Safety Consideration Software limits on robot controller Limit switches on the robot “wrist” to prevent excess rotations Limit switches on the vertical travel Contact detection on upper arm of robot Enable button on hand pendant E-Stop button on hand controller Couch can lower for patient egress during power outage

Case Study 2 Automated Motion Correction – Tracking the Spine

Challenges of Spinal Treatments The spine moves during treatment Vertebrae can move independent of one another Rigid transformation is not valid in most cases Adjacent structures (spinal cord) necessitate high precision and accuracy

Traditional Radiation Therapy Difficult to adequately immobilize the patient, internal structures, & the target Image guidance (IGRT) confirms treatment setup but no compensation for target movement during the treatment Implanted markers can increase accuracy but introduce additional challenges Invasive Delays time-to-treatment

Non-invasively registers non-rigid and bony anatomy landmarks Internal markers or frames not required Automatically tracks spine from DRR image pairs Cervical, thoracic, lumbar and sacral Sub-millimeter targeting accuracy, ( / mm) † ‡ † As measured in end-to-end testing. Reference: Muacevic, A., Staehler, M., Drexler, C., Wowra, B., Reiser, M. and Tonn, J. Technical description, phantom accuracy and clinical feasibility for fiducial-free frameless real-time image-guided spinal radiosurgery. J Neurosurgery Spine. ‡ Xsight accuracy specification of.95 mm. Spine Tracking

Step 3Step 2Step 1 How it Works… Hierarchical Mesh Tracking Identifies unique bony structures Enables registration of non-rigid skeletal anatomy Estimates local displacements in bony features

Live kV image Image B Image A DRR (from CT) Displacement Field How it Works…

Spine Tracking Animation

Case Study 3 Automated Motion Compensation – Tracking Respriation

Respiratory Tracking Challenges of respiratory motion Respiratory-induced motion of tumors causes significant targeting uncertainty Lung, liver, and pancreas Traditional radiation therapy margins are not optimized for high-dose radiosurgery

Traditional Radiation Therapy Solutions for compensating for motion plagued with repeatability and compliance issues Healthy tissues is unnecessarily treated

† Reference: Dieterich S, Taylor D, Chuang C, Wong K, Tang J, Kilby W, Main W. The CyberKnife Synchrony Respiratory Tracking System: Evaluation of Systematic Targeting Uncertainty. ‡Synchrony clinical accuracy specification of 1.5 mm for moving targets. Respiratory Tracking Tightly contoured beams following tumor motion in real-time Delivers throughout the respiratory cycle without gating or breath- holding Instantly adapts to variations in breathing patterns Proven accuracy Systemic error of /- 0.33mm † ‡

How It Works… (1) Two features to form the basis for accuracy Gold markers, implanted prior to treatment LED markers on a special patient vest

How It Works… (2) Prior to treatment start: creation of dynamic correlation model Imaging system takes positions of markers at discrete points of time LED’s are monitored in real time by a camera system

How It Works… (2) Prior to treatment start: creation of dynamic correlation model Markers are monitored in real time by a camera system Imaging system takes positions of fiducials at discrete points of time time displacement time

How It Works… (3) This process repeats throughout the treatment, updating and correcting beam delivery based upon the patient’s current breathing pattern time displacement time

Synchrony Animation

Summary There is a place for autonomous robotics in medicine Special consideration must me taken to adapt to dynamic environment Safety is most important requiring redundancy throughout Greater demand for precision and accuracy will pave the way for future applications