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Results of the induced voltage for the homogenous exposure for (a) the bipolar lead, and (b) the unipolar lead. The linear fit to the measured values is indicated by the solid lines. The dashed lines indicate the extrapolation of the linear fit to the ranges where no induced voltages were measured due to the operation range of the used differential amplifier of the measurement system.  

Results of the induced voltage for the homogenous exposure for (a) the bipolar lead, and (b) the unipolar lead. The linear fit to the measured values is indicated by the solid lines. The dashed lines indicate the extrapolation of the linear fit to the ranges where no induced voltages were measured due to the operation range of the used differential amplifier of the measurement system.  

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Article
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Electromagnetic interference is a concern for people wearing cardiovascular implantable electronic devices (CIEDs). The aim of this study was to assess the electromagnetic compatibility between CIEDs and the magnetic field of a common wireless charging technology. To do so the voltage induced in CIEDs by Qi A13 design magnetic fields were measured...

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... results of the induced voltage for the four implantation sites and the two lead types are shown in Figure 2 together with the performance limits of ISO 14117. The results of the linear fit of the measured voltage are given in Table 1 and shown in Figure 2. The induced voltage and the performance limit are always expressed as peak values, however, the magnetic flux density as root mean square. ...
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... results of the induced voltage for the four implantation sites and the two lead types are shown in Figure 2 together with the performance limits of ISO 14117. The results of the linear fit of the measured voltage are given in Table 1 and shown in Figure 2. The induced voltage and the performance limit are always expressed as peak values, however, the magnetic flux density as root mean square. ...
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... shown in Table 1 and Figure 2 the induced voltage was strongly dependent on the implantation site and the lead type (bipolar/unipolar). On the left-pectoral implantation sites the voltages induced in unipolar leads were 5.8 to 7.6 times higher in comparison to the bipolar leads (cf. ...
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... the performance limit is exceeded at lower magnetic flux densities (cf. Figure 2). The lowest magnetic flux density at which the bipolar performance limit (33.3 mV) was exceeded is 11.0 µT. ...
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... lowest magnetic flux density at which the unipolar performance limit (333 mV) was exceeded is 19.4 µT considering linear correlation between the flux density and the induced voltage (cf. Figure 2 dashed lines). In both cases the first exceedance occurred at the left-pectoral ventricle position (red curve in Figure 2). ...
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... lowest magnetic flux density at which the unipolar performance limit (333 mV) was exceeded is 19.4 µT considering linear correlation between the flux density and the induced voltage (cf. Figure 2 dashed lines). In both cases the first exceedance occurred at the left-pectoral ventricle position (red curve in Figure 2). On the right-pectoral implantation sites, clearly less voltage was induced than on the left pectoral implantation sites-2.3 to 5.7 times lower for the bipolar lead and 7.6 to 32.4 times lower for the unipolar lead (cf. ...
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... the right-pectoral ventricle position exceeded the performance limit at 25.6 µT (cf. green curve Figure 2a). The other three implantation sites (RPA unipolar and bipolar, RPV unipolar) kept clearly below the limits of ISO 14117 even at maximum exposure. ...
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... quality criterion states a very good compliance of the measured voltage with the linear functions (cf. Figure 2 compliance of black dots with colored lines). Figure 3 shows a typical pinging sequence recorded during pinging mode of the Qi-A13-Board. ...
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... to Figure 2 the exceedance of the performance limits occurred at LPV-, LPA-and RPA-position for the bipolar lead and LPV-and LPA-position for the unipolar lead. However, this result should be understood in the context of the test conditions of ISO 14117. ...
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... programmed to unipolar sensing mode ought to be tested in 2.0 mV sensitivity setting and devices in bipolar sensing mode ought to be tested in 0.3 mV sensitivity setting. This means, if for the unipolar lead the same sensitivity setting and thus the same performance limit than for the bipolar lead had been considered, the induced voltage would be exceeded already at 1.83 µT (LPV-position in Figure 2b). These findings that EMI with CIEDs occurs at lower field levels when using unipolar instead of bipolar leads complies with in vivo investigations by Tiikkaja et al. [26]. ...
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... our study the dependency of the unipolar induction area is clearly shown (cf. Figure 2b). ...

Citations

... The magnetic strength of the Qi A13 wireless charging board (Samsung, Seoul, South Korea) was experimentally measured and found to be up to 1.27 G during the pre-charging "pinging" mode 2 cm from the board surface, which rapidly decayed to 0.024 G at 10 cm (units converted to G), well below the 90-G threshold. 24 Additionally, fixed rare-earth magnets incorporating elements such as neodymium, which are significantly stronger than the more common ferrite magnets, are being broadly incorporated into devices to provide attachment stability. Measurements collected from the AirPods Pro and their wireless charging case (Apple), the Microsoft Surface Pen (Microsoft Corporation, Redmond, WA, USA), and the second-generation Apple Pencil show that they produce magnetic fields of 10 G at distances as far as 29 mm, which are sufficient enough to cause EMI (peak magnetic fields are not reported). ...
... The WPC's Qi specification is the world's de facto wireless charging standard for small personal electronics. In [93], the health and safety considerations are presented for Qi-enabled devices. The authors also assessed the potential EM interference of a COTS-based NXP Qi-A13-enabled device as shown in Figure 12, when operated in the presence of active cardiovascular implantable electronic devices (CIEDs) with wireless power sources [94]. ...
... (a) EM interference test using a Qi-A13-Board. Test performed on torso phantom with CIED implant [93]. (b) NXP Qi-A13-Board [95]. ...
... (b) NXP Qi-A13-Board [95]. (c) Avid Technologies Qi receiver stimulator [93]. Table 6 represents an assortment of OEM and vendor RF transceiver-based COTS components which have been used to manufacture miniaturized IWMDs presented in the literature. ...
Article
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Over the past decade, there has been exponential growth in the per capita rate of medical patients around the world, and this is significantly straining the resources of healthcare institutes. Therefore, the reliance on smart commercial off-the-shelf (COTS) implantable wireless medical devices (IWMDs) is increasing among healthcare institutions to provide routine medical services, such as monitoring patients’ physiological signals and the remote delivery of therapeutic drugs. These smart COTS IWMDs reduce the necessity of recurring visits of patients to healthcare institutions and also mitigate physical contact, which can minimize the possibility of any potential spread of contagious diseases. Furthermore, the devices provide patients with the benefit of recuperating in familiar surroundings. As such, low-cost, ubiquitous COTS IWMDs have engendered the proliferation of telemedicine in healthcare to provide routine medical services. In this paper, a review work on COTS IWMDs is presented at a macro level to discuss the history of IWMDs, different networked COTS IWMDs, health and safety regulations of COTS IWMDs and the importance of organized procurement. Furthermore, we discuss the basic building blocks of IWMDs and how COTS components can contribute to build these blocks over widely researched custom-built application-specific integrated circuits.
... Electroniccigarettes, fitness sports bands, wireless chargers, headphones, and tablet speakers were found to cause inadvertent trigger of the magnetic mode. [8][9][10][11][12][13][14] With respect to other situations, given the large diffusion of iPhone 12, and the possibility that people can put their smartphones in a breast pocket or fall asleep with an iPhone immediately over the device, the unintentional activation of the magnet mode caused by iPhone 12 cannot be excluded. ...
Article
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Background: Pacemaker (PM) and implantable cardioverter defibrillators (ICD) are equipped with a magnetic sensor activated by external application of magnets to easily manage some functions of these devices. If activated inadvertently or outside a controlled environment and without the supervision of clinical personnel, this magnetic mode introduces a potential risk. In reality, the possibility of a static magnetic field affecting a PM or ICD is remote. However, the presence of the magnet in the iPhone 12 made the possibility of inadvertently activating the magnetic switch of PM and ICD less remote. Objective: This study investigates the effects of magnetic interference of the iPhone 12 on a large set of cardiac implantable devices representative of the current market and proposes adequate rules of conduct. Methods: We investigated the risk of the magnetic interference of the iPhone 12 and its MagSafe accessories on a comprehensive set of PMs and ICDs, including the subcutaneous ICD. For the first time, the magnetic interference phenomena were correlated with the magnetic field levels measured all around iPhone 12. Results: We discovered that the magnets inside iPhone 12 trigger the magnetic mode in the 12 tested devices up to a distance of 1 cm. Conclusions: Considering the implications related to the activation of the magnetic switch, to date, it is advisable to follow Apple's indications relating to the safety distance of 15 cm, which is widely compatible with the results obtained from this paper and in line with the indications provided by the implantable cardiac device manufacturers. This article is protected by copyright. All rights reserved.
... 1,2 Wireless charging is a new technology that utilizes a charging base that generates a magnetic field and induces voltage in the receiver coil of the mobile device, allowing it to charge wirelessly. 3 The current generation of Apple's iPhones utilize a wireless charging system termed MagSafe. This technology can provide wireless charging up to 15W and it is optimized with a ring-shaped magnet array. ...
... 5 The magnetic field created by wireless charging technology is monitored for interactions with CIEDs and was found to be within the FDA standard ISO 14117. 3 Apple's MagSafe is a proprietary technology which utilizes wireless charging with an added neodymium magnet array for charging optimization. The newer generation iPhone 12 utilizes this technology, and it has more magnets than the previous generations. ...
Article
Background Magnet wireless charging is being utilized increasingly in current generation smartphones. Apple's MagSafe is a proprietary wireless charging technology with an array of magnets that has the capacity to generate magnet fieldstrength >50 gauss (G). We hypothesize that there is clinically significant magnet interference caused by Apple's MagSafe technology on cardiac implantable electronic devices (CIED). Methods and Results This study has an in vivo and an ex vivo component. The in vivo component consists of consecutive patients who presented to the electrophysiology laboratory with previously implanted CIEDs. The iPhone 12 Pro Max was directly placed on the skin over the pocket of these patients and the effect was studied by device interrogation. For the ex vivo component of the study, CIEDs from major device companies were tested for magnetic interference caused by iPhone 12 Pro Max through unopened packages. We found that iPhone 12 Pro Max resulted in clinically identifiable magnet interference in 3/3 (100%) participants in vivo and in 8/11 (72.7%) devices ex vivo. Conclusions Apple's iPhone 12 Pro Max MagSafe technology can cause magnet interference on CIEDs and has the potential to inhibit lifesaving therapy.
... Gustrau et al. 61 identified induced voltages at the PM terminals of 0.126 mV-131 mV (1 kHz-1 MHz, at 1 A/m, i.e. 1.26 mT). Gustrau et al., 61 Seckler et al., 58 and Mattei et al. 59 found a dependence of the induced voltage on lead configuration. ...
... 23 There is only limited data on EMI with CIEDs in the IF range and only a few of the evaluated studies correlated the documented EMI with exposure data (e.g. Refs 33,45,58 ). Likewise, the studies that did not report EMI, rarely provided detailed data on exposure conditions. ...
... 26,29,31,41,42,51 More than one-third of the studies investigated CIEDs which were exposed to security systems, including EAS, metal detectors, and RFID (n = 15), and five studies investigated potential EMI in the proximity of induction hobs. Single studies also investigated other electronic appliances, such as iPods, 56 a magnetically levitated linear motor car, 52 WPT systems, 40,58 or avalanche transceivers. 37 There is evidence that EMF sources of everyday life such as security systems may induce EMI. ...
Article
Full-text available
Electromagnetic fields (EMF) in the intermediate frequency (IF) range are generated by many novel electrical appliances, including electric vehicles, radiofrequency identification systems, induction hobs, or energy supply systems, such as wireless charging systems. The aim of this systematic review is to evaluate whether cardiovascular implantable electronic devices (CIEDs) are susceptible to electromagnetic interference (EMI) in the IF range (1 kHz–1 MHz). Additionally, we discuss the advantages and disadvantages of the different types of studies used to investigate EMI. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement, we collected and evaluated studies examining EMI in in vivo studies, in vitro studies (phantom studies, benchmark tests), and simulation studies. Our analysis revealed that cardiac implants are susceptible to malfunction induced by EMF in the IF range. Electromagnetic interference may in particular be provoked by security systems and induction hobs. The results of the studies evaluated in this systematic review further indicate that the likelihood for EMI is dependent on exposure-related parameters (field strength, frequency, and modulation) and on implant- as well as on lead-related parameters (model, type of implant, implant sensitivity setting, lead configuration, and implantation site). The review shows that the factors influencing EMI are not sufficiently characterized and EMF limit values for CIED patients cannot be derived yet. Future studies should therefore, consider exposure-related parameters as well as implant- and lead-related parameters systematically. Additionally, worst-case scenarios should be considered in all study types where possible.
... The WPC developed an open interface standard that defines wireless power transfer using inductive charging. Also, recent study regarding wireless power transmission for implantable devices revealed that the induced magnetic field using Qi wireless charging was well below the limits set by ISO 14117 evaluating the electromagnetic compatibility (EMC) of active implantable cardiovascular devices [40]. ...
Article
Full-text available
Recently, implantable devices have become widely used in neural prostheses because they eliminate endemic drawbacks of conventional percutaneous neural interface systems. However, there are still several issues to be considered: low-efficiency wireless power transmission; wireless data communication over restricted operating distance with high power consumption; and limited functionality, working either as a neural signal recorder or as a stimulator. To overcome these issues, we suggest a novel implantable wireless neural interface system for simultaneous neural signal recording and stimulation using a single cuff electrode. By using widely available commercial off-the-shelf (COTS) components, an easily reconfigurable implantable wireless neural interface system was implemented into one compact module. The implantable device includes a wireless power consortium (WPC)-compliant power transmission circuit, a medical implant communication service (MICS)-band-based radio link and a cuff-electrode path controller for simultaneous neural signal recording and stimulation. During in vivo experiments with rabbit models, the implantable device successfully recorded and stimulated the tibial and peroneal nerves while communicating with the external device. The proposed system can be modified for various implantable medical devices, especially such as closed-loop control based implantable neural prostheses requiring neural signal recording and stimulation at the same time.
... Res. Public Health 2017, 14, 157 2 of 15 vehicles [7][8][9][10][11][12], and bio-implanted applications [13][14][15][16][17][18][19][20]. Human models of adults, children, and pregnant woman [21][22][23][24][25][26][27][28][29] have also been built to estimate possible biological threats. ...
... The number of turns in the driving coil (Tx loop) and pick-up coil (Rx loop) is 1 and in the transmission coil (Tx coil) and receiving coil (Rx coil) this value is 5. The distance between the loop and the coil for both Tx and Rx is 1 cm, the distance between the Tx and Rx coil (d TR ) is 30 cm. been carried out by researchers in different scenarios such as housing environments [5,6], electrical vehicles [7][8][9][10][11][12], and bio-implanted applications [13][14][15][16][17][18][19][20]. Human models of adults, children, and pregnant woman [21][22][23][24][25][26][27][28][29] have also been built to estimate possible biological threats. ...
Article
Full-text available
The scenario of multiple wireless power transfer (WPT) systems working closely, synchronously or asynchronously with phase difference often occurs in power supply for household appliances and electric vehicles in parking lots. Magnetic field leakage from the WPT systems is also varied due to unpredictable asynchronous working conditions. In this study, the magnetic field leakage from parallel WPT systems working with phase difference is predicted, and the induced electric field and specific absorption rate (SAR) in a human body standing in the vicinity are also evaluated. Computational results are compared with the restrictions prescribed in the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs). The results show that the middle region between the two WPT coils is safer for the two WPT systems working in-phase, and the peripheral regions are safer around the WPT systems working anti-phase. Thin metallic plates larger than the WPT coils can shield the magnetic field leakage well, while smaller ones may worsen the situation. The orientation of the human body will influence the maximum magnitude of induced electric field and its distribution within the human body. The induced electric field centralizes in the trunk, groin, and genitals with only one exception: when the human body is standing right at the middle of the two WPT coils working in-phase, the induced electric field focuses on lower limbs. The SAR value in the lungs always seems to be greater than in other organs, while the value in the liver is minimal. Human exposure to EMFs meets the guidelines of the International Committee on Non-Ionizing Radiation Protection (ICNIRP), specifically reference levels with respect to magnetic field and basic restrictions on induced electric fields and SAR, as the charging power is lower than 3.1 kW and 55.5 kW, respectively. These results are positive with respect to the safe applications of parallel WPT systems working simultaneously.
... For electromagnetic-induction-based WPT of human implantable medical devices, previous studies have concentrated on the following aspects: the design of topology of magnetic coupled resonant circuits, including resonant circuits, rectifier circuits, and charging management circuits [14]- [16]; how to improve the efficiency of WPT through optimizing the structure and material of coils [17], [18]; how to optimally select frequency: low frequency (below 10 MHz) that can easily achieve high power energy transfer with small radiation [19], or high frequency (GHz) with efficient transfer but low power and large radiation [20], [21]; the effect of position displacement of coupling coils on the WPT [22]; and electromagnetic interference (EMI) [23], [24], etc. So far, studies on cardiac pacemaker have focused on wireless telemetry [25], energy management [26], EMI of external electromagnetic fields on the cardiac pacemaker (including radiation field, SAR in the body, etc.) [27], [28], etc. ...
Article
Patients with cardiac pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy devices (CRT) are exposed to different types of electromagnetic interference (EMI) at home and at work. Due to the constantly increasing role of electrically active appliances in daily use and the introduction of new therapy concepts such as the leadless cardiac pacemaker and the subcutaneous defibrillator, this topic is of great relevance. The further development of the implanted devices and the almost complete use of bipolar leads has reduced the overall risk of EMI. This review article provides information about the current status of possible interference in the private environment and how to avoid it. In addition, information is provided on how to deal with occupational sources of interference.