Equations for the temperature dependence of the spectral densities J(is)(m)(momega(I) +/-omega(T)), where m=1, 2, omega(I) and omega(T) are the resonance and tunnel splitting angular frequencies, in the presence of a complex motion, have been derived. The spin pairs of the protons or deuterons of the methyl group perform a complex ...

We report a technique for two-photon fluorescence imaging with cellular resolution in awake, behaving mice with minimal motion artifact. The apparatus combines an upright, table-mounted two-photon microscope with a spherical treadmill consisting of a large, air-supported Styrofoam ball. Mice, with implanted cranial windows, are head restrained under the objective while ...

In gated radiation therapy procedures, the lung tumor position is used directly (by implanted radiopaque markers) or indirectly (by external surrogate methods) to decrease the volume of irradiated healthy tissue. Due to a risk of pneumothorax, many clinics do not implant fiducials, and the gated treatment is primarily based on ...

Motion has an adverse effect on spectral quality and needs to be properly identified in MR spectroscopy (MRS) scans. Spectral subtraction-based techniques like J-difference editing are prone to be affected more by subject motion where motion can result in false peaks or inefficient subtraction of peaks. Introducing a water signal-based ...

Three-dimensional (3D) soft tissue tracking is of interest for monitoring organ motion during therapy. Our goal is to assess the tracking performance of a curvilinear 3D ultrasound probe in terms of the accuracy and precision of measured displacements. The first aim was to examine the depth dependence of the tracking ...

Differing degrees of head motion have long been recognized as a potential confound in functional neuroimaging studies comparing neuropsychiatric populations to healthy normal volunteers, and studies often cite excessive head motion as a possible reason for the different patterns of functional activation frequently observed between groups. We empirically tested the ...

This article shows the limitations of respiratory gating due to intrafraction deformations of the right liver lobe. The variability of organ shape and motion over tens of minutes was taken into account for this evaluation, which closes the gap between short-term analysis of a few regular cycles, as it is ...

BACKGROUND: Many surgical robotic interfaces allow users to interact with robots over a wide potential range of motion, yet variation in operator performance across a range of motion remains unexamined. This research identifies and explores a new construct, the surgeon's 'comfortable working envelope' within the available range of motion, as ...

PURPOSE: To evaluate the impact of a new, cross-correlation based method for compensation of respiratory induced motion of the heart using an individually adapted three-dimensional (3D) translation or affine transformation approach. MATERIALS AND METHODS: A total of 32 patients underwent a routine cardiac MR examination. In each patient, a calibration ...

Motion estimation methods can be broadly classified as being spatiotemporal or frequency domain in nature. The Gabor representation is an analysis framework providing localized frequency information. When applied to image sequences, the 3-D Gabor representation displays spatiotemporal/spatiotemporal-frequency (st/stf) information, enabling the application of robust frequency domain methods with adjustable spatiotemporal ...

Intrafraction tumour (e.g. lung) motion due to breathing can, in principle, be compensated for by applying identical breathing motions to the leaves of a multileaf collimator (MLC) as intensity-modulated radiation therapy is delivered by the dynamic MLC (DMLC) technique. A difficulty arising, however, is that irradiated voxels, which are in ...

The transition path sampling method previously applied in our group to the reaction catalyzed by lactate dehydrogenase was used to generate a transition path ensemble for this reaction. Based on analysis of the reactive trajectories generated, important residues behind the active site were implicated in a compressional motion that brought ...

Respiratory gating is used for reducing the effects of breathing motion in a wide range of applications from radiotherapy treatment to diagnostical imaging. Different methods are feasible for respiratory gating. In this study seven gating methods were developed and tested on positron emission tomography (PET) listmode data. The results of ...

By means of passive optical motion capture, real people can be authentically animated and photo-realistically textured. To import real-world characters into virtual environments, however, surface reflectance properties must also be known. We describe a video-based modeling approach that captures human shape and motion as well as reflectance characteristics from a ...

Operant animal behavioral tests require the interaction of the subject with sensors and actuators distributed in the experimental environment of the arena. In order to provide user independent reliable results and versatile control of these devices it is vital to use an automated control system. Commercial systems for control of ...

The analysis of periodic or repetitive motions is useful in many applications, such as the recognition and classification of human and animal activities. Existing methods for the analysis of periodic motions first extract motion trajectories using spatial information and then determine if they are periodic. These approaches are mostly based ...

Spinal cord (SC) motion is thought to be the dominant source of error in current diffusion and spinal functional MRI (fMRI) methods. However, until now, such motion has not been well characterized in three dimensions. While previous studies have predominantly examined motion in the superior/inferior (S/I) direction, the foci of ...

The purpose of this study was to develop a technique that could quantitatively monitor the nonrespiratory motion of a patient during stereotactic body radiotherapy (SBRT). Multiple infrared external markers were placed on the patient's chest and abdominal surface to obtain patient motion signals. These motion signals contained both respiratory and ...

Those motion parameters that cannot be recovered from image measurements are unobservable in the visual dynamic system. This paper studies this important issue of singularity in the context of kernel-based tracking and presents a novel approach that is based on a motion field representation which employs redundant but sparsely correlated ...

OBJECTIVE: One step toward motion analysis of the temporomandibular joint is pseudodynamic magnetic resonance imaging (i.e., with stepwise mouth opening controlled by a Burnett device). This study intends to clarify whether and how pseudodynamic motion differs from natural motion. Furthermore, the fixing efficiency (i.e., the reliability of the mechanical connection ...

We have developed a four-dimensional weighted radiotherapy (4DW-RT) technique. This method involves designing the motion of the linear accelerator beam to coincide with the tumour motion determined from 4D-CT imaging while including a weighting factor to account for irregular motion and limitations of the delivery system. Experiments were conducted with ...

As an extension of previous work on computer-generated phantoms, more accurate, realistic phantoms are generated by integrating image distortion and signal loss caused by susceptibility variations. With the addition of real motions and activations determined from actual functional MRI studies, these phantoms can be used by the fMRI community to ...

An effective fluence concept was employed to make forward dose calculations to investigate the effects of a distorted fluence map on dose plans. Fluence changes caused by organ motion were calculated using Chui's algorithm (2003 Med. Phys. 30 1736). In two test cases with various fluence maps, the effects of ...

The objectives of this study were to use computer-generated phantoms containing real subject motion to: (1) compare the sensitivity of four commonly used fMRI software packages and (2) compare the sensitivity of three statistical analysis strategies with respect to motion correction. The results suggest that all four packages perform similarly ...

This short paper investigates highly constrained organ-motion deconvolution in the context of the delivery of radiotherapy. Whereas unconstrained and unphysical deconvolution of regular intrafraction motion can generate a dose distribution exactly matching the plan (made on a supposedly static object), the addition of fluence-positivity, fluence-smoothing and fluence-capping constraints to create ...

PURPOSE: To detect motion-corrupted measurements in multi-average turbo-spin-echo (TSE) acquisitions and reduce motion artifacts in reconstructed images. MATERIALS AND METHODS: An average-specific phase encoding (PE) ordering scheme was developed for multi-average TSE sequences in which each echo train is assigned a unique PE pattern for each pre-averaged image (PAI). A ...

In this paper, we present a theory for combining the effects of motion, illumination, 3D structure, albedo, and camera parameters in a sequence of images obtained by a perspective camera. We show that the set of all Lambertian reflectance functions of a moving object, at any position, illuminated by arbitrarily ...

High precision motion control of gantry stages has found numerous applications in the manufacturing industries where precise positioning is crucial. This paper presents a survey of existing control schemes as well as the development of enhanced schemes for the coordinated motion control of moving gantry stages. In particular, a robust ...

Low-frequency internal motions in protein molecules play a key role in biological functions. A direct relationship between low-frequency motions and enzymatic activity has been suggested for bovine pancreatic ribonuclease (RNase A). The flexibility-function relationship in this enzyme has been attributed to a subtle and concerted breathing motion of the beta-sheet ...

This module introduces the concept of free energy and potential fields in the context of protein conformation spaces and motion planning. It then provides examples of applications of motion planning techniques to problems from structural computational biology.

Since the discovery of plate tectonics, the relative importance of driving forces of plate motion has been debated. Resolution of this issue has been hindered by uncertainties in estimates of basal traction, which controls the coupling between lithospheric plates and underlying mantle convection. Hotspot tracks preserve records of past plate ...

The current-induced motion of magnetic domain walls confined to nanostructures is of interest for applications in magnetoelectronic devices in which the domain wall serves as the logic gate or memory element. The injection of spin-polarized current below a threshold value through a domain wall confined to a pinning potential results ...

Hot-wire data acquired in a high Reynolds number facility are used to illustrate the need for adequate scale separation when considering the coherent structure in wall-bounded turbulence. It is found that a large-scale motion in the log region becomes increasingly comparable in energy to the near-wall cycle as the Reynolds ...

The nature of the interaction between the inner and outer regions of turbulent wall-bounded flow is examined. Townsend's theory of inactive motion is shown to be a first-order, linear approximation of the effect of the large eddies at the surface that acts as a quasi-inviscid, low-frequency modulation of the shear-stress-bearing ...

A general framework for performing event-driven simulations of systems with semiflexible or rigid bodies interacting under impulsive forces is outlined. The method consists of specifying a means of computing the free evolution of constrained motion, evaluating the times at which interactions occur, and determining the consequences of interactions on subsequent ...

It is well known that a rigid in-plane motion can be decomposed into a translation and a rotation around an origin. Based on our previous work, we first extend the Helgason-Ludwig consistency condition (HLCC) to cover a general rigid motion in fan-beam geometry. Then, we model the general motion by ...

Accurate detection of falls leading to injury is essential for providing timely medical assistance. In this paper, we describe a wireless sensor network system for automatic fall detection. To detect falls, we use a combination of a body-worn triaxial accelerometer with motion detectors placed in the monitored area. While accelerometer ...

This paper presents a motion artifact reduction algorithm for a real-time, wireless and wearable photoplethysmography (PPG) device for measuring heart beats. A wearable finger band PPG device consists of a 3-axis accelerometer, infrared LED, photo diode, a microprocessor and wireless module. Sources of the motion artifacts were investigated from the ...

This study evaluates the effects of respiratory motion on breast radiotherapy delivered using segmented multileaf collimator (SMLC) intensity modulation. An anthropomorphic breast phantom was constructed of polystyrene plates between which radiographic films were inserted. The phantom was mounted on a moving platform to simulate one-dimensional sinusoidal oscillation with variable amplitude ...

Gated radiation therapy is a promising method for improving the dose conformality of treatments to moving targets and reducing the total volume of irradiated tissue. Target motion is of particular concern in proton beam radiotherapy, due to the finite range of proton dose deposition in tissue. Gating allows one to ...

A new non-invasive approach is proposed to study joint motions. It is based on dynamic tracking of the skin shape. A robust simultaneous registration algorithm (Iterative Median Closest Point) is used to follow the evolving shape and compute the rigid motion of the underlying bone structures. This new method relies ...

We proposed the non-contact measurement method of the respiratory movement under pedal stroke motion, by the application of optical technique. By the simultaneous measurement with the expiration gas analyzer, we examined the effectiveness of the proposal method. As the results, we clarified that the calculated value obtained by our proposal ...

Emerging technologies such as four-dimensional computed tomography (4D CT) and implanted beacons are expected to allow clinicians to accurately model intrafraction motion and to quantitatively estimate internal target volumes (ITVs) for radiation therapy involving moving targets. In the case of intensity-modulated (IMRT) and stereotactic body radiation therapy (SBRT) delivery, clinicians ...

The photoplethysmogram (PPG) is an extremely useful wearable sensing medical diagnostic tool. However, the PPG signal becomes highly corrupted and unusable when the sensor wearer is in motion. This paper investigates how confidently Widrow's Adaptive Noise Cancellation can eliminate motion artifact and recover a motion corrupted PPG signal for a ...

As hovering feeders, hawkmoths cope with flower motions by tracking those motions to maintain contact with the nectary. This study examined the tracking, feeding and energetic performance of Manduca sexta feeding from flowers moving at varied frequencies and in different directions. In general we found that tracking performance decreased as ...

Motion estimation in the spatiotemporal domain has been extensively studied and many methodologies have been proposed, which, however, cannot handle both time-varying and multiple motions. Extending previously published ideas, we present an efficient method for estimating multiple, linearly time-varying motions. It is shown that the estimation of accelerated motions is ...

With the increasing sophistication of surgical robots, the use of motion stabilisation for enhancing the performance of micro-surgical tasks is an actively pursued research topic. The use of mechanical stabilisation devices has certain advantages, in terms of both simplicity and consistency. The technique, however, can complicate the existing surgical workflow ...

Conventional research on motion recognition using surface electromyogram (SEMG) is mainly focused on how to process with the signals for pattern recognition. However, it is of much consequence to the motion recognition that measurement channels position including useful information about SEMG pattern recognition is selected. In this paper, we present ...

This study was carried out during the second phase of the project "Video Technologies for Neonatal Seizures" and aimed at the development of a seizure detection system by training neural networks, using quantitative motion information extracted by motion tracking methods from short video segments of infants monitored for seizures. The ...

The use of complex amplitude correlation to compensate for large in-plane motion in digital speckle pattern interferometry is investigated. The result is compared with experiments where digital speckle photography (DSP) is used for compensation. An advantage of using complex amplitude correlation instead of intensity correlation (as in DSP) is that ...