A preliminary investigation into the development of 3-D printing of prosthetic sockets

A qualitative study exploring healthcare professionals' perceptions of lower limb 3D printed sockets

PURPOSE

The purpose of this study was to explore healthcare professionals' (HCPs) perceptions and experiences related to 3D scanning and 3D printing for fabricating lower limb prosthetic sockets.

MATERIALS AND METHODS

This study used a qualitative descriptive approach. Participants were recruited through HCPs' professional associations, social media posts, and snowball sampling. Purposive sampling was used to attain variation in provider type. One-on-one telephone interviews were conducted using a semi-structured interview guide. Inductive thematic analysis was performed to identify the main themes.

RESULTS

Three themes were identified: (1) 3D scanning of the residual limb for designing prosthetic sockets is perceived as clean, quick, and convenient; (2) concerns about the strength and safety of 3D printed sockets for long-term use; (3) Adoption of 3D scanning and 3D printing technology for fabricating prosthetic sockets.

CONCLUSION

We identified perceived benefits and challenges with digital technologies for fabricating prosthetic sockets. To increase adoption, more research demonstrating its efficacy compared to conventional methods, increasing 3D printing material quality, and improving software training programs are needed.Implications for Rehabilitation3D printing and 3D scanning are emerging digital technologies that can be used as alternative methods for prosthetic socket manufacturing in the field of rehabilitation.Our research identified perceived benefits of using digital technologies for fabricating prosthetics sockets (3D scanning is perceived as clean, quick, and convenient) and perceived challenges (concerns about the strength and safety of 3D printed sockets for long-term use and a prolonged learning curve).To increase adoption of these digital technologies, more training should be provided to prosthetists and support provided to integrate new processes into staff workloads.

A Data-Driven Design Framework for Structural Optimization to Enhance Wearing Adaptability of Prosthetic Hands

Prosthetic hands have significant potential to restore the manipulative capabilities and self-confidence of amputees and enhance their quality of life. However, incompatibility between prosthetic devices and residual limbs can lead to secondary injuries such as skin pressure ulcers and restricted joint motion, contributing to a high prosthesis abandonment rate. To address these challenges, this study introduces a data-driven design framework (D3Frame) utilizing a multi-index optimization method. By incorporating motion/ pressure data, as well as clinical criteria such as pain threshold/ tolerance, from various anatomical sites on the residual limbs of amputees, this framework aims to optimize the structural design of the prosthetic socket, including the Antecubital Channel (AC), Lateral Epicondylar Region Contour (LC), Medial Epicondylar Region Contour (MC), Olecranon Region Contour (OC), Lateral Flexor/ Extensor Region (LR), and Medial Flexor/ Extensor Region (MR). Experiments on five forearm amputees verified the improved adaptability of the optimized socket compared to traditional sockets under three load conditions. The experimental results revealed a modest score enhancement on standard clinical scales and reduced muscle fatigue levels. Specifically, the percent effort of muscles and slope value of mean/ median frequency decreased by 19%, 70%, and 99% on average, respectively, and the average values of mean/ median frequency in the motion cycle both increased by approximately 5%. The proposed D3Frame in this study was applied to optimize the structural aspects of designated regions of the prosthetic socket, offering the potential to aid prosthetists in prosthesis design and, consequently, augmenting the adaptability of prosthetic devices.

Preliminary characterization of rectification for transradial prosthetic sockets

Achieving proper socket fit is crucial for the effective use of a prosthesis. However, digital socket design lacks standardization and presents a steep learning curve for prosthetists. While research has focused on digital socket design for the lower-limb population, there is a research gap in upper-limb socket design. This study aimed to characterize the design (rectification) process for the transradial socket, specifically the three-quarter Northwestern-style design, towards the development of a more systematic, data-driven socket design approach. Fourteen (n = 14) pairs of unrectified and rectified plaster models were compared. Six common rectification zones were identified through shape analysis, with zones of plaster addition being the most prominent in terms of volume and surface area. A novel 3D vector mapping technique was employed, which revealed that most of the shape changes occurred in the anterior-posterior and proximal-distal directions. Overall, the interquartile range of each rectification zone demonstrated reasonable consistency in terms of volume, surface deviation, and 3D vector representation. The initial findings from this study support the potential for quantitively modelling the transradial socket design process. This opens the door for developing tools for categorizing and predicting socket designs across diverse populations through the application of techniques such as machine learning.

User perspectives of digital manufacturing for lower-limb prosthetic sockets

BACKGROUND

There is growing interest to use digital technology (DT) for manufacturing lower-limb prosthetic sockets to improve efficiency and clinical outcomes. However, little is known about how lower-limb prosthesis users perceive DTs, such as 3D scanning and 3D printing.

OBJECTIVES

This study aimed to provide an understanding of perceptions and experiences with DT for prosthetic socket manufacturing from the perspective of prosthesis users.

STUDY DESIGN

A qualitative descriptive research study.

METHODS

Nine lower-limb prosthesis users (mean age 56; 5 female; 4 male) participated in one-on-one semistructured telephone interviews. Inductive thematic analysis was performed to identify a codebook and emerging themes from the interview transcripts.

RESULTS

Two major themes were identified: (1) expectations and prioritization of 3D printed socket usability and (2) facilitators and barriers to uptake of DT among patients.

CONCLUSION

DT methods were found to be acceptable and feasible from a patient perspective, although technological advancements are still required, and real-time communication about the process may be vital for ensuring patient engagement. Consideration of these findings may improve patient satisfaction to emerging prosthesis treatment plans and ultimately support widespread adoption of DT as an additional tool for fabricating prosthetic sockets.

Challenges of Integrating New Technologies for Orthopedic Doctors to Face up to Difficulties during the Pandemic Era

In the field of orthopedics, competitive progress is growing faster because new technologies used to facilitate the work of physicians are continuously developing. Based on the issues generated in the pandemic era in this field, a research study was developed to identify the intention of orthopedic doctors to integrate new medical technologies. The survey was based on a questionnaire that was used for data collection. The quantitative study registered a sample of 145 orthopedic doctors. The data analysis was performed based on the IBM SPSS program. A multiple linear regression model was applied, which analyzed how the independent variables can influence the dependent variables. After analyzing the data, it was observed that the intention of orthopedic doctors to use new medical technologies is influenced by the advantages and disadvantages perceived by them, the perceived risks, the quality of the medical technologies, the experience of physicians in their use, and their receptivity to other digital tools. The obtained results are highly important both for hospital managers and authorities, illustrating the main factors that influence doctors to use emergent technologies in their clinical work.

Numerical Analysis of a Transtibial Prosthesis Socket Using 3D-Printed Bio-Based PLA

Lower-limb prosthesis design and manufacturing still rely mostly on the workshop process of trial-and-error using expensive unrecyclable composite materials, resulting in time-consuming, material-wasting, and, ultimately, expensive prostheses. Therefore, we investigated the possibility of utilizing Fused Deposition Modeling 3D-printing technology with inexpensive bio-based and bio-degradable Polylactic Acid (PLA) material for prosthesis socket development and manufacturing. The safety and stability of the proposed 3D-printed PLA socket were analyzed using a recently developed generic transtibial numeric model, with boundary conditions of donning and newly developed realistic gait cycle phases of a heel strike and forefoot loading according to ISO 10328. The material properties of the 3D-printed PLA were determined using uniaxial tensile and compression tests on transverse and longitudinal samples. Numerical simulations with all boundary conditions were performed for the 3D-printed PLA and traditional polystyrene check and definitive composite socket. The results showed that the 3D-printed PLA socket withstands the occurring von-Mises stresses of 5.4 MPa and 10.8 MPa under heel strike and push-off gait conditions, respectively. Furthermore, the maximum deformations observed in the 3D-printed PLA socket of 0.74 mm and 2.66 mm were similar to the check socket deformations of 0.67 mm and 2.52 mm during heel strike and push-off, respectively, hence providing the same stability for the amputees. We have shown that an inexpensive, bio-based, and bio-degradable PLA material can be considered for manufacturing the lower-limb prosthesis, resulting in an environmentally friendly and inexpensive solution.

Evolving 3D-Printing Strategies for Structural and Cosmetic Components in Upper Limb Prosthesis

The evolution of prosthetic limbs continues to develop, with novel manufacturing techniques being evaluated, including additive manufacturing. Additive manufacturing (AM), or 3D-printing, holds promise for enabling personalized and tailored medical device options. The requirements for personalized medicine, coupled with the limitations of small-batch manufacturing, have made the technique viable for exploration. In this manuscript, an approach is presented for incorporating additive manufacturing for prostheses, both as a final part and in applications as an intermediate manufacturing step. As a result, through the use of these methods a multi-gesture capable electromyographic prosthesis was designed and manufactured, currently being evaluated in clinical trials for pediatric patients. This paper explored the results of this unique method of applying additive manufacturing techniques, and assessed how the blend of different manufacturing techniques improved performance and reduced device weight. Creating unique and aesthetic cosmetic coverings for the device was achieved through using additive manufacturing as an intermediate manufacturing component and, then, applying thermoforming. Cosmesis components saw a 33% reduction in weight from this change in manufacturing. The approach is explored to blend multiple manufacturing techniques to create cosmesis components and structural components for the prosthesis. The techniques serve the design intent to reduce reported challenges with upper limb prosthesis devices and to encourage device retention. Recommendations for manufacturing strategies are discussed, including the limitations.

Constitutive parameter identification of transtibial residual limb soft tissue using ultrasound indentation and shear wave elastography

Finite element analysis (FEA) can be used to evaluate applied interface pressures and internal tissue strains for computational prosthetic socket design. This type of framework requires realistic patient-specific limb geometry and constitutive properties. In recent studies, indentations and inverse FEA with MRI-derived 3D patient geometries were used for constitutive parameter identification. However, long computational times and use of specialized equipment presents challenges for clinical, deployment. In this study, we present a novel approach for constitutive parameter identification using a combination of FEA, ultrasound indentation, and shear wave elastography. Local shear modulus measurement using elastography during an ultrasound indentation experiment has particular significance for biomechanical modeling of the residual limb since there are known regional dependencies of soft tissue properties such as varying levels of scarring and atrophy. Beyond prosthesis design, this work has broader implications to the fields of muscle health and monitoring of disease progression.

A qualitative study on stakeholder perceptions of digital prosthetic socket fabrication for transtibial amputations

BACKGROUND

Digital residual limb shape capture (three-dimensional [3D] scanning), computer-assisted design (CAD), and computer-assisted manufacturing with 3D printing technology show promise for a completely digital process of fabricating prosthetic sockets for patients with limb loss. The effectiveness and quality of digitally designed 3D-printed lower extremity prosthetic sockets is understudied, and there is lack of data on the patient and prosthetist experiences with this digital workflow.

OBJECTIVE

To obtain stakeholder feedback on the feasibility and acceptability of using a completely digital prosthetic fabrication process consisting of 3D scanning, CAD, and 3D printing in a rehabilitation setting for adults with transtibial limb amputations.

STUDY DESIGN

Qualitative design.

METHODS

Study participants with a transtibial-level amputation were fit with a prosthetic socket fabricated using digital shape capture with a 3D scanner, CAD, and 3D printing in addition to a traditionally handcasted manually fabricated socket. Participants tried on and evaluated both sockets. Semistructured interviews took place after the fitting appointments. A focus group was conducted with prosthetists to obtain their feedback. Audio data were transcribed verbatim, and an inductive content analysis was undertaken.

RESULTS

Eleven patient participants and 3 prosthetists identified 4 main themes: 1) openness and enthusiasm for digital prosthetic fabrication; 2) relative advantages of digital fabrication vs. traditional socket fabrication; 3) readiness of the technology used for adoption in practice; and 4) digital prosthetic workflow and 3D printing implementation considerations.

CONCLUSIONS

Patients and prosthetists were enthusiastic about digital prosthetic socket fabrication and saw potential advantages over traditional methods. Both patients and prosthetists had concerns about the durability, safety, and aesthetics of the 3D printed sockets in this study. Further studies are needed to optimize digital prosthetic fabrication with 3D printing in prosthetic practice.

Anatomical Engineering and 3D Printing for Surgery and Medical Devices: International Review and Future Exponential Innovations

Three-dimensional printing (3DP) has recently gained importance in the medical industry, especially in surgical specialties. It uses different techniques and materials based on patients' needs, which allows bioprofessionals to design and develop unique pieces using medical imaging provided by computed tomography (CT) and magnetic resonance imaging (MRI). Therefore, the Department of Biology and Medicine and the Department of Physics and Engineering, at the Bioastronautics and Space Mechatronics Research Group, have managed and supervised an international cooperation study, in order to present a general review of the innovative surgical applications, focused on anatomical systems, such as the nervous and craniofacial system, cardiovascular system, digestive system, genitourinary system, and musculoskeletal system. Finally, the integration with augmented, mixed, virtual reality is analyzed to show the advantages of personalized treatments, taking into account the improvements for preoperative, intraoperative planning, and medical training. Also, this article explores the creation of devices and tools for space surgery to get better outcomes under changing gravity conditions.

The Impact of Limited Prosthetic Socket Documentation: A Researcher Perspective

The majority of limb prostheses are socket mounted. For these devices, the socket is essential for adequate prosthetic suspension, comfort, and control. The socket is unique among prosthetic components as it is not usually mass-produced and must instead be custom-made for individual residual limbs by a prosthetist. The knowledge of what constitutes "good" socket fit is gained by expert prosthetists and technicians over years of experience, and rarely documented. The reliance on tacit knowledge makes it difficult to standardize the criteria for a well-fitting socket, leading to difficulties understanding the impact of socket fit. Despite its importance, the workflow for socket fitting is often overlooked in literature. Due to the customized nature of sockets, if information is provided in literature, generally only the type of socket and suspension mechanism is noted, with information regarding the fitting and manufacturing processes omitted. In this article, the concerns, issues and consequences arising from lack of upper and lower limb socket documentation are discussed from a researcher perspective, supported by healthcare professionals and socket fabrication specialists. Key changes are proposed to the way socket manufacturing and evaluation are documented to assist future research.

Strength testing of low-cost 3D-printed transtibial prosthetic socket

Measurement and production of traditional prosthetic sockets are time-consuming, labor-intensive, and highly dependent on the personnel involved. An alternative way to make prostheses is using computer-aided design (CAD) and computer-aided manufacturing (CAM). Fused Filament Fabrication (FFF) may be an alternative to make low-cost prosthetic sockets. This study investigates the tensile properties of potential printing materials suitable for FFF according to ISO527 (Standard Test Method for Tensile Properties of Plastics). To ensure that FFF-printed sockets are safe for patient usage, the structural integrity of the 3D-printed prosthesis will be investigated according to ISO10328 (International Standard Structural Testing of Lower Limb Prostheses). Tough PLA was the most suitable print material according to ISO 527 testing. The Tough PLA printed socket completed 2.27 million cycles and a static test target value of 4025 N. Future research remains necessary to continue testing new potential materials, improve print settings, and improve the socket design for the production of FFF-printed transtibial prosthetic sockets. FFF using Tough PLA can be used to create transtibial prostheses that almost comply with the International Standard for Structural Testing of Lower Limb Prostheses.

Additive manufacturing technology of polymeric materials for customized products: recent developments and future prospective

The worldwide demand for additive manufacturing (AM) is increasing due to its ability to produce more challenging customized objects based on the process parameters for engineering applications. The processing of conventional materials by AM processes is a critically demanded research stream, which has generated a path-breaking scenario in the rapid manufacturing and upcycling of plastics. The exponential growth of AM in the worldwide polymer market is expected to exceed 20 billion US dollars by 2021 in areas of automotive, medical, aerospace, energy and customized consumer products. The development of functional polymers and composites by 3D printing-based technologies has been explored significantly due to its cost-effective, easier integration into customized geometries, higher efficacy, higher precision, freedom of material utilization as compared to traditional injection molding, and thermoforming techniques. Since polymers are the most explored class of materials in AM to overcome the limitations, this review describes the latest research conducted on petroleum-based polymers and their composites using various AM techniques such as fused filament fabrication (FFF), selective laser sintering (SLS), and stereolithography (SLA) related to 3D printing in engineering applications such as biomedical, automotive, aerospace and electronics.

Digital healthcare technologies: Modern tools to transform prosthetic care

INTRODUCTION

Digital healthcare technologies are transforming the face of prosthetic care. Millions of people with limb loss around the world do not have access to any form of rehabilitative healthcare. However, digital technologies provide a promising solution to augment the range and efficiency of prosthetists.

AREAS COVERED

The goal of this review is to introduce the digital technologies that have the potential to change clinical methods in prosthetic healthcare. Our target audience are researchers who are unfamiliar with the field of prostheses in general, especially with the newest technological developments. This review addresses technologies for: scanning of amputated limbs, limb-to-socket rectification, additive manufacturing of prosthetic sockets, and quantifying patient response to wearing sockets. This review does not address biomechatronic prostheses or biomechanical design practices.

EXPERT OPINION

Digital technologies will enable affordable prostheses to be built on a scale larger than with today's clinical practices. Large technological gaps need to be overcome to enable the mass production and distribution of prostheses digitally. However, recent advances in computational methods and CAD/CAM technologies are bridging this gap faster than ever before. We foresee that these technologies will return mobility and economic opportunity to amputees on a global scale in the near future.

A review of history of CAD/CAM system application in the productionof transtibial prosthetic socket in developing countries (from 1980to 2019)

The development of the CAD/CAM (Computer-aided design and computer-aided manufacturing) system has globally changed the fabrication and delivery of prosthetics and orthotics. Furthermore, since the introduction of CAD/CAM in the 1980s, many successful CAD/CAM system are available in the market today. However, less than 20% of amputees have access to digital fabrication technology and large portion of the amputees are from the developing countries. This review designed to examine selected studies from 1980 to 2019 on CAD/CAM systems in the production of transtibial prosthetic sockets. A review was conducted based on articles gathered from Web of Science, Pubmed and Science Direct. From the findings, 92 articles found related to CAD/CAM-derived transtibial prosthetic socket (TPS). After a further screening of the articles, 20 studies were chosen and only one study was done in a developing country. The results showed an increase interest in CAD/CAM application in Transtibial prosthetic socket (TPS) production for both developed and developing countries, yet the technology has not fully utilised in the developing countries. Factors such as resources, accessibility, knowledge-gap and lack of experienced prosthetists remain the major causes of the lack of CAD/CAM system studies. Large-scale trials are required to employ digital fabrication in the developing regions, consequently advancing the production of high-quality CAD-CAM-derived TPS where most prosthetic and orthotics are needed.

THREE-DIMENSIONAL PRINTING IN ORTHOPEDICS: WHERE WE STAND AND WHERE WE ARE HEADING

Three-dimensional printing is a technology in expansion in the medical field. It also presents many applications in orthopedics. Our review article aims to describe 3D printing, types of 3D printers, and its use in the orthopedic field. 3D models can be created using tomography scans. Those models can then be manipulated, even simulating surgeries. It is possible to print biomodels, which will help us understand deformities and plan surgeries. Orthopedic surgeons must be updated in these disruptive technologies that may help their daily practice. Level of Evidence V, Expert opinion.

Polymers, plastics, & more – educating post-secondary students from different disciplines with polymer science

Polymers are excellent materials that provide concrete examples of concepts and learning objectives covered in different post-secondary level courses. Modules focused on polymer science can be used for teaching general, organic, material and green chemistry. These modules can be tailored to build on the students' prerequisite knowledge. Science 300 is a course offered at Simon Fraser University (SFU) to non-science, post-secondary students focused on the impact of science in society. Prosthetics and Orthotics (PROR) is a diploma program offered at the British Columbia Institute of Technology (BCIT). Both programs have incorporated polymer science as part of the curriculum. Design of the modules illustrates polymers as an important class of materials that possess both beneficial and environmental unfriendly properties. A variety of learning strategies are incorporated within the courses to aid students with understanding polymer science.

Application Experience and Patient Feedback Analysis of 3D Printed AFO with Different Materials: A Random Crossover Study

PURPOSE

This study is aimed at analyzing the application experience and feedback of the patients with poststroke ankle dorsiflexion disorders for 3D printed AFO with three different materials.

METHODS

15 patients were randomly divided into three groups; 3D printed AFO with 3 different materials (PA2200, Somos NeXt, and PA12) was used to each group, according to the crossover study design, in order to ask the three groups of patients to use three different materials of 3D printed AFO. Assessment was taken by the end of each test round. Through statistical processing, the patient feedback data of the three groups of materials of 3D printed AFO were obtained.

RESULTS

In the material comfort assessment of the AFO, Somos NeXt was compared with PA2200, and the p value was <0.05; in the item of surface smoothness of the AFO, Somos NeXt was compared with PA2200, and the p value was <0.01; at the same time, PA12 was compared with PA2200, and the p value was <0.05.

CONCLUSION

The 3 different materials of 3D printing AFO bring different experience, and we also have sufficient reason to believe that there will be differences in the auxiliary effect of this on patients, which leads the patient's selection too. The material Somos NeXt is much popular and has certain clinical advantages.

3D-Printing and Upper-Limb Prosthetic Sockets: Promises and Pitfalls

Modernising the way upper-limb prosthetic sockets are made has seen limited progress. The casting techniques that are employed in clinics today resemble those developed over 50 years ago and there is still a heavy reliance on manual labour. Modern manufacturing methods such as 3D scanning and printing are often presented as ready-to-use solutions for producing low-cost functional devices, with public perceptions being largely shaped by the superficial media representation and advertising. The promise is that modern socket manufacturing methods can improve patient satisfaction, decrease manufacturing times and reduce the workload in the clinic. However, the perception in the clinical community is that total conversion to digital methods in a clinical environment is not straightforward. Anecdotally, there is currently a disconnect between those developing technology to produce prosthetic devices and the actual needs of clinicians and people with limb difference. In this paper, we demonstrate strengths and drawbacks of a fully digitised, low-cost trans-radial diagnostic socket making process, informed by clinical principles. We present volunteer feedback on the digitally created sockets and provide expert commentary on the use of digital tools in upper-limb socket manufacturing. We show that it is possible to utilise 3D scanning and printing, but only if the process is informed by expert knowledge. We bring examples to demonstrate how and why the process may go wrong. Finally, we provide discussion on why progress in modernising the manufacturing of upper-limb sockets has been slow yet it is still too early to rule out digital methods.

Three-Dimensional Printing in Orthopedics: from the Basics to Surgical Applications

PURPOSE OF REVIEW

Additive manufacturing (AM) is a rapidly evolving field traditionally utilized in non-medical industries. Recently, the medical use of AM is expanding, especially in orthopedics. The goal of this article is presenting the principles of AM and its main applications in orthopedics.

RECENT FINDINGS

The main indications for AM in orthopedics are education, orthotics, surgical planning, surgical guides, and custom-made implants. Three-dimensional (3D) digital models can be obtained from tomographic scans using available free software. Then, it can be used to create a physical model, plan surgeries, or develop surgical guides which can aid the orthopedic surgeon during complex cases. Recent studies demonstrated the benefits of using printed models in educating patients and medical residents. Custom-made implants also have been evaluated with promising clinical outcomes. Using 3D technology has become a reality in orthopedics. Surgeons should expect exponential growth of its applications in the upcoming years. It is paramount that orthopedists get familiar with this disruptive technology.

Additive Manufacturing Processes in Medical Applications

Additive manufacturing (AM, 3D printing) is used in many fields and different industries. In the medical and dental field, every patient is unique and, therefore, AM has significant potential in personalized and customized solutions. This review explores what additive manufacturing processes and materials are utilized in medical and dental applications, especially focusing on processes that are less commonly used. The processes are categorized in ISO/ASTM process classes: powder bed fusion, material extrusion, VAT photopolymerization, material jetting, binder jetting, sheet lamination and directed energy deposition combined with classification of medical applications of AM. Based on the findings, it seems that directed energy deposition is utilized rarely only in implants and sheet lamination rarely for medical models or phantoms. Powder bed fusion, material extrusion and VAT photopolymerization are utilized in all categories. Material jetting is not used for implants and biomanufacturing, and binder jetting is not utilized for tools, instruments and parts for medical devices. The most common materials are thermoplastics, photopolymers and metals such as titanium alloys. If standard terminology of AM would be followed, this would allow a more systematic review of the utilization of different AM processes. Current development in binder jetting would allow more possibilities in the future.

A personalised prosthetic liner with embedded sensor technology: a case study

BACKGROUND

Numerous sensing techniques have been investigated in an effort to monitor the main parameters influencing the residual limb/prosthesis interface, fundamental to the optimum design of prosthetic socket solutions. Sensing integration within sockets is notoriously complex and can cause user discomfort. A personalised prosthetic liner with embedded sensors could offer a solution. However, to allow for a functional and comfortable instrumented liner, highly customised designs are needed. The aim of this paper is to presents a novel approach to manufacture fully personalised liners using scanned three-dimensional image data of the patient's residual limb, combined with designs that allow for sensor integration. To demonstrate the feasibility of the proposed approach, a personalised liner with embedded temperature and humidity sensors was realised and tested on a transtibial amputee, presented here as a case study.

METHODS

The residual limb of a below knee amputee was first scanned and a three-dimensional digital image created. The output was used to produce a personalised prosthesis. The liner was manufactured using a cryogenic Computer Numeric Control (CNC) machining approach. This method enables fast, direct and precise manufacture of soft elastomer products. Twelve Hygrochron Data Loggers, able to measure both temperature and humidity, were embedded in specific liner locations, ensuring direct sensor-skin contact. The sensor locations were machined directly into the liner, during the manufacturing process. The sensors outputs were assessed on the below amputee who took part in the study, during resting (50 min) and walking activities (30 min). To better describe the relative thermal properties of new liner, the same tests were repeated with the amputee wearing his existing liner. Quantitative comparisons of the thermal properties of the new liner solution with that currently used in clinical practice are, therefore, reported.

RESULTS

The liner machining process took approximately 4 h. Fifteen minutes after donning the prosthesis, the skin temperature reached a plateau. Physical activity rapidly increased residuum skin temperatures, while cessation of activity caused a moderate decrease. Humidity increased throughout the observation period. In addition, the new liner showed better thermal properties with respect to the current liner solution (4% reduction in skin temperature).

CONCLUSIONS

This work describes a personalised liner solution, with embedded temperature and humidity sensors, developed through an innovative approach. This new method allows for a range of sensors to be smoothly embedded into a liner, which is capable of measuring changes in intra-socket microclimate conditions, resulting in the design of advanced socket solutions personalised specifically for individual requirements. In future, this method will not only provide a personalised liner but will also enable dynamic assessment of how a residual limb behaves within the socket during daily activities.

Additive Manufacturing of Prostheses Using Forest-Based Composites

A custom-made prosthetic product is unique for each patient. Fossil-based thermoplastics are the dominant raw materials in both prosthetic and industrial applications; there is a general demand for reducing their use and replacing them with renewable, biobased materials. A transtibial prosthesis sets strict demands on mechanical strength, durability, reliability, etc., which depend on the biocomposite used and also the additive manufacturing (AM) process. The aim of this project was to develop systematic solutions for prosthetic products and services by combining biocomposites using forestry-based derivatives with AM techniques. Composite materials made of polypropylene (PP) reinforced with microfibrillated cellulose (MFC) were developed. The MFC contents (20, 30 and 40 wt%) were uniformly dispersed in the polymer PP matrix, and the MFC addition significantly enhanced the mechanical performance of the materials. With 30 wt% MFC, the tensile strength and Young´s modulus was about twice that of the PP when injection molding was performed. The composite material was successfully applied with an AM process, i.e., fused deposition modeling (FDM), and a transtibial prosthesis was created based on the end-user’s data. A clinical trial of the prosthesis was conducted with successful outcomes in terms of wearing experience, appearance (color), and acceptance towards the materials and the technique. Given the layer-by-layer nature of AM processes, structural and process optimizations are needed to maximize the reinforcement effects of MFC to eliminate variations in the binding area between adjacent layers and to improve the adhesion between layers.

Using mechanical testing to assess the effect of lower-limb prosthetic socket texturing on longitudinal suspension

To function effectively, a lower limb prosthetic socket must remain securely coupled to the residual limb during walking, running and other activities of daily living; this coupling is referred to as suspension. When this coupling is insufficient longitudinal pistoning of the socket relative to the residual limb occurs. Increasing friction of the socket/liner interface may improve socket suspension and textured sockets may be fabricated relatively easily with 3D printing. The aim of this study was to investigate longitudinal displacement of sockets with different types of textures under two suspension conditions: passive suction and active vacuum. In order to do this, we developed a mock residual limb and mechanical testing protocol. Prosthetic sockets, 14 textured sockets and an Original Squirt-Shape (OSS) Socket, were fabricated from polypropylene copolymer using the Squirt-Shape^™ 3D Printer and compared to a smooth socket thermoformed from polypropylene copolymer. Sockets were mounted onto a dual durometer mock residual limb and subjected to four levels of distraction forces (100 N, 250 N, 500 N and 650 N) using a hydraulic material testing system. There was a statistically significant three-way interaction between suspension, force level and texture (p < 0.0005). Longitudinal displacements between textured and reference sockets, for all force levels and both suspension conditions, were significantly different (p < 0.0005). Using these newly developed mechanical testing protocols, it was demonstrated that texturing of polypropylene copolymer sockets fabricated using Squirt-Shape significantly decreased longitudinal displacements compared to a smooth socket. However, none of the novel textured sockets significantly reduced longitudinal displacement compared to the OSS socket under passive suction suspension.

3D Printing Technologies: Recent Development and Emerging Applications in Various Drug Delivery Systems

The 3D printing is considered as an emerging digitized technology that could act as a key driving factor for the future advancement and precise manufacturing of personalized dosage forms, regenerative medicine, prosthesis and implantable medical devices. Tailoring the size, shape and drug release profile from various drug delivery systems can be beneficial for special populations such as paediatrics, pregnant women and geriatrics with unique or changing medical needs. This review summarizes various types of 3D printing technologies with advantages and limitations particularly in the area of pharmaceutical research. The applications of 3D printing in tablets, films, liquids, gastroretentive, colon, transdermal and intrauterine drug delivery systems as well as medical devices have been briefed. Due to the novelty and distinct features, 3D printing has the inherent capacity to solve many formulation and drug delivery challenges, which are frequently associated with poorly aqueous soluble drugs. Recent approval of Spritam® and publication of USFDA technical guidance on additive manufacturing related to medical devices has led to an extensive research in various field of drug delivery systems and bioengineering. The 3D printing technology could be successfully implemented from pre-clinical phase to first-in-human trials as well as on-site production of customized formulation at the point of care having excellent dose flexibility. Advent of innovative 3D printing machineries with built-in flexibility and quality with the introduction of new regulatory guidelines would rapidly integrate and revolutionize conventional pharmaceutical manufacturing sector.

3-D printed spectacles: potential, challenges and the future

Three-dimensional (3-D) printing offers the potential to custom-produce a wide range of manufactured objects and improve manufacturing processes. The additive manufacturing process involves material (resin, metal, ceramics or biological cells) being deposited layer upon layer, which is fused to create a 3-D object. While 3-D printing has been readily available in the aerospace and automotive industries, and is being used increasingly in the medical field, its potential for optometry and ophthalmic optics has rarely been discussed in depth. 3-D printing of spectacles has the potential to provide customised experiences, to cater for those who do not fit standardised frames or for those with irregular prescriptions, and to reduce delivery times and inventory with the opportunity of increasing access to underserved populations. Here we review available 3-D printing technologies, and the current 3-D printed spectacle market, including testing three commercially available spectacle frames to assess compliance with ISO:12870 standards. The article then explores the challenges faced and environmental impact of implementing 3-D printing of spectacles.

Quantitative assessment of compress-type osseointegrated prosthetic implants in human bone using electromechanical impedance spectroscopic methods

Osseointegrated (OI) prostheses are a promising alternative to traditional socket prostheses. They can enhance the quality of life of amputees by avoiding fit and comfort issues commonly associated with sockets. The main structural element of the OI prosthesis is a biocompatible metallic implant that is surgically implanted into the bone of the residual limb. The implant is designed to provide a conducive surface for the host bone to osseointegrate with. The osseointegration process of the implant is difficult to clinically evaluate, leading to conservative postoperative rehabilitation approaches. Elastic stress waves generated in an OI prosthesis have been previously proposed to interrogate the implant-bone interface for quantitative assessment of the osseointegration process. This paper provides a detailed overview of the various elastic stress wave methods previously explored for in situ characterization of OI implants. Specifically, the paper explores the use of electromechanical impedance spectroscopy (EIS) to assess the OI process in compress-type OI prostheses. The EIS approach measures the electrical impedance spectrum of lead zirconate titanate elements bonded to the free end of the implant. The research utilizes both numerical simulation and experimental verification to establish that the electromechanical impedance spectrum is sensitive (between 400 and 460 kHz) to both the degree and location of osseointegration. A baseline-free OI index is proposed to quantify the degree of osseointegration at the implant-bone interface and to assess the stability of the OI implant for clinical decision making.

Advances in Orthotic and Prosthetic Manufacturing: A Technology Review

In this work, the recent advances for rapid prototyping in the orthoprosthetic industry are presented. Specifically, the manufacturing process of orthoprosthetic aids are analysed, as thier use is widely extended in orthopedic surgery. These devices are devoted to either correct posture or movement (orthosis) or to substitute a body segment (prosthesis) while maintaining functionality. The manufacturing process is traditionally mainly hand-crafted: The subject's morphology is taken by means of plaster molds, and the manufacture is performed individually, by adjusting the prototype over the subject. This industry has incorporated computer aided design (CAD), computed aided engineering (CAE) and computed aided manufacturing (CAM) tools; however, the true revolution is the result of the application of rapid prototyping technologies (RPT). Techniques such as fused deposition modelling (FDM), selective laser sintering (SLS), laminated object manufacturing (LOM), and 3D printing (3DP) are some examples of the available methodologies in the manufacturing industry that, step by step, are being included in the rehabilitation engineering market-an engineering field with growth and prospects in the coming years. In this work we analyse different methodologies for additive manufacturing along with the principal methods for collecting 3D body shapes and their application in the manufacturing of functional devices for rehabilitation purposes such as splints, ankle-foot orthoses, or arm prostheses.

Review of functional materials for potential use as wearable infection sensors in limb prostheses

The fundamental goal of prosthesis is to achieve optimal levels of performance and enhance the quality of life of amputees. Socket type prostheses have been widely employed despite their known drawbacks. More recently, the advent of osseointegrated prostheses have demonstrated potential to be a better alternative to socket prosthesis eliminating most of the drawbacks of the latter. However, both socket and osseointegrated limb prostheses are prone to superficial infections during use. Infection prone skin lesions from frictional rubbing of the socket against the soft tissue are a known problem of socket type prosthesis. Osseointegration, on the other hand, results in an open wound at the implant-stump interface. The integration of infection sensors in prostheses to detect and prevent infections is proposed to enhance quality of life of amputees. Pathogenic volatiles having been identified to be a potent stimulus, this paper reviews the current techniques in the field of infection sensing, specifically focusing on identifying portable and flexible sensors with potential to be integrated into prosthesis designs. Various sensor architectures including but not limited to sensors fabricated from conducting polymers, carbon polymer composites, metal oxide semiconductors, metal organic frameworks, hydrogels and synthetic oligomers are reviewed. The challenges and their potential integration pathways that can enhance the possibilities of integrating these sensors into prosthesis designs are analysed.

[Current concepts and new developments of 3D printing in trauma surgery]

The use of 3D printing (synonyms "rapid prototyping" and "additive manufacturing") has played an increasing role in the industry for many years and finds more and more interest and application in musculoskeletal surgery, especially orthopedic trauma surgery.In this article the current literature is systematically reviewed, presented and evaluated in a condensed and comprehensive way according to anatomical (upper and lower extremities) and functional aspects. As many of the publications analyzed were feasibility studies, the degree of evidence is low and methodological weaknesses are obvious and numerous; however, this pioneering work is extremely stimulating and important for further development because the technical, medical and economic potential of this technology is huge and interesting for all those involved in the treatment of musculoskeletal problems.

3D printing and amputation: a scoping review

PURPOSE

Three-dimensional (3D) printing is an innovative technology being utilized to create prostheses for individuals with limb loss. However, there is a paucity of research on the feasibility of using this technology to fabricate prostheses. A scoping review was conducted to map the literature on 3D printing and its applications in the field of amputation.

MATERIALS AND METHODS

Using a scoping review framework, a systematic literature search was conducted in three electronic databases (MEDLINE, EMBASE and CINAHL) for all indexed literature up to 29 June 2018.

RESULTS

Twenty-eight articles met the inclusion criteria. The majority of studies had small sample sizes (five participants or less; n = 20) and used a case study design (n = 17). The benefits of 3D printing technology include higher levels of customization and lower production costs. However, the functionality of 3D printed prostheses is lacking. There is also a need for more robust research designs to obtain a better understanding of the advantages and disadvantages of 3D printed prostheses and its impact on end-user outcomes.

CONCLUSIONS

The use of 3D printing technology has a number of benefits for improving the manufacturing process of devices for people with lower and upper limb loss. However, more research and technological advancements are required to fully understand the impact of this technology on patients and how it will affect their daily life. The long-term effects of this technology will also need to be investigated in order to produce a more sustainable alternative to traditional prostheses.IMPLICATIONS FOR REHABILITATIONThe use of 3D printing technology for the fabrication of prosthetics for persons with limb-loss has a number of promising features to improve the fitting and customization of these devices for this patient population.Although the costs of producing 3D printed devices is less expensive and burdensome than traditional approaches to manufacturing techniques, there is a need for additional technological advancements to improve the functionality of these devices.Future research needs to adopt more robust research designs with larger sample sizes to provide a better understanding of the viability of using 3D printing technology to improve patient outcomes.

A new methodology for design and manufacturing of a customized silicone partial foot prosthesis using indirect additive manufacturing

The production of customized prostheses for the foot and ankle still relies on slow and laborious steps of the traditional plaster molding fabrication techniques. Additive manufacturing techniques where three-dimensional objects can be constructed directly based on the object's computer-aided-design data in a layerwise manner has opened the door to new opportunities for manufacturing of novel and personalized medical devices. The purpose of the present study was to develop a new methodology for design and manufacturing of a customized silicone partial foot prosthesis via an indirect additive manufacturing process. Furthermore, the biomechanics of gait of a subject with partial foot amputation wearing the custom silicone foot prosthesis manufactured by the indirect additive manufacturing was characterized, in comparison with a matched healthy participant. This study has confirmed the possibility of producing silicone partial foot prosthesis by indirect additive manufacturing procedure. The amputated subject reported total comfort using the custom prosthesis during walking, as well as cosmetic advantages. The prosthesis restored the foot geometry and normalized many of gait characteristics. The findings presented here contribute to introduce a proper understanding of biomechanics of walking after wearing silicone partial foot prosthesis and are useful for prosthetists and rehabilitation therapists when treating patients after partial foot amputation.

3D Printing: Applications in evolution and ecology

In the commercial and medical sectors, 3D printing is delivering on its promise to enable a revolution. However, in the fields of Ecology and Evolution we are only on the brink of embracing the advantages that 3D printing can offer. Here we discuss examples where the process has enabled researchers to develop new techniques, work with novel species, and to enhance the impact of outreach activities. Our aim is to showcase the potential that 3D printing offers in terms of improved experimental techniques, greater flexibility, reduced costs and promoting open science, while also discussing its limitations. By taking a general overview of studies using the technique from fields across the broad range of Ecology and Evolution, we show the flexibility of 3D printing technology and aim to inspire the next generation of discoveries.

DEVELOPMENTS, MECHANICAL PROPERTY MEASUREMENTS AND STRENGTH EVALUATIONS OF THE WRIST BRACES FOR THE WRIST FRACTURE PATIENTS

In this paper, the wrist braces for the wrist fracture patients are developed. Geometry of the patient’s wrist surface anatomy was digitalized and recorded by an optical 3D scanner. An expert software was developed to generate the brace model, on which several holes are distributed to increase the air permeability. Finally, the brace is fabricated by commercial FDM 3D printer. For ensuring the strength of the wrist brace, the tensile test and impact test were conducted to measure the elastic modulus, yielding strength and fracture strength. A finite element model was established to investigate the stresses and deformations when the wrist brace is subjected to a static load. The mechanical properties measured in the tensile tests are as input parameters in the model. The static analysis showed that, for four considered movements of the wrist, the maximum von-Mises stress is less than the yielding strength. An impact analysis was also conducted to simulate brace impacted by a moving rigid ball with a mass of 0.3768[Formula: see text]kg. The results showed that the deformation at the impact point remains in the elastic range when the impact speed is 3[Formula: see text]m/s. The finite element calculations give us rules to design the number of holes and the thickness of the brace.

Comparative study of the circumferential and volumetric analysis between conventional casting and three-dimensional scanning methods for transtibial socket: A preliminary study

Transtibial prosthetic sockets can be fabricated either by the conventional way, which involve using plaster of Paris bandages for casting. This will include modifications through hand, scanning and digital imaging of software. The aim of this study is to determine the circumferential profiles and conduct a volumetric analysis of a conventional socket that has fabrication using biosculptor technology. In doing this, a male transtibial amputee, age 28 years old with stable health condition was studied, where circumferential measurements were taken at intervals of 1 cm from the distal end of the residual limb to the medial tibial plateau level. Furthermore, the interior volume of both sockets and residuum were determined directly using water displacement method. A comparative value for the calculation of volume was also carried out using engineering mathematical equations. From these measurements, a total surface bearing transtibial sockets was fabricated to compare the changes of circumferential values of both sockets. The finding shows a percentage of the difference between the volume of the residual limb and conventional sockets to be 6.09%, whereas the biosculptor fabrication socket was 7.84% using the water displacement method. A comparison of circumferential profiles and volumetric analysis findings on the contrary showed that socket fabricated using the biosculptor technology is interchangeable with the conventional socket with more advantages, where biosculptor technology produces cheaper sockets and faster process with digital function in the procedure, unlike the conventional manual technique.

3D Printing in Pharmaceutical and Medical Applications - Recent Achievements and Challenges

Growing demand for customized pharmaceutics and medical devices makes the impact of additive manufacturing increased rapidly in recent years. The 3D printing has become one of the most revolutionary and powerful tool serving as a technology of precise manufacturing of individually developed dosage forms, tissue engineering and disease modeling. The current achievements include multifunctional drug delivery systems with accelerated release characteristic, adjustable and personalized dosage forms, implants and phantoms corresponding to specific patient anatomy as well as cell-based materials for regenerative medicine. This review summarizes the newest achievements and challenges of additive manufacturing in the field of pharmaceutical and biomedical research that have been published since 2015. Currently developed techniques of 3D printing are briefly described while comprehensive analysis of extrusion-based methods as the most intensively investigated is provided. The issue of printlets attributes, i.e. shape and size is described with regard to personalized dosage forms and medical devices manufacturing. The undeniable benefits of 3D printing are highlighted, however a critical view resulting from the limitations and challenges of the additive manufacturing is also included. The regulatory issue is pointed as well.

3D printing and its applications in orthopaedic trauma: A technological marvel

BACKGROUND

With rapid emergence of 3D printing technology, surgeons have recently started to apply this for nearly all areas of orthopaedic trauma surgery. Computed tomography or magnetic resonance images of trauma patients can be utilized for making graspable objects from 3D reconstructed images. Patient specific anatomical models can thereby be created. They enhance surgeon's knowledge of their patients' precise patho-anatomy, regarding both traumatized bones and soft tissue as well as normal areas, and therefore help in accurate preoperative planning. 3D printed patient specific instrumentation can help to achieve precise implant placement, and better surgical results. Most importantly, customized implants, casts, orthoses and prosthetics can be manufactured to match an individual's anatomy. Three dimensional (3D) printing, also called as 'additive manufacturing' and 'rapid prototyping' is considered as the "second industrial revolution", and this appears to be especially true for orthopaedic trauma surgery.

METHODS

A literature search was performed for extracting all papers related to 3D Printing applications in orthopaedics and allied sciences on the Pubmed, and SCOPUS; using suitable key terms and Boolean operators ("3D Printing" OR "3 dimensional printing" OR "3D printed" OR "additive manufacturing" OR "rapid prototyping") AND (''Orthopaedics" OR "Orthopaedics'') AND ("Trauma" OR "Injury")in June 2018. Search was also performed in Web of Science, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews. No limits were set on the time period or evidence level, as 3D printing in orthopaedics is relatively recent and mainly low level evidence is available. Titles and abstracts were screened and all duplicate and unrelated papers were excluded. Papers related to orthopaedic trauma were manually selected for this review.

RESULTS

The search on Pubmed retrieved 144 Papers and similar search on SCOPUS retrieved 94 papers. Additional searches did not reveal more relevant papers. After excluding duplicates and unrelated papers, and on screening of titles and abstracts, 59 papers were considered for review. Papers related to spine fractures only were not included, as they have been covered in another paper in this journal issue.

CONCLUSION

All over the world, orthopaedic Surgeon's and allied professionals and scientists are enthusiastically using 3D printing technology for designing patient specific models, instrumentation, implants, orthosis and prosthesis, besides 3D bioprinting of bone and cartilage scaffolding, and the same has been applied for nearly all areas of orthopaedic trauma surgery, from head to foot.

Weld formation during material extrusion additive manufacturing

Material extrusion (ME) is a layer-by-layer additive manufacturing process that is now used in personal and commercial production where prototyping and customization are required. However, parts produced from ME frequently exhibit poor mechanical performance relative to those from traditional means; moreover, fundamental knowledge of the factors leading to development of inter-layer strength in this highly non-isothermal process is limited. In this work, we seek to understand the development of inter-layer weld strength from the perspective of polymer interdiffusion under conditions of rapidly changing mobility. Our framework centers around three interrelated components: in situ thermal measurements (via infrared imaging), temperature dependent molecular processes (via rheology), and mechanical testing (via mode III fracture). We develop the concept of an equivalent isothermal weld time and test its relationship to fracture energy. For the printing conditions studied the equivalent isothermal weld time for Tref = 230 °C ranged from 0.1 ms to 100 ms. The results of these analysis provide a basis for optimizing inter-layer strength, the limitations of the ME process, and guide development of new materials.

Evaluation of 3D printed anatomically scalable transfemoral prosthetic knee

This case study compares a transfemoral amputee's gait while using the existing Ossur Total Knee 2000 and our novel 3D printed anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee is 3D printed out of a carbon-fiber and nylon composite that has a gear-mesh coupling with a hard-stop weight-actuated locking mechanism aided by a cross-linked four-bar spring mechanism. This design can be scaled using anatomical dimensions of a human femur and tibia to have a unique fit for each user. The transfemoral amputee who was tested is high functioning and walked on the Computer Assisted Rehabilitation Environment (CAREN) at a self-selected pace. The motion capture and force data that was collected showed that there were distinct differences in the gait dynamics. The data was used to perform the Combined Gait Asymmetry Metric (CGAM), where the scores revealed that the overall asymmetry of the gait on the Ossur Total Knee was more asymmetric than the anatomically scalable transfemoral prosthetic knee. The anatomically scalable transfemoral prosthetic knee had higher peak knee flexion that caused a large step time asymmetry. This made walking on the anatomically scalable transfemoral prosthetic knee more strenuous due to the compensatory movements in adapting to the different dynamics. This can be overcome by tuning the cross-linked spring mechanism to emulate the dynamics of the subject better. The subject stated that the knee would be good for daily use and has the potential to be adapted as a running knee.

Dynamic elasticity measurement for prosthetic socket design

The paper proposes a novel apparatus to measure the dynamic elasticity of human limb in order to help the design and fabrication of the personalized prosthetic socket. To take measurements of the dynamic elasticity, the desired force generated as an exponential chirp signal in which the frequency increases and amplitude is maintained according to time progress is applied to human limb and then the skin deformation is recorded, ultimately, to obtain the frequency response of its elasticity. It is referred to as a Dynamic Elasticity Measurement Apparatus (DEMA) in the paper. It has three core components such as linear motor to provide the desired force, loadcell to implement the force feedback control, and potentiometer to record the skin deformation. After measuring the force/deformation and calculating the dynamic elasticity of the limb, it is visualized as 3D color map model of the limb so that the entire dynamic elasticity can be shown at a glance according to the locations and frequencies. For the visualization, the dynamic elasticities measured at specific locations and frequencies are embodied using the color map into 3D limb model acquired by using 3D scanner. To demonstrate the effectiveness, the visualized dynamic elasticities are suggested as outcome of the proposed system, although we do not have any opportunity to apply the proposed system to the amputees. Ultimately, it is expected that the proposed system can be utilized to design and fabricate the personalized prosthetic socket in order for releasing the wearing pain caused by the conventional prosthetic socket.

Bioengineering cardiac constructs using 3D printing

To date, 3D bioprinting has found many actual and potential applications in medicine through assembling cells, biomaterials and supporting factors into living tissues. In particular, the combination of bioprinting and tissue engineering has emerged as a new promising strategy to address the growing need for tissues and organs for both transplantation and basic research. This review summarizes the current progress in the design and printing of bioengineered cardiac tissues for various applications. We highlight the specific biological and technical complexities such as the choice of cells and biomaterials, cell viability and function, vasculature design and tissue architecture. Current challenges and future perspectives in the field of cardiovascular tissue printing are also discussed.

Using computed tomography and 3D printing to construct custom prosthetics attachments and devices

Background

The prosthetic devices the military uses to restore function and mobility to our wounded warriors are highly advanced, and in many instances not publically available. There is considerable research aimed at this population of young patients who are extremely active and desire to take part in numerous complex activities. While prosthetists design and manufacture numerous devices with standard materials and limb assemblies, patients often require individualized prosthetic design and/or modifications to enable them to participate fully in complex activities.

Methods

Prosthetists and engineers perform research and implement digitally designs in collaboration to generate equipment for their patient’s rehabilitation needs. 3D printing allows for these devices to be manufactured from an array of materials ranging from plastic to titanium alloy. Many designs require form fitting to a prosthetic socket or a complex surface geometry. Specialty items can be scanned using computed tomography and digitally reconstructed to produce a virtual 3D model the engineer can use to design the necessary features of the desired prosthetic, device, or attachment. Completed devices are tested for fit and function.

Results

Numerous custom prostheses and attachments have been successfully translated from the research domain to clinical reality, in particular, those that feature the use of computed tomography (CT) reconstructions. The purpose of this project is to describe the research pathways to implementation for the following clinical designs: sets of bilateral hockey skates; custom weightlifting prosthetic hands; and a wine glass holder.

Conclusion

This article will demonstrate how to incorporate CT imaging and 3D printing in the design and manufacturing process of custom attachments and assistive technology devices. Even though some of these prosthesis attachments may be relatively simple in design to an engineer, they have an enormous impact on the lives of our wounded warriors.

Three-dimensional bio-printing equipment technologies for tissue engineering and regenerative medicine

Three-Dimensional (3D) printing technologies have been widely used in the medical sector for the production of medical assistance equipment and surgical guides, particularly 3D bio-printing that combines 3D printing technology with biocompatible materials and cells in field of tissue engineering and regenerative medicine. These additive manufacturing technologies can make patient-made production from medical image data. Thus, the application of 3D bio-printers with biocompatible materials has been increasing. Currently, 3D bio-printing technology is in the early stages of research and development but it has great potential in the fields of tissue and organ regeneration. The present paper discusses the history and types of 3D printers, the classification of 3D bio-printers, and the technology used to manufacture artificial tissues and organs.

Three-Dimensional (3-D) Printing: A Cost-Effective Solution for Improving Global Accessibility to Prostheses

The lack of access to prostheses is a global problem, partially caused by the high cost associated with the current manufacturing process. Three-dimensional printing is gaining use in the medical field, and one such area is prosthetics. In addition to using cost-effective materials, this technology allows for rapid prototyping, making it an efficient solution for the development of affordable prostheses. If the rehabilitation medicine community embraces this novel technology, we can help alleviate the global disparity of access to prostheses.

3D printed nervous system on a chip

Bioinspired organ-level in vitro platforms are emerging as effective technologies for fundamental research, drug discovery, and personalized healthcare. In particular, models for nervous system research are especially important, due to the complexity of neurological phenomena and challenges associated with developing targeted treatment of neurological disorders. Here we introduce an additive manufacturing-based approach in the form of a bioinspired, customizable 3D printed nervous system on a chip (3DNSC) for the study of viral infection in the nervous system. Micro-extrusion 3D printing strategies enabled the assembly of biomimetic scaffold components (microchannels and compartmented chambers) for the alignment of axonal networks and spatial organization of cellular components. Physiologically relevant studies of nervous system infection using the multiscale biomimetic device demonstrated the functionality of the in vitro platform. We found that Schwann cells participate in axon-to-cell viral spread but appear refractory to infection, exhibiting a multiplicity of infection (MOI) of 1.4 genomes per cell. These results suggest that 3D printing is a valuable approach for the prototyping of a customized model nervous system on a chip technology.