A Cable-Actuated Robotic Lumbar Spine for Palpatory Training of Medical Students

2010 ◽  
Author(s):  
Ernur Karadogan ◽  
Robert L. Williams
Keyword(s):  
Lumbar Spine ◽  
Medical Students ◽  
Lumbar Vertebrae ◽  
Lumbar Vertebra ◽  
Professional Lives ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Hands On ◽  
Spine Robot

This paper presents the kinematic and pseudostatic analyses of a fully cable-actuated robotic lumbar spine (RLS) which can mimic in vivo human lumbar spine movements to provide better hands-on training for medical students. The design incorporates five active lumbar vertebrae between the first lumbar vertebra and the sacrum, with dimensions of an average adult human spine. Medical schools can benefit from a tool, system, or method that will help instructors train students and assess their tactile proficiency throughout their education. The robotic lumbar spine has the potential to satisfy these needs in palpatory diagnosis. Medical students will be given the opportunity to examine their own patient that can be programmed with many dysfunctions related to the lumbar spine before they start their professional lives as doctors. The robotic lumbar spine can be used to teach and test medical students in their capacity to be able to recognize normal and abnormal movement patterns of the human lumbar spine under flexion-extension and lateral bending. This project focus is on palpation, but the spine robot could also benefit surgery training/planning and other related biomedical applications.

scholarly journals The Robotic Lumbar Spine: Dynamics and Feedback Linearization Control

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Ernur Karadogan ◽  
Robert L. Williams
Keyword(s):  
Lumbar Spine ◽  
Medical Students ◽  
Feedback Linearization ◽  
Lumbar Vertebrae ◽  
Professional Lives ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Hands On ◽  
Feedback Linearization Control

The robotic lumbar spine (RLS) is a 15 degree-of-freedom, fully cable-actuated robotic lumbar spine which can mimicin vivohuman lumbar spine movements to provide better hands-on training for medical students. The design incorporates five active lumbar vertebrae and the sacrum, with dimensions of an average adult human spine. It is actuated by 20 cables connected to electric motors. Every vertebra is connected to the neighboring vertebrae by spherical joints. Medical schools can benefit from a tool, system, or method that will help instructors train students and assess their tactile proficiency throughout their education. The robotic lumbar spine has the potential to satisfy these needs in palpatory diagnosis. Medical students will be given the opportunity to examine their own patient that can be programmed with many dysfunctions related to the lumbar spine before they start their professional lives as doctors. The robotic lumbar spine can be used to teach and test medical students in their capacity to be able to recognize normal and abnormal movement patterns of the human lumbar spine under flexion-extension, lateral bending, and axial torsion. This paper presents the dynamics and nonlinear control of the RLS. A new approach to solve for positive and nonzero cable tensions that are also continuous in time is introduced.

Dynamics and Control of the Robotic Lumbar Spine (RLS)

2012 ◽  
Author(s):  
Ernur Karadogan ◽  
Robert L. Williams
Keyword(s):  
Lumbar Spine ◽  
Lumbar Vertebrae ◽  
New Approach ◽  
Human Lumbar Spine ◽  
Hands On ◽  
Current Design ◽  
Dynamics And Control ◽  
And Control ◽  
Average Adult

This paper presents the dynamics and nonlinear control of the Robotic Lumbar Spine (RLS). The RLS is a 15 degree-of-freedom, fully cable-actuated robotic lumbar spine which can mimic in vivo human lumbar spine movements to provide better hands-on training for medical students. The current design includes five active lumbar vertebrae and the sacrum, with dimensions of an average adult human spine. It is actuated by 20 cables connected to electric motors. Every vertebra is connected to the neighboring vertebrae by spherical joints. Medical schools can benefit from a tool, system, or method that will help instructors train students and assess their tactile proficiency throughout their education. The robotic lumbar spine has the potential to satisfy these needs in palpatory diagnosis. Additionally, a new approach to solve for positive and nonzero cable tensions that are also continuous in time is introduced.

scholarly journals Force Analysis of Human Lumbar Spine Using a Forward Kinematics Model

2021 ◽  
Author(s):  
Krunal Patel
Keyword(s):  
Lumbar Spine ◽  
In Vivo Studies ◽  
Forward Kinematics ◽  
Compression Force ◽  
Trunk Flexion ◽  
Kinematics Model ◽  
In Vivo Measurement ◽  
Human Lumbar Spine ◽  
Flexion Extension

The purpose of this study is to present a forward kinematics model of the human lumbar spine and to compare the internal loads and trunk flexion extension with existing literature. The forward kinematics model of lumbar spine with 30 DOF was designed using Solidworks and used Matlab to simulate the results for different postures. The forward kinematics model predicted similar trend for trunk flexion extension, compression force, shear forces and moment as described in literature for in vivo studies. The comparison between the proposed model and in vivo measurement showed a pressure difference of less than 15% on the disc L4-L5 for all activities whereas the compression force and moment differed by ~17% on the disc L5-S1. The modeling methodology presented in this thesis provides a more accurate representation of compression forces and moments of the human lumbar spine since the model makes no assumptions regarding muscle force and does not rely on any other software for kinematics data.

Capturing Three-Dimensional In Vivo Lumbar Intervertebral Joint Kinematics Using Dynamic Stereo-X-Ray Imaging

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Ameet K. Aiyangar ◽  
Liying Zheng ◽  
Scott Tashman ◽  
William J. Anderst ◽  
Xudong Zhang
Keyword(s):  
Lumbar Spine ◽  
Three Dimensional ◽  
Lumbar Vertebrae ◽  
Lumbar Vertebra ◽  
Weight Lifting ◽  
Data Set ◽  
X Ray ◽  
Biomechanical Models ◽  
Lifting Task

Availability of accurate three-dimensional (3D) kinematics of lumbar vertebrae is necessary to understand normal and pathological biomechanics of the lumbar spine. Due to the technical challenges of imaging the lumbar spine motion in vivo, it has been difficult to obtain comprehensive, 3D lumbar kinematics during dynamic functional tasks. The present study demonstrates a recently developed technique to acquire true 3D lumbar vertebral kinematics, in vivo, during a functional load-lifting task. The technique uses a high-speed dynamic stereo-radiography (DSX) system coupled with a volumetric model-based bone tracking procedure. Eight asymptomatic male participants performed weight-lifting tasks, while dynamic X-ray images of their lumbar spines were acquired at 30 fps. A custom-designed radiation attenuator reduced the radiation white-out effect and enhanced the image quality. High resolution CT scans of participants' lumbar spines were obtained to create 3D bone models, which were used to track the X-ray images via a volumetric bone tracking procedure. Continuous 3D intervertebral kinematics from the second lumbar vertebra (L2) to the sacrum (S1) were derived. Results revealed motions occurring simultaneously in all the segments. Differences in contributions to overall lumbar motion from individual segments, particularly L2–L3, L3–L4, and L4–L5, were not statistically significant. However, a reduced contribution from the L5–S1 segment was observed. Segmental extension was nominally linear in the middle range (20%–80%) of motion during the lifting task, but exhibited nonlinear behavior at the beginning and end of the motion. L5–S1 extension exhibited the greatest nonlinearity and variability across participants. Substantial AP translations occurred in all segments (5.0 ± 0.3 mm) and exhibited more scatter and deviation from a nominally linear path compared to segmental extension. Maximum out-of-plane rotations (<1.91 deg) and translations (<0.94 mm) were small compared to the dominant motion in the sagittal plane. The demonstrated success in capturing continuous 3D in vivo lumbar intervertebral kinematics during functional tasks affords the possibility to create a baseline data set for evaluating the lumbar spinal function. The technique can be used to address the gaps in knowledge of lumbar kinematics, to improve the accuracy of the kinematic input into biomechanical models, and to support development of new disk replacement designs more closely replicating the natural lumbar biomechanics.

scholarly journals Force Analysis of Human Lumbar Spine Using a Forward Kinematics Model

2021 ◽  
Author(s):  
Krunal Patel
Keyword(s):  
Lumbar Spine ◽  
In Vivo Studies ◽  
Forward Kinematics ◽  
Compression Force ◽  
Trunk Flexion ◽  
Kinematics Model ◽  
In Vivo Measurement ◽  
Human Lumbar Spine ◽  
Flexion Extension

The purpose of this study is to present a forward kinematics model of the human lumbar spine and to compare the internal loads and trunk flexion extension with existing literature. The forward kinematics model of lumbar spine with 30 DOF was designed using Solidworks and used Matlab to simulate the results for different postures. The forward kinematics model predicted similar trend for trunk flexion extension, compression force, shear forces and moment as described in literature for in vivo studies. The comparison between the proposed model and in vivo measurement showed a pressure difference of less than 15% on the disc L4-L5 for all activities whereas the compression force and moment differed by ~17% on the disc L5-S1. The modeling methodology presented in this thesis provides a more accurate representation of compression forces and moments of the human lumbar spine since the model makes no assumptions regarding muscle force and does not rely on any other software for kinematics data.

scholarly journals Effect of facet-joint degeneration on the in vivo motion of the lower lumbar spine

2020 ◽  
Author(s):  
Jun Yin ◽  
Zhang Liu ◽  
Chao Li ◽  
Shiwei Luo ◽  
Qi Lai ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Facet Joint ◽  
Imaging Techniques ◽  
Lumbar Vertebra ◽  
Joint Degeneration ◽  
Lower Lumbar Spine ◽  
Significant Difference ◽  
Flexion Extension ◽  
Facet Joint Degeneration

Abstract Objective This research studied the in vivo motion characteristics of the L3-S1 lumbar spine with facet-joint degeneration during functional activities. Methods Thirteen male and 21 female patients with facet-joint degeneration at the L3-S1 spinal region were included in the study. The L3-S1 lumbar segments of all the patients were divide into 3 groups according to the degree of facet joints degeneration (mild, moderate or severe). The ranges of motion (ROM) of the vertebrae was analyzed using a combination of computed tomography and dual fluoroscopic imaging techniques. During functional postures, the ROMs were compared between the 3 groups at each spinal level (L3-L4, L4-L5, and L5-S1). Results At L3-L4 level, the primary rotations between the mild and moderate groups during left-right twisting activity were significantly different. At L4-L5 level, the primary rotation of the moderate group was significantly higher than the other groups during flexion-extension. During left-right bending activities a significant difference was observed only between the moderate and severe groups. At L5-S1 level, the rotation of the moderate group was significantly higher than the mild group during left-right bending activity. Conclusions Degeneration of the facet joint alters the ROMs of the lumbar spine. As the degree of facet-joint degeneration increased, the ROMs of the lumbar vertebra that had initially increased, declined. However, when there was severe facet-joint degeneration, the ROMs of lumbar spine declined to levels comparative to the moderate group. The relationship between the stability of the lumbar vertebra and the degree of facet-joint degeneration requires further study.

Three-Dimensional Static Modeling of the Lumbar Spine

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Ernur Karadogan ◽  
Robert L. Williams
Keyword(s):  
Experimental Data ◽  
Lumbar Spine ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Lumbar Vertebrae ◽  
Lumbar Vertebra ◽  
Body Motion ◽  
Human Lumbar Spine ◽  
Static Modeling ◽  
Elastic Elements

This paper presents three-dimensional static modeling of the human lumbar spine to be used in the formation of anatomically-correct movement patterns for a fully cable-actuated robotic lumbar spine which can mimic in vivo human lumbar spine movements to provide better hands-on training for medical students. The mathematical model incorporates five lumbar vertebrae between the first lumbar vertebra and the sacrum, with dimensions of an average adult human spine. The vertebrae are connected to each other by elastic elements, torsional springs and a spherical joint located at the inferoposterior corner in the mid-sagittal plane of the vertebral body. Elastic elements represent the ligaments that surround the facet joints and the torsional springs represent the collective effect of intervertebral disc which plays a major role in balancing torsional load during upper body motion and the remaining ligaments that support the spinal column. The elastic elements and torsional springs are considered to be nonlinear. The nonlinear stiffness constants for six motion types were solved using a multiobjective optimization technique. The quantitative comparison between the angles of rotations predicted by the proposed model and in the experimental data confirmed that the model yields angles of rotation close to the experimental data. The main contribution is that the new model can be used for all motions while the experimental data was only obtained at discrete measurement points.

scholarly journals Effect of facet-joint degeneration on the in vivo motion of the lower lumbar spine

2020 ◽  
Author(s):  
Jun Yin ◽  
Zhang Liu ◽  
Chao Li ◽  
Shiwei Luo ◽  
Qi Lai ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Facet Joint ◽  
Imaging Techniques ◽  
Lumbar Vertebra ◽  
Joint Degeneration ◽  
Lower Lumbar Spine ◽  
Significant Difference ◽  
Flexion Extension ◽  
Facet Joint Degeneration

Abstract Objective: This research studied the in vivo motion characteristics of the L3-S1 lumbar spine with facet-joint degeneration during functional activities.Methods: Thirteen male and 21 female patients with facet-joint degeneration at the L3-S1 spinal region were included in the study. The L3-S1 lumbar segments of all the patients were divide into 3 groups according to the degree of facet joints degeneration (mild, moderate or severe). The ranges of motion (ROM) of the vertebrae was analyzed using a combination of computed tomography and dual fluoroscopic imaging techniques. During functional postures, the ROMs were compared between the 3 groups at each spinal level (L3-L4, L4-L5, and L5-S1). Results: At L3-L4 level, the primary rotations between the mild and moderate groups during left-right twisting activity were significantly different. At L4-L5 level, the primary rotation of the moderate group was significantly higher than the other groups during flexion-extension. During left-right bending activities a significant difference was observed only between the moderate and severe groups. At L5-S1 level, the rotation of the moderate group was significantly higher than the mild group during left-right bending activity.Conclusions: Degeneration of the facet joint alters the ROMs of the lumbar spine. As the degree of facet-joint degeneration increased, the ROMs of the lumbar vertebra that had initially increased, declined. However, when there was severe facet-joint degeneration, the ROMs of lumbar spine declined to levels comparative to the moderate group. The relationship between the stability of the lumbar vertebra and the degree of facet-joint degeneration requires further study.

Mechanical Properties of Human Lumbar Spine Motion Segments—Part I: Responses in Flexion, Extension, Lateral Bending, and Torsion

1979 ◽  
Vol 101 (1) ◽  
pp. 46-52 ◽  
Author(s):  
A. B. Schultz ◽  
D. N. Warwick ◽  
M. H. Berkson ◽  
A. L. Nachemson
Keyword(s):  
Mechanical Properties ◽  
Lumbar Spine ◽  
Mechanical Behavior ◽  
Human Cadaver ◽  
Lateral Bending ◽  
Human Lumbar Spine ◽  
Flexion Extension ◽  
Spine Motion ◽  
Pressure Changes ◽  
Posterior Elements

In this first part of a three-part report, the mechanical behavior of 42 fresh human cadaver lumbar motion segments in flexion, extension, lateral bending, and torsion is examined. Motions and intradiskal pressure changes that occurred in response to these loads, with posterior elements both intact and excised, are reported.

Corrigendum to “The in vivo three-dimensional motion of the human lumbar spine during gait” [Gait & Posture (2008) 378–384]

2009 ◽  
Vol 29 (1) ◽  
pp. 165 ◽  
Author(s):  
Adam Rozumalski ◽  
Michael H. Schwartz ◽  
Roy Wervey ◽  
Andrew Swanson ◽  
Daryll C. Dykes ◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Three Dimensional ◽  
Human Lumbar Spine ◽  
Gait Posture
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