A Six-Degree-of-Freedom Acoustic Transducer for Rotation and Translation Measurements Across the Knee

1990 ◽  
Vol 112 (4) ◽  
pp. 371-378 ◽  
Author(s):  
T. P. Quinn ◽  
C. D. Mote
Keyword(s):  
Soft Tissue ◽  
External Rotation ◽  
Worst Case ◽  
Mechanical Coupling ◽  
Acoustic Transducer ◽  
Transducer Design ◽  
Cadaver Specimen ◽  
Soft Tissue Motion ◽  
Tissue Motion

An acoustic transducer design to measure the relative translations and rotations across the knee with no mechanical coupling between the tibia and femur is presented. Platforms attached to femoral and tibial tracking fixtures hold acoustic sources and receivers, respectively. The distance from each source to each receiver is measured by the acoustic transit time and the translations and rotations across the knee joint are computed. For rotations less than 30 deg around the expected operating position, the resolution of the transducer is 0.3 deg; for translations less than 1.5 cm around the expected operating position, the resolution is 0.03 cm. Theoretical error analysis using a Monte Carlo method shows that the uncertainty in the measurement depends on the relative position of the sources and receivers. The analysis predicts the worst case resolution of the transducer as 0.09 cm in translation and 0.6 deg in rotation when the receiver platform is translated 8.0 cm parallel to the source platform. The transducer and fixturing system are demonstrated on a cadaver specimen for applied anterior force and applied internal-external rotation. Errors due to (soft tissue) motion of the transducer relative to the bone during in vivo measurements are assessed on the cadaver specimen. For internal-external rotation the error due to soft tissue motion is a maximum of 0.5 cm in translation and 1.8 deg in rotation. For applied anterior force the error due to soft tissue motion is a maximum of 0.16 cm in translation and 2.7 deg in rotation.

Investigating the needle dynamic response during insertion into soft tissue

2009 ◽  
Vol 224 (4) ◽  
pp. 531-540 ◽  
Author(s):  
T Alja'afreh
Keyword(s):  
Soft Tissue ◽  
Ex Vivo ◽  
Surgical Techniques ◽  
Needle Insertion ◽  
Limiting Factor ◽  
Minimally Invasive Surgical ◽  
Soft Tissue Motion ◽  
Insertion Process ◽  
Tissue Motion

This paper investigates the effect of the needle velocity on soft-tissue motion ex vivo and in vivo. In many needle-based intervention procedures, which are common minimally invasive surgical techniques, the needle can be assumed to be rigid and the tissue deforms and displaces considerably as the needle moves forwards to its target. This paper presents an energy-based fracture mechanics approach to show that the increasing needle velocity can reduce tissue motion during the insertion process. The main feature of this paper is that it extends the proposed approach to model the insertion dynamics, whereas most of the literature treats needle insertion as a quasi-static process. Ex-vivo test results on lamb heart samples show that the force required to initiate penetration decreases with increasing needle velocity up to a critical velocity, above which the rate-independent penetration force of the underlying tissue becomes the limiting factor. In-vivo tests show that increased needle velocity results in reduced force and displacement for needle insertion into the heart. Results indicate that automated insertion could substantially improve performance in some applications.

scholarly journals Real-time soft tissue motion estimation for lung tumors during radiotherapy delivery

2013 ◽  
Vol 40 (9) ◽  
pp. 091713 ◽  
Author(s):  
Joerg Rottmann ◽  
Paul Keall ◽  
Ross Berbeco
Keyword(s):  
Soft Tissue ◽  
Motion Estimation ◽  
Real Time ◽  
Lung Tumors ◽  
Soft Tissue Motion ◽  
Tissue Motion

Soft tissue motion tracking with application to tablet-based incision planning in laser surgery

2016 ◽  
Vol 11 (12) ◽  
pp. 2325-2337 ◽  
Author(s):  
Andreas Schoob ◽  
Max-Heinrich Laves ◽  
Lüder Alexander Kahrs ◽  
Tobias Ortmaier
Keyword(s):  
Soft Tissue ◽  
Laser Surgery ◽  
Motion Tracking ◽  
Soft Tissue Motion ◽  
Tissue Motion

scholarly journals Stereo vision-based tracking of soft tissue motion with application to online ablation control in laser microsurgery

2017 ◽  
Vol 40 ◽  
pp. 80-95 ◽  
Author(s):  
Andreas Schoob ◽  
Dennis Kundrat ◽  
Lüder A. Kahrs ◽  
Tobias Ortmaier
Keyword(s):  
Soft Tissue ◽  
Stereo Vision ◽  
Laser Microsurgery ◽  
Soft Tissue Motion ◽  
Tissue Motion

scholarly journals Soft Tissue Motion Influences Skeletal Loads During Impacts

2008 ◽  
Vol 36 (2) ◽  
pp. 71-75 ◽  
Author(s):  
John H. Challis ◽  
Matthew T.G. Pain
Keyword(s):  
Soft Tissue ◽  
Soft Tissue Motion ◽  
Tissue Motion

scholarly journals Soft Tissue Motion during Impacts: Their Potential Contributions to Energy Dissipation

2002 ◽  
Vol 18 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Matthew T.G. Pain ◽  
John H. Challis
Keyword(s):  
Soft Tissue ◽  
Muscle Tension ◽  
Force Plate ◽  
Soft Tissue Deformation ◽  
Skin Marker ◽  
Frequency Components ◽  
Distinct Frequency ◽  
Soft Tissue Motion ◽  
Kinetics Of ◽  
Tissue Motion

The aims of this study were to quantify intrasegmental motion using an array of 28 surface-mounted markers to examine frequency and amplitude measurements of the intrasegmental motion to calculate forces and energy transfer; and to show that the underlying muscles are a major contributor to the skin marker motion. One participant performed 27 trials under three conditions in which his forearm was struck against a solid object fixed to a force plate while the locations of the markers were recorded at 240 Hz. For impacts with equal peak forces, the muscle tension significantly affected the amount of intrasegmental motion. Tensing the arm reduced the intrasegmental motion by 50%. The quadrilateral sectors defined by the markers changed in area by 11% with approximately equal motion in the vertical and horizontal direction. The maximum linear marker motion was 1.7 cm. The intrasegmental motion had distinct frequency components around 14 and 20 Hz. Soft tissue deformation could account for 70% of the energy lost from the forearm during these impacts. The study has demonstrated the important role that intrasegment soft tissue motion can have on the kinetics of an impact.

A NEW TECHNIQUE FOR COMPENSATING THE SOFT TISSUE ARTEFACT AT THE UPPER-ARM: IN VITRO VALIDATION

2005 ◽  
Vol 05 (02) ◽  
pp. 333-347 ◽  
Author(s):  
ANDREA GIOVANNI CUTTI ◽  
ANGELO CAPPELLO ◽  
ANGELO DAVALLI
Keyword(s):  
Soft Tissue ◽  
Mean Squared Error ◽  
External Rotation ◽  
Axial Rotation ◽  
New Technique ◽  
Future Application ◽  
Upper Arm ◽  
A New Technique

Soft tissue artefact is the dominant source of error in human movement analysis whenever this is carried out using systems based on skin-mounted markers. At the upper-arm, the most corrupted measure is the humerus internal-external rotation: the aim of this work is to propose a new technique for compensating the artefact affecting this measure. The technique is based on the definition of a humerus bone-embedded frame (H2) almost "artefact free" but influenced by the elbow orientation in the measurement of the humeral axial rotation, and on an algorithm designed to solve this kinematic coupling. The algorithm was tested in vitro correcting H2 distortions during different tasks imposed to a mechanical model of the upper-limb; in the most general case of a motion involving all the degrees of freedom of shoulder and elbow, the application of the algorithm reduced the root mean squared error between the known and the measured axial rotation from 8.60° to just 0.12°. By means of the algorithm, therefore, H2 becomes a reliable humerus reference system and its future application for in vivo artefact compensation appears promising.

A Quasi-Spherical Triangle-Based Approach for Efficient 3-D Soft-Tissue Motion Tracking

2013 ◽  
Vol 18 (5) ◽  
pp. 1472-1484 ◽  
Author(s):  
Wai-Keung Wong ◽  
Bo Yang ◽  
Chao Liu ◽  
Philippe Poignet
Keyword(s):  
Soft Tissue ◽  
Motion Tracking ◽  
Spherical Triangle ◽  
Soft Tissue Motion ◽  
Tissue Motion
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