Digital mobile telephones and interference of ophthalmic equipment

Primary Salvage Survey of the Interference of Radiowaves Emitted by Smartphones on Medical Equipment

Use of mobile phones has become a standard reality of everyday living for many people worldwide, including medical professionals, as data sharing has drastically helped to improve quality of care. This increase in the use of mobile phones within hospitals and medical facilities has raised concern regarding the influence of radio waves on medical equipment. Although comprehensive studies have examined the effects of electromagnetic interference from 2G wireless communication and personal digital cellular systems on medical equipment, similar studies on more recent wireless technologies such as Long Term Evolution, wideband code division multiple access, and high-speed uplink access have yet to be published. Numerous tests targeting current wireless technologies were conducted between December 2012 and March 2013 in an anechoic chamber, shielded from external radio signals, with a dipole antenna to assess the effects of smartphone interference on several types of medical equipment. The interference produced by electromagnetic waves across five frequency bands from four telecommunication standards was assessed on 49 components from 22 pieces of medical equipment. Of the 22 pieces of medical equipment tested, 13 experienced interference at maximum transmission power. In contrast, at minimum transmission power, the maximum interference distance varied from 2 to 5 cm for different wireless devices. Four machines were affected at the minimum transmission power, and the maximum interference distance at the maximum transmission power was 38 cm. Results show that the interference from smartphones on medical equipment is very controllable.

The electromagnetic interference of mobile phones on the function of a γ-camera

PURPOSE

The aim of the present study is to evaluate whether or not the electromagnetic field generated by mobile phones interferes with the function of a SPECT γ-camera during data acquisition.

METHODS

We tested the effects of 7 models of mobile phones on 1 SPECT γ-camera. The mobile phones were tested when making a call, in ringing mode, and in standby mode. The γ-camera function was assessed during data acquisition from a planar source and a point source of Tc with activities of 10 mCi and 3 mCi, respectively. A significant visual decrease in count number was considered to be electromagnetic interference (EMI).

RESULTS

The percentage of induced EMI with the γ-camera per mobile phone was in the range of 0% to 100%. The incidence of EMI was mainly observed in the first seconds of ringing and then mitigated in the following frames.

CONCLUSIONS

Mobile phones are portable sources of electromagnetic radiation, and there is interference potential with the function of SPECT γ-cameras leading to adverse effects on the quality of the acquired images.

An update on mobile phones interference with medical devices

Mobile phones' electromagnetic interference with medical devices is an important issue for the medical safety of patients who are using life-supporting medical devices. This review mainly focuses on mobile phones' interference with implanted medical devices and with medical equipment located in critical areas of hospitals. A close look at the findings reveals that mobile phones may adversely affect the functioning of medical devices, and the specific effect and the degree of interference depend on the applied technology and the separation distance. According to the studies' findings and the authors' recommendations, besides mitigating interference, using mobile phones at a reasonable distance from medical devices and developing technology standards can lead to their effective use in hospital communication systems.

Patient safety and electromagnetic protection: a review

A systematic literature review was carried out to study patient security and possible harmful effects, immunity and interferences on medical devices, and effectiveness and transmission problems in healthcare and hospital environments due to electromagnetic interferences. The objective was to determine already-reported cases of patient security, immunity of medical devices, and transmission/reception failure in order to evaluate safety and security of patients. Literature published in the last 10 years has been reviewed by searching in bibliographic databases, journals, and proceedings of conferences. Search strategies developed in electronic databases identified a total of 820 references, with 50 finally being included. The study reveals the existence of numerous publications on interferences in medical devices due to radiofrequency fields. However, literature on effectiveness, transmission problems and measurements of electromagnetic fields is limited. From the studies collected, it can be concluded that several cases of serious interferences in medical instruments have been reported. Measures of electromagnetic fields in healthcare environments have been also reported, concluding that special protective measures should be taken against electromagnetic interferences by incoming radio waves.