scholarly journals In-Vivo Measurement of Dynamic Joint Motion Using High Speed Biplane Radiography and CT: Application to Canine ACL Deficiency

2003 ◽  
Vol 125 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Scott Tashman ◽  
William Anderst
Keyword(s):  
Coordinate System ◽  
High Speed ◽  
Motion Artifacts ◽  
Frame Rate ◽  
Joint Motion ◽  
High Frame Rate ◽  
Flexion Extension ◽  
Standard Deviations ◽  
Skeletal Kinematics

Dynamic assessment of three-dimensional (3D) skeletal kinematics is essential for understanding normal joint function as well as the effects of injury or disease. This paper presents a novel technique for measuring in-vivo skeletal kinematics that combines data collected from high-speed biplane radiography and static computed tomography (CT). The goals of the present study were to demonstrate that highly precise measurements can be obtained during dynamic movement studies employing high frame-rate biplane video-radiography, to develop a method for expressing joint kinematics in an anatomically relevant coordinate system and to demonstrate the application of this technique by calculating canine tibio-femoral kinematics during dynamic motion. The method consists of four components: the generation and acquisition of high frame rate biplane radiographs, identification and 3D tracking of implanted bone markers, CT-based coordinate system determination, and kinematic analysis routines for determining joint motion in anatomically based coordinates. Results from dynamic tracking of markers inserted in a phantom object showed the system bias was insignificant (−0.02 mm). The average precision in tracking implanted markers in-vivo was 0.064 mm for the distance between markers and 0.31° for the angles between markers. Across-trial standard deviations for tibio-femoral translations were similar for all three motion directions, averaging 0.14 mm (range 0.08 to 0.20 mm). Variability in tibio-femoral rotations was more dependent on rotation axis, with across-trial standard deviations averaging 1.71° for flexion/extension, 0.90° for internal/external rotation, and 0.40° for varus/valgus rotation. Advantages of this technique over traditional motion analysis methods include the elimination of skin motion artifacts, improved tracking precision and the ability to present results in a consistent anatomical reference frame.

Future trends in the use of X-ray fluoroscopy for the measurement and modelling of joint motion

2011 ◽  
Vol 225 (12) ◽  
pp. 1136-1148 ◽  
Author(s):  
D C Ackland ◽  
F Keynejad ◽  
M G Pandy
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Joint Kinematics ◽  
Joint Motion ◽  
Computationally Efficient ◽  
Surgical Interventions ◽  
X Ray ◽  
The Subject ◽  
Skeletal Kinematics

Knowledge of three-dimensional skeletal kinematics during functional activities such as walking, is required for accurate modelling of joint motion and loading, and is important in identifying the effects of injury and disease. For example, accurate measurement of joint kinematics is essential in understanding the pathogenesis of osteoarthritis and its symptoms and for developing strategies to alleviate joint pain. Bi-plane X-ray fluoroscopy has the capacity to accurately and non-invasively measure human joint motion in vivo. Joint kinematics obtained using bi-plane X-ray fluoroscopy will aid in the development of more complex musculoskeletal models, which may be used to assess joint function and disease and plan surgical interventions and post-operative rehabilitation strategies. At present, however, commercial C-arm systems constrain the motion of the subject within the imaging field of view, thus precluding recording of motions such as overground gait. These fluoroscopy systems also operate at low frame rates and therefore cannot accurately capture high-speed joint motion during tasks such as running and throwing. In the future, bi-plane fluoroscopy systems may include computer-controlled tracking for the measurement of joint kinematics over entire cycles of overground gait without constraining motion of the subject. High-speed cameras will facilitate measurement of high-impulse joint motions, and computationally efficient pose-estimation software may provide a fast and fully automated process for quantification of natural joint motion.

Motion Artifacts and Correction in Multipulse High-Frame Rate Contrast-Enhanced Ultrasound

2019 ◽  
Vol 66 (2) ◽  
pp. 417-420 ◽  
Author(s):  
A. Stanziola ◽  
M. Toulemonde ◽  
Y. Li ◽  
V. Papadopoulou ◽  
R. Corbett ◽  
...  
Keyword(s):  
Motion Artifacts ◽  
Frame Rate ◽  
Contrast Enhanced Ultrasound ◽  
High Frame Rate ◽  
Contrast Enhanced

Real-Time Image Mosaicing System Using a High-Frame-Rate Video Sequence

2015 ◽  
Vol 27 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Qingyi Gu ◽  
◽  
Sushil Raut ◽  
Ken-ichi Okumura ◽  
Tadayoshi Aoyama ◽  
...  
Keyword(s):  
Real Time ◽  
High Speed ◽  
Video Sequence ◽  
Frame Rate ◽  
Image Mosaicing ◽  
Current Frame ◽  
High Frame Rate ◽  
Harris Corner ◽  
Real Time Image ◽  
Time Image

<div class=""abs_img""><img src=""[disp_template_path]/JRM/abst-image/00270001/02.jpg"" width=""300"" />Synthesized panoramic images</div> In this paper, we propose a real-time image mosaicing system that uses a high-frame-rate video sequence. Our proposed system can mosaic 512 × 512 color images captured at 500 fps as a single synthesized panoramic image in real time by stitching the images based on their estimated frame-to-frame changes in displacement and orientation. In the system, feature point extraction is accelerated by implementing a parallel processing circuit module for Harris corner detection, and hundreds of selected feature points in the current frame can be simultaneously corresponded with those in their neighbor ranges in the previous frame, assuming that frame-to-frame image displacement becomes smaller in high-speed vision. The efficacy of our system for improved feature-based real-time image mosaicing at 500 fps was verified by implementing it on a field-programmable gate array (FPGA)-based high-speed vision platform and conducting several experiments: (1) capturing an indoor scene using a camera mounted on a fast-moving two-degrees-of-freedom active vision, (2) capturing an outdoor scene using a hand-held camera that was rapidly moved in a periodic fashion by hand. </span>

scholarly journals Architecture and implementation of a high frame-rate stereo vision system

2021 ◽  
Author(s):  
Jamin Islam
Keyword(s):  
Integrated Circuits ◽  
Stereo Vision ◽  
High Speed ◽  
Vision System ◽  
Low Cost ◽  
Cost Effective ◽  
Frame Rate ◽  
Superior Performance ◽  
High Frame Rate ◽  
Stereo Vision System

For the purpose of autonomous satellite grasping, a high-speed, low-cost stereo vision system is required with high accuracy. This type of system must be able to detect an object and estimate its range. Hardware solutions are often chosen over software solutions, which tend to be too slow for high frame-rate applications. Designs utilizing field programmable gate arrays (FPGAs) provide flexibility and are cost effective versus solutions that provide similar performance (i.e., Application Specific Integrated Circuits). This thesis presents the architecture and implementation of a high frame-rate stereo vision system based on an FPGA platform. The system acquires stereo images, performs stereo rectification and generates disparity estimates at frame-rates close to 100 fpSi and on a large-enough FPGA, it can process 200 fps. The implementation presents novelties in performance and in the choice of the algorithm implemented. It achieves superior performance to existing systems that estimate scene depth. Furthermore, it demonstrates equivalent accuracy to software implementations of the dynamic programming maximum likelihood stereo correspondence algorithm.

Spontaneous Extension Wave for In Vivo Assessment of Arterial Wall Anisotropy

2021 ◽  
Author(s):  
Dan Ran ◽  
Jinping Dong ◽  
He Li ◽  
Wei-Ning Lee
Keyword(s):  
Carotid Artery ◽  
Arterial Wall ◽  
Guided Wave ◽  
Frame Rate ◽  
Mechanical Anisotropy ◽  
Natural Wave ◽  
High Frame Rate ◽  
Longitudinal Stiffness ◽  
Anisotropy Index

Another type of natural wave, traced from longitudinal wall motion and propagation along the artery, is unprecedentedly observed in our in vivo human carotid artery experiments. We coin it as extension wave (EW) and hypothesize that EW velocity (EWV) is associated with arterial longitudinal stiffness. The EW is thus assumed to complement the PW, whose velocity (PWV) is tracked from the radial wall displacement and linked to arterial circumferential stiffness through the Moens-Korteweg equation, as indicators for arterial mechanical anisotropy quantification by noninvasive high-frame-rate ultrasound. The relationship between directional arterial stiffnesses and the two natural wave speeds was investigated in wave theory, finite-element simulations based on isotropic and anisotropic arterial models, and in vivo human common carotid artery (N=10) experiments. Excellent agreement between the theory and simulations showed that EWV was 2.57 and 1.03 times higher than PWV in an isotropic and an anisotropic carotid artery model, respectively, while in vivo EWV was consistently lower than PWV in all 10 healthy human subjects. A strong linear correlation was substantiated in vivo between EWV and arterial longitudinal stiffness quantified by a well-validated vascular guided wave imaging technique (VGWI). We thereby proposed a novel index calculated as EWV2/PWV2 as an alternative to assess arterial mechanical anisotropy. Simulations and in vivo results corroborated the effect of mechanical anisotropy on the propagation of spontaneous waves along the arterial wall. The proposed anisotropy index demonstrated the feasibility of the concurrent EW and PW imaged by high frame-rate ultrasound in grading of arterial wall anisotropy.

Preliminary study on estimation of flow velocity vectors using focused transmit beams

2021 ◽  
Author(s):  
Hideyuki Hasegawa ◽  
Michiya Mozumi ◽  
Masaaki Omura ◽  
Ryo Nagaoka ◽  
Kozue Saito
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Soft Tissues ◽  
Estimation Error ◽  
Frame Rate ◽  
High Frame Rate ◽  
In Vivo Measurement ◽  
Preliminary Study

Abstract High-frame-rate ultrasound imaging with plane wave transmissions is a predominant method for blood flow imaging, and methods for estimation of blood flow velocity vectors have been developed based on high-frame-rate imaging. On the other hand, in imaging of soft tissues, such as arterial walls and atherosclerotic plaques, high-frame-rate imaging sometimes suffers from high-level clutters. Even in observation of the arterial wall with a focused transmit beam, it would be highly beneficial if blood flow velocity vectors could be estimated simultaneously. We conducted a preliminary study on estimation of blood flow velocity vectors based on a multi-angle Doppler method with focused transmit beam and parallel receive beamforming. It was shown that the lowest estimation error was achieved at a steering angle of 25 degrees by simulation. Also, velocity vectors with typical velocity magnitudes and directions could be obtained by the proposed method in in vivo measurement of a carotid artery.

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