Development of a 6DOF robotic motion phantom for radiation therapy

Belcher, AH; Liu, Xinmin; Grelewicz, Z; Pearson, Erik; Wiersma, R

doi:10.1118/1.4900828

Cited by 18 publications

(27 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The robot uses this measurement data in the closed loop feedback configuration shown in Figure 1, where it attempts to zero out detected camera deviations, after appropriate transformations have been applied. Given that the robot can perform such corrections at the sub-millimeter level (Belcher et al, 2014), overall accuracy was primarily limited by the 6DOF tracking accuracy of the head tracking system. This can be observed in Figure 4, where positional control is limited by the 0.25 mm accuracy of the IR camera used for this pre-clinical evaluation.…”

Section: Discussionmentioning

confidence: 99%

“…A robot capable of performing highly precise movements from translational and rotational inputs was designed and fabricated following the Stewart-Gough platform archetype of parallel kinematics, with response time, weight load, repeatability, and compactness serving as the primary considerations for the design and choice over stacked serial systems (Belcher et al, 2014; Stewart, 1965). The robotic stage is capable of performing 6DOF motions of a mobile top platform relative to the stationary bottom platform using inverse kinematics control.…”

Section: Methodsmentioning

confidence: 99%

“…The individual’s head motion, through the tracking of the four reflective IR markers, was subsequently transmitted automatically to an in-house developed LabVIEW (2012, National Instruments) code (Figure 1) which controls the robotic device shown in the volunteer setup in Figure 2. This control code communicates between the IR camera system and the robotic device simultaneously, transmitting the six linear actuator trajectories using an 8-axis stepper motor controller (PCI-7358, National Instruments) (Belcher et al, 2014). The real-time head stabilization response of the robot produces a response motion in the volunteer’s head by moving the cranial support structure, which is rigidly connected to the mobile top platform of the robot and upon which the volunteer’s head rests.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Towards frameless maskless SRS through real-time 6DoF robotic motion compensation

Belcher¹,

Liu²,

Chmura³

et al. 2017

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

Purpose Stereotactic radiosurgery (SRS) uses precise dose placement to treat conditions of the CNS. Frame-based SRS uses a metal head ring fixed to the patient’s skull to provide high treatment accuracy, but patient comfort and clinical workflow may suffer. Frameless SRS, while potentially more convenient, may increase uncertainty of treatment accuracy and be physiologically confining to some patients. By incorporating highly precise robotics and advanced software algorithms into frameless treatments, we present a novel frameless and maskless SRS system where a robot provides real-time 6DOF head motion stabilization allowing positional accuracies to match or exceed those of traditional frame-based SRS. Methods A 6DOF parallel kinematics robot was developed and integrated with a real-time infrared camera in a closed loop configuration. A novel compensation algorithm was developed based on an iterative closest-path correction approach. The robotic SRS system was tested on six volunteers, whose motion was monitored and compensated for in real-time over 15-minute simulated treatments. The system’s effectiveness in maintaining the target’s 6DOF position within preset thresholds was determined by comparing volunteer head motion with and without compensation. Results Comparing corrected and uncorrected motion, the 6DOF robotic system showed an overall improvement factor of 21 in terms of maintaining target position within 0.5 mm and 0.5 degree thresholds. Although the system’s effectiveness varied among the volunteers examined, for all volunteers tested the target position remained within the preset tolerances 99.0% of the time when robotic stabilization was used, compared to 4.7% without robotic stabilization. Conclusion The pre-clinical robotic SRS compensation system was found to be effective at responding to sub-millimeter and sub-degree cranial motions for all volunteers examined. The system’s success with volunteers has demonstrated its capability for implementation with frameless and maskless SRS treatments, potentially able to achieve the same or better treatment accuracies compared to traditional frame-based approaches.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Towards frameless maskless SRS through real-time 6DoF robotic motion compensation

Belcher¹,

Liu²,

Chmura³

et al. 2017

Phys. Med. Biol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This would require improvement of the current algorithm to allow identification of highly irregular motion and the use of multidegree of freedom motion phantoms. 7,8 The oscilloscope provided a temporal resolution of 0.4 ms/sample. As shown in Fig.…”

Section: Discussionmentioning

confidence: 99%

Technical Note: High temporal resolution characterization of gating response time

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…For the phantom study, an in-house 6D motion phantom 19 was placed on the top of the 4D stage and programmed to simulate actual 6D human head motion. The 4D stage was used to compensate such motion [ Fig.…”

Section: D Experimental Verification Of 4d Stagementioning

confidence: 99%

Robotic real-time translational and rotational head motion correction during frameless stereotactic radiosurgery

et al. 2015

Self Cite

View full text Add to dashboard Cite

Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XYZ + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation.

show abstract

Development of a 6DOF robotic motion phantom for radiation therapy

Abstract: This 6D robotic phantom has proven to be accurate under clinical standards and capable of reproducing tumor motion in 6D. Such functionality makes the robotic phantom usable for either quality assurance or research purposes.

Cited by 18 publications

References 45 publications

Towards frameless maskless SRS through real-time 6DoF robotic motion compensation

Towards frameless maskless SRS through real-time 6DoF robotic motion compensation

Technical Note: High temporal resolution characterization of gating response time

Robotic real-time translational and rotational head motion correction during frameless stereotactic radiosurgery

Contact Info

Product

Resources

About