Characterization of electromagnetic interference of medical devices in the hospital due to cell phones.

Concern over electromagnetic interference with medical devices due to cell phone emissions has stemmed from anecdotal reports and unpublished observations of hospital staff. In an effort to characterize electromagnetic interference concerns, representative medical devices from four large teaching hospitals were exposed to standard North American and European communication signal emissions. Of 33 medical devices tested, only 4 showed disruption of critical function due to cell phone emissions at a distance of 25 cm or greater. Although other cases of electromagnetic interference were observed, these were not critically disruptive and mainly occurred when the transmitters were at full power and placed 5 cm or closer to the medical device. Overall, no cell phone signal was exempt from producing electromagnetic interference effects. While sensitive medical devices were often affected by more than one signal type, the effects were not entirely predictable based upon the results of other signals or related medical device units or models. Because a comprehensive analysis of all medical devices in all possible electromagnetic environments was not performed, the data presented here are only intended to provide a general idea of the magnitude of electromagnetic interference effects that might be encountered in a hospital environment, as well as a standard protocol for clinical engineering groups to perform ad hoc electromagnetic interference surveys and methods to manage and/or eliminate electromagnetic interference with appropriate system engineering design including supplementary communication infrastructure, medical device shielding and positioning, and appropriate cell phone user guidelines.     

Securing the communication of medical information using local biometric authentication and commercial wireless links

Medical information is extremely sensitive in nature - a compromise, such as eavesdropping or tampering by a malicious third party, may result in identity theft, incorrect diagnosis and treatment, and even death. Therefore, it is important to secure the transfer of medical information from the patient to the recording system. We consider a portable, wireless device transferring medical information to a remote server. We decompose this problem into two sub-problems and propose security solutions to each of them: (1) to secure the link between the patient and the portable device, and (2) to secure the link between the portable device and the network. Thus we push the limits of the network security to the edge by authenticating the user using their biometric information; authenticating the device to the network at the physical layer; and strengthening the security of the wireless link with a key exchange mechanism. The proposed authentication methods can be used for recording the readings of medical data in a central database and for accessing medical records in various settings.     

Wireless live streaming video of surgical operations: an evaluation of communication quality

We evaluated a mobile video system for surgical teleconsultation. A video streaming server in the operating room transmitted video and audio to a hand-held computer (personal digital assistant [PDA]) over a wireless local area network. Two groups of 20 surgeons (each with 12 qualified surgeons and eight surgeons between the 2nd and the 4th year of training) participated in the tests. For voice transmission, correct understanding of numbers was achieved in 100% of the cases (n = 1000) and 98% of medical terms (n = 400). The quality of the video displayed on the PDA was assessed by the recognition of different operating room scenarios. Only 62% (SD 17) of the structures were identified clearly on the hand-held device (n = 400). The accuracy improved to 78% (SD 15) (n = 400) if the same scenario was observed on a larger (50 cm) video screen (p < 0.001). Accuracy was significantly better if audio conversation was possible. The quality evaluation by the consultants showed that the PDA display size and quality were sufficient for clinical use.     

Electromagnetic interference from GSM and TETRA phones with life-support medical devices

Disturbances in hospital devices caused by cellular telephone signals were investigated. The interference sources were GSM900, GSM1800, and TETRA380 phones. The number of medical appliances tested was 23. Most measurements were taken in a semi-anechoic laboratory. To simulate the worst situation, the phones were adjusted to emit at their maximum power levels. No interference was observed if the distance from GSM1800 phone was over 5 cm. Corresponding safety distance for GSM900 phone was 70 cm, and for TETRA phones over 3 m. Hence, the use of GSM1800 type mobile phones can be considered safe, whereas GSM 900 and TETRA phones may cause considerable interference in hospital devices, which can result in life-endangering situations.     

野战医疗信息管理系统无线网络的设计与应用

目的：解决在野外条件下机动医疗队医疗信息管理系统的网络问题。方法：采用双频三模功能的电信级无线AP/网桥与定向和全向无线接送网络,实现WLAN无线局域网。结果：在近2 a参加濒海对接演练中,该系统使用效果很好。结论：无线网络保密功能强,网络设备展开和撤收方便快捷,重复使用投资少。     

利用安卓智能移动设备助力医院设备管理

以医院信息网络为基础,利用安卓（Android）智能移动设备,开发平板电脑与无线局域网无缝连接的移动设备管理系统。系统的应用确保了设备的安全使用,提高了医疗设备的完好率和利用率,促进了医院数字化建设的发展。     

无线医疗设备的应用及安全

本文介绍了无线通信技术在医疗领域的应用情况,分析了电磁干扰与医疗安全的相关性,针对无线医疗设备应用的安全性研究,给出了无线医疗设备应用的注意事项。     

Electromagnetic compatibility management of wireless transceivers in electromagnetic-interference-sensitive medical environments

The diffusion of wireless technology has caused concerns about interference in the hospital environment. Most hospitals have banned the use of cell phones on their premises although wireless technology can help in delivering time critical help to patients. We discuss some factors of radio frequency (RF) near field interference. These phenomena do not lend themselves easily to theoretical evaluation. It is possible to avert medical equipment interference by performing ad hoc tests. The method requires measurements of electromagnetic fields and the observation of interference events with increasing distance between equipment and RF transmitters. The results are applicable only to the specific testing environment. The ad hoc proposed method can be found in the draft document C63.18 of the American National Standard Institute.     

Electromagnetic interference with infusion pumps from GSM mobile phones

Electromagnetic interference with critical medical care devices has been reported by various groups. Previous studies have demonstrated that volumetric and syringe pumps are susceptible to false alarm buzzing and blocking when exposed to various electromagnetic sources. The risk of electromagnetic interference depends on several factors such as the phone-emitted power, distance, and carrier frequency. The aim of this study was to assess the risk of GSM phone-induced electromagnetic interference with volumetric and syringe pumps, at various distances and emitted powers. Malfunctions were observed in 6 out of 8 volumetric pumps and in 1 out of 4 syringe pumps exposed to mobile phones at their maximum output, at distances up to 30 cm. The maximum power that did not induce any malfunction at zero distance was 50 mW at 900 MHz and 2.5 mW at 1,800 MHz. In state-of-the-art pumps, the presence of moderate-good base station coverage would significantly reduce the risk of electromagnetic interference.     

我院卫校无线网络工程改造与实施

无线局域网（WLAN）作为有线局域网的补充,有效地克服了有线网络的弊端。本文介绍了我院卫校无线网络的具体组网架构、网络硬件的选择及网络安全设计与实施过程。WLAN的应用,有效地解决了网络同频信号干扰严重、切换频繁等诸多问题,实现了整个医院安全、可管理的无线信号均匀覆盖。     

Wireless local area network security

Wireless local area networks (WLANs) are increasingly popular in clinical settings because they facilitate the use of wireless PDAs, laptops, and other pervasive computing devices at the point of care. However, because of the relative immaturity of wireless network technology and evolving standards, WLANs, if improperly configured, can present significant security risks. Understanding the security limitations of the technology and available fixes can help minimize the risks of clinical data loss and maintain compliance with HIPAA guidelines.     

基于野战RFID医疗卡读写器的使用设计

目的：实现RFID医疗卡信息的编辑、采集和传递,便于与野战信息管理系统信息平台互动。方法：采用C#语言编写程序,与RFID专用读写器结合,借助于无线射频识别技术进行信息传输。结果：对基于RFID技术的医疗卡格式化,信息输入、采集、修改以及与PC无线局域网连接进行了尝试,解决了伤员信息后送问题。结论：该野战医疗卡读写器在大规模演练中投入试用,收到了满意效果。     

Walkie talkies cause more electromagnetic interference to medical equipment than mobile phones

It is generally realised that mobile phones can interfere with medical electrical equipment and many hospitals have policies which aim to minimise the risk to their patients from this cause. Walkie talkies are also used in hospitals, but very little information is available concerning their ability to interfere with hospital equipment. Two walkie talkies and three mobile phones have been used to study and compare interference in 29 items of patient-connected equipment in a large hospital. Test results show that with some equipment there will be signal distortion and/or false alarms, and a Power off/on Reset may be necessary. In rare cases, when equipment is subjected to extreme signal strengths, it is possible to observe equipment failure requiring the replacement of failed components. For these tests the walkie talkies were set at 4W of output power and they caused significantly more interference than the mobile phones. The observed effects have been classified according to the maximum distance at which they were observed and according to the criticality of the possible outcome for the patient. It is concluded that, except for emergency services, the use of walkie talkies should be restricted in hospital buildings.     

Cell phones and electromagnetic interference revisited

Some media reports have inaccurately and incompletely interpreted recent studies, creating the impression that newer cell phone technology doesn't create enough electromagnetic interference (EMI) to affect medical equipment. As a result, hospitals are questioning whether existing restrictions on cell phone use can be eliminated. This article takes a closer look at the available evidence and explains that the evidence does, in fact, demonstrate an ongoing risk that EMI will affect medical devices. In addition, the article provides guidance on the impact that some newer communications technologies--namely, in-building cordless telephones, microcell systems, and Voice over Internet Protocol (VoIP) phones--may have on cell phone use and policies. Note that while this article focuses on cell phones--since they are the most common concern among hospitals--other types of wireless devices can also interfere with medical equipment. These include handheld messaging devices (e.g., BlackBerry products); multicommunication devices that combine the use of Wi-Fi, Bluetooth, and cellular communications; and cellular-capable computers. Healthcare facilities should apply the same policies to these devices as to cell phones. Two-way radios likewise present an interference risk, but require different policies, as we describe in a supplementary article within this Guidance Article.     

ECRI institute recommends reporting EMI events

Electromagnetic interference (EMI), though rare, can have a detrimental effect on the performance of electronic medical devices, potentially posing a patient safety risk. We encourage healthcare facilities to report EMI events (both known and suspected) to external entities such as device manufacturers, regulatory bodies (e.g., the U.S. Food and Drug Administration [FDA]), and ECRI Institute. Reporting such events will allow these organizations to analyze a greater number of reports in order to recognize trends that can help identify the susceptibility of devices to this problem; this information can then be disseminated to the healthcare community.     

Protecting computer-based medical devices: defending against viruses and other threats

The increasing integration of computer hardware has exposed medical devices to greater risks than ever before. More and more devices rely on commercial off-the-shelf software and operating systems, which are vulnerable to the increasing proliferation of viruses and other malicious programs that target computers. Therefore, it is necessary for hospitals to take steps such as those outlined in this article to ensure that their computer-based devices are made safe and continue to remain safe in the future. Maintaining the security of medical devices requires planning, careful execution, and a commitment of resources. A team should be created to develop a process for surveying the security status of all computerized devices in the hospital and making sure that patches and other updates are applied as needed. These patches and updates should be approved by the medical system supplier before being implemented. The team should consider using virtual local area networks to isolate susceptible devices on the hospital's network. All security measures should be carefully documented, and the documentation should be kept up-to-date. Above all, care must be taken to ensure that medical device security involves a collaborative, supportive partnership between the hospital's information technology staff and biomedical engineering personnel.     

Framework conditions and requirements to ensure the technical functional safety of reprocessed medical devices

Testing and restoring technical-functional safety is an essential part of medical device reprocessing. Technical functional tests have to be carried out on the medical device in the course of the validation of reprocessing procedures. These ensure (in addition to the hygiene tests) that the reprocessing procedure is suitable for the medical device. Functional tests are, however, also a part of reprocessing procedures. As a stage in the reprocessing, they ensure for the individual medical device that no damage or other changes limit the performance. When determining which technical-functional tests are to be carried out, the current technological standard has to be taken into account in the form of product-specific and process-oriented norms. Product-specific norms primarily define safety-relevant requirements. The risk management method described in DIN EN ISO 14971 is the basis for recognising hazards; the likelihood of such hazards arising can be minimised through additional technical-functional tests, which may not yet have been standardised. Risk management is part of a quality management system, which must be bindingly certified for manufacturers and processors of critical medical devices with particularly high processing demands by a body accredited by the competent authority.     

Hospital choice by rural medicare beneficiaries: does hospital ownership matter?--a Colorado case

About 45 percent of rural patients in Colorado bypassed their local rural hospitals during the 1990s. The effect of this phenomenon is a reduction in occupancy rates and a decrease in the competitiveness of rural hospitals, thereby ultimately causing rural hospitals to close and adversely affecting the communities that they were designed to serve. This study tests whether hospital ownership affects hospital choice by patients after controlling for institutional and individual dimensions. A conditional logistic regression is used to analyze Colorado Inpatient Discharge Data (CIDD) on 85,529 patients in addition to hospital data. Rural Medicare beneficiaries are influenced to choose a particular hospital by a combination of hospital characteristics (the number of beds, the number of services, accreditation, ownership type, and distance from patient residence) and patient characteristics (medical condition, age, gender, race, and total charge for services). Increasing rural hospitals' survivability, collaborating with other rural hospitals, expanding the number of available services, making strategic alliance with other providers are possible strategies that may help ward off encroachment by urban competitors.     

紧急医疗救援车载通讯系统的设计与分析

本文通过对紧急医疗救援车载系统概念和功能的理解,从车载信息采集分系统、无线传输分系统、综合保障分系统设计3方面入手,分析了目前救援车所配置的有线和无线网络设备、视频监控显示设备、视频录像设备、卫星通信设备的组成和特点,指出今后要进一步对无线网络、软件、移动设备进行改进,以更好地提高医疗救援工作效率。     

基层医疗机构卫勤数据无线传输方案设计与应用

目的：设计一种无线传输方案并应用于基层医疗机构的卫勤数据传输。方法：客户端通过小型化移动数据加密接入网关连接到3G网络,传输软件将数据经过公网传送到专网侧,相关设备对数据进行分析处理后通过公网发送到服务器端。结果：基层医疗机构通过3G网络可将卫勤数据传送到上级部门的服务器。结论：3G无线传输系统能够安全有效地传输基层医疗机构的卫勤数据。