Impacts of respiratory phase shifts on motion‐tracking accuracy of the CyberKnife Synchrony™ Respiratory Tracking System

2019 ◽  
Vol 46 (9) ◽  
pp. 3757-3766 ◽  
Author(s):  
Yuichi Akino ◽  
Hiroya Shiomi ◽  
Iori Sumida ◽  
Fumiaki Isohashi ◽  
Yuji Seo ◽  
...  
2013 ◽  
Vol 694-697 ◽  
pp. 927-935 ◽  
Author(s):  
Yi Sun ◽  
Tao Ma ◽  
Chia Yung Han ◽  
Joseph Ross ◽  
William Wee

This paper presents a simple and accurate coordinate transformation method for extending the tracking space of the Intersense IS-900 spatial and motion tracking system using multiple pre-configured emitter towers to form the emitter constellation, but without resorting to the use of a surveyor machine. The proposed approach uses the differences of positional coordinate readings from each emitter tower among a set of commonly viewed spatial points to calculate the parameters needed to define the coordinate transformation. By applying this method, the tracking accuracy using the entire emitter constellation can be achieved by less than 0.5 inches error in most of the working space, and as low as 0.2 inches error in the frontal part of the working space.


Algorithms ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 155
Author(s):  
Jang-Hwan Choi ◽  
Sooyeul Lee

In this paper we propose a novel method for tracking the respiratory phase and 3D tumor position in real time during treatment. The method uses planning four-dimensional (4D) computed tomography (CT) obtained through the respiratory phase, and a kV projection taken during treatment. First, digitally rendered radiographs (DRRs) are generated from the 4DCT, and the structural similarity (SSIM) between the DRRs and the kV projection is computed to determine the current respiratory phase and magnitude. The 3D position of the tumor corresponding to the phase and magnitude is estimated using non-rigid registration by utilizing the tumor path segmented in the 4DCT. This method is evaluated using data from six patients with lung cancer and dynamic diaphragm phantom data. The method performs well irrespective of the gantry angle used, i.e., a respiration phase tracking accuracy of 97.2 ± 2.5%, and tumor tracking error in 3D of 0.9 ± 0.4 mm. The phantom study reveals that the DRRs match the actual projections well. The time taken to track the tumor is 400 ± 53 ms. This study demonstrated the feasibility of a technique used to track the respiratory phase and 3D tumor position in real time using kV fluoroscopy acquired from arbitrary angles around the freely breathing patient.


2019 ◽  
Author(s):  
Ivan Vishniakou ◽  
Paul G. Plöger ◽  
Johannes D. Seelig

AbstractBackgroundVirtual reality combined with spherical treadmills is used across species for studying neural circuits underlying navigation.New MethodWe developed an optical flow-based method for tracking treadmil ball motion in real-time using a single high-resolution camera.ResultsTracking accuracy and timing were determined using calibration data. Ball tracking was performed at 500 Hz and integrated with an open source game engine for virtual reality projection. The projection was updated at 120 Hz with a latency with respect to ball motion of 30 ± 8 ms.Comparison with Existing Method(s)Optical flow based tracking of treadmill motion is typically achieved using optical mice. The camera-based optical flow tracking system developed here is based on off-the-shelf components and offers control over the image acquisition and processing parameters. This results in flexibility with respect to tracking conditions – such as ball surface texture, lighting conditions, or ball size – as well as camera alignment and calibration.ConclusionsA fast system for rotational ball motion tracking suitable for virtual reality animal behavior across different scales was developed and characterized.


Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S209-S221
Author(s):  
Lu Han ◽  
Hechen Zhang ◽  
Zhongxia Xiang ◽  
Jinze Shang ◽  
Shabila Anjani ◽  
...  

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.


2017 ◽  
Vol 14 (5) ◽  
pp. 172988141773275 ◽  
Author(s):  
Francisco J Perez-Grau ◽  
Fernando Caballero ◽  
Antidio Viguria ◽  
Anibal Ollero

This article presents an enhanced version of the Monte Carlo localization algorithm, commonly used for robot navigation in indoor environments, which is suitable for aerial robots moving in a three-dimentional environment and makes use of a combination of measurements from an Red,Green,Blue-Depth (RGB-D) sensor, distances to several radio-tags placed in the environment, and an inertial measurement unit. The approach is demonstrated with an unmanned aerial vehicle flying for 10 min indoors and validated with a very precise motion tracking system. The approach has been implemented using the robot operating system framework and works smoothly on a regular i7 computer, leaving plenty of computational capacity for other navigation tasks such as motion planning or control.


2008 ◽  
Author(s):  
Mohammed Goryawala ◽  
Misael Del Valle ◽  
Jiali Wang ◽  
James Byrne ◽  
Juan Franquiz ◽  
...  

2021 ◽  
Vol 11 (14) ◽  
pp. 6390
Author(s):  
Marcin Maciejewski

The paper presents the research of the SteamVR tracker developed for a man-portable air-defence training system. The tests were carried out in laboratory conditions, with the tracker placed on the launcher model along with elements ensuring the faithful reproduction of operational conditions. During the measurements, the static tracker was moved and rotated in a working area. The range of translations and rotations corresponded to the typical requirements of a shooting simulator application. The results containing the registered position and orientation values were plotted on 3D charts which showed the tracker’s operation. Further analyses determined the values of the systematic and random errors for measurements of the SteamVR system operating with a custom-made tracker. The obtained results with random errors of 0.15 mm and 0.008° for position and orientation, respectively, proved the high precision of the measurements.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2528
Author(s):  
Songlin Bi ◽  
Yonggang Gu ◽  
Jiaqi Zou ◽  
Lianpo Wang ◽  
Chao Zhai ◽  
...  

A high precision optical tracking system (OTS) based on near infrared (NIR) trinocular stereo vision (TSV) is presented in this paper. Compared with the traditional OTS on the basis of binocular stereo vision (BSV), hardware and software are improved. In the hardware aspect, a NIR TSV platform is built, and a new active tool is designed. Imaging markers of the tool are uniform and complete with large measurement angle (>60°). In the software aspect, the deployment of extra camera brings high computational complexity. To reduce the computational burden, a fast nearest neighbor feature point extraction algorithm (FNNF) is proposed. The proposed method increases the speed of feature points extraction by hundreds of times over the traditional pixel-by-pixel searching method. The modified NIR multi-camera calibration method and 3D reconstruction algorithm further improve the tracking accuracy. Experimental results show that the calibration accuracy of the NIR camera can reach 0.02%, positioning accuracy of markers can reach 0.0240 mm, and dynamic tracking accuracy can reach 0.0938 mm. OTS can be adopted in high-precision dynamic tracking.


2021 ◽  
Vol 161 ◽  
pp. S1461-S1462
Author(s):  
W. Okada ◽  
M. Tanooka ◽  
H. Doi ◽  
K. Sano ◽  
M. Shibata ◽  
...  

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