A vision system for patient positioning in radiation therapy

Shukla, Salil; Bradley, Colin; Beckham, Wayne; Wells, Derek

doi:10.1108/02602280510620114

Cited by 3 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This situation happened due to the properties of an electro hydraulic actuator system itself, which can provide a high power density, good positioning capability and having a fast response characteristic [2][3][4][5]. However, despite the ability inherent in the system, electro hydraulic actuator system is still holding a drawback of having uncertainty behaviour together with the nonlinearities properties that makes modelling and controller design process for the electro hydraulic actuator system a challenging task [6][7][8][9][10][11][12][13]. Thus, in order to acquire the best performance of an electro hydraulic actuator system, a proper method should be used in modelling the system model and a suitable controller needs to be designed to control the system.…”

Section: Electro Hydraulic Actuator Systemmentioning

confidence: 99%

See 1 more Smart Citation

Application of Draw Wire Sensor in the Tracking Control of An Electro Hydraulic Actuator System

et al. 2015

View full text Add to dashboard Cite

A draw wire sensor is considered as a contact measurement method. It is normally used to measure the speed and position of a system. A draw wire sensor is convenient especially when a low cost solution and a small sensor dimension are desired. The objective of this paper is to describe the application of draw wire sensor in control tracking of electro hydraulic actuator system. This research started with the modelling of electro hydraulic actuator system by using system identification approach. During the data taking process, an experiment is conducted using electro hydraulic actuator test bed. A draw wire sensor is attached to the load of electro hydraulic actuator system to measure the output displacement when the system is injected with the desired input signal. Draw wire sensor is measuring the output displacement in millimeters and then the signal is converted to voltage reading regarding to the given input signal. The input and output signal is collected and is used in system identification technique to obtain the best mathematical model that can represent the electro hydraulic actuator system. Once a model is obtained, a Self Tuning Controller (STC) with Generalize Minimum Variance Control (GMVC) strategy is designed to control the tracking performance of the electro hydraulic actuator system. The designed controller is tested in simulation and experiment mode. Then, the output result from both modes is compared. The results show that the output performance from both modes are almost similar. Thus, this research had shown that a draw wire sensor has a significant role in capturing an accurate output data from electro hydraulic actuator system even with or without the controller.

show abstract

Section: Electro Hydraulic Actuator Systemmentioning

confidence: 99%

“…13) where;𝐸 = 1 + 𝑒 1 𝑧 −1 + ⋯ + 𝑒 𝑛 𝑒 𝑧 −𝑛 𝑒 𝐺 = 𝑔 0 + 𝑔 1 𝑧 −1 + ⋯ + 𝑔 𝑛 𝑔 𝑧 −𝑛 𝑔 and 𝑛 𝑒 = 𝑘 − 1 𝑛 𝑔 = max (𝑛 𝑎 − 1, 𝑛 𝑝 + 𝑛 𝑐 − 𝑘)Finally, the control law for STC with GMVC strategy is obtained as:…”

mentioning

confidence: 99%

Application of Draw Wire Sensor in the Tracking Control of An Electro Hydraulic Actuator System

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Salil Shukla and Colin Bradley [ 4] improvements to existing methods of measuring position in automation, sports and general applications is described by Christine Connolly [5] in his research. Another research on positioning sensor is done by Gary Pepka [6].…”

Section: B Electro-hydraulic Actuator Systemmentioning

confidence: 99%

“…Though this research focused on the role of draw-wire sensor in positioning tracking of electro-hydraulic system, there are many previous research on positing applications on other system by using variety types of sensor. Salil Shukla and Colin Bradley [ 4] improvements to existing methods of measuring position in automation, sports and general applications is described by Christine Connolly [5] in his research. Another research on positioning sensor is done by Gary Pepka [6].…”

Section: B Electro-hydraulic Actuator Systemmentioning

confidence: 99%

Application Of Draw Wire Sensor In Position Tracking Of Electro Hydraulic Actuator System

Rahmat

Rozali

Wahab

et al. 2010

International Journal on Smart Sensing and Intelligent Systems

View full text Add to dashboard Cite

-Draw-wire sensor is classified as a contact measurement method. This sensor is ideal forapplications with large measuring ranges, small sensor dimensions and when a low cost solution is required. The objective of this research is to explain the application of a draw-wire sensor in position tracking of electro-hydraulic actuator system. The work started with the modeling of the electro hydraulic actuator system. Draw wire sensor is attached to the load of electro hydraulic system to measure its motion when an input signal is injected to the system. The sensor output is the displacement in millimeter and converted to the voltage based on the input signal given. These input and output readings are collected and applied to a system identification procedure in order to obtain the best mathematical model of the system. The modeling process is followed by designed a proportional integral and derivative controller (PID) for the system to assure the output is tracking the input given. The designed controller is applied to the system in both simulation and real time mode. The output performance of the system for these two modes is compared and it can be seen that the simulation and real-time output are almost similar. The overall process of this work shows the important role of draw wire sensor in capturing the output data of the electro hydraulic actuator system precisely either with or without controller. Other displacement transducer might be used in future work of position tracking of electro-hydraulic actuator system.

show abstract

3D Reconstruction and alignment by consumer RGB-D sensors and fiducial planar markers for patient positioning in radiation therapy

Sarmadi

Muñoz-Salinas

Berbís³

et al. 2019

Computer Methods and Programs in Biomedicine

View full text Add to dashboard Cite

Background and Objective: Patient positioning is a crucial step in radiation therapy, for which non-invasive methods have been developed based on surface reconstruction using optical 3D imaging. However, most solutions need expensive specialized hardware and a careful calibration procedure that must be repeated over time.This paper proposes a fast and cheap patient positioning method based on inexpensive consumer level RGB-D sensors.Methods: The proposed method relies on a 3D reconstruction approach that fuses, in real-time, artificial and natural visual landmarks recorded from a hand-held RGB-D sensor. The video sequence is transformed into a set of keyframes with known poses, that are later refined to obtain a realistic 3D reconstruction of the patient. The use of artificial landmarks allows our method to automatically align the reconstruction to a reference one, without the need of calibrating the system with respect to the linear accelerator coordinate system. Results:The experiments conducted show that our method obtains a median of 1 cm in translational error, and 1°of rotational error with respect to reference pose. Additionally, the proposed method shows as visual output overlayed poses (from the reference and the current scene) and an error map that can be used to correct the patient's current pose to match the reference pose.Conclusions: A novel approach to obtain 3D body reconstructions for patient positioning without requiring expensive hardware or dedicated graphic cards is proposed. The method can be used to align in real time the patient's current pose to a preview pose, which is a relevant step in radiation therapy.

show abstract

A vision system for patient positioning in radiation therapy

Cited by 3 publications

References 19 publications

Application of Draw Wire Sensor in the Tracking Control of An Electro Hydraulic Actuator System

Application of Draw Wire Sensor in the Tracking Control of An Electro Hydraulic Actuator System

Application Of Draw Wire Sensor In Position Tracking Of Electro Hydraulic Actuator System

3D Reconstruction and alignment by consumer RGB-D sensors and fiducial planar markers for patient positioning in radiation therapy

Contact Info

Product

Resources

About