Effects of Steam Sterilization on 3D Printed Biocompatible Resin Materials for Surgical Guides-An Accuracy Assessment Study.

Computer-assisted surgery with three-dimensional (3D) printed surgical guides provides more accurate results than free-hand surgery. Steam sterilization could be one of the factors that affect the dimensions of surgical guide resin materials, leading to inaccuracies during surgeries. The purpose of this study was to evaluate the effects of steam sterilization on the dimensional accuracy of indication-specific hollow cube test bodies, manufactured in-house using Class IIa biocompatible resin materials (proprietary and third-party). To evaluate the pre- and post-sterilization dimensional accuracy, root mean square (RMS) values were calculated. The results indicate that, in all the groups, steam sterilization resulted in an overall linear expansion of the photopolymeric resin material, with an increase in outer dimensions and a decrease in inner dimensions. The effects on the dimensional accuracy of test bodies were not statistically significant in all the groups, except PolyJet Glossy (p > 0.05). The overall pre- and post-sterilization RMS values were below 100 and 200 µm, respectively. The highest accuracies were seen in proprietary resin materials, i.e., PolyJet Glossy and SLA-LT, in pre- and post-sterilization measurements, respectively. The dimensional accuracy of third-party resin materials, i.e., SLA-Luxa and SLA-NextDent, were within a comparable range as proprietary materials and can serve as an economical alternative.

"Green Fingerprint" Project: Evaluation of the Power Consumption of Reporting Stations in a Radiology Department.

RATIONALE AND OBJECTIVES: To quantify the power or energy consumption of reporting stations in a radiology department and to consider a hypothetical scenario to reduce energy waste. METHODS: We measured the energy consumption of 36 radiology reporting stations over a mean time frame of about 194 days and then extrapolated results to 1 year. Reporting stations were configured (by default) to enter a stand-by mode after 4 hours of inactivity. A hypothetical scenario was calculated in which stand-by was skipped and the reporting stations were shut down after 1 hour of inactivity. RESULTS: Data from four stations was corrupted. The overall power consumption of the 32 remaining reporting stations was 53,170 kWh/a, equivalent to 12 family households (4500 kWh/a per household in Switzerland in 2014) or 97.2 barrels of oil. We identified three main power consumption patterns of the reporting stations: mainly off, mainly on, and always off. The on-mode consumption per year was 40,763 kWh/a, the stand-by consumption was 10,010 kWh/a, and the off-mode consumption was 2397 kWh/a. The reporting stations spent half of their on-mode time awaiting the initiation of stand-by, resulting in a wait-time consumption of 18,243 kWh/a. With the hypothetical scenario, we achieved an energy consumption saving of 23,692 kWh/a, a reduction of about 45% of the initial energy consumption, equivalent to 5 households or 40.8 barrels of oil consumed. CONCLUSION: The power consumption of the reporting stations is not negligible. Reducing energy waste in the radiology department can be established through simple changes in device configuration which will simultaneously promote energywise habits. ADVANCES IN KNOWLEDGE: Minor changes to the settings of the reporting stations in a radiology department can result in significant long-term energy savings and promote energy-wise habits.

Three-dimensional Assessment of the Breast: Validation of a Novel, Simple and Inexpensive Scanning Process.

BACKGROUND/AIM: Methods to assess three-dimensionally the breast surface are increasingly used in plastic and reconstructive surgery. The aim of this study was to validate the use of the Structure Sensor 3D scanner (Occipital, Inc., Boulder, CO, USA) connected to an iPad Pro (Apple, Inc., Cupertino, CA, USA) as a novel, inexpensive and handheld three-dimensional scanning process. MATERIALS AND METHODS: Surface images of a medical human female anatomy torso model of rigid plastic were repeatedly acquired with Structure Sensor 3D scanner and compared with those obtained using two clinically established 3D imaging systems. Digital measurements of vector and surface breast distances were analyzed using Mimics® Innovation Suite 20 medical imaging software (Materialise, Leuven, Belgium). RESULTS: The analysis of variance (ANOVA) revealed no statistically significant difference among measurements obtained using different scanning processes for all the variables examined (p>0.05). CONCLUSION: The study demonstrates analogous practicability and reliability for surface image acquisition using the newly introduced Structure Sensor 3D scanner and other clinically established scanners.