Integrated Respiratory Sensing and Gated Control for Autonomous Needle Insertion Via CT Bore Robotic Arm
Authors: Emma Huang, Moira Bohley, Krishna Jamakhandi, Rebecca Fellbaum, Sophia Tang, Sean Tutton, Albert Hsiao, Alexander Norbash, Changwei Chen, Derek Chen, Ananya Rao, Lizzie Peiros, Michael C. Yip
Organizations: Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093 USA. · Department of Bioengineering, University of California San Diego, La Jolla, CA 92093 USA. · Columbia Engineering, Columbia University, New York, NY 10027 USA. · School of Medicine, University of California San Diego, La Jolla, CA 92093 USA. · School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64110 USA.
Currently, CT-guided lung biopsy is a highly manual procedure requiring patient breath-holding, iterative manual needle insertions, and repeated CT confirmation scans to accurately target a tumor. Automating this process within the CT bore--without relying on manual needle placement or patient breath-holding--has the potential to reduce procedure time, patient discomfort, and radiation exposure. In this work, we present an integrated sensing and control system capable of performing a gated needle insertion within the CT bore. The experiments demonstrate the system's ability to track and predict patient breath cycles, perform autonomous respiratory-gated needle insertion, and detect breath cycle anomalies.
Figures & tables
Parameter
Value
Observed range
Literature reference values
Breath duration (s)
4.335
–
Displacement amplitude (mm)
4.33
–
Inhalation/exhalation ratio
0.64
–
Experimental measurements
Breath duration (s)
4.03±0.97
2.41–6.44
TABLE I : Breathing characteristics and sensing design targets. Measurements show mean ± SD and observed range.
Fig. 2 : Representative dorsoventral chest displacement trajectories recorded with OptiTrack during (a) normal breathing, (b) coughing, (c) hiccups, and (d) talking.
Fig. 3 : Assembly (a) shows the testbed used to emulate CT bore robot motion and to run tests within a controlled system. The design features a linear rail with two carriages driven by motorized capstan drives. Attached to the breathing model drive is a replaceable skin phantom that can be punctured. The needle insertion mechanism is used to control and drive the needle motion and has a clamp-based mechanism to allow the needle to be fixed and also exchanged after use. Assemblies (b) and (c) show a zoomed view of the contact sensors for the testbed and CT bore robot respectively, each of which read through a Hall effect sensor. Assembly (d) shows the assembly on the CT bore robot. The open circles in (b) and (c) indicate the point of contact on the contact sensor.
Fig. 4 : The gated needle insertion process involves four steps: (1) The robot base and wrist bring the needle to a position suitable for insertion. (2) The contact sensor is brought within range of the torso to maintain contact and sense breathing. (3) Once the breathing motion is captured, the needle is driven into the skin. (4) The needle is allowed to passively move with the breathing motion, applying a gated insertion when the suitable breathing stage is detected.
Name
Peak-to-Peak (mm)
SD (mm)
ToF Sensor
8
2
Contact Sensor
0.011
0.002
TABLE II : Sensor Noise
Fig. 5 : Comparison of the EKF forecast (red) and raw sensor values (gray) overlaid with the ground truth breathing motion (green) shows that the EKF forecast successfully adjusts for lag in sensor readings and closely tracks the ground truth.
Fig. 6 : The torso phantom and the measured breathing signal are shown in green and gray above respectively. In (a) the background colors indicate the phase of the sequence. Gray indicates initialization. Red indicates the needle carriage approaching. Orange indicates contact incremental pushes to reach full breath detection. Green indicates full breath detection and EKF settling. Blue slices indicate motions of gated insertion. The gated insertion segment is further detailed in (b), showing insertion highlighted by blue during full exhales.
Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093 USA · School of Medicine, University of California San Diego, La Jolla, CA 92093 USA · School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64110 USA
Manchester Centre for Robotics and AI and the Department of Mechanical and Aerospace Engineering, University of Manchester, Manchester, UK · Manchester Centre for Robotics and AI and the Department of Electrical and Electronic Engineering, University of Manchester, Manchester, UK · Manchester University Foundation Trust Wythenshawe Hospital Intensive Care Unit, Manchester, UK