Mass customization of medical devices and implants: state of the art and future directions

The medical field is one in which the need for customization can be clear cut, as providing tailored devices and implants for unique physiologies can provide for a better overall treatment than the use of ‘off the shelf’ devices and implants. Customization in the production of medical products can be roughly divided into consideration of medical devices, and of implantable parts or systems. The present paper outlines the current state of the art in both of these areas, presents details of projects that are ongoing at the University of Leeds and outlines future research directions.     

Advances in Medical Applications of Additive Manufacturing

In the past few decades, additive manufacturing (AM) has been developed and applied as a cost-effective and versatile technique for the fabrication of geometrically complex objects in the medical industry. In this review, we discuss current advances of AM in medical applications for the generation of pharmaceuticals, medical implants, and medical devices. Oral and transdermal drugs can be fabricated by a variety of AM technologies. Different types of hard and soft clinical implants have also been realized by AM, with the goal of producing tissue-engineered constructs. In addition, medical devices used for diagnostics and treatment of various pathological conditions have been developed. The growing body of research on AM reveals its great potential in medical applications. The goal of this review is to highlight the usefulness and elucidate the current limitations of AM applications in the medical field.     

Advanced biomaterials for skeletal tissue regeneration: Instructive and smart functions

The past half century has seen explosive growth in the use of medical implants. Orthopedic, cardiac, oral, maxillofacial and plastic surgeons are examples of medical specialists treating millions of patients each year by implanting devices varying from pace makers, artificial hip joints, breast and dental implants, to implantable hearing aids. All such medical implants make use of special materials, known as biomaterials, defined as “materials intended to interface with biological systems to evaluate, treat, augment or replace any tissue, organ, or function of the body” [D.F. Williams, The Williams Dictionnary of Biomaterials, Liverpool University Press, Liverpool, 1999]. While the priority for the first generation of biomaterials was inertness with living tissues, the field is shifting towards biologically active systems in order to improve their performance and to expand their use. Biomaterials can be combined as scaffolds with cells (i.e. tissue engineering), growth factors or genetic material in order to trigger tissue regeneration. In addition, recent reports have shown the possibility to design biomaterials that can activate cellular processes and tissue formation solely by their intrinsic physicochemical and three dimensional spatial properties. This article reviews the recent developments in the design of biomaterials that integrate our understanding of cellular and molecular mechanisms with materials science. After an overview of the physicochemical and biological processes occurring at the interface between the biomaterials and biological milieu, we will address the biological principles contributing to the design and engineering of advanced biomaterials for application towards recent therapeutic strategies for tissue regeneration. Finally, future directions for the design of advanced biomaterials will be discussed.     

我国医疗器械产业发展现状及对策分析

现代医疗器械产业是反映一个国家制造业和整体工业发展水平的高新技术产业，也是世界发展最快、贸易往来最为活跃的产业之一。本文针对国内外医疗器械产业现状，提出了我国发展医疗器械产业的必要性及未来发展对策。     

Book review

This article outlines how adolescents are currently overlooked as a specific user group of medical devices and positions the contribution that ergonomics (human factors) can make in mitigating this issue. Details are provided of the current barriers to adolescent inclusion in medical device design research. The discussion then provides guidance and suggested strategies for researchers, clinical staff and medical device developers about how to overcome difficulties such as ethical considerations and gaining access to this specific population. This is tackled through discussion of: informed consent, assent, gatekeepers, confidentiality, appropriateness of topics and proxies. The overall aim of this article is to raise awareness about adolescents in ergonomics research, specifically for the elicitation of requirements for medical devices.     

Superelastic Multimaterial Electronic and Photonic Fibers and Devices via Thermal Drawing

Electronic and photonic fiber devices that can sustain large elastic deformation are becoming key components in a variety of fields ranging from healthcare to robotics and wearable devices. The fabrication of highly elastic and functional fibers remains however challenging, which is limiting their technological developments. Simple and scalable fiber‐processing techniques to continuously codraw different materials within a polymeric structure constitute an ideal platform to realize functional fibers and devices. Despite decades of research however, elastomeric materials with the proper rheological attributes for multimaterial fiber processing cannot be identified. Here, the thermal drawing of hundreds‐of‐meters long multimaterial optical and electronic fibers and devices that can sustain up to 500% elastic deformation is demonstrated. From a rheological and microstructure analysis, thermoplastic elastomers that can be thermally drawn at high viscosities (above 10³ Pa s), allowing the encapsulation of a variety of microstructured, soft, and rigid materials are identified. Using this scalable approach, fiber devices combining high performance, extreme elasticity, and unprecedented functionalities, allowing novel applications in smart textiles, robotics, or medical implants, are demonstrated.     

Designation and development of biomedical Ti alloys with finer biomechanical compatibility in long-term surgical implants

Developing the new titanium alloys with excellent biomechanical compatibility has been an important research direction of surgical implants materials. Present paper summarizes the international researches and developments of biomedical titanium alloys. Aiming at increasing the biomechanical compatibility, it also introduces the exploration and improvement of alloy designing, mechanical processing, microstructure and phase transformation, and finally outlines the directions for scientific research on the biomedical titanium alloys in the future.     

Ultrasonic Cleaning-Induced Failures in Medical Devices

Ultrasonic cleaning is often used as part of the manufacturing process of small medical devices such as guide wires and vascular implants. Ultrasonic cleaning at frequencies close to the natural frequency of the device can result in resonance, resulting in significant mechanical damage and possibly premature failure. This paper provides case studies of ultrasonic cleaning-induced fatigue and corresponding failures in small medical devices. Preventative measures, including analytical tools such as finite element analysis (FEA), to ensure that ultrasonic cleaning frequencies do not result in resonance and stresses sufficient to cause fatigue damage are also discussed.     

Design of an Information Security Service for Medical Artificial Intelligence

The medical convergence industry has gradually adopted ICT devices, which has led to legacy security problems related to ICT devices. However, it has been difficult to solve these problems due to data resource issues. Such problems can cause a lack of reliability in medical artificial intelligence services that utilize medical information. Therefore, to provide reliable services focused on security internalization, it is necessary to establish a medical convergence environment-oriented security management system. This study proposes the use of system identification and countermeasures to secure system reliability when using medical convergence environment information in medical artificial intelligence. We checked the life cycle of medical information and the flow and location of information, analyzed the security threats that may arise during the life cycle, and proposed technical countermeasures to overcome such threats. We verified the proposed countermeasures through a survey of experts. Security requirements were defined based on the information life cycle in the medical convergence environment. We also designed technical countermeasures for use in the security management systems of hospitals of diverse sizes.     

Ion track-based electronic elements

In the past years, fundaments were set for a new type of electronics which is based on tracks in insulators formed by individual or multiple swift heavy ions. Due to the possibility of inserting any (semi)conducting material into these tracks, various active and passive electronic devices can be created. Among them are also transistor-like and Esaki diode-like elements. As many of these structures have sensing properties and the capability to undergo logic decisions, autonomous intelligent sensors appear to be a favourite field for future application. The use of liquid conductors may even expand the range of applicability towards medical implants.     

Development of a new calcium phosphate powder-binder system for the 3D printing of patient specific implants

A key requirement for three-dimensional printing (3-DP) of medical implants is the availability of printable and biocompatible powder-binder systems. In this study we developed a powder mixture comprising tetracalcium phosphate (TTCP) as reactive component and β-tricalcium phosphate (β-TCP) or calcium sulfate as biodegradable fillers, which can be printed with an aqueous citric acid solution. The potential of this material combination was demonstrated printing various devices with intersecting channels and filigree structures. Two post-processing procedures, a sintering and a polymer infiltration process were established to substantially improve the mechanical properties of the printed devices. Preliminary examinations on relevant application properties including in vitro cytocompatibility testing indicate that the new powder-binder system represents an efficient approach to patient specific ceramic bone substitutes and scaffolds for bone tissue engineering.     

Monitoring, diagnostic, and therapeutic technologies for nanoscale medicine

The advent of medically-relevant technologies forged at the interface of life science and engineering will undoubtedly play a major role in shaping the next-generation of experimental as well as clinical medicine. This review will explore the development of a suite of platform modalities that can be employed towards medical diagnostics and therapeutics. Their specific relevance and impact towards cardiovascular medicine will be realized through biotic-abiotic coalescence, or the bridging of biological materials such as cells and proteins with non-biological materials such as polymers or solid-state devices. These modalities include: (1) Real-Time Cellular Interrogation Technology, which enables real-time investigation, or examination of cellular signal transduction and gene expression as a response to environmental conditions; (2) Diagnostic Devices, which include the fabrication of micro/nano sensors for the targeting of molecules indicative of cellular disorders; and (3) Therapeutics, or the engineering of membrane mimetics, or biomolecule-functionalized thin films as strategies for synthetic biological regenerative medicine, as well as therapeutically-active polymers as biocompatible coatings for implants, to name a few. These approaches collectively represent a universally-applicable, and comprehensive diagnostic-treatment strategy whereby cardiovascular disorders, or medical diseases in general can be diagnosed, monitored, and fundamentally understood to unprecedented levels. In turn, these conditions can be therapeutically addressed using drug-releasing nanostructured polymers with minimal intrusion upon normal cellular behavior, or biologically-active hybrid membrane devices based upon the interface of proteins with robust biomimetic polymers.     

生物医用可降解锌基合金的研究进展

锌基合金是近几年新兴的一种医用可降解材料,有望应用于心血管支架及骨植入等医疗器械。锌是人体必需的营养元素,具有良好的生物相容性及适宜的体内降解速率,作为可降解合金的基体有很广的应用前景。然而,生物可降解锌基合金的设计、加工、强化及降解机理等研究尚处于起步阶段,还需要做大量的基础研究工作。本文以最终医疗器械产品的理想标准要求为切入点,从生物相容性、力学性能及抗腐蚀性能等方面对近几年医用锌基合金的研究成果进行了综述分析,并展望了其未来的发展方向。     

3D打印技术在骨科医疗植入物方面的应用及其对民用飞机结构件适航认证的启示

3D打印技术是一种先进的制造技术,在医疗、航空航天、汽车、模具、文化创意、教育等领域有广阔的应用前景。目前3D打印个性化骨科医疗植入物已有多起成功的应用案例,在如何通过主管部门审核方面积累了丰富的经验。民用飞机结构件与骨科医疗植入物在重要程度、审批方式、认证流程等方面有很多类似的地方,因此在进行民机3D打印结构件适航认证时可以借鉴骨科医疗植入物审批时的诸多宝贵经验。总结了3D打印骨科医疗植入物的应用现状、审批方式及面临的问题,分析了其借鉴价值,旨在为民用飞机3D打印结构件的适航认证提供参考。     

Cell membrane-inspired phospholipid polymers for developing medical devices with excellent biointerfaces

Abstract

This review article describes fundamental aspects of cell membrane-inspired phospholipid polymers and their usefulness in the development of medical devices. Since the early 1990s, polymers composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) units have been considered in the preparation of biomaterials. MPC polymers can provide an artificial cell membrane structure at the surface and serve as excellent biointerfaces between artificial and biological systems. They have also been applied in the surface modification of some medical devices including long-term implantable artificial organs. An MPC polymer biointerface can suppress unfavorable biological reactions such as protein adsorption and cell adhesion – in other words, specific biomolecules immobilized on an MPC polymer surface retain their original functions. MPC polymers are also being increasingly used for creating biointerfaces with artificial cell membrane structures.     

形态与功能融合的医疗器械创新设计研究

目的通过对医疗器械形态的"嵌合"设计进行研究,使设计者掌握医疗器械创新设计的方法,以满足医疗器械的作业者与被作业者在使用时的舒适性、功能的协调性、安全性和便利性,减少操作的难度,同时也给医生与患者带来福音。方法通过对市场上优秀的医疗器械产品的使用功能、操作流程、使用者与被使用者的需求进行分析,总结出人与医疗器械有机"嵌合"的设计原则与设计方法。结论医疗器械形态与功能融合是人、机、环境、效果的有机嵌合,设计者只有对医疗器械使用流程的精确掌握,才能进行系统的构思与设计,创造出优秀的医疗器械。     

A Review on the 3D Printing of Functional Structures for Medical Phantoms and Regenerated Tissue and Organ Applications

Medical models, or “phantoms,” have been widely used for medical training and for doctor-patient interactions. They are increasingly used for surgical planning, medical computational models, algorithm verification and validation, and medical devices development. Such new applications demand high-fidelity, patient-specific, tissue-mimicking medical phantoms that can not only closely emulate the geometric structures of human organs, but also possess the properties and functions of the organ structure. With the rapid advancement of three-dimensional (3D) printing and 3D bioprinting technologies, many researchers have explored the use of these additive manufacturing techniques to fabricate functional medical phantoms for various applications. This paper reviews the applications of these 3D printing and 3D bioprinting technologies for the fabrication of functional medical phantoms and bio-structures. This review specifically discusses the state of the art along with new developments and trends in 3D printed functional medical phantoms (i.e., tissue-mimicking medical phantoms, radiologically relevant medical phantoms, and physiological medical phantoms) and 3D bio-printed structures (i.e., hybrid scaffolding materials, convertible scaffolds, and integrated sensors) for regenerated tissues and organs.     

Biomaterials and tissue engineering in reconstructive surgery

This paper provides an account of the rationale for the development of implantable medical devices over the last half-century and explains the criteria that have controlled the selection of biomaterials for these critical applications. In spite of some good successes and excellent materials, there are still serious limitations to the performance of implants today, and the paper explains these limitations and develops this theme in order to describe the recent innovations in tissue engineering, which involves a different approach to reconstruction of the body     

Toxicity screening of candidate materials for the fabrication of a bubble oxygenator: A preliminary report

The hazards encountered in the clinical use of medical devices and implants have been referred in this paper to emphasise the need for and relevance of carrying out appropriate toxicological investigations before such items are manufactured and marketed. Different formulations of polyvinyl chloride, low density polyethylene, high density polyethylene and polyester fabric were subjected to various tests to determine their biocompatibility/safety for their eventual use as components in a bubble oxygenator. The test methods together with the results obtained are described and discussed.