A Reconfigurable High-Speed Stereo-Radiography System for Sub-Millimeter Measurement of In Vivo Joint Kinematics

2015 ◽  
Vol 9 (4) ◽  
Author(s):  
John C. Ivester ◽  
Adam J. Cyr ◽  
Michael D. Harris ◽  
Martin J. Kulis ◽  
Paul J. Rullkoetter ◽  
...  
Keyword(s):  
Motion Capture ◽  
Human Body ◽  
High Speed ◽  
Knee Kinematics ◽  
High Accuracy ◽  
Joint Motion ◽  
Radiography System ◽  
Rapid Sequence ◽  
Speed And Accuracy

Relative motions within normal and pathological joints of the human body can occur on the sub-millimeter and sub-degree scale. Dynamic radiography can be used to create a rapid sequence of images from which measurements of bone motion can be extracted, but available systems have limited speed and accuracy, limit normal subject movement, and do not easily integrate into existing traditional motion capture laboratories. A high-speed stereo radiography (HSSR) system is described that addresses these limitations. The custom radiography system was placed on a standalone reconfigurable gantry structure designed to allow freedom of subject movement while integrating into an existing motion capture laboratory. Validation of the system and measurement of knee kinematics of subjects during gait confirmed the ability to record joint motion with high accuracy and high-speed.

scholarly journals Static and Dynamic Error of a Biplanar Videoradiography System Using Marker-Based and Markerless Tracking Techniques

2011 ◽  
Vol 133 (12) ◽  
Author(s):  
Daniel L. Miranda ◽  
Joel B. Schwartz ◽  
Andrew C. Loomis ◽  
Elizabeth L. Brainerd ◽  
Braden C. Fleming ◽  
...  
Keyword(s):  
Systematic Error ◽  
Gold Standard ◽  
High Speed ◽  
Angular Displacement ◽  
High Accuracy ◽  
Tracking Algorithm ◽  
Future Research ◽  
Markerless Tracking ◽  
Standard Instrumentation

The use of biplanar videoradiography technology has become increasingly popular for evaluating joint function in vivo. Two fundamentally different methods are currently employed to reconstruct 3D bone motions captured using this technology. Marker-based tracking requires at least three radio-opaque markers to be implanted in the bone of interest. Markerless tracking makes use of algorithms designed to match 3D bone shapes to biplanar videoradiography data. In order to reliably quantify in vivo bone motion, the systematic error of these tracking techniques should be evaluated. Herein, we present new markerless tracking software that makes use of modern GPU technology, describe a versatile method for quantifying the systematic error of a biplanar videoradiography motion capture system using independent gold standard instrumentation, and evaluate the systematic error of the W.M. Keck XROMM Facility’s biplanar videoradiography system using both marker-based and markerless tracking algorithms under static and dynamic motion conditions. A polycarbonate flag embedded with 12 radio-opaque markers was used to evaluate the systematic error of the marker-based tracking algorithm. Three human cadaveric bones (distal femur, distal radius, and distal ulna) were used to evaluate the systematic error of the markerless tracking algorithm. The systematic error was evaluated by comparing motions to independent gold standard instrumentation. Static motions were compared to high accuracy linear and rotary stages while dynamic motions were compared to a high accuracy angular displacement transducer. Marker-based tracking was shown to effectively track motion to within 0.1 mm and 0.1 deg under static and dynamic conditions. Furthermore, the presented results indicate that markerless tracking can be used to effectively track rapid bone motions to within 0.15 deg for the distal aspects of the femur, radius, and ulna. Both marker-based and markerless tracking techniques were in excellent agreement with the gold standard instrumentation for both static and dynamic testing protocols. Future research will employ these techniques to quantify in vivo joint motion for high-speed upper and lower extremity impacts such as jumping, landing, and hammering.

Downsized Evolutionary Video Processing for Lips Tracking and Data Acquisition

2007 ◽  
Vol 11 (8) ◽  
pp. 1030-1042 ◽  
Author(s):  
Takuya Akashi ◽  
◽  
Yuji Wakasa ◽  
Kanya Tanaka ◽  
Stephen Karungaru ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Video Processing ◽  
High Speed ◽  
Processing Time ◽  
High Accuracy ◽  
Natural Scenes ◽  
Trade Off ◽  
Region Detection ◽  
Detection And Tracking ◽  
Speed And Accuracy

In this paper, high-speed lips tracking and data acquisition of a talking person in natural scenes are presented. Our approach is based on the Evolutionary Video Processing. This method has a trade-off between accuracy and a processing time. To solve this problem, in this paper, we proposed Evolutionary Video Processing with automatic SD-Control. In our simulations, the effectiveness of the proposed method is verified by a comparison experiment. The proposed method improves the performance, speed and accuracy, from 68.4% to 86.2%. Furthermore, it is evaluated that our proposed method can continue to chase the lips region even in such a case. It is demonstrated that the lips region detection and tracking at high speed and with high accuracy is possible, with acquisition of its numerical geometric change information.

Speed and Accuracy in the Learning of a Complex Motor Skill

1997 ◽  
Vol 85 (3) ◽  
pp. 1011-1017 ◽  
Author(s):  
Richard Engelhorn
Keyword(s):  
Motor Skill ◽  
Repeated Measures ◽  
High Speed ◽  
High Accuracy ◽  
Practice Session ◽  
Complex Motor ◽  
Speed Group ◽  
Speed And Accuracy

The effect of emphasizing speed or accuracy on the learning of a high speed-high accuracy skill, the fastpitch Softball pitch was investigated. 26 10- and 11-yr.-old girls were randomly assigned to two groups receiving feedback on speed of throwing or accuracy of throwing during a 6-wk. training. Measurements of speed and accuracy were made and recorded on all participants at each practice session and a videotape of their pitching technique was also made at each session. Data were subjected to 2 × 3 (2 groups by 3 testing times) repeated-measures analyses of variance. The speed group threw faster and with better technique during the study and was able to maintain speed and accuracy in the reversed test condition.

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.

scholarly journals SCALABLE PHOTOGRAMMETRIC MOTION CAPTURE SYSTEM “MOSCA”: DEVELOPMENT AND APPLICATION

2015 ◽  
Vol XL-5/W6 ◽  
pp. 43-49 ◽  
Author(s):  
V. A. Knyaz
Keyword(s):  
Motion Capture ◽  
High Speed ◽  
High Accuracy ◽  
Object Motion ◽  
Frame Rate ◽  
Motion Capture System ◽  
Interest Points ◽  
Flexible Tool ◽  
3D Measurements ◽  
3D Information

Wide variety of applications (from industrial to entertainment) has a need for reliable and accurate 3D information about motion of an object and its parts. Very often the process of movement is rather fast as in cases of vehicle movement, sport biomechanics, animation of cartoon characters. Motion capture systems based on different physical principles are used for these purposes. The great potential for obtaining high accuracy and high degree of automation has vision-based system due to progress in image processing and analysis. Scalable inexpensive motion capture system is developed as a convenient and flexible tool for solving various tasks requiring 3D motion analysis. It is based on photogrammetric techniques of 3D measurements and provides high speed image acquisition, high accuracy of 3D measurements and highly automated processing of captured data. Depending on the application the system can be easily modified for different working areas from 100 mm to 10 m. The developed motion capture system uses from 2 to 4 technical vision cameras for video sequences of object motion acquisition. All cameras work in synchronization mode at frame rate up to 100 frames per second under the control of personal computer providing the possibility for accurate calculation of 3D coordinates of interest points. The system was used for a set of different applications fields and demonstrated high accuracy and high level of automation.

Elevated Joint Contact Forces in ACL-Reconstructed Knees: A Finite Element Analysis Driven by In Vivo Kinematic Data

2003 ◽  
Author(s):  
George Papaioannou ◽  
William Anderst ◽  
Scott Tashman
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Knee Kinematics ◽  
Poor Quality ◽  
Contact Forces ◽  
Element Analysis ◽  
Human Cartilage ◽  
Joint Contact ◽  
Contact Pressures

Assessment of in vivo human cartilage loading generally requires computer modeling, since loads usually cannot be directly measured. The utility of these models for assessing knee behavior during complex activities has been limited by the relatively poor quality of experimental data on in vivo knee function. We have developed a method combining high-accuracy knee kinematics (from high-speed stereo-radiography) with subject-specific finite-element models to estimate in vivo cartilage contact pressures during stressful tasks. When applied to ACL reconstruction, significantly higher contact pressures were found in reconstructed knees as compared to the contralateral (uninjured) knees of the same individuals.

scholarly journals An Anatomical-Based Subject-Specific Model of In-Vivo Knee Joint 3D Kinematics From Medical Imaging

2020 ◽  
Vol 10 (6) ◽  
pp. 2100 ◽  
Author(s):  
Fabrizio Nardini ◽  
Claudio Belvedere ◽  
Nicola Sancisi ◽  
Michele Conconi ◽  
Alberto Leardini ◽  
...  
Keyword(s):  
Knee Joint ◽  
Spatial Models ◽  
Knee Kinematics ◽  
Specific Model ◽  
Absolute Difference ◽  
Joint Motion ◽  
Parallel Mechanisms ◽  
Biomechanical Models ◽  
Subject Specific

Biomechanical models of the knee joint allow the development of accurate procedures as well as novel devices to restore the joint natural motion. They are also used within musculoskeletal models to perform clinical gait analysis on patients. Among relevant knee models in the literature, the anatomy-based spatial parallel mechanisms represent the joint motion using rigid links for the ligaments’ isometric fibres and point contacts for the articular surfaces. To customize analyses, therapies and devices, there is the need to define subject-specific models, but relevant procedures and their accuracy are still questioned. A procedure is here proposed and validated to define a customized knee model based on a spatial parallel mechanism. Computed tomography, magnetic resonance and 3D-video-fluoroscopy were performed on a healthy volunteer to define the personalized model geometry. The model was then validated by comparing the measured and the replicated joint motion. The model showed mean absolute difference and standard deviations in translations and rotations, respectively of 0.98 ± 0.40 mm and 0.68 ± 0.29 ° for the tibia–femur motion, and of 0.77 ± 0.15 mm and 2.09 ± 0.69 ° for the patella–femur motion. These results show that accurate personalized spatial models of knee kinematics can be obtained from in-vivo imaging.

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.

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

Sign in / Sign up

Export Citation Format

Share Document