DOI: 10.5061/dryad.37pvmcvsm
title: Residual limb models scanned using the EINScan Pro 2X Plus scanner with added HD Prime Pack

description: This dataset contains limb models scanned using the EINScan Pro 2X Plus
 scanner. At each of 3 sites, operator 1 (OP1) scanned the four limb models
 twice (OP1-A and OP1-B) with the structured-light scanner, and operator 2
 (OP2) scanned the four limb models once with the same scanner, for a total
 of 12 scans per site. At the European site, an additional reference scan
 of each positive model (4 scans) was conducted by an independent
 professional Operator (OP0) using the metrological scanner (EINScan Laser
 FreeScan 5X). 
description: All limb models were scanned using the EINScan Pro 2X Plus with
 added HD Prime Pack (SHINING 3D Tech. Co. Ltd., China): an external add-on
 camera mechanically locked to the scanner with a latch-on USB port that
 allows for HD scanning. At the beginning of each measurement session the
 scanner was calibrated following the manufacturer’s instructions and using
 the etched glass board provided with the scanner. All scans were completed
 in hand-held HD Scan mode, without markers (“features mode”), setting a
 resolution of 0.5mm, at 20 frames per second, with 1 million points
 collected per second. A metrological scanner was used as a reference and
 assumed as ground truth: the EINScan Laser FreeScan X5 (SHINING 3D Tech.
 Co. Ltd., China). Four distinct limb shapes were
 selected from a digital database of over 1000 sockets from one of the
 clinical sites: <br>A. Transfemoral socket for a long residual limb,
 with ischial containment producing undercuts/indentations around the
 proximal brim, referred to as “TF Ischial”;<br>B. Transfemoral
 socket for a long residual limb, with ischial containment but no
 undercuts/indentations around the proximal brim. Since this socket was
 based on hydrostatic casting with the Symphonie Aqua system (Romedis GmbH,
 Germany), it will be referred to as “TF Aqua”;<br>C. Transtibial
 socket for a mid-length residual limb, with a total surface bearing design
 and a cylindrical shape, referred to as “TT Cylindrical”;<br>D.
 Transtibial socket for a long residual limb, with patellar tendon bearing
 design and a conical shape, referred to as “TT Conical”.
 Once selected, the four limb models were carved from polyurethane
 foam by a robot (Ortis, Fabrica Machinale, Caschina, PI, Italy). This
 material was chosen because it is lightweight and less fragile than
 plaster casts and less likely to be damaged during shipping to different
 sites. To prevent the limb models from deteriorating due to impact or
 abrasion, they were covered in polyethylene terephthalate glycol (PETG) by
 vacuum forming, starting from a 0.12mm sheet. The PETG surface was then
 sanded and sprayed with matte paint. Finally, 7mm holes were drilled in
 the extension above the proximal socket trim lines to serve as technical
 landmarks to align (i.e., spatially register) the scanned shapes during
 data analysis. Three sites participated in the
 assessments, two in the United States (USA1 and USA2) and one in Europe
 (EU). Each site had its own structured-light scanner (same model). Two
 individuals participated at each site: Operator 1 (OP1) with experience
 using the scanner, and Operator 2 (OP2) with minimal prior experience
 using the scanner. The same four limb models were mailed to each site. At
 each site, OP1 scanned the four limb models twice (OP1-A and OP1-B) with
 the structured-light scanner, and OP2 scanned the four limb models once
 with the same scanner, for a total of 12 scans per site. At the European
 site an additional reference scan of each positive model (4 scans) was
 conducted by an independent professional Operator (OP0) using the
 metrological scanner (EINScan Laser FreeScan 5X).  For
 each model, scans were processed as follows. First, the EINScan software
 was used to remove background surfaces and geometries and to generate
 watertight meshes in STL file format. Then, the obtained digital meshes
 were processed, using custom Python software, which takes advantage of
 Meshlab and Visual Toolkit (VTK) libraries as computational geometry
 engines, with Qt to support the graphical user interface. To decrease
 computational costs, all seven scans from each limb model were decimated
 to 30%, i.e. removing 70% of mesh vertices, to obtain meshes of reduced
 dimension in PLY file format. 
description: # Residual limb models scanned using the EINScan Pro 2X Plus scanner with
 added HD Prime Pack
 [https://doi.org/10.5061/dryad.37pvmcvsm](https://doi.org/10.5061/dryad.37pvmcvsm) ## Description of the data and file structure The file names are composed as follows: \- Level of amputation (TT, TF) \- Socket type (Cylindrical and Conical for TTs; Aqua and Ischial for TFs) \- Operator (OP0, OP1_A, OP1_B, OP2) \- Acquisition center (EU, USA1, USA2)