This paper presents several algorithms for hashing directed graphs. The algorithms given are capable of hashing entire graphs as well as assigning hash values to specific nodes in a given graph. The notion of node symmetry is made precise via computation of vertex orbits and the graph automorphism group, and nodes that are symmetrically identical are assigned equal hashes. We also present a novel Merkle-style hashing algorithm that seeks to fulfill the recursive principle that a hash of a node should depend only on the hash of its neighbors. This algorithm works even in the presence of cycles, which would not be possible with a naive approach. Structurally hashing trees has seen widespread use in blockchain, source code version control, and web applications. Despite the popularity of tree hashing, directed graph hashing remains unstudied in the literature. Our algorithms open new possibilities to hashing both directed graphs and more complex data structures that can be reduced to directed graphs such as hypergraphs.
Payment channel networks provide a fast and scalable solution to relay funds, acting as a second layer to slower and less scalable blockchain protocols. In this paper, we present an accessible, low-cost attack in which the attacker paralyzes multiple payment network channels for several days. The attack is based on overloading channels with requests that are kept unresolved until their expiration time. Reaching the maximum allowed unresolved requests (HTLCs) locks the channel for new payments. The attack is in fact inherent to the way off-chain networks are constructed, since limits on the number of unresolved payments are derived from limits on the blockchain. We consider three main versions of the attack: one in which the attacker attempts to block as many high liquidity channels as possible, one in which it disconnects as many pairs of nodes as it can, and one in which it tries to isolate individual nodes from the network. We evaluate the costs of these attacks on Bitcoin's Lightning Network and compare how changes in the network have affected the cost of attack. Specifically, we consider how recent changes to default parameters in each of the main Lightning implementations contribute to the attacks. As we evaluate the attacks, we also look at statistics on parameters in the Lightning Network, which are of independent interest and compare the various implementations of Lightning nodes. Finally, we suggest mitigation techniques that make these attacks much harder to carry out.
With a view to overcome the shortcomings of traditional Electronic Health Record (EHR) system so as to assure the interoperability by providing open access to sensitive health data, while still preserving personal data privacy, anonymity and avoiding data misuse, Decentralized Electronic Health Record System was developed. The aforementioned issue concerning traditional EHR system can be addressed by implication of emerging technology of the era namely Block chain, together with Inter Planetary File System (IPFS) which enables data sharing in decentralized and transactional fashion, thereby maintaining delicate balance between privacy and accessibility of electronic health records. A block chain based EHR system has been built for secure, efficient and interoperable access to medical records by both patients and doctors while preserving privacy of the sensitive patient’s information. Patients can easily and comprehensively access to their medical records across providers and treatment sites using unique properties of block chain and decentralized storage. A separate portal for both the patients and doctors has been built enabling the smart contracts to handle further interaction between doctors and patients. So, in this system, it is demonstrated how principles of decentralization and block chain architectures could contribute to EHR system using Ethereum smart contracts and IPFS to orchestrate a suitable system governing the medical record access while providing patients with comprehensive record review along with consideration for audit ability and data sharing.
National elections are a big deal which has a major role in the development and progress of a country. The security of an election is in fact the matter of national security. Current voting systems in the context of Nepal and other parts of the world are still traditional and insecure. From the dawn of democracy, elections are still based on pen and papers. While there are new electronic voting machines, these systems have a high risk of rigging and are prone to failure, crashes, and attacks from intruders. The stated problems can be addressed through the implementation of new technology namely Blockchain for a transparent and reliable voting process. A blockchain based voting platform has been built to make the voting process digital, secure, reliable and intuitive. The votes casted by voters are stored in the blockchain, thus making it immutable and secure. The system can be scaled based on the requirements of an election. Voters can login to the system with the help of encrypted identification. This encrypted identification will lead to secure voting process. A separate portal for both voters and the election commission reduces the election hassle and time. So, in this system, it is demonstrated how the use of blockchain platform could contribute to modern elections using Ethereum, smart contracts and distributed systems to provide voters with secure, transparent and reliable voting platform.
Tayebeh Rajab, Mohammad Hossein Manshaei, Mohammad Dakhilalian, Murtuza Jadliwala · 5 authors
Bitcoin's single leader consensus protocol (Nakamoto consensus) suffers from significant transaction throughput and network scalability issues due to the computational requirements of it Proof-of-Work (PoW) based leader selection strategy. To overcome this, committee-based approaches (e.g., Elastico) that partition the outstanding transaction set into shards and (randomly) select multiple committees to process these transactions in parallel have been proposed and have become very popular. However, by design these committee or shard-based blockchain solutions are easily vulnerable to the Sybil attacks, where an adversary can easily compromise/manipulate the consensus protocol if it has enough computational power to generate multiple Sybil committee members (by generating multiple valid node identifiers). Despite the straightforward nature of these attacks, they have not been systematically analyzed. In this paper, we fill this research gap by modelling and analyzing Sybil attacks in a representative and popular shard-based protocol called Elastico. We show that the PoW technique used for identifier or ID generation in the initial phase of the protocol is vulnerable to Sybil attacks, and a node with high hash-power can generate enough Sybil IDs to successfully compromise Elastico. We analytically derive conditions for two different categories of Sybil attacks and perform numerical simulations to validate our theoretical results under different network and protocol parameters.
Aman Sharma, Ankit Agrawal, Ashutosh Bhatia, Kamlesh Tiwari
Bitcoin is the most popular cryptocurrency used worldwide. It provides pseudonymity to its users by establishing identity using public keys as transaction end-points. These transactions are recorded on an immutable public ledger called Blockchain which is an append-only data structure. The popularity of Bitcoin has increased unreasonably. The general trend shows a positive response from the common masses indicating an increase in trust and privacy concerns which makes an interesting use case from the analysis point of view. Moreover, since the blockchain is publicly available and up-to-date, any analysis would provide a live insight into the usage patterns which ultimately would be useful for making a number of inferences by law-enforcement agencies, economists, tech-enthusiasts, etc. In this paper, we study various applications and techniques of performing data analytics over Bitcoin blockchain from a graph theoretic perspective. We also propose a framework for performing such data analytics and explored a couple of use cases using the proposed framework.
The block chain is attaining popularity day to day as it is acting as distributed ledger for Cryptocurrency such as Bitcoin and ripple. This research paper has focused on the Blockchain and its working pattern with technical implementation of block creation. This technical paper is considering the prevention of DNS Cache poisoning attack in Blockchain which is known as larger class of name-based attacks. DNS Packet interceptions may be made using various attacks like Cache poisoning attack, man-in-the-middle attacks etc. As there are numerous security mechanisms to secure the Blockchain but in order to make Blockchain immune from cache poisoning attack, there is need to update the block creation module. Therefore, this research work is proposed to make reduction in probability of data corruption that can be created from different attacks. It resolves the issue of cache poisoning attacks using user defined port instead of predefined port. However, the initialization of transmission is performed here using predefined port number. In second step, the encrypted port number is decrypted to initiate communication using user defined port number. The use of port with IP address would restrict attacks during data transmission. The paper has presented the comparative analysis of existing DNS attacking prevention mechanism to proposed work.
Information systems and technology has changed the world in every aspect. One of them is how a contract is made. Smart contract technology has offered a new, efficient, and secure way to automatically execute the terms of the agreement with no third-party to perform such contracts. The objective of this paper is to conduct a systematic overview of how the smart contract can bring opportunities and also challenges to Indonesia. We propose this paper due to the benefits Indonesian businesses will have by implementing smart contracts. Apart from the benefits, in Indonesia, there are still very few journals discussing smart contracts implementation. In this paper, there will be our findings of how smart contracts are utilized currently in industries, the challenges, and the current smart contract in Indonesia. The result will be used as guidance when considering, planning, and applicating smart contracts in Indonesia.
Advanced wireless technology in Internet of Things (IoT) devices is increasing and facing various security threats. The authentication of IoT devices is the first line of defense for the wireless network. Especially in a Wi-Fi network, the existing authentication methods mainly use a password or digital certificate, these methods are inconvenient to manage due to certificate issuance or prone to be attacked because passwords are easily cracked. In this paper, we propose a location-aware authentication scheme using smart contracts to ensure that IoT devices can securely perform Wi-Fi network authentication. The scheme adopts the concept of secondary authentication and consists of two phases: the registration phase, which is mainly designed to complete the generation of the public and private keys, and to link the device information with its related device information; the authentication phase, which is mainly designed to determine whether the requesting device is within a legal location range. We use the smart contract to ensure the credibility and irreparability of the authentication process. Analysis of the attack model and the attacks at different stages proves that this certification scheme is assured, and the simulation results show that the overhead introduced by this scheme is acceptable, this scheme can provide greater security for the Wi-Fi authentication of IoT devices.
Although recent advances of blockchain systems, notably in the form of cryptocurrency, have drawn tremendous interests from both researchers and practitioners, limited studies existed toward the theoretical foundation of blockchains. This paper presents the first study on the algebraic structure of blockchains with an emphasis on the internal properties under algebraic groups. We axiomatically construct a blockchain group and derive some interesting properties that can be potentially taken into the design space and parametric analysis of real-world blockchain systems.
Open innovation is a concept in flux; from the practice of large-scale, internet-mediated collaboration, to a strategic option and business model for firms. However, the scope and breadth of its transformative dynamic is arguably restrained. Despite the theoretical and empirical benefits of openness, established firms face significant challenges deploying the coordination patterns of open innovation communities, further reducing the potential of spill-overs in the supply chain. Viewed differently, open innovation presents more user-centric and responsible innovation paths. These are manifested in the processes and outputs of open innovation by empowering participation and by successfully employing the capacities of user communities. To reap the benefits of open innovation, a rapid reconfiguration of the production and exchange structures is needed in intrafirm and interfirm relations. Sensorica is an open enterprise that achieves such forms of organization and a unique techno-social infrastructure supporting them. It illustrates a potential path that can realize the full potential of open innovation, for users, firms, and the economic system as a whole.
Maurizio Talamo, Franco Arcieri, Andrea Dimitri, Christian H. Schunck
Public key infrastructures (PKIs) are the cornerstone for the security of the communication layer of online services relying on certificate-based authentication, such as e-commerce, e-government, online banking, cloud services, and many others. A PKI is an infrastructure based on a hierarchical model, but the use of PKIs in non-hierarchical contexts has exposed them to many types of attacks. Here, we discuss weaknesses exploited in past attacks and we propose a solution based on an original consensus algorithm developed for use on blockchain technology. In this implementation we retain the full functionality around X.509 certificates, i.e., for the triad (server name, server address, X.509 server certificate), and demonstrate a mechanism for obtaining fast consensus. The main properties of the solution are that a consensus may be reached even when not all members of the involved PKI participate in a transaction, and that no advanced trust agreement among PKIs is needed. The proposed solution is able to detect PKI attacks and can distinguish errors from attacks, allowing precise management of anomalies.
Currently, there are hundreds of Bitcoin exchanges on the market, so choosing a reliable exchange is a critical issue for users. We know that the amount of Bitcoin holdings is an essential indicator for evaluating an exchange, but people have very few ways to access this information. Besides, many reports indicate that the trading volumes of most Bitcoin exchanges do not match their real situations, and the fake volume has become an unspoken rule of the whole industry. It causes the public to doubt the actual amount of Bitcoin owned by each exchange. To solve the problem of information asymmetry between users and exchanges, we propose a method for tagging Bitcoin addresses of exchanges. Through vertical, forward, and backward address mining, the method can utilize only one or several addresses of an exchange to find out all its addresses and distinguish different address types: deposit wallet, hot wallet, and cold wallet. Then the balance and transfers of the exchange can be further obtained through these addresses, helping users understand the real Bitcoin holdings of the exchange. Several experiments are conducted to evaluate the effectiveness of the proposed Bitcoin address tagging method. Our method has very little dependence on off-chain information. Only one address is needed for each exchange as a seed to find out all the other addresses. Such a seed address can be easily obtained by depositing some Bitcoin into the exchange or withdrawing some from it, which makes our method feasible for all exchanges.
Digitalization in finance is an irreversible process, which manifests itself in many different dimensions. Blockchain is an innovative technology that can significantly increase the operational effectiveness of key processes in the financial services industry by reducing costs, enhancing the security and transparency of transactions, and speeding up the settlement process. The idea of smart contracts’ implementation in blockchain is suitable for financial transactions, where a link between fulfilling contractual terms and performing actual transactions is established. The ‘’blockchain - smart contract’’ combination forces the execution of all transactions in accordance with the contract terms and leaves a door, wide open for the automation of key processes. What makes using a ‘smart contract’ beneficial is its ability to eliminate mediation from third parties, such as agents or trustees. The invasion of digital technology is expected to bring dramatic changes in the nature of financial intermediation. This research paper is focused on assessing the expected degree of blockchain penetration and its impact on selected key segments of the financial industry (e.g. global payments, trade finance, capital market trading, syndicated lending, insurance and compliance). Barriers and challenges to the new application’s wide spreading are also analyzed. Based on this research, conclusions about the expected degree of applicability of blockchain in the financial sphere are drawn, and proposals for the initial steps in this direction are made.
Aleksandar Erceg, Jovanka Damoska Sekuloska, Ivan Kelić
As one of the most interactive economic activities, tourism has improved significantly since the Internet allowed customers (travelers) to look for and create their trips without the need to go to a travel agency. Through the development of Internet marketing, tourists are able to receive information in real-time and view them on the screens of their devices (computers, laptops, mobile phones or tablets), and consequently they can create their own content and share it with others. Due to this development, we are witnessing a new phenomenon, so-called app capitalism, in which companies like Uber and Airbnb make money on services and goods they do not own and finding new business models in the tourism sector which enable customer-to-customer models. To be able to respond to these changes, the tourism industry needs to bring together knowledge, money, and technology for the purpose of creating new business models. The development of technology in all social spheres, including tourism, has provided a strong tool for consumers in terms of both acquiring and disclosing information to others. One of the rapidly growing technologies which is also one of the cutting-edge technologies entering tourism is blockchain. Blockchain technology captured worldwide attention in 2017 and its implementation has been revolutionizing various industries (e.g., retail, healthcare, tourism). The aim of this paper is to analyze the potential of the tourism industry in terms of blockchain implementation. Blockchain technology provides significant benefits to the tourism industry since its implementation can help increase competitive advantage, improve customer satisfaction and enhance performance. In this paper, the authors present the current situation in the Republic of Croatia and the Republic of Macedonia regarding the use of blockchain technology in the tourism industry. The main findings of this paper comprise the detection of key areas regarding why blockchain technology is not implemented in the tourist industry, and what processes should be handled. By presenting a case study of the implementation of blockchain technology in tourism, the authors analyze the potential of using blockchain technology in the tourism industry and discuss topics for further research.
EOSIO has become one of the most popular blockchain platforms since its mainnet launch in June 2018. In contrast to the traditional PoW-based systems (e.g., Bitcoin and Ethereum), which are limited by low throughput, EOSIO is the first high throughput Delegated Proof of Stake system that has been widely adopted by many applications. Although EOSIO has millions of accounts and billions of transactions, little is known about its ecosystem, especially related to security and fraud. In this paper, we perform a large-scale measurement study of the EOSIO blockchain and its associated DApps. We gather a large-scale dataset of EOSIO and characterize activities including money transfers, account creation and contract invocation. Using our insights, we then develop techniques to automatically detect bots and fraudulent activity. We discover thousands of bot accounts (over 30\% of the accounts in the platform) and a number of real-world attacks (301 attack accounts). By the time of our study, 80 attack accounts we identified have been confirmed by DApp teams, causing 828,824 EOS tokens losses (roughly 2.6 million US\$) in total.
Yueyue Dai, Du Xu, Ke Zhang, Sabita Maharjan · 5 authors
Vehicular Edge Computing (VEC) is a promising paradigm to enable huge amount of data and multimedia content to be cached in proximity to vehicles. However, high mobility of vehicles and dynamic wireless channel condition make it challenge to design an optimal content caching policy. Further, with much sensitive personal information, vehicles may be not willing to caching their contents to an untrusted caching provider. Deep Reinforcement Learning (DRL) is an emerging technique to solve the problem with high-dimensional and time-varying features. Permission blockchain is able to establish a secure and decentralized peer-to-peer transaction environment. In this paper, we integrate DRL and permissioned blockchain into vehicular networks for intelligent and secure content caching. We first propose a blockchain empowered distributed content caching framework where vehicles perform content caching and base stations maintain the permissioned blockchain. Then, we exploit the advanced DRL approach to design an optimal content caching scheme with taking mobility into account. Finally, we propose a new block verifier selection method, Proof-of-Utility (PoU), to accelerate block verification process. Security analysis shows that our proposed blockchain empowered content caching can achieve security and privacy protection. Numerical results based on a real dataset from Uber indicate that the DRL-inspired content caching scheme significantly outperforms two benchmark policies.
Subhra Mazumdar, Sushmita Ruj, Ram Govind Singh, Arindam Pal
Payment channel networks (PCN) are used in cryptocurrencies to enhance the performance and scalability of off-chain transactions. Except for opening and closing of a payment channel, no other transaction requests accepted by a PCN are recorded in the Blockchain. Only the parties which have opened the channel will know the exact amount of fund left at a given instant. In real scenarios, there might not exist a single path which can enable transfer of high value payments. For such cases, splitting up the transaction value across multiple paths is a better approach. While there exists several approaches which route transactions via several paths, such techniques are quite inefficient, as the decision on the number of splits must be taken at the initial phase of the routing algorithm (e.g., SpeedyMurmur [42]). Algorithms which do not consider the residual capacity of each channel in the network are susceptible to failure. Other approaches leak sensitive information, and are quite computationally expensive [28]. To the best of our knowledge, our proposed scheme HushRelay is an efficient privacy preserving routing algorithm, taking into account the funds left in each channel, while splitting the transaction value across several paths. Comparing the performance of our algorithm with existing routing schemes on real instances (e.g., Ripple Network), we observed that HushRelay attains a success ratio of 1, with an execution time of 2.4 sec. However, SpeedyMurmur [42] attains a success ratio of 0.98 and takes 4.74 sec when the number of landmarks is 6. On testing our proposed routing algorithm on the Lightning Network, a success ratio of 0.99 is observed, having an execution time of 0.15 sec, which is 12 times smaller than the time taken by SpeedyMurmur.
Haoqian Zhang, Yancheng Zhao, Abhishek Paryani, Ke Yi
Internet censorship has been implemented in several countries to prevent citizens from accessing information and to suppress discussion of specific topics. This paper presents Infnote, a platform that helps eliminate the problem of sharing content in these censorship regimes. Infnote is a decentralized information sharing system based on blockchain and peer-to-peer network, aiming to provide an easy-to-use medium for users to share their thoughts, insights and views freely without worrying about data tampering and data loss. Infnote provides a solution that is able to work on any level of Internet censorship. Infnote uses multi-chains architecture to support various independent applications or different functions in an application.
Lloyd W. Klein, James A. Goldstein, David E. Haines, Charles E. Chambers · 8 authors
Renewed attention has focused on the occupational health hazards posed by working in the fluoroscopic laboratory.1-6 Accumulated occupational radiation exposure is associated with health risks to physicians, nurses, and technologists working in this environment. Health care workers are subject to insidious health effects of radiation exposure over many years. Adverse effects include the established predilection to posterior subcapsular cataracts, as well as worrisome signals of lifetime risks of cancer induction, particularly in the unprotected brain.7-12 A further consequence is the extensively documented incidence of orthopedic illnesses reported in physicians as well as nurses and technologists and injuries linked to the cumulative burden of bearing the weight of only partly protective lead aprons mandatory to reduce radiation risk.13-16 The increased volume and complexity of procedures, together with the physical stresses inherent in procedural performance, have exacerbated the prevalence and magnitude of such orthopedic injuries.17 The high prevalence of orthopedic afflictions not only affects individual health but also could be potential career ending, with workforce implications for both the profession as well as for society.15 Advances in interventional imaging techniques and treatments over the last three decades have achieved significant success with clear benefits to our patients18; yet protective measures for workers have unfortunately lagged the pace, magnitude, and impact of this therapeutic progress. The purpose of this position statement is to review the data documenting occupational health injuries, summarize current equipment and processes that can be widely applied to optimize protection, emphasize the importance of investment by hospitals and health systems in protective equipment established to enhance workplace safety, examine barriers that need to be overcome to spur advances to enhance the occupational safety of the fluoroscopic laboratory environment, and propose enhanced advocacy for innovation. Future processes and proposals to improve the fluoroscopic laboratory environment should be based on the following precepts: (a) there is ample clinical data documenting the prevalence of serious occupational health risks engendered by the fluoroscopic laboratory environment; (b) sufficient attention to these occupational health issues has been drawn in annual meetings and published clinical scientific studies; (c) despite these data and advocacy efforts, advances to improve worker safety in the fluoroscopic laboratory remain inadequate; and (d) a concerted effort by all stakeholders (physicians, catheterization laboratory nurses, and technologists, sonographers, hospitals, professional societies, and industry) in the fluoroscopic laboratory is necessary to further advance occupational safety and health. Radiation exposure is inherent to procedural performance in the fluoroscopic laboratory. Exposure to ionizing radiation imposes health risks to both patients and operators, resulting in an increased likelihood of numerous illnesses and diseases.1-8 The association with posterior subcapsular cataracts is well documented.11, 12 There are growing concerns for cancer induction,7, 8 with recent reports of a cluster of predominantly left-sided brain cancers in interventionists,9, 10 as well as a signal for increased breast19-22 and skin cancers.23-26 Radiation exposure generally, not necessarily as part of occupational exposure, is associated with leukemia/lymphoma, myeloma, numerous gastrointestinal and bone cancers, and thyroid and parathyroid adenomas. These disquieting signals fuel the increasing anxiety regarding radiation exposure-related oncogenesis, though no mortality impact has been proven.27 Recent studies have also suggested that occupational radiation exposure is associated with hypertension, hypercholesterolemia, and possibly atherosclerosis.28-30 Evidence of lengthening sarcomere length and early vascular aging in epidemiologic studies suggests that workers who are occupationally exposed to radiation during interventional procedures may be at increased risk to develop these same illnesses.30, 31 There is now overwhelming evidence demonstrating that working in the interventional laboratory is associated with an increased incidence of orthopedic illnesses, particularly those related to the cervical and lumbar spine. These orthopedic injuries have been linked to the cumulative effects of bearing the weight of leaded aprons.5, 15, 16 Additionally, the design of the catheterization laboratory environment promotes awkward orthopedic ergonomic postures (e.g., monitors placed out of the line of natural working sight views). As procedures become increasingly complex and prolonged, and their volume increase in number, it should not be surprising that interventional practice is attended by a high rate (40–50%) of occupational-induced orthopedic injuries.15-17 Over a career's duration, the likelihood of suffering such illnesses are 2–7 times27, 28 higher than other medical occupations. Studies report substantial differences in orthopedic injuries between those wearing lead aprons working in the fluoroscopic laboratory compared to colleagues working in the same department not working in the fluoroscopic laboratory and thus not bearing the burden of wearing lead aprons.27-29 These occupational-related injuries not uncommonly result in missed days of work, surgery, and, in some cases, curtailed careers. This issue has significant implications for the interventional workforce, particularly in view of the aging of the population and anticipated increased procedural demand concomitant with aging of the operators who pioneered these advances.17, 27-29 These occupational health concerns potentially affect several medical specialties, including cardiologists, radiologists, and surgeons working with fluoroscopy, as well as pain management specialists performing nonvascular fluoroscopic procedures. Importantly, all such issues also pertain to the other personnel who are essential members of the “interventional team” (e.g., nurses and technologists, interventional imagers, and cardiac anesthesiologists) who are exposed to the harmful effects of scattered ionizing radiation.30-33 Electrophysiologists and their team are also exposed to radiologic risks and orthopedic injury34 and perhaps even more so, given the duration of their procedures and lack of upper torso shielding during device cases (e.g., implantable defibrillators and cardiac resynchronization therapy). These issues also have particular importance to women; although radiation effects on the fetus have not been demonstrated, women report concerns for adverse effects during reproduction as an obstacle to choice of an interventional career. These radiation exposure concerns have sometimes been considered a reason for disproportionately low representation of women in the field.35 As noninvasive cardiologists specialized in imaging are now required to guide interventions in the catheterization and electrophysiology laboratories, pursuing career in imaging is no longer radiation free and a safer choice for women. This may result in shifts in gender distribution in various cardiology subspecialties, further impacting strategies to improve diversity and inclusion in out profession. The past three decades have witnessed astounding progress in interventional equipment, technique, therapeutics, and the clinical research that catalyzed these advances. Progress in interventional laboratory protection and safety has comparatively lagged, despite the growing mounting data emphasizing occupational health concerns. A paradigm shift to dramatically improve the occupational safety for all stakeholders in the fluoroscopic laboratory (members of the interventional team, professional societies, hospitals, and industry) is required. In particular, there is an opportunity and obligation for industry and hospitals, who clearly benefit from the workers' commitment to their profession, to play a leadership role in correcting these deficiencies. A template exists based on the collaboration established by recent FDA-led efforts aimed to reduce patient exposure.36 Leveraging the concept and practice of the “Image Wisely” and “Image Gently” campaigns codified by Radiological Society of North America37 and Pediatric Cardiology community38 to minimize radiation exposure to patients, in 2010, the FDA Center for Devices and Radiological Health launched an Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging. As part of this initiative, the FDA held a public meeting on ways to improve devices to reduce unnecessary radiation exposure to help the agency decide on any new, targeted requirements for manufacturers of computed tomographic and fluoroscopic devices. This effort resulted in an industry-driven enhanced awareness, with mandates to recognize both the needs for and market potential of innovations focused on minimizing patient radiation exposure. These initiatives rapidly resulted in dramatic changes to improve the X-ray systems. Examples of these improvements include minimizing radiation exposure through lower emission X-ray systems as well as monitoring, recording of each procedure's patient exposure, and standardization in laboratory reports and patient charts. These efforts have also stimulated industry to develop X-ray systems that provide high-quality imaging at low-radiation exposure dose levels. Hospitals should be encouraged to invest in adopting such platforms that have potential to mitigate occupational risk. Physicians working with our professional societies should strive to establish a culture of safety encompassing both patients and catheterization laboratory personnel (Table 1). The pathway forward should be focused to assure: (1) consistent application and adherence to established and procedural processes; (2) widespread adoption and utilization of novel commercially available protection systems; and (3) encouragement and support to further develop even more effective equipment and processes that facilitate enhanced safety and protection in the workspace. Our professional societies must support individual physicians, teams, and practices, especially those that are hospital owned. It is critical that clinician leaders speak authoritatively to hospital administration and industry partners regarding these concerns without fear of reprisal; societal support could be influential in these situations. The following specific steps should be endorsed by our professional societies to enhance hospital and physician compliance: Whether or not to comply with appropriate shielding and other safety measures should not be at the discretion of the operator. The imaging team (physician, sonographer, radiologic technologist, physicist, and other medical personnel) should be responsible for developing optimized protocols, implementing regular equipment quality control tests, and monitoring radiation doses to patients and members of the team. This group and their products should be recognized as an essential part of the quality assurance program, present in all laboratories, for emphasizing radiation management. Operator dose is directly proportional to patient dose; thus, reducing the dose to the patient will benefit the operator. Knowledge of radiation and methods to reduce risk should be stressed to all operators who perform fluoroscopically guided interventions, practiced routinely, and all staff educated in these measures and assuring they are adhered. These methods and concepts have been well described previously.1-7 Recently, publications from the Society of Cardiovascular Angiography and Interventions, The Heart Rhythm Society, and the American College of Cardiology/multi-society consensus document18 articulate detailed procedural systems and processes, as well as practical approaches, to assist cardiac catheterization laboratories in establishing optimal radiation safety program. The components of a radiation safety program include essential personnel, radiation monitoring, protective shielding (at minimum strict adherence to protective aprons and leaded glasses), imaging equipment, and training/education.39-41 Fundamental principles of radiation safety teach the tenet that radiation exposure should be “as low as reasonably achievable (ALARA)”, with monitoring to assure individuals do not exceed annual or lifetime “safe limits.” Unfortunately, the term “reasonably achievable” is ambiguous and not actionable, and may unintentionally inhibit innovative strides to improve safety both for patients who require medically necessary procedures and for workers in radiation-exposed environments. The phrase might incorrectly imply that as long as one's exposure is “minimized,” then that is all that need to be accomplished. Rather, the ultimate goal of innovation efforts should strive to achieve a completely safe environment wherein the ultimate definition of ALARA translates to as close to a zero radiation exposure work environment as possible. Meticulous application of established prudent radiation techniques is obvious and essential. Standard shielding combines laboratory based (e.g., movable ceiling suspended and fixed table-side shielding). Personal protective aprons and eyewear should be properly fitted and maintained, and hospitals should finance these protective devices for all of their employees, including trainees. Newer personal protective choices, including two-piece aprons that are much lighter, may be beneficial; accessory sleeves for arm protection are also available. Despite these advances, the orthopedic burden of only partially protective leaded apparel continues. Institutions and operators must partner to develop a program specific for their laboratory that will result in the adoption of appropriate recent innovations to reduce radiation exposure. Strategies should also include usage of adjunctive devices for which there is substantial data documenting their capability to reduce exposure. Specifically, there is now compelling data demonstrating reductions in exposure with accessory drapes42 (Supplementary Tables); such disposable radiation shielding pads should NOT be refused by hospitals due to their expense. The use of leaded caps has been proposed with mixed results regarding reduction in exposure.43, 44 Simple accessory mobile shields afford significant protection to both nurses and technologists45 as well as to the interventional imaging team.30 More expansive and encompassing lead shielding systems are commercially available,46 and there is a need for more clinical research data supporting their capabilities to reduce exposure. Robotic systems developed to enhance procedural performance also provide protection from radiation exposure to the physician and reduce leaded apron orthopedic burden.47 Thus far, robotics has had limited adoption, due mostly to cost considerations but also fear from the loss of a “hands-on” sensibility. In electrophysiology, intracardiac navigation systems48 have shown efficacy to navigate catheters for ablation procedures with lesser exposure. Simultaneously, industry and physicians must partner to expedite development of a fluoroless catheterization laboratory, using echocardiography, magnetic resonance imaging, 3D mapping, or other technologies. Removing the necessity of lead aprons should be the ultimate goal. Although the proximate cause of many orthopedic complications may be wearing lead, there are other important factors, such as screen height and position, and other ergonometric considerations, which may account for much cervical spine pathology.49 This growing portfolio of enhanced/innovative protective technology will continue to yield a growing pipeline of solutions providing optimism for a healthier work environment. Table 1 summarizes the responsibilities of professional societies going forward. A direct role is a necessity to coordinate the policy matters raised in this document. Table 2 lists the specific future directions recommended for all stakeholders to achieve. It is essential to emphasize that the operator has the responsibility to understand how to use protective equipment optimally to minimize exposure to both patients and personnel.50 Education in this area is already part of cardiology trainee education and is tested in certification exams. Nevertheless, formal training for those who are planning to be interventional operators and imagers should be considered, and compliance monitored on site. Real-time radiation dose monitoring should become standard. Further, physicians must accept the challenge to adopt new technologies for the reduction of occupational hazards. Expense is one reason that new innovations are often not adopted, as it is difficult to advocate for expensive nonrevenue-enhancing equipment in the current fiscal environment. Other obstacles to overcome include potential discomfort with the design modifications and the resistance to making changes in familiar techniques even if there are improvements. The question always arises as to “proof” as to whether the changes are really beneficial, which sometimes become a justification to maintain an unsatisfactory status quo. Therefore, it is incumbent on our profession to continue to produce high-quality clinical research that documents the capabilities of novel imaging equipment, protective devices, and processes designed to improve workplace safety and health. As previously discussed, structural heart interventions depend on procedural image guidance/interventional echocardiography using transthoracic (TTE) or transesophageal echocardiography (TEE) in addition to fluoroscopy. Interventional imagers who operate the TTE or TEE probe and echo console are highly exposed to the harmful effects of scattered ionizing radiation. Protection for these workers also needs to be incorporated and mandated.30, 45, 46 Professional societies should develop programs to assist hospitals and health systems to address occupational safety. It is in everyone's interest to assure the health of medical caregivers.17 The establishment of new, and coordination with existing, comprehensive programs for clinician health in the catheterization and electrophysiology laboratories consistent with recommended wellness programs are an opportunity to highlight this problem. This may include an on-site physical or massage therapist, programs for core strengthening and stretching, and improved posture techniques to prevent orthopedic injury.34 Moreover, this issue can be an opportunity for societies to share and collaborate with international colleagues, who face similar problems. Since the inception of radiologic imaging, the biomedical industry has taken primary responsibility for development and refinement of catheterization laboratory equipment with associated financial benefits. As this equipment engenders intrinsic radiation exposure hazards, industry should assume a level of fiduciary responsibility to optimize the safety of the equipment they design and sell. It is our role to communicate the cardiology community's widespread support for innovations and catheterization laboratory design reformation. Though definite progress has occurred in the past two decades, particularly the advent of high-quality X-ray systems that produce high-quality imaging at lower radiation dose, further innovations are needed to achieve maximal operator radiation protection. The goal is a laboratory design that achieves a completely environment that the need for personal protective apparel and the orthopedic progress has been by the FDA to industry and medical to improve equipment and processes designed to achieve radiation exposure to are that efforts can be to enhance operator safety by providing a template by which this may be innovation will be that market are to such of worker health to increase worker is both the to and a workforce (physicians, nurses, and Hospitals and health care systems should recognize that protective equipment and wellness processes to at the of the health of their workers is more it increased more and increased training Hospitals have the responsibility to and assure worker safety and optimal occupational radiation exposure. radiation provide training and monitoring of personnel and It that hospitals have a responsibility for those working in their and an responsibility not only to maintain and present imaging systems but also to catheterization laboratories with the equipment and established to benefits to the safety and of their of the X-ray with of imaging and equipment are the responsibilities of the will if (e.g., Health and might in on these occupational safety issues and issue that require a for of imaging and protective In this of and commitment on the part of hospitals is critical to industry to invest in research and development of in the that there is an and In our professional societies play a role to help establish is considered and necessary for practice in radiation safety and clinician The is not responsible for the or of any supporting by the than should be to the for the
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