Electromagnetic Interference of Communication Devices on ECG Machines

Abstract

Background: Use of communication devices in the hospital environment remains controversial. Electromagnetic interference (EMI) can affect different medical devices. Potential sources for EMI on ECG machines were systematically tested. Hypothesis: Communication devices produce EMI on ECG machines. EMI impairs ECG interpretation.Methods: The communication devices tested were: a global system for mobile communication (GSM) receiver, a code division multiple access (CDMA) receiver, an analog phone, a wireless local area network, and an alpha-numeric pager. EMI was tested on 3 ECG machines: MAC 5000, MAC 1200, and ELI 100. The devices were tested at 2 and 1 meter, 50, 25, and 0 cm from the acquisition module. The ECGs were presented to a heterogeneous group of clinical providers, (medical students, residents, nurses, industry representatives from cardiac devices companies, and attending cardiologists) to evaluate the impact of EMI on ECG interpretation skills. Results: EMI was detected on the MAC 5000 ECG machine when activated GSM, CDMA, and analog phones were placed on top of the acquisition module. No EMI was seen on the other ECG machines or when phones were at a longer distance or deactivated. EMI was incorrectly diagnosed in 18% of the cases. EMI was confused most frequently with atrial fibrillation or flutter (52%), ventricular arrhythmias (22%), and pacemaker dysfunction (26%). Medical students ( p<0.003) and non-cardiology residents ( p = 0.05) demonstrated significantly worse performance on EMI interpretation. Conclusions: Digital and analog phones produce EMI on modern ECG machines when activated in direct contact to the acquisition module. EMI impairs ECG interpretation.

Electrocardiography Pitfalls and Artifacts: The 10 Commandments

“…[18][19][20][21] Even though considerable controversy remains about the use of cell phones in hospitals, the evidence is clear that cell phones can produce EMI with many different medical devices (eg, ECG monitor, ventilator, infusion pump, dialysis machine, apnea monitor, external pacemaker, internal pacemaker, and defibrillator). The ability of a cell phone or a wireless device to induce EMI depends on the distance, the ability of medical equipment to resist EMI, and the technology of the cell phone (digital vs analog, which are the 2 basic systems cell phones use to operate, and single-band of operation vs dual and frequency band of operation).…”

“…Only a few cases in which cell phones and wireless devices interfered with ECG machines have been reported. 20 We simulated a case created in our laboratory by activating a cell phone (digital) less than 25 cm (9.8 in) from the ECG machine acquisition module (MAC 5000 Resting ECG Analysis System, GE Medical Systems, Waukesha, Wisconsin). The rapid, sharp, and low-amplitude signals disappeared when the cell phone was removed or deactivated ( Figure 7).…”

Influence of Mobile Phones on the Quality of ECG Signal Acquired by Medical Devices

“…In the hospitals many medical devices can produce EMI, e.g., magnetic resonance image scanners, electrosurgery, defibrillation, neurostimulators, radiofrequency catheter ablation, and therapeutic diathermy. There are numerous reports of the influence of various types of radio transmitters on medical equipment [1][2][3][4][5][6]. Adverse event reports related, inter alia, to EMI between medical devices and wireless communication equipment are available at the special US database [7].…”

“…EMI, like other artifacts, could result in wrong diagnosis leading to inappropriate medical treatment and medical errors [2,32,33].…”

Distance and Location of Both Mobile Phones and Health Care Units: Determines the Interference Level

“…It has been reported [1,2] that mobile phones are interfering recordings and results incorrect data collection which is well known that any electromagnetic source [3] can harm electronic equipments as well as the living [4]. Mobile phones are very important interfering sources especially in the area having poor coverage (low signal level, <-90dBm).…”