0
Technical Brief

Validation of Single C-Arm Fluoroscopic Technique for Measuring In Vivo Abdominal Wall Deformation

[+] Author and Article Information
Lindsey G. Kahan

Department of Surgery,
Washington University in St. Louis School of Medicine,
St. Louis, MO 63130
e-mail: l.kahan@wustl.edu

Charlotte Guertler

Department of Mechanical Engineering
and Materials Science,
Washington University in St. Louis,
St. Louis, MO 63130
e-mail: Charlotte.guertler@wustl.edu

Jeffrey A. Blatnik

Department of Surgery,
Washington University in St. Louis School of Medicine,
St. Louis, MO 63130
e-mail: jblatnik@wustl.edu

Spencer P. Lake

Mem. ASME
Department of Mechanical Engineering
and Materials Science,
Washington University in St. Louis,
1 Brookings Drive,
Campus Box 1185,
St. Louis, MO 63130;
Department of Orthopaedic Surgery,
Washington University in St. Louis,
1 Brookings Drive, Campus Box 1185,
St. Louis, MO 63130;
Department of Biomedical Engineering,
Washington University in St. Louis,
1 Brookings Drive, Campus Box 1185,
St. Louis, MO 63130
e-mail: Lake.s@wustl.edu

Manuscript received January 13, 2017; final manuscript received June 5, 2017; published online June 28, 2017. Assoc. Editor: Jeffrey Ruberti.

J Biomech Eng 139(8), 084502 (Jun 28, 2017) (7 pages) Paper No: BIO-17-1021; doi: 10.1115/1.4037073 History: Received January 13, 2017; Revised June 05, 2017

Hernia meshes significantly reduce the recurrence rates in hernia repair. It is known that they affect the abdominal wall postimplantation, yet the understanding of in vivo mechanics in the mesh placement area is lacking. We established a single C-arm biplane fluoroscopic system to study strains at the interface between the mesh and repaired abdominal tissues. We aimed to validate this system for future porcine hernia repair studies. Custom matlab programs were written to correct for pincushion distortion, and direct linear transformation (DLT) reconstructed objects in 3D. Using a custom biplane-trough setup, image sets were acquired throughout the calibrated volume to evaluate a radio-opaque test piece with known distances between adjacent beads. Distances were measured postprocessing and compared to known measurements. Repeatability testing was conducted by taking image sets of the test piece in a fixed location to determine system movement. The error in areal stretch tracking was evaluated by imaging a square plate with fixed radio-opaque beads and using matlab programs to compare the measured areal stretch to known bead positions. Minor differences between measured and known distances in the test piece were not statistically different, and the system yielded a 0.01 mm bias in the XY plane and a precision of 0.61 mm. The measured areal stretch was 0.996, which was not significantly different than the expected value of 1. In addition, preliminary stretch data for a hernia mesh in a porcine model demonstrated technique feasibility to measure in vivo porcine abdominal mechanics.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Computed-aided design setup of porcine trough and calibration planes (a) and actual setup with animal (b). The calibration planes were constructed of Plexiglas (61 × 46 × 0.9 cm), and bead distance was 25.4 mm between centroids.

Grahic Jump Location
Fig. 2

Computer-aided design model of test object constructed of Plexiglas and stainless steel beads (a). Radiographic images of test object and calibration planes at both angles of C-arm rotation (b). Triangles represent chosen calibration beads on top and bottom planes, and circles represent beads in test object. Three-dimensional reconstruction of all chosen calibration points and test object beads (c).

Grahic Jump Location
Fig. 3

Schematic of C-arm placement, calibration planes, and animal setup to acquire images at both angles in relation to the vertical axis

Grahic Jump Location
Fig. 4

Three-dimensional printed square plate with 16 beads used for strain tracking (a). Three-dimensional triangulation mesh plot of the square plate with 16 beads, where each triangle node represents a radio-opaque bead embedded in the square plate (b). Large circular (a) oriented in 3D (b).

Grahic Jump Location
Fig. 5

Overlay of binary radiographic images. Original grid positions are represented by white dots, and corrected grid positions are represented by black dots. Direct overlap at the center represents no correction needed. Distortion correction increased radially from the center.

Grahic Jump Location
Fig. 6

Application of technique to porcine ventral hernia repair model with implanted mesh. Mesh area expanded 5.23% with increased intra-abdominal pressure (IAP), as indicated by an areal stretch greater than 1 across the surface of the mesh.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In