Mobile phone interference with medical equipment and its clinical relevance: a systematic review

Concentrating in a Loud Crowd: Sonographer Perceptions of Policies to Limit Distractions in Obstetric Sonography Examinations

Objective

The objective was to identify sonographer perceptions of distractions and policies for improving obstetric sonography examinations (OBUS).

Materials and Methods

A survey, with closed- and open-ended questions, was sent to OBUS practicing members of the Society of Diagnostic Medical Sonography (SDMS). Descriptive analyses, including frequency distributions overall and by various groups, were performed. Chi-square analyses were used to examine the relationships between categorical variables, including level of perceived distraction, and concordance with policies.

Results

Of the 3525 accessed e-mails, 807 responses were eligible for analysis. Over half (62%) of the respondents reported no observer policy. Sonographers reported strong agreement with observer policies and desired limits on observers. Policy disagreement themes included number of observers, children observers, patient satisfaction, and patient truthfulness. Most sonographers reported existence of (85%) and strong agreement (97%) with recording policies. Disagreements centered around the strictness of policies, policy enforcement and notification, distraction of recording, medico-legal issues, and finding anomalies while being recorded.

Conclusion

Discrepancies existed between policies regarding observers and recording in OBUS. Sonographers both desired and agreed with protocols to limit distractions. However, there were concerns regarding stringency, notification, and enforcement of policies. Further research is needed to determine if policies help limit distractions during OBUS.

Deep brain stimulation and electromagnetic interference

Deep brain stimulation (DBS) has evolved into an approved and efficacious treatment for movement, obsessive-compulsive, and epilepsy disorders that are refractory to medical therapy, with current investigation into other disease conditions. However, there are unintentional and intentional sources of external electromagnetic interference (EMI) that can lead to either malfunctioning or damaged DBS devices, as well as injury to human tissue. Comprehensive studies and guidelines on such topics in the medical literature are scarce. Herein, we review the principles behind EMI, as well as the various potential sources of interference, both unintentional (e.g. stray EMI fields) and intentional (e.g. MRI scans, "brainjacking"). Additionally, we employ the Manufacturer and User Device Facility Experience (MAUDE) database to assess real-world instances of EMI (e.g., airport body scanners, magnetic resonance imaging (MRI), and electrosurgery) affecting DBS devices commonly implanted in the United States (US).

Los teléfonos móviles como potencial vehículo de infección en un entorno hospitalario

ResumenEl objetivo de este artículo es investigar el posible papel desempeñado por los teléfonos móviles como depósitos de colonización bacteriana y los factores de riesgo que ésta conlleva en un ambiente hospitalario. Entre enero de 2013 y marzo de 2014 examinamos a 226 miembros del personal de un hospital regional de Australia (146 médicos y 80 estudiantes de medicina). Los principales resultados de interés se relacionaron con los tipos de microorganismos y la cantidad de contaminación encontrados en los teléfonos móviles. Este estudio mostró la existencia de un alto nivel de contaminación bacteriana (n = 168/226, 74%) en los teléfonos móviles de los funcionarios de un hospital de atención terciaria, aislándose organismos similares en la mano dominante del personal y en sus teléfonos móviles. Mientras que la mayoría de los organismos aislados pertenecía a la flora cutánea normal, un pequeño porcentaje era potencialmente patógeno (n = 12/226, 5%). Además, se encontró que ser miembro subalterno del personal médico constituía un factor de riesgo para un importante crecimiento microbiano (OR 4.00, 95% CI 1.54, 10.37). Sólo 31% (70/226) de los participantes en el estudio informó que limpiaba sus teléfonos regularmente y sólo 21% (47/226) reportó que usa toallitas con alcohol para la limpieza de su teléfono. Este estudio demuestra que los teléfonos móviles son potenciales vehículos de bacterias patógenas en un ambiente hospitalario. Sólo una minoría de participantes informó que limpia su teléfono regularmente. Deberían elaborarse y aplicarse directrices de desinfección utilizando toallitas con alcohol.

Review of Polymer Composites with Diverse Nanofillers for Electromagnetic Interference Shielding

Polymer matrix composites have generated a great deal of attention in recent decades in various fields due to numerous advantages polymer offer. The advancement of technology has led to stringent requirements in shielding materials as more and more electronic devices are known to cause electromagnetic interference (EMI) in other devices. The drive to fabricate alternative materials is generated by the shortcomings of the existing metallic panels. While polymers are more economical, easy to fabricate, and corrosion resistant, they are known to be inherent electrical insulators. Since high electrical conductivity is a sought after property of EMI shielding materials, polymers with fillers to increase their electrical conductivity are commonly investigated for EMI shielding. Recently, composites with nanofillers also have attracted attention due to the superior properties they provide compared to their micro counterparts. In this review polymer composites with various types of fillers have been analysed to assess the EMI shielding properties generated by each. Apart from the properties, the manufacturing processes and morphological properties of composites have been analysed in this review to find the best polymer matrix composites for EMI shielding.

Can active signals of cellphone interfere with electronic working length determination of a root canal in a dental clinic? An in vivo study

Objective:

To evaluate the interference of active cellphones during electronic working length (EWL) determination of a root canal.

Materials and Methods:

Thirty patients requiring root canal treatment in the anterior teeth or premolars having single canal and mature apices were selected for this study. Working length determination was done using no. 15 K-file. Electronic apex locators ProPex Pixi and Root ZX mini were used for working length determination. Cellphones iPhone 6s and Xolo Q3000 were evaluated for their interference. The experiment was conducted in a closed room (9 feet × 9 feet). Working length was measured with no cellphone in the room, iPhone 6s in a calling mode, Xolo Q3000 in a calling mode, and Xolo Q3000 and iPhone 6s simultaneously in a calling mode. Stability of the readings was also determined for every condition.

Statistical Analysis:

The data were statistically analyzed using one-way ANOVA and paired t-test at 0.05 level of significance.

Results:

Results were not statistically significant.

Conclusion:

Within the limitations of the present study, cellphones do not interfere with the EWL determination.

Questionnaire-based evaluation of mobile phone interference with medical-electrical equipment in Swedish hospitals

National recommendations in Sweden recommend a safety distance of 3 meter (m) between mobile phones and medical-electrical (ME) equipment in hospitals. A questionnaire was used to investigate how often mobile phones were reported to interfere with ME products in clinical practice across Sweden. The results confirmed that ME equipment can be affected by mobile phone use but, the risk of the patient's outcome being affected were minimal; no cases were identified which led to injury or death. In conclusion, the results support recommendations for a general safety distance of 0.5 m between mobile phones and ME equipment in care environments.

Segregated Hybrid Poly(methyl methacrylate)/Graphene/Magnetite Nanocomposites for Electromagnetic Interference Shielding

Nanocomposites of poly(methyl methacrylate)/reduced graphene oxide (PMMA/rGO) without and with decorated magnetite nanoparticles with a segregated structure were prepared using emulsifier-free emulsion polymerization. Various characterization techniques were employed to validate the presence of the nanofillers and the formation of the segregated structure within the nanocomposites. The percolation threshold of the nanocomposites was found to be 0.3 vol %, while a maximum electrical conductivity of 91.2 S·m^-1 and electromagnetic interference shielding effectiveness (EMI SE) of 63.2 dB (2.9 mm thickness) were achieved for the PMMA/rGO nanocomposites at a loading of 2.6 vol % rGO. It was also observed that decorating rGO with magnetite nanoparticles (hybrid nanocomposites) led to a tremendous increase in EMI SE. For instance, 1.1 vol % PMMA/rGO nanocomposites indicated an EMI SE of 20.7 dB, while adding 0.5 vol % magnetite nanoparticles enhanced EMI SE to 29.3 dB. The excellent electrical properties obtained for these nanocomposites were ascribed to both superiorities of the segregated conductive structure and magnetic properties of the magnetite nanoparticles.

ELISA reader does not interfere by mobile phone radiofrequency radiation

BACKGROUND

The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory.

MATERIALS AND METHODS

Human serum samples were collected from 14 healthy donors (9 women and 5 men) and each sample was divided into four aliquots and was placed into four batches for the in-vitro quantitative determination of human chorionic gonadotropin (hCG). During colorimetric reading of the first, second, and third batches, the ELISA reader (Stat Fax 2100, Awareness Technology, Inc., USA) was exposed to 0.5, 1.0, and 2.0 W exposure of 900 MHz radiation, respectively. For the forth batch (control group), no radiation was applied. All experiments were performed comparing ELISA read out results of the I, II, and III batches with the control batch, using the Wilcoxon test with criterion level of P = 0.050.

RESULTS

The final scores in the exposed batches I, II, and III were not statistically significant relative to the control batch (P > 0.05). The results showed that 900 MHz radiation exposure did not alter the ELISA measured levels of hCG hormone in I (P = 0.219), II (P = 0.909), and III (P = 0.056) batches compared to the control batch.

CONCLUSION

This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance). However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors.

Evaluation of Interference of Cellular Phones on Electronic Apex Locators: An In Vitro Study

INTRODUCTION

Use of mobile phone has been prohibited in many hospitals to prevent interference with medical devices. Electromagnetic radiation emitted from cellular phones might interfere with electronic working length determination. The purpose of this in vitro study was to evaluate the effect of a smart phone (Samsung Galaxy Note Edge) on working length determination of electronic apex locators (EALs) Propex II and Rootor.

METHODS

Fifteen intact, non-carious single-rooted teeth were decoronated at the cementoenamel junction. Visually, working length was determined by using a #15 K-file under stereomicroscope (×20). The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: (1) in a closed room with poor signal strength and (2) in a polyclinic set up with good signal strength and 5 conditions: (1) electronically, without cellular phone in room; (2) electronically, with cellular phone in physical contact with EAL; (3) electronically, with mobile phone in physical contact with EAL and in calling mode for a period of 25 seconds; (4) electronically, mobile phone placed at a distance of 40 cm from the EAL; and (5) electronically, mobile phone placed at a distance of 40 cm and in calling mode for a period of 25 seconds. The EWL was measured 3 times per tooth under each condition. Stability of the readings was scored from 1 to 3: (1) good stability, (2) stable reading after 1 attempt, and (3) stable reading after 2 attempts. The data were compared by using analysis of variance.

RESULTS

The EWL measurements were not influenced by the presence of cellular phone and could be determined under all experimental conditions.

CONCLUSIONS

Within the limitations of this study, it can be concluded that mobile phones do not interfere with the EWL determination.

Synergic effect of graphene and MWCNT fillers on electromagnetic shielding properties of graphene–MWCNT/ABS nanocomposites

Graphene–MWCNT/ABS nanocomposites have been prepared using a solvent-free dry tumble mixing process followed by hot compaction.

Interference of mobile phones and digitally enhanced cordless telecommunications mobile phones in renal scintigraphy

PURPOSE

The aim of the study was to assess the potential negative impact of cellular phones and digitally enhanced cordless telecommunication (DECT) devices on the quality of static and dynamic scintigraphy to avoid repeated testing in infant and teenage patients to protect them from unnecessary radiation exposure.

METHODS

The assessment was conducted by performing phantom measurements under real conditions. A functional renal-phantom acting as a pair of kidneys in dynamic scans was created. Data were collected using the setup of cellular phones and DECT phones placed in different positions in relation to a camera head to test the potential interference of cellular phones and DECT phones with the cameras.

RESULTS

Cellular phones reproducibly interfered with the oldest type of gamma camera, which, because of its single-head specification, is the device most often used for renal examinations. Curves indicating the renal function were considerably disrupted; cellular phones as well as DECT phones showed a disturbance concerning static acquisition.

CONCLUSIONS

Variable electromagnetic tolerance in different types of γ-cameras could be identified. Moreover, a straightforward, low-cost method of testing the susceptibility of equipment to interference caused by cellular phones and DECT phones was generated. Even though some departments use newer models of γ-cameras, which are less susceptible to electromagnetic interference, we recommend testing examination rooms to avoid any interference caused by cellular phones. The potential electromagnetic interference should be taken into account when the purchase of new sensitive medical equipment is being considered, not least because the technology of mobile communication is developing fast, which also means that different standards of wave bands will be issued in the future.

Increasing clinical presence of mobile communication technology: avoiding the pitfalls

Mobile communication technologies are employed in many diverse areas of healthcare delivery to provide improved quality and efficiency of communication and facilitate increased rapidity of data or information transfer. Mobile phones enable healthcare professionals to possess a portable platform from which to provide many healthcare-related applications and are a popular means to directly communicate with colleagues and patients. As involvement of mobile communication technology in healthcare delivery continues to rapidly expand, there are also important considerations of relevance to patient safety and security as a result. Here, we review the previous evidence of reported clinical risks associated with mobile communication technology, such as electromagnetic interference, confidentiality and data security, distraction/noise, infection control, and cross contamination. In conclusion, although mobile phones provide much putative potential improvement to healthcare delivery, further evaluation and research are required to both inform and protect health professionals and users of such technology in the healthcare environment and provide the evidence base to support the provision of clear and comprehensive guidelines.

Perceptions and attitudes of hospital staff toward paging system and the use of mobile phones

OBJECTIVES

Our objective was to document the pattern of mobile phone usage by medical staff in a hospital setting, and to explore any perceived benefits (such as improved communications) associated with mobile phones.

METHODS

This cross-sectional survey was conducted in Waterford Regional Hospital, Ireland, where bleep is the official system of communication. All non-consultant hospital doctors, of medical disciplines only, were asked to participate. The questionnaire was designed to explore the pattern and different aspects of mobile phone usage.

RESULTS

At the time of study, there were sixty medical junior doctors, and the response rate was 100 percent. All participants used mobile phones while at work, and also for hospital-related work. For 98.3 percent the mobile phone was their main mode of communication while in the hospital. Sixty-two percent (n = 37) made 6-10 calls daily purely for work-related business, and this comprised of ≥ 80 percent of their daily usage of mobile phones. For 98 percent of participants, most phone calls were work-related. Regarding reasons for using mobile phones, all reported that using mobile phone is quicker for communication.

CONCLUSIONS

Mobile phone usage is very common among the medical personnel, and this is regarded as a more efficient means of communication for mobile staff than the hospital paging system.

Effects of mobile phone use on specific intensive care unit devices

Background and Aims:

To observe the effects of mobile phone use in the vicinity of medical devices used in a critical care setting.

Subjects and Methods:

Electromagnetic interference (EMI) was tested by using two types of mobile phones – GSM and CDMA. Mobile phones were placed at a distance of one foot from three medical devices – syringe pump, mechanical ventilator, and the bedside monitor – in switch off, standby, and talking modes of the phone. Medical devices were observed for any interference caused by the electromagnetic radiations (EMR) from the mobile phones.

Results:

Out of the three medical devices that were tested, EMI occurred while using the mobile phone in the vicinity of the syringe pump, in the ‘talk mode.’ The mean variation observed in the calculated and delivered volume of the syringe pump was 2.66 ml. Mechanical ventilator did not show any specific adverse effects with mobile phone use in the one-foot vicinity. No other adverse effects or unexplained malfunctions or shutdown of the syringe pump, mechanical ventilator, or the bedside monitor was noted during the study period of 36 hours.

Conclusion:

EMI from mobile phones have an adverse effect on the medical devices used in critical care setup. They should be used at least one foot away from the diameter of the syringe pump.

Text message communication in primary care research: a randomized controlled trial

BACKGROUND

Text message communication is increasingly used in clinical practice but rarely in research. Particularly in young people, this method of participation in primary care research appears both feasible and acceptable. However, previous experience shows that text messaging for research may lead to lower response rates. Aim. To test the hypothesis that text message communication in primary care research does not lead to lower response rates compared to a paper-based method.

METHODS

This randomized controlled trial took place in 26 randomly selected practices in Victoria, Australia. Consecutive patients aged 16-24 years attending general practice appointments were recruited as part of a larger study on patients' perspectives. Patients owning a mobile phone were randomized to receive a question about satisfaction with the consultation either by text message or on a card completed before leaving the practice. Logistic regression was used to estimate the effect on the response rate of using text message rather than the card method, adjusting for clustering within practices and for differences in baseline characteristics among participants.

RESULTS

In total, 402 of 409 eligible young people agreed to participate and were randomized to either receive a text message (n = 193) or a card enquiry (n = 209). The response rate was 80.2% [95% confidence interval (CI): 73.3-87.1%] with text message and 85.6% (95% CI: 79.6-91.7%) with the card. The adjusted odds of responding (odds ratio: 0.62; 95% CI: 0.30-1.27) were not significantly lower in the group using text messaging compared to the group using the card response method.

CONCLUSION

These findings offer new perspectives for use of text message communication to gather information from patients in primary care research.

Effect of a printed reminder in the waiting room to turn off mobile phones during consultation: a before and after study

BACKGROUND

Telephone interruptions during consultations are one cause of work-related stress amongst general practitioners. Many health care centers recommend that patients turn off any mobile phones to avoid interruptions to the discussion with the physicians.

METHODS

The purpose of this before and after study was to determine whether a printed reminder for turning off the mobile phone in the waiting room is helpful in decreasing the number of interruptions during consultation. A visual phone off sign utilizing the International "No" symbol of a diagonal line through a circle, along with a "please turn off your phone during consultation" reminder was used in the waiting room in the "after" period.

RESULTS

A significant difference was found in the proportion of patients receiving or making a call during the consultation (8.8% vs. 13.5%, RR = 0.66; 95%CI 0.46-0.94; p = 0.021) and in the total number of calls (10.4% vs. 17.3%, RR = 0.60; 95%CI 0.44-0.83, p = 0.003) between the exposed and the non-exposed groups. However, no significant differences were found in the total time or the median time spent talking during consultation. The duration of the calls had median times of 20.5 seconds and 22.3 seconds in the exposed and the non-exposed groups respectively. Women from both groups who received a call during consultation answered significantly more when compared to men (70% vs. 52%; p = 0.05);

CONCLUSION

Our findings suggest that a printed reminder in the waiting room is helpful in decreasing the number of interruptions by mobile phone during consultation in our settings. The study provides the basis for further quantitative and qualitative research on this topic.

Review of mobile communication devices as potential reservoirs of nosocomial pathogens

Innovation in mobile communication technology has provided novel approaches to the delivery of healthcare and improvements in the speed and quality of routine medical communication. Bacterial contamination of mobile communication devices (MCDs) could be an important issue affecting the implementation of effective infection control measures and might have an impact on efforts to reduce cross-contamination. This review examines recent studies reporting bacterial contamination of MCDs, most demonstrating that 9-25% of MCDs are contaminated with pathogenic bacteria. We examine previously investigated risk factors for MCD contamination in addition to work on surface decontamination of the device. Recommendations to reduce contamination risks include staff education, strict hand hygiene measures, guidelines on device cleaning and consideration of the restrictions regarding use of mobile phone technology in certain high risk areas, for example, operating theatres, intensive care units and burns units. Further work is required to evaluate the benefit of such interventions on MCD contamination and to determine whether a link exists between contamination and subsequent patient infection.

Use of mobile phones by medical staff at Queen Elizabeth Hospital, Barbados: evidence for both benefit and harm

All members of medical staff, including students, were asked to participate in a self-administered questionnaire concerning patterns of mobile phone use and care. Participants' phones were cultured for micro-organisms. Healthcare professionals working in close proximity to sensitive equipment were surveyed concerning adverse events associated with mobile phones. Telephone operators were asked to monitor time elapsed as they attempted to contact medical staff by various methods. Of 266 medical staff and students at the time of the study, 116 completed questionnaires (response rate=44%). Almost all (98%) used mobile phones: 67% used their mobile phones for hospital-related matters; 47% reported using their phone while attending patients. Only 3% reported washing their hands after use and 53% reported never cleaning their phone. In total, 101 mobile phones were cultured for micro-organisms; 45% were culture-positive and 15% grew Gram-negative pathogens. The survey of staff working in close proximity to sensitive equipment revealed only one report of minor interference with life-saving equipment. Telephone operators were able to contact medical staff within 2 min most easily by mobile phone. Mobile phones were used widely by staff and were considered by most participants as a more efficient means of communication. However, microbial contamination is a risk associated with the infrequent cleaning of phones. Hospitals should develop policies to address the hygiene of mobile phones.

Interference by new-generation mobile phones on critical care medical equipment

Introduction

The aim of the study was to assess and classify incidents of electromagnetic interference (EMI) by second-generation and third-generation mobile phones on critical care medical equipment.

Methods

EMI was assessed with two General Packet Radio Service (GPRS) signals (900 MHz, 2 W, two different time-slot occupations) and one Universal Mobile Telecommunications System (UMTS) signal (1,947.2 MHz, 0.2 W), corresponding to maximal transmit performance of mobile phones in daily practice, generated under controlled conditions in the proximity of 61 medical devices. Incidents of EMI were classified in accordance with an adjusted critical care event scale.

Results

A total of 61 medical devices in 17 categories (27 different manufacturers) were tested and demonstrated 48 incidents in 26 devices (43%); 16 (33%) were classified as hazardous, 20 (42%) as significant and 12 (25%) as light. The GPRS-1 signal induced the most EMI incidents (41%), the GRPS-2 signal induced fewer (25%) and the UMTS signal induced the least (13%; P < 0.001). The median distance between antenna and medical device for EMI incidents was 3 cm (range 0.1 to 500 cm). One hazardous incident occurred beyond 100 cm (in a ventilator with GRPS-1 signal at 300 cm).

Conclusion

Critical care equipment is vulnerable to EMI by new-generation wireless telecommunication technologies with median distances of about 3 cm. The policy to keep mobile phones '1 meter' from the critical care bedside in combination with easily accessed areas of unrestricted use still seems warranted.

Clinical testing of cellular phone ringing interference with automated external defibrillators

OBJECTIVE

This study examined cellular phone ringing interference with automated external defibrillators (AED).

METHODS

The phone systems tested were two single band handheld telephones: (1) a Global System for Mobile Communication (GSM) receiver; and (2) a Personal Communication Services (PCS) receiver. The ringing phase of a digital cellular phone includes a brief burst of peak-emitted power. The GSM had a maximum power output of 2 W, operating on a 900 MHz carrier frequency, and the PCS had a maximum output of 1 W, operating on a 1800 MHz carrier frequency. During AED monitoring, the digital cellular telephone was placed successively in three positions: (1) on the AED; (2) on the patient's chest between the electrodes; and (3) on the connector between the electrodes and the AED cable. After positioning the cellular phone, calls were placed during the AED analyzing phase.

RESULTS

Three AED models were tested using their original electrodes: (1) LifePak 20 monitor/defibrillator device; (2) Lifepak 20 P monitor/defibrillator/stimulator (Medtronic Emergency Response Systems, Redmond, WA, USA); and (3) HeartStart XL M4735A monitor/defibrillator (Philips Medical Systems, Andover, MA, USA). The first two devices had Quik-Combo electrodes and the third device had Adults Plus multifunction electrodes. Ninety-one tests were performed on 13 patients. The only disturbance provoked by testing was noise emitted by the AED speaker when the receiver was close to the device. The noise began 2-4 s before the first audible ringing tone and persisted throughout the ringing phase. The distance at which this effect could be prevented was 15 cm.

CONCLUSION

Clinical testing during ECG monitoring by an AED during call from a cellular phone did not show any analysis dysfunction during unshockable rhythms and provoked only transient dysfunction of the speaker device.

Electromagnetic interference in critical care

Mobile communication and wireless data transmission are playing an increasing role in health care. Reports describing medical device malfunction related to cellular phones have raised awareness about the problem of electromagnetic interference. Although initial institutional responses were to ban cellular devices in hospitals, these restrictions are relaxing as the knowledge base in this area expands. Medical device malfunction is extremely rare if the distance from the transmitting device is greater than 1 m. This article reviews the current understanding of electromagnetic interference as it applies to the technology-rich critical care environment.

Evidence-based policy? The use of mobile phones in hospital

BACKGROUND

Evidence-based policies have become increasingly accepted in clinical practice. However, policies on many of the non-clinical activities that take place in health care facilities may be less frequently evidence based.

METHODS

We carried out a review of literature on safety of mobile phones in hospitals and survey of practice in selected European countries.

RESULTS

When first evidence on the dangers of electronic interference associated with mobile phones appeared in the 1990s, hospitals in many countries introduced complete bans on mobile phones. Yet a review of recent evidence suggests that there is no significant risk from using mobile phones in hospitals as long as they are more than a metre away from sensitive equipment, whereas the risk to the most modern equipment is even less. With the technological evolution of mobile phones, the residual risk of interference appears to be minimal and controllable. Although some countries are reluctant to relax regulation, others now limit bans to areas in which sensitive equipment is used and some discourage the use of mobile phones on the grounds of noise exposure.

CONCLUSION

With new technology on the doorstep, the potential benefits and risks associated with mobile phones should be examined explicitly in the light of the evidence.

Wireless technologies and patient safety in hospitals

In the development of policies for wireless technologies, it is important for healthcare organizations to reduce risks to patients from use of wireless devices. Policy should be devised for instructing hospital staff, visitors, and patients, avoiding unwarranted restrictions but not ignoring evidence regarding potential interference problems, and allowing comparison with other clinical facilities of benefits of policy. To inform policy developers and a general audience of hospital personnel, a review was conducted on the safety of wireless devices for communication within hospitals. This review targeted electromagnetic interference effects of devices on medical devices and summarises key recommendations from published reports and international standards. There is consensus that the highest risk of interference occurs with two-way radios used by emergency crews, followed by mobile phones, while radio local area networks produce negligible interference. Wireless technologies are deemed suitable for use throughout hospital areas including intensive care units and operating rooms, given that recommended separation distances from medical equipment are observed.

Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m(-1) (E-field 400 V m(-1)). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy.

Digital mobile telephones and interference of ophthalmic equipment

AIM

To assess the effect of mobile telephone electromagnetic interference on electronic ophthalmic equipment.

METHODS

Prospective audit with mobile telephones placed at distances of 3 m, 1 m, and 30 cm from, and in contact with, electronic ophthalmic equipment. Any interruption or cessation of the function of the ophthalmic device was assessed with the mobile telephones in standby, and in dialling or receiving modes. Any alterations of displayed digital figures or numbers were also assessed.

RESULTS

A total of 23 electronic ophthalmic devices in two hospital ophthalmology outpatient departments were evaluated. All six mobile telephones used, and 22 (95.7%) of the 23 ophthalmic equipment evaluated had the Conformité Européene (CE) mark. No device showed any interruption or cessation of function. There were no alterations of displayed digital figures or numbers. The only effect of any kind was found with four instruments (1 non-CE marked), where there was temporary flickering on the screen, and only occurred when the mobile telephones were dialling or receiving at a distance of 30 cm or less from the instruments.

CONCLUSION

This study shows that among the electronic ophthalmic devices tested, none suffered failure or interruption of function, from mobile telephone interference. Although not comprehensive for all ophthalmic equipment, the results question the need for a complete ban of mobile telephones in ophthalmic departments. It highlights the need for a controlled, objectively measured study of the clinically relevant effects of mobile telephones in the ophthalmology outpatient setting.

Mobile phones and health: a literature overview

The rapidly evolving mobile phone technology raised public concern about the possibility of associated adverse health effects. The current body of evidence is summarized addressing epidemiological studies, studies investigating adverse biological effects, other biological effects, basic mechanisms and indirect effects. Currently, the balance of evidence from epidemiological studies suggests that there is no association between mobile phone radiation and cancer. This finding is consistent with experimental results. There is some evidence for biological effects, which, however, are not necessarily hazardous for humans. No basic mechanisms of biological effects have been consistently identified yet. Using a mobile phone while driving a car is significantly associated with a higher risk of vehicle collisions, independently of the use of hands-free kits. Medical equipment or implanted pacemakers may be affected by mobile phone radiation under very specific conditions. Current studies, however are affected by several limitations and do not generally exclude any increased health risk. Further high-quality research is therefore necessary. Furthermore, it is important that the results of scientific research are communicated to the public in a transparent and differentiated way.

Clinical review: communication and logistics in the response to the 1998 terrorist bombing in Omagh, Northern Ireland

The Omagh bombing in August 1998 produced many of the problems documented in other major incidents. An initial imbalance between the demand and supply of clinical resources at the local hospital, poor information due to telecommunication problems, the need to triage victims and the need to transport the most severely injured significant distances were the most serious issues. The Royal Group Hospitals Trust (RGHT) received 30 severely injured secondary transfers over a 5-hour period, which stressed the hospital's systems even with the presence of extra staff that arrived voluntarily before the hospital's major incident plan was activated. Many patients were transferred to the RGHT by helicopter, but much of the time the gained advantage was lost due to lack of a helipad within the RGHT site. Identifying patients and tracking them through the hospital system was problematic. While the major incident plan ensured that communication with the relatives and the media was effective and timely, communication between the key clinical and managerial staff was hampered by the need to be mobile and by the limitations of the internal telephone system. The use of mobile anaesthetic teams helped maintain the flow of patients between the Emergency Department and radiology, operating theatres or the intensive care unit (ICU). The mobile anaesthetic teams were also responsible for efficient and timely resupply of the Emergency Department, which worked well. In the days that followed many victims required further surgical procedures. Coordination of the multidisciplinary teams required for many of these procedures was difficult. Although only seven patients required admission to adult general intensive care, no ICU beds were available for other admissions over the following 5 days. A total of 165 days of adult ICU treatment were required for the victims of the bombing.

Cell-phone interference with pocket dosimeters

Accurate reporting of personal dose is required by regulation for hospital personnel that work with radioactive material. Pocket dosimeters are commonly used for monitoring this personal dose. We show that operating a cell phone in the vicinity of a pocket dosimeter can introduce large and erroneous readings of the dosimeter. This note reports a systematic study of this electromagnetic interference. We found that simple practical measures are enough to mitigate this problem, such as increasing the distance between the cell phone and the dosimeter or shielding the dosimeter, while maintaining its sensitivity to ionizing radiation, by placing it inside a common anti-static bag.