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Quantitative imaging technology for the musculoskeletal system
$446
Journal of Biomechanics 2006, Vol. 39 (Suppl 1)
4014 Th, 17:00-17:15 (P47) Physical simulation for mobile nanorobot in the bloody laminar flows A. Shojaie, M. Safaeinezhad. Department of Nanotechnology, Sozhin Intelligent Process CO. LTD, Sanandaj, Kurdistan, Iran the aim of this project is designing and simulating the best model for medical and drug deliver nanorobots. We study the most important fabrication and using affairs, and then try to suggest the best solution with less danger and more efficiency. We use artificial neural network and virtual reality simulations for autonomous controlling the multi-nanorobotic teams in a complex wet nanotechnological environment. The sensor, motor and processors are following the biotechnological systems such as enzymes, cellular flues and DNA molecule. This paper presents the principle of operation of the VPL motor, the development of dynamic and kinematics models to study their performance. The neural motion control was successfully used in the scenery with real time response for the circumstance where the nanorobots must capture molecules and visit a pre-defined set of delivery points, avoiding random obstacles and collision with other mobile nanorobots, and trying at the same time to minimize the time required. The coherent behaviors displayed for the transport task can also be attributed to the common goal shared by the individual medical nanorobots along with an identical set of interaction rules, similar to the effect observed by collective decision-making in honey bees.
Thread 4
Imaging T4.2 New Imaging Advancements in Musculoskeletal Systems and Performance 5652 Th, 14:00-14:30 (P45) Quantitative imaging technology for the musculoskeletal system F. Eckstein. Institute of Anatomy and Musculoskeletal Research, Paracelsus Private Medical University Salzburg, Austria Research in the musculoskeletal system has seen a recent boost by the emergence of non-invasive imaging technology, in particular magnetic resonance imaging. In conjunction with quantitative image analysis methods these new imaging methodologies have started to permit one to analyze physiological and patho-physiological processes and their relationship with mechanical stimuli (mechanobiology) in the living subject. The presentation reviews imaging and image analysis methods that are currently used in musculoskeletal research, with a focus on MR imaging technology and its use in joint and cartilage research. The paper will review MR imaging sequences and scoring systems used for whole organ (joint) evaluation (e.g. WORMS), sequences and image analysis tools for cartilage segmentation and quantitative determination of cartilage and joint morphology, sequences for analysis of cartilage composition (e.g. T2, Tlrho, T1Gd=dGEMRIC index) and current methodologies used for quantitative measurement of subchondral trabecular bone structure (e.g. app. BV/TV, app. TbTh, app. Tb. N, app. Tb. Sp). For each of these fields we will report specifics on hardware and MR pulse sequences, the technical accuracy and precision of the measurements reported to date, and examples from ongoing research studies with a focus on the relationship of tissue form, structure and composition with mechanical signals. 5968 Th, 14:30-14:45 (P45) A robotic radiographic imaging platform for observation of dynamic skeletal motion and tomography S.A. Banks 1,2, C. Lightcap 1, J.D. Yamokoski 1. 1Department of Mechanical & Aerospace Engineering, 2Departments of Orthopaedics and Rehabilitation, University of Florida, Gainesville, Florida, USA The main purpose of our bones and joints is to support dynamic terrestrial locomotion. Thus, the great irony of modern orthopaedic diagnosis is that it is accomplished almost exclusively with the patient motionless, muscles relaxed, often holding their breath. There is no argument that direct observation of dynamic joint motion would be clinically useful, yet no systems for this purpose are in routine clinical use. The purpose of this presentation is to introduce work on a novel imaging platform for dynamic observation of skeletal motion, discuss technical requirements and component technologies, and explore research and clinical observations this platform may facilitate. The goals of the imaging platform are (1) to permit single-plane dynamic radiographic observation of joint motion in freely moving patients, and (2) to provide 3D tomographic reconstruction of the musculoskeletal system. With these two capabilities, it is possible to provide 3D kinematic measurement of skeletal motion using single-plane 2D-to-3D model registration techniques.
Oral Presentations The imaging platform is comprised of three systems: real-time motion capture (MoCap), dual robotic arms, and a radiographic system formed from a lightweight pulsed beam generator and a solid-state, video-rate x-ray image sensor. Real-time MoCap will identify the target joint location as the patient moves in clinically relevant volitional activity. The MoCap information will be used to control the trajectory of the robotic arms, maintaining focus on the moving joint. The x-ray system will acquire dynamic motion sequences of the joint in motion and will acquire image sequences of the static skeleton for reconstruction using cone-beam computed tomography techniques. Numerical and experimental assessment of the MoCap and robotic systems for the imaging platform have been completed and the results of these evaluations will be presented. Integration of the radiographic systems is ongoing, but results using a visible light video camera will be provided. 6003 Th, 14:45-15:00 (P45) Noninvasive measurement of ligament strain using deformable image registration N.S. Phatak 1, Q. Sun 1, S.E. Kim 2, D.L. Parker2, R.K. Sanders2, A.I. Veress 1, J.A. Weiss 1. 1Department of Bioengineering, 2Department of Radiology, University of Utah, Salt Lake City, Utah, USA The form and function of musculoskeletal tissues are closely associated with the mechanical stresses and strains that they experience. Noninvasive methods for the measurement of stresses/strains are currently limited. Advances in medical imaging, particularly magnetic resonance, have improved the visualization of soft tissue, and the resulting image data can potentially be used to extract quantitative information regarding the deformation of various tissues. Hyperelastic Warping, a deformable image registration technique, uses an energy functional calculated from signal intensity differences between two image datasets to drive deformation between template and target images, Diffeomorphic deformations are ensured by representing the deformable image as a hyperelastic material. The purpose of this study was to validate the use of Hyperelastic Warping for noninvasive strain measurement in the human medial collateral ligament using direct comparisons with video-based experimental strain measurement. Ten cadaveric knees were subjected to a detailed experimental protocol with six loading scenarios. Fiber stretches were calculated for five loading configurations in comparison to a reference configuration with the knee at full extension. Predictions of fiber stretch from Hyperelastic Warping were strongly correlated with experimental results, and regression lines yielded the following coefficients of determination: 12 =0.81 for 30 degrees passive knee flexion; 12 =0.87 for 60 degrees passive knee flexion; 12 =0.76 for 90 degrees; 12 =0.78 for 0 degrees flexion with valgus load; and R2=0.86 for 30 degrees flexion with valgus load. In conclusion, Hyperelastic Warping represents a powerful technique for noncontact strain measurement in musculoskeletal tissues, and it can be easily adapted to noninvasive measurement of soft tissue strain in vive. 6292 Th, 15:00-15:15 (P45) Developing dynamic MRI based tools for the understanding of musculoskeletal function at the joint-impairment level F.T. Sheehan, A.R. Seisler, S.J. Stanhope. The Physical Disabilities Branch, The National Institutes of Health, Bethesda, MD, USA In order to improve diagnostic accuracy, prevent injury and reduce the impact of impairments on function, we must be able to quantify the demands placed on the neurological and musculoskeletal systems by the activities of daily living, as well as the capabilities of these systems to meet such demands. Numerous dynamic imaging techniques have demonstrated an ability to quantify in vive 3D skeletal motion, for example, single and bi-plane radiography as well as fast-PC MRI, but only the latter provides an ability to track combined softtissue and skeletal motion non-invasively and without ionizing radiation. Yet, fast-PC MRI alone is not enough to quantify complete joint dynamics. Thus, this work has focused on developing a combined set of tools that apply kinematic data quantified from 3D fast-PC MRI velocity data to subject-specific 3D joint models. These models allow for the quantification of 3D joint kinematics, tendinous and ligamentous moment arms along with length changes in these structures and cartilage contact patterns during volitional tasks. The ultimate goal of this work is to use these models to quantify forces in the individual structures of the joints. This work has currently been focused on defining basic joint kinematic parameters in the knee and ankle in a normative population. Exploratory studies into specific pathologies, particularly Cerebral Palsy and Ehlers Danlos Syndrome, have been conducted with excellent results. For example, a study of the 3D patellar tendon moment arm length demonstrated an increased moment arm in the majority of the CP subjects studied, as compared to the normative population. Thus, the muscle weakness often associated with CP might not be due to "lever-arm dysfunction", as has been hypothesized. A collaboration between the National Institute of Child Health and Human Development and the Warren G. Magnuson Clinical Center, NIH.
Journal of Biomechanics 2006, Vol. 39 (Suppl 1)
4014 Th, 17:00-17:15 (P47) Physical simulation for mobile nanorobot in the bloody laminar flows A. Shojaie, M. Safaeinezhad. Department of Nanotechnology, Sozhin Intelligent Process CO. LTD, Sanandaj, Kurdistan, Iran the aim of this project is designing and simulating the best model for medical and drug deliver nanorobots. We study the most important fabrication and using affairs, and then try to suggest the best solution with less danger and more efficiency. We use artificial neural network and virtual reality simulations for autonomous controlling the multi-nanorobotic teams in a complex wet nanotechnological environment. The sensor, motor and processors are following the biotechnological systems such as enzymes, cellular flues and DNA molecule. This paper presents the principle of operation of the VPL motor, the development of dynamic and kinematics models to study their performance. The neural motion control was successfully used in the scenery with real time response for the circumstance where the nanorobots must capture molecules and visit a pre-defined set of delivery points, avoiding random obstacles and collision with other mobile nanorobots, and trying at the same time to minimize the time required. The coherent behaviors displayed for the transport task can also be attributed to the common goal shared by the individual medical nanorobots along with an identical set of interaction rules, similar to the effect observed by collective decision-making in honey bees.
Thread 4
Imaging T4.2 New Imaging Advancements in Musculoskeletal Systems and Performance 5652 Th, 14:00-14:30 (P45) Quantitative imaging technology for the musculoskeletal system F. Eckstein. Institute of Anatomy and Musculoskeletal Research, Paracelsus Private Medical University Salzburg, Austria Research in the musculoskeletal system has seen a recent boost by the emergence of non-invasive imaging technology, in particular magnetic resonance imaging. In conjunction with quantitative image analysis methods these new imaging methodologies have started to permit one to analyze physiological and patho-physiological processes and their relationship with mechanical stimuli (mechanobiology) in the living subject. The presentation reviews imaging and image analysis methods that are currently used in musculoskeletal research, with a focus on MR imaging technology and its use in joint and cartilage research. The paper will review MR imaging sequences and scoring systems used for whole organ (joint) evaluation (e.g. WORMS), sequences and image analysis tools for cartilage segmentation and quantitative determination of cartilage and joint morphology, sequences for analysis of cartilage composition (e.g. T2, Tlrho, T1Gd=dGEMRIC index) and current methodologies used for quantitative measurement of subchondral trabecular bone structure (e.g. app. BV/TV, app. TbTh, app. Tb. N, app. Tb. Sp). For each of these fields we will report specifics on hardware and MR pulse sequences, the technical accuracy and precision of the measurements reported to date, and examples from ongoing research studies with a focus on the relationship of tissue form, structure and composition with mechanical signals. 5968 Th, 14:30-14:45 (P45) A robotic radiographic imaging platform for observation of dynamic skeletal motion and tomography S.A. Banks 1,2, C. Lightcap 1, J.D. Yamokoski 1. 1Department of Mechanical & Aerospace Engineering, 2Departments of Orthopaedics and Rehabilitation, University of Florida, Gainesville, Florida, USA The main purpose of our bones and joints is to support dynamic terrestrial locomotion. Thus, the great irony of modern orthopaedic diagnosis is that it is accomplished almost exclusively with the patient motionless, muscles relaxed, often holding their breath. There is no argument that direct observation of dynamic joint motion would be clinically useful, yet no systems for this purpose are in routine clinical use. The purpose of this presentation is to introduce work on a novel imaging platform for dynamic observation of skeletal motion, discuss technical requirements and component technologies, and explore research and clinical observations this platform may facilitate. The goals of the imaging platform are (1) to permit single-plane dynamic radiographic observation of joint motion in freely moving patients, and (2) to provide 3D tomographic reconstruction of the musculoskeletal system. With these two capabilities, it is possible to provide 3D kinematic measurement of skeletal motion using single-plane 2D-to-3D model registration techniques.
Oral Presentations The imaging platform is comprised of three systems: real-time motion capture (MoCap), dual robotic arms, and a radiographic system formed from a lightweight pulsed beam generator and a solid-state, video-rate x-ray image sensor. Real-time MoCap will identify the target joint location as the patient moves in clinically relevant volitional activity. The MoCap information will be used to control the trajectory of the robotic arms, maintaining focus on the moving joint. The x-ray system will acquire dynamic motion sequences of the joint in motion and will acquire image sequences of the static skeleton for reconstruction using cone-beam computed tomography techniques. Numerical and experimental assessment of the MoCap and robotic systems for the imaging platform have been completed and the results of these evaluations will be presented. Integration of the radiographic systems is ongoing, but results using a visible light video camera will be provided. 6003 Th, 14:45-15:00 (P45) Noninvasive measurement of ligament strain using deformable image registration N.S. Phatak 1, Q. Sun 1, S.E. Kim 2, D.L. Parker2, R.K. Sanders2, A.I. Veress 1, J.A. Weiss 1. 1Department of Bioengineering, 2Department of Radiology, University of Utah, Salt Lake City, Utah, USA The form and function of musculoskeletal tissues are closely associated with the mechanical stresses and strains that they experience. Noninvasive methods for the measurement of stresses/strains are currently limited. Advances in medical imaging, particularly magnetic resonance, have improved the visualization of soft tissue, and the resulting image data can potentially be used to extract quantitative information regarding the deformation of various tissues. Hyperelastic Warping, a deformable image registration technique, uses an energy functional calculated from signal intensity differences between two image datasets to drive deformation between template and target images, Diffeomorphic deformations are ensured by representing the deformable image as a hyperelastic material. The purpose of this study was to validate the use of Hyperelastic Warping for noninvasive strain measurement in the human medial collateral ligament using direct comparisons with video-based experimental strain measurement. Ten cadaveric knees were subjected to a detailed experimental protocol with six loading scenarios. Fiber stretches were calculated for five loading configurations in comparison to a reference configuration with the knee at full extension. Predictions of fiber stretch from Hyperelastic Warping were strongly correlated with experimental results, and regression lines yielded the following coefficients of determination: 12 =0.81 for 30 degrees passive knee flexion; 12 =0.87 for 60 degrees passive knee flexion; 12 =0.76 for 90 degrees; 12 =0.78 for 0 degrees flexion with valgus load; and R2=0.86 for 30 degrees flexion with valgus load. In conclusion, Hyperelastic Warping represents a powerful technique for noncontact strain measurement in musculoskeletal tissues, and it can be easily adapted to noninvasive measurement of soft tissue strain in vive. 6292 Th, 15:00-15:15 (P45) Developing dynamic MRI based tools for the understanding of musculoskeletal function at the joint-impairment level F.T. Sheehan, A.R. Seisler, S.J. Stanhope. The Physical Disabilities Branch, The National Institutes of Health, Bethesda, MD, USA In order to improve diagnostic accuracy, prevent injury and reduce the impact of impairments on function, we must be able to quantify the demands placed on the neurological and musculoskeletal systems by the activities of daily living, as well as the capabilities of these systems to meet such demands. Numerous dynamic imaging techniques have demonstrated an ability to quantify in vive 3D skeletal motion, for example, single and bi-plane radiography as well as fast-PC MRI, but only the latter provides an ability to track combined softtissue and skeletal motion non-invasively and without ionizing radiation. Yet, fast-PC MRI alone is not enough to quantify complete joint dynamics. Thus, this work has focused on developing a combined set of tools that apply kinematic data quantified from 3D fast-PC MRI velocity data to subject-specific 3D joint models. These models allow for the quantification of 3D joint kinematics, tendinous and ligamentous moment arms along with length changes in these structures and cartilage contact patterns during volitional tasks. The ultimate goal of this work is to use these models to quantify forces in the individual structures of the joints. This work has currently been focused on defining basic joint kinematic parameters in the knee and ankle in a normative population. Exploratory studies into specific pathologies, particularly Cerebral Palsy and Ehlers Danlos Syndrome, have been conducted with excellent results. For example, a study of the 3D patellar tendon moment arm length demonstrated an increased moment arm in the majority of the CP subjects studied, as compared to the normative population. Thus, the muscle weakness often associated with CP might not be due to "lever-arm dysfunction", as has been hypothesized. A collaboration between the National Institute of Child Health and Human Development and the Warren G. Magnuson Clinical Center, NIH.