, Michelle Dunn, Jagannatha Charjee Pyaraka
AI summary
Problem
Teleoperated robotic echocardiography reduces diagnostic delays but currently requires lengthy, expert-dependent manual probe placement. Existing vision-based automation methods fail in clinical settings due to sensitivity to lighting, texture, and anatomical variability.
Approach
The system uses a robot-mounted 2D LiDAR to perform two linear sweeps across the chest, reconstructing the surface in 3D. Scale-augmented rigid registration then aligns this reconstruction with anatomical templates to automatically compute the optimal initial probe position and orientation.
Key results
- First 3D human surface reconstruction using robot-mounted 2D LiDAR
- Extrinsic calibration achieving 1.82 mm RMS residual and <0.2° rotational uncertainty
- Mannequin validation yielding 2.78±0.21 mm mean surface reconstruction error
- Human trials achieving 20–30 mm placement accuracy with <4 mm inter-trial variation
Why it matters
Provides a robust, lighting-invariant, and privacy-preserving method to automate probe initialization, reducing operator workload and procedure time in teleoperated cardiac imaging.
Abstract
Echocardiography is a key imaging modality for cardiac assessment but remains highly operator-dependent, and access to trained sonographers is limited in underserved settings. Teleoperated robotic echocardiography has been pro- posed as a solution. However, clinical studies report longer ex- amination times than manual procedures, increasing diagnostic delays and operator workload. Automating non-expert tasks, such as automatically moving the probe to an ideal starting pose, offers a pathway to reduce this burden. Prior vision- and depth-based approaches to estimate an initial probe pose are sensitive to lighting, texture, and anatomical variability. We propose a robot-mounted 2D LiDAR-based approach that reconstructs the chest surface in 3D and estimates the initial probe pose automatically. To the best of our knowledge, this is the first demonstration of robot-mounted 2D LiDAR used for 3D reconstruction of a human body surface. Through plane-based extrinsic calibration, the transformation between the LiDAR and robot base frames was estimated with an overall root mean square (RMS) residual of 1.82 mm and rotational uncertainty below 0.2◦. The chest front surface, reconstructed from two linear LiDAR sweeps, was aligned with scale-augmented rigid registration to identify an initial probe pose. Mannequin-based study assessing reconstruction accuracy showed mean surface errors of 2.78±0.21 mm. Human trials (N=5) evaluating the proposed approach found probe initial points typically 20–30 mm from the clinically defined initial point, while the variation across repeated trials on the same subject was less than 4 mm.