Related Experiment Video
Updated: Aug 14, 2026
07:52
Mouse Lumbar Vertebra Uniaxial Compression Testing with Embedding of the Loading Surface
Published on: December 1, 2023
Calculating the 2D motion of lumbar vertebrae using splines
Brendan McCane1, Tamara I King, J Haxby Abbott
1Department of Computer Science, University of Otago, Box 56, Dunedin, New Zealand. mccane@cs.otago.ac.nz
Journal of Biomechanics
|December 6, 2005
Summary
This study introduces splines and the Iterative Closest Point (ICP) method for precise 3D shape registration. The technique accurately estimates lumbar spine rotation and FCR, outperforming existing methods.
Area of Science:
- Biomechanics
- Medical Imaging
- Computer Vision
Background:
- Accurate 3D shape registration is crucial for analyzing rigid body motion.
- Existing methods for calculating transformation parameters have limitations in precision and efficiency.
Purpose of the Study:
- To investigate the efficacy of splines and the ICP method for calculating transformation parameters in planar motion.
- To estimate the finite center of rotation (FCR) and angle of rotation from lumbar spine radiographs.
Main Methods:
- Utilized splines to represent planar shapes and the ICP algorithm for shape registration.
- Applied the method to lateral flexion/extension radiographs of the lumbar spine.
- Conducted an in vitro error study to assess accuracy.
Main Results:
- The spline and ICP method achieved an average rotational error of 0.44 +/- 0.45 degrees.
- Average error in FCR calculation was 7.6 +/- 8.5 mm.
- Demonstrated superiority over existing methods like Crisco et al. and Brinckmann et al.
Conclusions:
- Splines offer a superior representation of planar shapes compared to digitized curves or landmarks due to compactness and sub-pixel accuracy.
- The ICP algorithm provides a well-defined method for registering spline-represented shapes.
- The developed application offers an efficient tool for these computations.
Related Concept Videos
01:23Curvilinear Motion: Rectangular Components
Curvilinear motion characterizes the movement of a particle or object along a curved path, notably evident when envisioning a car navigating a winding road. If the car starts at point A, its position vector is established within a fixed frame of reference, where the ratio of the position vector to its magnitude signifies the unit vector pointing in the position vector's direction.
As the car advances, its position evolves over time. Quantifying the car's velocity involves computing the time...
As the car advances, its position evolves over time. Quantifying the car's velocity involves computing the time...
01:16Vertebral Column: Regions and Curvature
The vertebral column or spine is a flexible column that supports the head, neck, and body and allows for their movements. It also protects the spinal cord.
Regions of the Vertebral Column
In an adult, the spine is subdivided into five regions: the cervical, the thoracic, the lumbar, the sacral, and the coccygeal region. The spine initially develops as a series of 33 vertebrae; after 20 years of age, the nine bones in the sacral region, five sacral, and four coccygeal bones fuse to form the...
Regions of the Vertebral Column
In an adult, the spine is subdivided into five regions: the cervical, the thoracic, the lumbar, the sacral, and the coccygeal region. The spine initially develops as a series of 33 vertebrae; after 20 years of age, the nine bones in the sacral region, five sacral, and four coccygeal bones fuse to form the...
01:27Curvilinear Motion: Normal and Tangential Components
When a car traverses a curved road, its motion can be elucidated by breaking it down into tangential and normal components. The car-centric coordinates attached to the vehicle move with it.
The positive direction of the t-axis aligns with the increasing position of the car along the curved path, denoted by the unit vector ut. Simultaneously, the n-axis, perpendicular to the t-axis, dissects the curved path into differential arc segments, each forming the arc of a circle with a radius of...
The positive direction of the t-axis aligns with the increasing position of the car along the curved path, denoted by the unit vector ut. Simultaneously, the n-axis, perpendicular to the t-axis, dissects the curved path into differential arc segments, each forming the arc of a circle with a radius of...
01:29Relative Motion Analysis using Rotating Axes-Problem Solving
Consider a crane whose telescopic boom rotates with an angular velocity of 0.04 rad/s and angular acceleration of 0.02 rad/s2. Along with the rotation, the boom also extends linearly with a uniform speed of 5 m/s. The extension of the boom is measured at point D, which is measured with respect to the fixed point C on the other end of the boom. For the given instant, the distance between points C and D is 60 meters.
Here, in order to determine the magnitude of velocity and acceleration for point...
Here, in order to determine the magnitude of velocity and acceleration for point...
01:27Curvilinear Motion: Polar Coordinates
In polar coordinates, the motion of a particle follows a curvilinear path. The radial coordinate symbolized as 'r,' extends outward from a fixed origin to the particle, while the angular coordinate, 'θ,' measured in radians, represents the counterclockwise angle between a fixed reference line and the radial line connecting the origin to the particle.
The particle's location is described using a unit vector along the radial direction. Deriving the particle's position with respect to time...
The particle's location is described using a unit vector along the radial direction. Deriving the particle's position with respect to time...
01:24Relative Motion Analysis - Velocity
A stroke engine has a slider-crank mechanism that converts rotational motion from the crank into linear motion of the slider or vice versa. This mechanism consists of three main parts: the crank, the connecting rod, and the slider.
When an external force is exerted, it sets the crank into a rotational movement. This, in turn, instigates the motion of the connecting rod, leading to what is referred to as a general plane motion. This process involves two key points - point A on the connecting rod...
When an external force is exerted, it sets the crank into a rotational movement. This, in turn, instigates the motion of the connecting rod, leading to what is referred to as a general plane motion. This process involves two key points - point A on the connecting rod...