Measurement of 3D Vertebral Body Position and Orientation Using Single Plane Fluoroscopy

2010 ◽  
Author(s):  
Bryan P. Conrad ◽  
Scott A. Banks
Keyword(s):  
Image Registration ◽  
Vertebral Body ◽  
Body Position ◽  
Single Plane ◽  
Kinematic Measurement ◽  
Measurement Tools ◽  
Significant Extension ◽  
Total Knee ◽  
Position And Orientation

The increasing use of motion preserving devices in the spine has highlighted the need for accurate kinematic measurement tools to evaluate the performance of these new implants. In addition to quantifying the motion of the implant itself, it is also desirable to measure how implants affect the motion at adjacent vertebral levels. Single plane fluoroscopy has been used for over 15 years to analyze the in vivo motions of total knee replacement implants, with reported accuracies of 0.5–1.0 deg for rotations and 0.5 mm for in plane translations1,2. It is our goal to apply this type of image registration technique to the spine, so that accurate 3D kinematics of vertebral motion can be measured in vivo. This involves a significant extension to previous work, instead of tracking silhouettes of implants, we proposed to use digitally reconstructed radiograph images generated from a CT as the basis for image registration. The purpose of this project was to develop a methodology that would enable the 3D position and orientation (pose) of a vertebral body to be accurately measured from a single plane fluoroscopic image.

Accuracy of single-plane fluoroscopy in determining relative position and orientation of total knee replacement components

2011 ◽  
Vol 44 (4) ◽  
pp. 784-787 ◽  
Author(s):  
Stacey Acker ◽  
Rebecca Li ◽  
Heather Murray ◽  
Paul St. John ◽  
Scott Banks ◽  
...  
Keyword(s):  
Total Knee Replacement ◽  
Knee Replacement ◽  
Relative Position ◽  
Single Plane ◽  
Total Knee ◽  
Position And Orientation

Validation of three-dimensional total knee replacement kinematics measurement using single-plane fluoroscopy

2016 ◽  
Vol 7 (1) ◽  
pp. 14
Author(s):  
R. Daems ◽  
Jan Victor ◽  
Patrick De Baets ◽  
S. Van Onsem ◽  
Matthias Verstraete
Keyword(s):  
Motion Tracking ◽  
Sagittal Plane ◽  
Tracking System ◽  
Knee Kinematics ◽  
In Vivo Evaluation ◽  
Single Plane ◽  
Validation Experiment ◽  
Flexion Extension ◽  
Total Knee

Instability of the knee after total knee arthroplasty (TKA) is today the number one reason for aseptic revision surgery. In vivo evaluation of knee kinematics using single-plane fluoroscopy has become an important method to investigate knee stability and compare dierent implant designs. A validation experiment was performed to assess the accuracy of this method. A total knee implant was installed on sawbones and a flexion extension movement was performed with the sagittal plane parallel to the detector panel of the fluoroscope. Simultaneously, the sawbones were tracked using a conventional motion tracking system and rigidly attached markers. That measurement can be seen as a golden standard and is therefore believed to represent the real positions. The results indicate that knee rotations can be measured with an accuracy of approximately 0.6 and sagittal plane translations can be measured with an accuracy of approximately 0.4 mm. These results prove that the method is sufficiently accurate for clinical use.

Errors in Calculating Anterior–Posterior Tibial Contact Locations in Total Knee Arthroplasty Using Three-Dimensional Model to Two-Dimensional Image Registration in Radiographs: An In Vitro Study of Two Methods

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Derrick S. Ross ◽  
Stephen M. Howell ◽  
Maury L. Hull
Keyword(s):  
Total Knee Arthroplasty ◽  
Image Registration ◽  
Knee Arthroplasty ◽  
Three Dimensional ◽  
Force Sensor ◽  
Point Method ◽  
Two Dimensional ◽  
Single Plane ◽  
Total Knee ◽  
Anterior Posterior

Knowledge of anterior–posterior (A-P) tibial contact locations provides an objective assessment of the relative motion of the tibia on the femur following total knee arthroplasty (TKA), which can be used to compare the effects of different components, surgical techniques, and alignment goals on knee function in vivo. Both the lowest point method and the penetration method have been used to calculate A-P tibial contact locations using three-dimensional (3D) model to two-dimensional (2D) image registration. The primary objective of this study was to quantify errors in calculating the A-P tibial contact location using the lowest point and penetration methods because the errors in calculating the A-P tibial contact locations using these two methods are unknown. The A-P tibial contact locations were calculated with the two methods and simultaneously measured with a tibial force sensor in ten fresh-frozen cadaveric knee specimens with a TKA. Single-plane radiographs of the knee specimens were acquired at 0 deg, 30 deg, 60 deg, and 90 deg of flexion in neutrally, internally, and externally rotated orientations. While the radiographs were exposed, reference A-P tibial contact locations were simultaneously collected using the tibial force sensor to be compared to the calculated A-P tibial contact locations. The overall root-mean-squared-errors (RMSEs) in the A-P tibial contact location calculated with the lowest point method, the penetration method with penetration, and penetration method without penetration were 5.5 mm, 3.6 mm, and 8.9 mm, respectively. The overall RMSE was lowest for the penetration method with penetration, making it the superior method for calculating A-P tibial contact locations.

scholarly journals Performance of microvascular anastomosis with a new robotic visualization system: proof of concept

2021 ◽  
Author(s):  
F. Boehm ◽  
P. J. Schuler ◽  
R. Riepl ◽  
L. Schild ◽  
T. K. Hoffmann ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Body Position ◽  
Head Movements ◽  
Camera System ◽  
Visualization System ◽  
Head Mounted Display ◽  
General Evaluation ◽  
Surgical Field ◽  
Technical Instructions

AbstractMicrovascular procedures require visual magnification of the surgical field, e.g. by a microscope. This can be accompanied by an unergonomic posture with musculoskeletal pain or long-term degenerative changes as the eye is bound to the ocular throughout the whole procedure. The presented study describes the advantages and drawbacks of a 3D exoscope camera system. The RoboticScope®-system (BHS Technologies®, Innsbruck, Austria) features a high-resolution 3D-camera that is placed over the surgical field and a head-mounted-display (HMD) that the camera pictures are transferred to. A motion sensor in the HMD allows for hands-free change of the exoscope position via head movements. For general evaluation of the system functions coronary artery anastomoses of ex-vivo pig hearts were performed. Second, the system was evaluated for anastomosis of a radial-forearm-free-flap in a clinical setting/in vivo. The system positioning was possible entirely hands-free using head movements. Camera control was intuitive; visualization of the operation site was adequate and independent from head or body position. Besides technical instructions of the providing company, there was no special surgical training of the surgeons or involved staff upfront performing the procedures necessary. An ergonomic assessment questionnaire showed a favorable ergonomic position in comparison to surgery with a microscope. The outcome of the operated patient was good. There were no intra- or postoperative complications. The exoscope facilitates a change of head and body position without losing focus of the operation site and an ergonomic working position. Repeated applications have to clarify if the system benefits in clinical routine.

A Comparison of Image Registration Methods Used for Printed Circuit Board Inspection

2008 ◽  
Vol 381-382 ◽  
pp. 295-298
Author(s):  
Shin Chieh Lin ◽  
C.T. Chen ◽  
C.H. Chou
Keyword(s):  
Image Registration ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Loading Test ◽  
Area Method ◽  
Printed Circuit ◽  
Feature Based ◽  
Position And Orientation ◽  
Inspection Machine

In this study, registration methods used to estimate both position and orientation differences between two images had been evaluated. This is an important issue since that there are always some position and orientation differences when loading test samples on the inspection machine. These differences should be calculated and compensated before further analysis. Registration methods tested including one area method and three feature based method. It was shown that the area method had better performance than other feature based method in these cases studied. And it is shown that it is much easy to detect defect by analyzing the subtracted image with position and orientation compensation instead of those without compensation.

Determination of sclerotome to the cartilage fate

Development ◽  
1998 ◽  
Vol 125 (11) ◽  
pp. 2113-2124 ◽  
Author(s):  
J.L. Dockter ◽  
C.P. Ordahl
Keyword(s):  
Vertebral Body ◽  
Host Age ◽  
Somite Stage ◽  
Dorsal Position ◽  
Lineage Diversification

When the somite first forms the cells appear to be equivalent in potential. In order to understand the lineage diversification of the somite, the determination of sclerotome cells to the cartilage fate was tested using an in vivo challenge assay in which quail sclerotome fragments were grafted into a dorsal position in a chick host. Grafts containing undetermined cells were expected to differentiate into other tissues while grafts containing determined chondrocyte precursors were expected to consistently give rise to cartilage. We found that grafted sclerotome fragments from somite stages V-XX were capable of giving rise to integrated muscle and dermis and that it was not until fragments from stage XII somites were grafted that cartilage was consistently produced in the assay. Sclerotomal tissue from embryonic day 4–6 embryos remained as morphologically unintegrated mesenchyme when grafted into an embryonic day 2 host, but formed only cartilage when placed into an identically aged host. Vertebral body cartilage from embryonic day 7 and embryonic day 8 embryos formed exclusively ectopic cartilage in an embryonic day 2 host. We conclude that cells determined to the cartilage fate do not appear until somite stage XII, but that not all sclerotome cells are determined at this time. The effect of host age on the differentiation and morphogenetic behavior of sclerotome fragment grafts in this assay indicate the existence of developmental eras within the embryo.

Effect of Gait on Patellofemoral Mechanics

2008 ◽  
Author(s):  
Jeffrey E. Bischoff ◽  
Justin S. Hertzler
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Clinical Studies ◽  
Patellofemoral Joint ◽  
Knee Kinematics ◽  
Component Design ◽  
Total Knee ◽  
The Impact ◽  
Reconstructed Knee

Computational modeling of the reconstructed knee is an important tool in designing components for maximum functionality and life. Utilization of boundary conditions consistent with in vivo gait loading in such models enables predictions of knee kinematics and polyethylene damage [1–4], which can then be used to optimize component design. Several recent clinical studies have focused on complications associated with the patellofemoral joint [5–6], highlighting the need to better understand the mechanics of this compartment of total knee arthroplasty (TKA). This study utilizes a computational model to characterize the impact of gait loading on the mechanics of the patella in TKA.

In Vivo Tibiofemoral Contact Kinematics and Contact Forces During Dynamic Weight-Bearing Activities Following Total Knee Arthroplasty

2008 ◽  
Author(s):  
Kartik M. Varadarajan ◽  
Angela Moynihan ◽  
Darryl D’Lima ◽  
Clifford W. Colwell ◽  
Harry E. Rubash ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Computational Models ◽  
Imaging System ◽  
Weight Bearing ◽  
Contact Forces ◽  
Inverse Dynamic ◽  
Contact Kinematics ◽  
Total Knee

Accurate knowledge of in vivo articular contact kinematics and contact forces is required to quantitatively understand factors limiting life of total knee arthroplasty (TKA) implants, such as polyethylene component wear and implant loosening [1]. Determination of in vivo tibiofemoral contact forces has been a challenging issue in biomechanics. Historically, instrumented tibial implants have been used to measure tibiofemoral forces in vitro [2] and computational models involving inverse dynamic optimization have been used to estimate joint forces in vivo [3]. Recently, D’Lima et al. reported the first in vivo measurement of 6DOF tibiofemoral forces via an instrumented implant in a TKA patient [4]. However this technique does not provide a direct estimation of tibiofemoral contact forces in the medial and lateral compartments. Recently, a dual fluoroscopic imaging system has been used to accurately determine tibiofemoral contact locations on the medial and lateral tibial polyethylene surfaces [5]. The objective of this study was to combine the dual fluoroscope technique and the instrumented TKAs to determine the dynamic 3D articular contact kinematics and contact forces on the medial and lateral tibial polyethylene surfaces during functional activities.

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