3D Printed Surgical Instruments Evaluated by a Simulated Crew of a Mars Mission.

INTRODUCTION: The first space-based fused deposition modeling (FDM) 3D printer became operational in 2014. This study evaluated whether Mars simulation crewmembers of the Hawai'i Space Exploration Analog and Simulation (HI-SEAS) II mission with no prior surgical experience could utilize acrylonitrile butadiene styrene (ABS) thermoplastic surgical instruments FDM 3D printed on Earth to complete simulated surgical tasks. METHODS: This study sought to examine the feasibility of using 3D printed surgical tools when the primary crew medical officer is incapacitated and the back-up crew medical officer must conduct a surgical procedure during a simulated extended space mission. During a 4 mo duration ground-based analog mission, five simulation crewmembers with no prior surgical experience completed 16 timed sets of simulated prepping, draping, incising, and suturing tasks to evaluate the relative speed of using four ABS thermoplastic instruments printed on Earth compared to conventional instruments. RESULTS: All four simulated surgical tasks were successfully performed using 3D printed instruments by Mars simulation crewmembers with no prior surgical experience. There was no substantial difference in time to completion of simulated tasks with control vs. 3D printed sponge stick, towel clamp, scalpel handle, and toothed forceps. DISCUSSION: These limited findings support further investigation into the creation of an onboard digital catalog of validated 3D printable surgical instrument design files to support autonomous, crew-administered healthcare on Mars missions. Future work could include addressing sterility, biocompatibility, and having astronaut crew medical officers test a wider range of surgical instruments printed in microgravity during actual surgical procedures. Wong JY, Pfahnl AC. 3D printed surgical instruments evaluated by a simulated crew of a Mars mission. Aerosp Med Hum Perform. 2016; 87(9):806-810.

On-Site 3D Printing of Functional Custom Mallet Splints for Mars Analogue Crewmembers.

INTRODUCTION: The first off-Earth fused deposition modeling (FDM) 3D printer is investigating acrylonitrile butadiene styrene (ABS) thermoplastic manufacturing applications for long-duration space missions. This study assessed the feasibility of FDM 3D printing ABS thermoplastic customized mallet splints on site for Mars analogue crewmembers. METHODS: Seven caliper measurements were taken of the right ring finger of 13 healthy Mars Desert Research Station mission crewmembers. These measurements were input into a free 3D modeling software program to create customized digital splint models. These digital files were uploaded to a desktop FDM 3D printer and custom splints were printed on site with ABS thermoplastic. Splint fit was assessed via subject feedback. Joint active range of motion was recorded when the splint was worn briefly. RESULTS: The time it took the software program to digitally render each splint model was less than 2 min and 30 s. The print duration for the splints ranged from 21 to 29 min. All 13 subjects reported that their 3D printed custom mallet splints fit securely and comfortably. All splints permitted full active range of motion of the proximal interphalangeal joint (0-100°) while maintaining the distal interphalangeal joint in extension. DISCUSSION: It is feasible to 3D print functional ABS thermoplastic custom mallet splints on site for Mars analogue crewmembers. This technology could be used clinically in the future when a custom mallet splint is required in a remote, resource-constrained setting.

Ultra-Portable Solar-Powered 3D Printers for Onsite Manufacturing of Medical Resources.

INTRODUCTION: The first space-based fused deposition modeling (FDM) 3D printer is powered by solar photovoltaics. This study seeks to demonstrate the feasibility of using solar energy to power a FDM 3D printer to manufacture medical resources at the Mars Desert Research Station and to design an ultra-portable solar-powered 3D printer for off-grid environments. METHODS: Six solar panels in a 3×2 configuration, a voltage regulator/capacitor improvised from a power adapter, and two 12V batteries in series were connected to power a FDM 3D printer. Three designs were printed onsite and evaluated by experts post analogue mission. A solar-powered 3D printer composed of off-the-shelf components was designed to be transported in airline carry-on luggage. RESULTS: During the analogue mission, the solar-powered printer could only be operated for <1 h/d, but was able to fabricate a functional dental tool, scalpel handle, and customized mallet splint over 2 d. Post analogue mission, an ultra-portable plug-and-play solar-powered 3D printer was designed that could print an estimated 16 dental tools or 8 mallet finger splints or 7 scalpel handles on one fully charged 12V 150Wh battery with a 110V AC converter. CONCLUSION: It is feasible to use solar energy to power a 3D printer to manufacture functional and personalized medical resources at a Mars analogue research station. Based on these findings, a solar-powered suitcase 3D printing system containing solar panels, 12V battery with charge controller and AC inverter, and back-up solar charge controller and inverter was designed for transport to and use in off-grid communities.

3D printing of surgical instruments for long-duration space missions.

INTRODUCTION: The first off-Earth fused deposition modeling (FDM) 3D printer will explore thermoplastic manufacturing capabilities in microgravity. This study evaluated the feasibility of FDM 3D printing 10 acrylonitrile butadiene styrene (ABS) thermoplastic surgical instruments on Earth. METHODS: Three-point bending tests compared stiffness and yield strength between FDM 3D printed and conventionally manufactured ABS thermoplastic. To evaluate the relative speed of using four printed instruments compared to conventional instruments, 13 surgeons completed simulated prepping, draping, incising, and suturing tasks. Each surgeon ranked the performance of six printed instruments using a 5-point Likert scale. RESULTS: At a thickness of 5.75 mm or more, the FDM printing process had a less than 10% detrimental effect on the tested yield strength and stiffness of horizontally printed ABS thermoplastic relative to conventional ABS thermoplastic. Significant weakness was observed when a bending load was applied transversely to a 3D printed layer. All timed tasks were successfully performed using a printed sponge stick, towel clamp, scalpel handle, and toothed forceps. There was no substantial difference in time to completion of simulated surgical tasks with control vs. 3D printed instruments. Of the surgeons, 100%, 92%, 85%, 77%, 77%, and 69% agreed that the printed smooth and tissue forceps, curved and straight hemostats, tissue and right angle clamps, respectively, would perform adequately. DISCUSSION: It is feasible to 3D print ABS thermoplastic surgical instruments on Earth. Loadbearing structures were designed to be thicker, when possible. Printing orientations were selected so that the printing layering direction of critical structures would not be transverse to bending loads.

Validity and reliability of craniofacial anthropometric measurement of 3D digital photogrammetric images.

BACKGROUND: Direct anthropometry performed during a patient examination is the standard technique for quantifying craniofacial dysmorphology, as well as for surgical planning and outcome assessment. Several new technologies have been designed to computerize anthropometric measurements, including three-dimensional (3D) digital photogrammetry. These digital systems have the advantage of acquiring patient craniofacial surface images quickly and noninvasively. Before morphometry using digital photogrammetry can be applied in clinical and research practice, it must be assessed against direct anthropometry. OBJECTIVE: To evaluate the validity and reliability of facial anthropometric linear distances imaged by 3D digital photogrammetry with respect to direct anthropometry. DESIGN, SETTING, PARTICIPANTS, MEASURES: Standard craniofacial distances were directly measured twice on 20 normal adult volunteers. Craniofacial surfaces were also imaged using the 3dMDface digital photogrammetry system, and distances were digitally measured twice for each subject. Validity measures of accuracy and bias (for direct versus digital measurements) and reproducibility measures of precision and test-retest reliability (for repeated sets of digital measurements) were computed. RESULTS: Seventeen of the 18 direct measurements correlated highly with digital values (mean r = 0.88). The correlation for one measurement (upper prolabial width) was not statistically significant. The overall precision of all 17 digital measurements was less than 1 mm, and the reliability was high (mean r = 0.91). CONCLUSIONS: Craniofacial anthropometry using the 3dMDface System is valid and reliable. Digital measurements of upper prolabial width may require direct marking, prior to imaging, to improve landmark identification.

The Bellagio Report: Cardiovascular risks of spaceflight: implications for the future of space travel.

BACKGROUND: Long-duration space missions, as well as emerging civilian tourist space travel activities, prompted review and assessment of data available to date focusing on cardiovascular risk and available risk mitigation strategies. The goal was the creation of tools for risk priority assessments taking into account the probability of the occurrence of an adverse cardiovascular event and available and published literature from spaceflight data as well as available risk mitigation strategies. METHODS: An international group of scientists convened in Bellagio, Italy, in 2004 under the auspices of the Aerospace Medical Association to review available literature for cardiac risks identified in the Bioastronautics Critical Path Roadmap (versions 2000, 2004). This effort led to the creation of a priority assessment framework to allow for an objective assessment of the hazard, probability of its occurrence, mission impact, and available risk mitigation measures. RESULTS/CONCLUSIONS: Spaceflight data are presented regarding evidence/ no evidence of cardiac dysrhythmias, cardiovascular disease, and cardiac function as well as orthostatic intolerance, exercise capacity, and peripheral resistance in presyncopal astronauts compared to non-presyncopal astronauts. Assessment of the priority of different countermeasures was achieved with a tabular framework with focus on probability of occurrence, mission impact, compliance, practicality, and effectiveness of countermeasures. Special operational settings and circumstances related to sensitive portions of any mission and the impact of environmental influences on mission effectiveness are addressed. The need for development of diagnostic tools, techniques, and countermeasure devices, food preparation, preservation technologies and medication, as well as an infrastructure to support these operations are stressed. Selected countermeasure options, including artificial gravity and pharmacological countermeasures need to be systematically evaluated and validated in flight, especially after long-duration exposures. Data need to be collected regarding the emerging field of suborbital and orbital civilian space travel, to allow for sound risk assessment.