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Head rotations in roll

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https://www.readbyqxmd.com/read/29692881/quantitative-approach-based-on-wearable-inertial-sensors-to-assess-and-identify-motion-and-errors-in-techniques-used-during-training-of-transfers-of-simulated-c-spine-injured-patients
#1
Karina Lebel, Vanessa Chenel, John Boulay, Patrick Boissy
Patients with suspected spinal cord injuries undergo numerous transfers throughout treatment and care. Effective c-spine stabilization is crucial to minimize the impacts of the suspected injury. Healthcare professionals are trained to perform those transfers using simulation; however, the feedback on the manoeuvre is subjective. This paper proposes a quantitative approach to measure the efficacy of the c-spine stabilization and provide objective feedback during training. Methods . 3D wearable motion sensors are positioned on a simulated patient to capture the motion of the head and trunk during a training scenario...
2018: Journal of Healthcare Engineering
https://www.readbyqxmd.com/read/29649150/self-alignment-mems-imu-method-based-on-the-rotation-modulation-technique-on-a-swing-base
#2
Haifeng Xing, Zhiyong Chen, Haotian Yang, Chengbin Wang, Zhihui Lin, Meifeng Guo
The micro-electro-mechanical-system (MEMS) inertial measurement unit (IMU) has been widely used in the field of inertial navigation due to its small size, low cost, and light weight, but aligning MEMS IMUs remains a challenge for researchers. MEMS IMUs have been conventionally aligned on a static base, requiring other sensors, such as magnetometers or satellites, to provide auxiliary information, which limits its application range to some extent. Therefore, improving the alignment accuracy of MEMS IMU as much as possible under swing conditions is of considerable value...
April 12, 2018: Sensors
https://www.readbyqxmd.com/read/29624212/effectiveness-of-base-of-skull-immobilization-system-in-a-compact-proton-therapy-setting
#3
Ghazal Shafai-Erfani, Twyla Willoughby, Naren Ramakrishna, Sanford Meeks, Patrick Kelly, Omar Zeidan
PURPOSE: The purpose of this study was to investigate daily repositioning accuracy by analyzing inter- and intra-fractional uncertainties associated with patients treated for intracranial or base of skull tumors in a compact proton therapy system with 6 degrees of freedom (DOF) robotic couch and a thermoplastic head mask indexed to a base of skull (BoS) frame. MATERIALS AND METHODS: Daily orthogonal kV alignment images at setup position before and after daily treatments were analyzed for 33 patients...
April 6, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29548880/the-advantages-of-advanced-computer-assisted-diagnostics-and-three-dimensional-preoperative-planning-on-implant-position-in-orbital-reconstruction
#4
Jesper Jansen, Ruud Schreurs, Leander Dubois, Thomas J J Maal, Peter J J Gooris, Alfred G Becking
OBJECTIVE: Advanced three-dimensional (3D) diagnostics and preoperative planning are the first steps in computer-assisted surgery (CAS). They are an integral part of the workflow, and allow the surgeon to adequately assess the fracture and to perform virtual surgery to find the optimal implant position. The goal of this study was to evaluate the accuracy and predictability of 3D diagnostics and preoperative virtual planning without intraoperative navigation in orbital reconstruction. METHODS: In 10 cadaveric heads, 19 complex orbital fractures were created...
February 26, 2018: Journal of Cranio-maxillo-facial Surgery
https://www.readbyqxmd.com/read/29508529/sensitivity-study-of-an-automated-system-for-daily-patient-qa-using-epid-exit-dose-images
#5
Audrey H Zhuang, Arthur J Olch
The dosimetric consequences of errors in patient setup or beam delivery and anatomical changes are not readily known. A new product, PerFRACTION (Sun Nuclear Corporation), is designed to identify these errors by comparing the exit dose image measured on an electronic portal imaging device (EPID) from each field of each fraction to those from baseline fraction images. This work investigates the sensitivity of PerFRACTION to detect the deviation caused by these errors in a variety of realistic scenarios. Integrated EPID images were acquired in clinical mode and saved in ARIA...
March 6, 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/29464087/3d-printed-masks-as-a-new-approach-for-immobilization-in-radiotherapy-a-study-of-positioning-accuracy
#6
Matthias Felix Haefner, Frederik Lars Giesel, Matthias Mattke, Daniel Rath, Moritz Wade, Jacob Kuypers, Alan Preuss, Hans-Ulrich Kauczor, Jens-Peter Schenk, Juergen Debus, Florian Sterzing, Roland Unterhinninghofen
We developed a new approach to produce individual immobilization devices for the head based on MRI data and 3D printing technologies. The purpose of this study was to determine positioning accuracy with healthy volunteers. 3D MRI data of the head were acquired for 8 volunteers. In-house developed software processed the image data to generate a surface mesh model of the immobilization mask. After adding an interface for the couch, the fixation setup was materialized using a 3D printer with acrylonitrile butadiene styrene (ABS)...
January 19, 2018: Oncotarget
https://www.readbyqxmd.com/read/29459843/hypothesis-the-vestibular-and-cerebellar-basis-of-the-mal-de-debarquement-syndrome
#7
Bernard Cohen, Sergei B Yakushin, Catherine Cho
The Mal de Debarquement syndrome (MdDS) generally follows sea voyages, but it can occur after turbulent flights or spontaneously. The primary features are objective or perceived continuous rocking, swaying, and/or bobbing at 0.2 Hz after sea voyages or 0.3 Hz after flights. The oscillations can continue for months or years and are immensely disturbing. Associated symptoms appear to be secondary to the incessant sensation of movement. We previously suggested that the illness can be attributed to maladaptation of the velocity storage integrator in the vestibular system, but the actual neural mechanisms driving the MdDS are unknown...
2018: Frontiers in Neurology
https://www.readbyqxmd.com/read/29400689/effect-of-spaceflight-on-the-spatial-orientation-of-the-vestibulo-ocular-reflex-during-eccentric-roll-rotation-a-case-report
#8
Millard F Reschke, Scott J Wood, Gilles Clément
BACKGROUND: Ground-based studies have reported shifts of the vestibulo-ocular reflex (VOR) slow phase velocity (SPV) axis toward the resultant gravito-inertial force vector. The VOR was examined during eccentric roll rotation before, during and after an 8-day orbital mission. On orbit this vector is aligned with the head z-axis. Our hypothesis was that eccentric roll rotation on orbit would generate horizontal eye movements. METHODS: Two subjects were rotated in a semi-supine position with the head nasal-occipital axis parallel to the axis of rotation and 0...
2018: Journal of Vestibular Research: Equilibrium & Orientation
https://www.readbyqxmd.com/read/29170018/ocular-torsion-responses-to-sinusoidal-electrical-vestibular-stimulation
#9
Stuart W Mackenzie, Raymond F Reynolds
BACKGROUND: Eye movements evoked by electrical vestibular stimulation (EVS) offer potential for diagnosing vestibular dysfunction. However, ocular recording techniques are often too invasive or impractical for routine clinical use. Furthermore, the kinematic nature of the EVS signal is not fully understood in terms of movement sensations. NEW METHOD: We apply sinusoidal EVS stimuli varying from 0.05 to 20Hz, and record the eye in darkness using an infrared camera...
January 15, 2018: Journal of Neuroscience Methods
https://www.readbyqxmd.com/read/29119677/minimal-mask-immobilization-with-optical-surface-guidance-for-head-and-neck-radiotherapy
#10
Bo Zhao, Genevieve Maquilan, Steve Jiang, David L Schwartz
PURPOSE: Full face and neck thermoplastic masks provide standard-of-care immobilization for patients receiving H&N IMRT. However, these masks are uncomfortable and increase skin dose. The purpose of this pilot trial was to investigate the feasibility and setup accuracy of minimal face and neck mask immobilization with optical surface guidance. METHODS: Twenty patients enrolled onto this IRB-approved protocol. Patients were immobilized with masks securing only forehead and chin...
January 2018: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28983570/updating-of-visual-orientation-in-a-gravity-based-reference-frame
#11
Nynke Niehof, Julian J Tramper, Christian F Doeller, W Pieter Medendorp
The brain can use multiple reference frames to code line orientation, including head-, object-, and gravity-centered references. If these frames change orientation, their representations must be updated to keep register with actual line orientation. We tested this internal updating during head rotation in roll, exploiting the rod-and-frame effect: The illusory tilt of a vertical line surrounded by a tilted visual frame. If line orientation is stored relative to gravity, these distortions should also affect the updating process...
October 1, 2017: Journal of Vision
https://www.readbyqxmd.com/read/28945777/effects-of-head-tilt-on-visual-field-testing-with-a-head-mounted-perimeter-imo
#12
Sayaka Yamao, Chota Matsumoto, Hiroki Nomoto, Takuya Numata, Mariko Eura, Marika Yamashita, Shigeki Hashimoto, Sachiko Okuyama, Shinji Kimura, Kenzo Yamanaka, Yasutaka Chiba, Makoto Aihara, Yoshikazu Shimomura
PURPOSE: A newly developed head-mounted perimeter termed "imo" enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject's head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results...
2017: PloS One
https://www.readbyqxmd.com/read/28861030/coding-of-velocity-storage-in-the-vestibular-nuclei
#13
Sergei B Yakushin, Theodore Raphan, Bernard Cohen
Semicircular canal afferents sense angular acceleration and output angular velocity with a short time constant of ≈4.5 s. This output is prolonged by a central integrative network, velocity storage that lengthens the time constants of eye velocity. This mechanism utilizes canal, otolith, and visual (optokinetic) information to align the axis of eye velocity toward the spatial vertical when head orientation is off-vertical axis. Previous studies indicated that vestibular-only (VO) and vestibular-pause-saccade (VPS) neurons located in the medial and superior vestibular nucleus could code all aspects of velocity storage...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28529496/treatment-of-the-mal-de-debarquement-syndrome-a-1-year-follow-up
#14
Mingjia Dai, Bernard Cohen, Catherine Cho, Susan Shin, Sergei B Yakushin
The mal de debarquement syndrome (MdDS) is a movement disorder, occurring predominantly in women, is most often induced by passive transport on water or in the air (classic MdDS), or can occur spontaneously. MdDS likely originates in the vestibular system and is unfamiliar to many physicians. The first successful treatment was devised by Dai et al. (1), and over 330 MdDS patients have now been treated. Here, we report the outcomes of 141 patients (122 females and 19 males) treated 1 year or more ago. We examine the patient's rocking frequency, body drifting, and nystagmus...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28462690/comparison-of-online-6-degree-of-freedom-image-registration-of-varian-truebeam-cone-beam-ct-and-brainlab-exactrac-x-ray-for-intracranial-radiosurgery
#15
Jun Li, Wenyin Shi, David Andrews, Maria Werner-Wasik, Bo Lu, Yan Yu, Adam Dicker, Haisong Liu
PURPOSE: The study was aimed to compare online 6 degree-of-freedom image registrations of TrueBeam cone-beam computed tomography and BrainLab ExacTrac X-ray imaging systems for intracranial radiosurgery. METHODS: Phantom and patient studies were performed on a Varian TrueBeam STx linear accelerator (version 2.5), which is integrated with a BrainLab ExacTrac imaging system (version 6.1.1). The phantom study was based on a Rando head phantom and was designed to evaluate isocenter location dependence of the image registrations...
June 2017: Technology in Cancer Research & Treatment
https://www.readbyqxmd.com/read/28449202/barn-owls-maximize-head-rotations-by-a-combination-of-yawing-and-rolling-in-functionally-diverse-regions-of-the-neck
#16
Markus Krings, John A Nyakatura, Mark L L M Boumans, Martin S Fischer, Hermann Wagner
Owls are known for their outstanding neck mobility: these birds can rotate their heads more than 270°. The anatomical basis of this extraordinary neck rotation ability is not well understood. We used X-ray fluoroscopy of living owls as well as forced neck rotations in dead specimens and computer tomographic (CT) reconstructions to study how the individual cervical joints contribute to head rotation in barn owls (Tyto furcata pratincola). The X-ray data showed the natural posture of the neck, and the reconstructions of the CT-scans provided the shapes of the individual vertebrae...
April 27, 2017: Journal of Anatomy
https://www.readbyqxmd.com/read/28357113/identification-of-animal-movement-patterns-using-tri-axial-magnetometry
#17
Hannah J Williams, Mark D Holton, Emily L C Shepard, Nicola Largey, Brad Norman, Peter G Ryan, Olivier Duriez, Michael Scantlebury, Flavio Quintana, Elizabeth A Magowan, Nikki J Marks, Abdulaziz N Alagaili, Nigel C Bennett, Rory P Wilson
BACKGROUND: Accelerometers are powerful sensors in many bio-logging devices, and are increasingly allowing researchers to investigate the performance, behaviour, energy expenditure and even state, of free-living animals. Another sensor commonly used in animal-attached loggers is the magnetometer, which has been primarily used in dead-reckoning or inertial measurement tags, but little outside that. We examine the potential of magnetometers for helping elucidate the behaviour of animals in a manner analogous to, but very different from, accelerometers...
2017: Movement Ecology
https://www.readbyqxmd.com/read/28297354/quantitative-evaluation-of-patient-setup-uncertainty-of-stereotactic-radiotherapy-with-the-frameless-6d-exactrac-system-using-statistical-modeling
#18
Vance Keeling, Sabbir Hossain, Hosang Jin, Ozer Algan, Salahuddin Ahmad, Imad Ali
The purpose of this study is to evaluate patient setup accuracy and quantify individual and cumulative positioning uncertainties associated with different hardware and software components of the stereotactic radiotherapy (SRS/SRT) with the frameless 6D ExacTrac system. A statistical model is used to evaluate positioning uncertainties of the different components of SRS/SRT treatment with the Brainlab 6D ExacTrac system using the positioning shifts of 35 patients having cranial lesions. All these patients are immobilized with rigid head-and-neck masks, simulated with Brainlab localizer and planned with iPlan treatment planning system...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28297352/improved-setup-and-positioning-accuracy-using-a-three-point-customized-cushion-mask-bite-block-immobilization-system-for-stereotactic-reirradiation-of-head-and-neck-cancer
#19
He Wang, Congjun Wang, Samuel Tung, Andrew Wilson Dimmitt, Pei Fong Wong, Mark A Edson, Adam S Garden, David I Rosenthal, Clifton D Fuller, Gary B Gunn, Vinita Takiar, Xin A Wang, Dershan Luo, James N Yang, Jennifer Wong, Jack Phan
The purpose of this study was to investigate the setup and positioning uncertainty of a custom cushion/mask/bite-block (CMB) immobilization system and determine PTV margin for image-guided head and neck stereotactic ablative radiotherapy (HN-SABR). We analyzed 105 treatment sessions among 21 patients treated with HN-SABR for recurrent head and neck cancers using a custom CMB immobilization system. Initial patient setup was performed using the ExacTrac infrared (IR) tracking system and initial setup errors were based on comparison of ExacTrac IR tracking system to corrected online ExacTrac X-rays images registered to treatment plans...
May 2016: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28134966/coordinated-control-of-three-dimensional-components-of-smooth-pursuit-to-rotating-and-translating-textures
#20
Janick Edinger, Dinesh K Pai, Miriam Spering
Purpose: The neural control of pursuit eye movements to visual textures that simultaneously translate and rotate has largely been neglected. Here we propose that pursuit of such targets-texture pursuit-is a fully three-dimensional task that utilizes all three degrees of freedom of the eye, including torsion. Methods: Head-fixed healthy human adults (n = 8) tracked a translating and rotating random dot pattern, shown on a computer monitor, with their eyes. Horizontal, vertical, and torsional eye positions were recorded with a head-mounted eye tracker...
January 1, 2017: Investigative Ophthalmology & Visual Science
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