OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Combat Casualty Care OBJECTIVE: Develop and demonstrate 3D printed synthetic soft tissue for military medical training which improve training logistics, anatomical and physiological accuracy, and enable printing of pathologies or patient-specific tissues. DESCRIPTION: Healthcare simulation is used in the military to enable realistic training and improve readiness for the medical force. Psychomotor skills associated with medical care are practiced using simulation technology, in particular medical manikins, and part-task trainers. For point of injury care, these skills include tourniquet application, airway management, needle decompression of the chest, and more. For prolonged care or surgical combat casualty care, these skills extend to fasciotomy, chest tube insertion, and more. Pairing simulation technology with educational principles like deliberate practice has shown improvement in knowledge and skills for medical providers. Further, simulation-based training provides a risk-free platform to repeat skills until proficiency is reached. However, repetition has an associated cost, in terms of both time and resources. Specifically, many simulators have consumable pieces which are replaced after a procedure is complete, such as skin or muscle patches. Traditionally, these consumable components are cast using a latex or silicone mold by a manufacturer; these are ordered by end users and shipped. For simulation centers with multiple simulation technologies, this requires ordering consumables from various vendors, tracking inventory for multiple procedures, and storing simulation components often requiring climate control. To alleviate this issue, 3D printing can be utilized to print consumables at the point of demand. 3D printing can enable the user to print consumables as needed, based on student throughput and specific training objectives. Further, 3D printed tissue can be created with improved tissue characteristics, enabling higher fidelity training. Finally, 3D printing allows for the printing of specific pathologies or patient-specific components, providing a new capability which molding cannot support. 3D printing soft materials can enable printing based on injuries seen in a particular operating environment, providing training that is tailored to a unit's needs. In the civilian sector, this would enable printing of patient-specific components, enabling realistic surgical rehearsal. Desired characteristics of the capability are listed below: Printing in variable geometries (flat plane, concave / convex surfaces) to enable consumables for a variety of anatomical regions. Printed material shall have material properties consistent with human tissue in terms of tensile strength, puncture strength, etc. Printed material shall have sufficient fidelity in terms of appearance and texture to provide realistic training. Printed material shall be capable of exhibiting anisotropy similar to human tissue. Printing materials shall be shelf stable and non-toxic, ideally not requiring a venting hood or specialized mixing equipment. Ability to print or embed sensors and other components into the printed product. Ability of the system to process medical imaging (MRI, CT, OCT, etc.) to generate material properties for printing. Ability to print the consumables at the point of demand with a non-technical user Low-cost and/or self-healing materials to enable task repetition during training. PHASE I: The initial phase should develop and demonstrate a capability for 3D printing soft tissue simulants. The effort should identify the appropriate materials and printing technologies and develop an initial design for printing technology. The specifics of printer design for soft materials must be identified, including modifications necessary to software to ensure print path, cure time, and variable geometry are feasible. The offeror should define the proposed concept and develop key component technological milestones. The required Phase I deliverables will include: 3D printed soft tissue components for at least one anatomical regions / structures (eg: arm skin or chest muscle). Overall system design documentation. Demonstration of printing technologies. The printed tissue component must demonstrate sufficient fidelity for training, as well as tissue properties similar to live human tissue. PHASE II: Phase II of this effort shall develop and demonstrate a capability to 3D print a variety of soft tissue simulants. Using results from Phase I, the offeror shall mature and further develop the 3D printing capability. The ultimate goal should be to enable training centers and hospitals to print simulated tissues at the point of need. As such, materials and printing capability should be matured with a focus on cost and ease of use, in addition to technical metrics associated with printing capability and tissue characteristics. Required Phase II deliverables will include: Validation of 3D printed materials compared with human tissue properties. Testing of 3D printed consumables as a training aid in a military medical training environment. Demonstration of the software path from (1) medical imaging data to (2) 3D computer model with tissue property metadata to (3) 3D printed component. Demonstration of the printing capability at the point of need usable by non-technical personnel Demonstration should encompass full printing process including material preparation, software operation, and hardware operation. Materials should be usable without any hood or specialized lab equipment (i.e. centrifuge). Printing hardware should be sufficiently hardened for use in a fixed training facility. Printed sensors embedded into printed tissue components. Multiple printed components showing variable geometries, tissue regions, and tissue properties. Finalized material components for printing. Finalized design of printing technologies. PHASE III DUAL USE APPLICATIONS: Follow-on activities are expected to include product maturation and commercialization of the printing capability. Anticipated transition targets include the Army's Medical Simulation Training Center (MSTC) Program, the Air Force Medical Modeling and Simulation program, and the Navy Medical Modeling and Simulation program. Additionally, military hospital simulation centers and standalone training sites are within the expected military market. Additionally, the ability for shipboard utilization or a fully portable system is also a potential transition avenue. In order to do this, both the materials and printer must be sufficiently mature (TRL 7+) for use by instructors, simulation operators, or other end users. Further, the cost of the printer and materials must be reasonable compared to current molding methods, while maintaining the significant benefit of flexibility inherent from 3D printing. Beyond the military, commercialization is expected to target civilian hospitals, residency training programs, and health profession training facilities. Any teaching institution or medical treatment facility that conducts training serves as a potential market. The offeror shall focus on transitioning the technology from research to operational capability and shall demonstrate the system for use in a broad range of military and civilian medical training applications. The offeror shall also pursue transitioning of the capability for use related to larger mannequin platforms, including currently commercially available medical mannequins and emerging research platforms. Beyond training, it is expected that 3D printing soft tissue simulants also enables improved surgical planning as well as patient education, which are alternative use cases that should be explored during a Phase III. REFERENCES: 1. Zhou, Lu Yu, Jianzhong Fu, and Yong He. "A review of 3D printing technologies for soft polymer materials." Advanced Functional Materials 30.28 (2020): 2000187. https://doi.org/10.1002/adfm.202000187 2. Garcia, Justine, et al. "3D printing materials and their use in medical education: a review of current technology and trends for the future." BMJ simulation & technology enhanced learning 4.1 (2018): 27. https://doi.org/10.1136%2Fbmjstel-2017-000234 3. Leitch, R. A., Moses, G. R., & Magee, H. (2002). Simulation and the future of military medicine. Military medicine, 167(4), 350-354. https://doi.org/10.1093/milmed/167.4.350 KEYWORDS: 3D Printing, simulation, training, consumable, additive manufacturing, medical imaging, healthcare, manikin, mannequin
