THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY Int J Med Robotics Comput Assist Surg (2015) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/rcs.1686

ORIGINAL ARTICLE

Patient exposure to extremely low-frequency magnetic fields during laparoscopic and robotic surgeries

Jai Won Chung1,2 Jee Soo Park3 Soo Beom Choi1,2 Deok Won Kim1,2* 1

Department of Medical Engineering, Yonsei University College of Medicine, Seoul, Korea

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Graduate Program in Biomedical Engineering, Yonsei University, Seoul, Korea

Abstract Background Laparoscopic and robotic surgeries require many electronic devices, and the hazard of extremely low-frequency magnetic fields (ELF-MFs) from these devices to humans remains uncertain. This study aimed to measure and compare patients’ exposure levels to ELF-MFs in laparoscopic and robotic surgeries. Methods The intensity of ELF-MF exposure to patients was measured every 10 s during 30 laparoscopic surgeries and 30 robotic surgeries using portable ELF-MF measuring devices with logging capabilities.

Department of Medicine, Yonsei University College of Medicine, Seoul, Korea

Results The mean ELF-MF exposures were 0.11 ± 0.07 μT for laparoscopic surgeries and 0.12 ± 0.10 μT for robotic surgeries. There were no significant differences between the laparoscopic and robotic surgeries.

*Correspondence to: Deok Won Kim, Department of Medical Engineering, Yonsei University College of Medicine, CPO Box 8044, Seoul, Republic of Korea. Email: [email protected]

Conclusions Patients’ mean ELF-MF exposure levels in laparoscopic and robotic surgeries were lower than 0.2 μT, which is considered safe according to previous studies. However, because many medical devices have been implemented for multiple purposes in hospitals, the MF environment in hospitals regarding patient health should not be overlooked. Copyright © 2015 John Wiley & Sons, Ltd.

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Keywords magnetic field; patients; robotic surgery; laparoscopic surgery; da Vinci surgical system

Introduction

Accepted: 14 June 2015

Copyright © 2015 John Wiley & Sons, Ltd.

There is growing concern about the electromagnetic fields caused by electric devices because of the increased use of electronic devices for convenience and availability. Electromagnetic fields are a combination of electric and magnetic fields (MFs). Electric fields are easily shielded by conducting objects, even human skin, but MFs are not as readily blocked, although they are easier to measure than electric fields (1); therefore, recent studies have focused on the health effects of MFs (2). MFs within the 3–3000 Hz frequency range are defined as extremely low-frequency (ELF)-MFs, which include MFs with 50 and 60 Hz frequencies used in power lines and electric devices (3).

J. W. Chung et al.

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The International Agency for Research on Cancer classified ELF-MFs as possibly carcinogenic to humans (Group 2B) in 2002 (4). Guidelines by the International Commission on Non-Ionizing Radiation Protection, which were published to establish limits on instantaneous exposure to electromagnetic fields in 2010, restrict MF exposure to 200 μT at 60 Hz for any length of time as a means of limiting current density and preventing effects on nervous system function (5). However, 0.2 μT was considered the maximum permissible level of exposure to ELF-MFs in many epidemiologic studies (6–8). The 0.2–0.3 μT range has been a reference level between the exposure and nonexposure groups in epidemiologic studies. Guidelines from the Swedish Board for Technical Accreditation state that computer monitors should not produce ELF-MFs of more than 0.2 μT at 30 cm (9). In our previous study, we measured for the first time surgeons’ levels of exposure to ELF-MFs during laparoscopic and robotic surgeries (10); however, there have been no reports on patient exposure during laparoscopic and robotic surgeries. It is important to confirm that the ELF-MFs during laparoscopic and robotic surgeries are lower than the epidemiologically suggested level of 0.2 μT. Our study is the first to measure ELF-MFs at the patient’s head during laparoscopic and robotic surgeries and to compare patients’ exposure levels to ELF-MFs during laparoscopic and robotic surgeries.

Materials and methods Subjects Patients’ exposure levels to ELF-MFs in 30 laparoscopic surgeries and 30 robotic surgeries using the da Vinci surgical system (Intuitive Surgical, Mountain View, CA) at the Yonsei University Health System in Seoul, Korea, were measured between July and October 2014. The surgeries were selected from the colorectal surgery, hepato-biliarypancreatic surgery, and gynecologic oncology divisions. Low anterior resection was chosen from the colorectal surgery division and cholecystectomy was chosen from the hepato-biliary-pancreatic surgery division; myomectomy, hysterectomy, and salpingo-oophorectomy were chosen from the gynecologic oncology division. Nearly the same equipment was used in laparoscopic and robotic surgeries, except for a robot system. All subjects were informed of the purpose and procedure of the experiments and provided written consent before joining the study. The Yonsei University Health System Institutional Review Board approved the study protocol (project no: 4-2014-0398). Copyright © 2015 John Wiley & Sons, Ltd.

ELF-MF measurement To measure patients’ exposure levels to ELF-MF during the surgeries, an EMDEX II (Enertech Consultants, Campbell, CA), which is a portable device that periodically measures ELF-MF intensity, was installed near the patients’ heads below the operating table during surgery. The EMDEX II can measure ELF-MFs between 40 and 800 Hz, ranging from 0.01 to 300 μT with a resolution of 0.01 μT and accuracy of ±1%. The ELF-MF intensities were measured at 10 s intervals during each surgery. ELF-MF can be disturbed only by compound metals with very high permeability such as mu-metal. Therefore, as ELF-MF are not readily distorted or blocked by conducting objects (1), the ELF-MFs would not be significantly affected by the operation table. Exposure-level data of each patient from the start to finish of each surgery were retrieved by connecting the EMDEX II to a personal computer; EMCALC 2000 (Enertech Consultants) analysis and graphical software was used.

Statistical analyses The mean and standard deviation of ELF-MF intensity during each surgery were calculated, as were the distributions of ELF-MF exposures in the laparoscopic and robotic surgeries. The Mann–Whitney U test was used to compare patients’ mean ELF-MF exposure levels. The U value calculated by the Mann–Whitney U test for each group is the difference between the possible minimum rank that a group can take [n(n + 1)/2] and the sum of the ranks in the group, where n is the group sample size (11). The calculations in the Mann–Whitney U test use the smallest U value from the two groups. The smaller the U value, the less likely it has occurred by chance. The null hypothesis was that the patients’ mean ELFMF exposure levels were the same in laparoscopic and robotic surgeries. We did not accept a null hypothesis for a U value ≤316 (the critical value for total surgeries) and a U value ≤23 (the critical value for surgeries for each division), each corresponding to P < 0.05. All reported P values were two-sided, and P values less than 0.05 were considered statistically significant. All statistical analyses were performed using Statistical Package for the Social Sciences software (version 20, IBM SPSS Statistics; IBM Corp., Armonk, NY).

Results Tables 1 and 2 show patients’ ELF-MF exposure levels in the 30 laparoscopic surgeries and 30 robotic surgeries, respectively. Table 3 compares patients’ mean ELF-MF Int J Med Robotics Comput Assist Surg (2015) DOI: 10.1002/rcs

Magnetic fields during laparoscopic and robotic surgeries

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Table 1. Patients’ exposure levels to extremely low-frequency magnetic fields in 30 laparoscopic surgeries Measurement Surgery LS 1 LS 2 LS 3 LS 4 LS 5 LS 6 LS 7 LS 8 LS 9 LS 10 LS 11 LS 12 LS 13 LS 14 LS 15 LS 16 LS 17 LS 18 LS 19 LS 20 LS 21 LS 22 LS 23 LS 24 LS 25 LS 26 LS 27 LS 28 LS 29 LS 30

Number of

MF exposure (μT) a

Division

duration (h)

measurements

Min.

Max.

Mean ± SD

Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology

6.6 5.4 5.1 4.3 4.8 6.5 5.3 3.8 4.6 3.3 2.0 1.7 1.9 1.0 1.2 1.5 1.3 1.6 1.7 1.7 1.1 1.2 2.3 1.7 1.7 1.6 1.9 1.7 1.8 1.3

2380 1945 1840 1535 1716 2323 1898 1352 1646 1176 719 598 671 369 423 527 486 564 596 600 395 424 818 626 630 585 670 620 636 484

0.01 0.03 0.01 0.03 0.07 0.09 0.07 0.07 0.07 0.01 0.06 0.05 0.05 0.03 0.02 0.03 0.03 0.04 0.01 0.05 0.01 0.01 0.02 0.01 0.01 0.03 0.01 0.01 0.02 0.01

0.51 0.34 0.66 0.51 0.79 0.87 0.26 0.90 0.50 0.58 0.16 0.12 0.12 0.11 0.10 0.16 0.13 0.11 0.15 0.16 0.05 0.10 0.40 0.07 0.28 0.26 0.07 0.09 0.74 0.25

0.15 ± 0.04 0.19 ± 0.06 0.22 ± 0.06 0.21 ± 0.03 0.17 ± 0.05 0.22 ± 0.05 0.11 ± 0.02 0.13 ± 0.03 0.11 ± 0.03 0.22 ± 0.04 0.07 ± 0.01 0.07 ± 0.01 0.07 ± 0.01 0.07 ± 0.01 0.06 ± 0.01 0.07 ± 0.01 0.07 ± 0.02 0.06 ± 0.02 0.06 ± 0.01 0.07 ± 0.01 0.01 ± 0.01 0.04 ± 0.03 0.24 ± 0.08 0.04 ± 0.01 0.18 ± 0.09 0.17 ± 0.09 0.03 ± 0.01 0.03 ± 0.01 0.09 ± 0.08 0.13 ± 0.07

MF: magnetic field, Min.: minimum, Max.: maximum, SD: standard deviation, LS: laparoscopic surgery. The number of measurements was determined by the repeated measurements every 10 s within the designated time.

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exposures in the surgeries. Patients’ mean ELF-MF exposure levels during the 30 laparoscopic surgeries and 30 robotic surgeries were 0.11 ± 0.07 μT and 0.12 ± 0.10 μT, respectively. There are no significant differences between the laparoscopic and robotic surgeries (Mann–Whitney U = 437.5, P = 0.852). In the colorectal surgery division, patients’ mean ELFMF exposures were 0.17 ± 0.05 μT, ranging from 3.3 to 6.6 h for the 10 laparoscopic surgeries (Table 1) and 0.17 ± 0.13 μT, ranging from 4.0 to 7.0 h for the 10 robotic surgeries (Table 2). They were not significant (Mann– Whitney U = 48.5, P = 0.909) (Table 3). In the 10 laparoscopic surgeries and the 10 robotic surgeries from the hepato-biliary-pancreatic surgery division, patients’ mean ELF-MF exposures were 0.07 ± 0.01 μT, ranging from 1.0 to 2.0 h, and 0.07 ± 0.01 μT, ranging from 1.9 to 2.7 h, respectively. They were not significant (Mann– Whitney U = 40.0, P = 0.374). In the gynecologic oncology division, patients’ mean ELF-MF exposure during the 10 laparoscopic surgeries was 0.10 ± 0.08 μT, ranging from 1.1 to 2.3 h, while that during the 10 robotic surgeries was 0.13 ± 0.08 μT, ranging from 2.7 to 3.9 h; the difference was not significant (Mann–Whitney U = 33.5, P = 0.211). Copyright © 2015 John Wiley & Sons, Ltd.

Discussion There are a few reports that have evaluated the strength of ELF-MF in hospitals in which a variety of sophisticated electronic equipment is used. Moreover, to our knowledge, no previous study has addressed patients’ ELF-MF exposure levels during laparoscopic and robotic surgeries. In our study, the mean ELF-MF exposures in the 30 laparoscopic and 30 robotic surgeries were 0.11 ± 0.07 μT and 0.12 ± 0.10 μT, respectively, and were lower than 0.2 μT, which is the level considered to signify no hazard to humans, as reported in many studies (6–9). Moreover, the patients’ mean ELF-MF exposure levels were no different between the laparoscopic and robotic surgeries and were approximately same as the mean ELF-MF exposure level of 0.11 μT in homes in North America (12). Previous studies reported a mean strength of ELF-MFs ranging from 0.03 μT to 0.58 μT in various hospital locations (13–16). Our previous study report on ELF-MFs of surgeons during 20 laparoscopic and 20 robotic surgeries showed mean exposure levels of 0.06 ± 0.01 μT and 0.03 ± 0.00 μT, respectively, with significant differences (10). Although exposure of ELF-MFs to both surgeons and patients was below the suggested safe level, the exposure level of Int J Med Robotics Comput Assist Surg (2015) DOI: 10.1002/rcs

J. W. Chung et al.

4 Table 2. Patients’ exposure levels to extremely low-frequency magnetic fields in 30 robotic surgeries Measurement

MF exposure (μT) a

Division

duration (h)

measurements

Min.

Max.

Mean ± SD

Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Colorectal Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Hepato-biliary-pancreas Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology Gynecologic oncology

7.0 4.0 5.7 6.7 5.1 6.9 5.6 6.1 6.5 6.0 2.7 2.2 2.5 2.2 1.9 2.6 2.4 2.0 2.2 2.1 3.0 3.1 3.9 3.9 2.9 2.9 3.3 2.7 2.9 2.8

2531 1428 2063 2395 1825 2482 2003 2181 2329 2170 988 781 892 785 692 921 855 735 802 752 1098 1115 1412 1403 1036 1041 1193 966 1032 1016

0.01 0.01 0.01 0.01 0.01 0.19 0.01 0.09 0.01 0.01 0.01 0.05 0.05 0.05 0.02 0.05 0.05 0.03 0.05 0.01 0.01 0.01 0.01 0.01 0.06 0.09 0.04 0.01 0.02 0.01

0.34 1.10 0.12 0.13 0.87 0.86 0.46 0.54 0.05 0.45 0.08 0.08 0.08 0.09 0.08 0.09 0.09 0.08 0.08 0.08 0.21 0.19 0.07 0.17 0.90 0.63 0.09 0.11 0.48 0.27

0.06 ± 0.05 0.25 ± 0.08 0.03 ± 0.02 0.05 ± 0.02 0.31 ± 0.09 0.39 ± 0.11 0.22 ± 0.06 0.21 ± 0.07 0.02 ± 0.01 0.15 ± 0.05 0.06 ± 0.01 0.07 ± 0.01 0.07 ± 0.01 0.06 ± 0.01 0.06 ± 0.01 0.07 ± 0.01 0.07 ± 0.01 0.07 ± 0.01 0.06 ± 0.01 0.06 ± 0.01 0.12 ± 0.04 0.10 ± 0.04 0.04 ± 0.01 0.11 ± 0.04 0.29 ± 0.08 0.26 ± 0.08 0.06 ± 0.01 0.06 ± 0.03 0.12 ± 0.05 0.18 ± 0.06

Surgery RS 1 RS 2 RS 3 RS 4 RS 5 RS 6 RS 7 RS 8 RS 9 RS 10 RS 11 RS 12 RS 13 RS 14 RS 15 RS 16 RS 17 RS 18 RS 19 RS 20 RS 21 RS 22 RS 23 RS 24 RS 25 RS 26 RS 27 RS 28 RS 29 RS 30

Number of

MF: magnetic field, Min.: minimum, Max.: maximum, SD: standard deviation, RS: robotic surgery. The number of measurements was determined by the repeated measurements every 10 s within the designated time.

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Table 3. Comparisons of the mean extremely low-frequency magnetic field exposures of patients in laparoscopic and robotic surgeries MF exposure (μT)a Category of surgery

Laparoscopic surgery

Robotic surgery

U valueb

P valueb

Colorectal Hepato-biliary-pancreas Gynecologic oncology Total

0.17 ± 0.05 (n = 10) 0.07 ± 0.01 (n = 10) 0.10 ± 0.08 (n = 10) 0.11 ± 0.07 (n = 30)

0.17 ± 0.13 (n = 10) 0.07 ± 0.01 (n = 10) 0.13 ± 0.08 (n = 10) 0.12 ± 0.10 (n = 30)

48.5 40.0 33.5 437.5

0.909 0.374 0.211 0.852

MF: magnetic field. Values are given as mean ± standard deviation. U and P values were obtained by Mann-Whitney U test.

a

b

ELF-MFs in patients was higher than that of surgeons. This was probably because of the anesthetic equipment. Our previous study reported that anesthesiologists’ mean ELF-MF exposure during surgery was 0.58 ± 0.52 μT (15). MF strength decreases quickly because of the inverse square of the distance and returns to background levels at 3 or 4 feet away from an electric appliance (2,17). Because the distance between surgeons and anesthetic equipment was greater than the distance between patients and anesthetic equipment, the effect from anesthetic equipment was greater in patients. Furthermore, patients’ mean Copyright © 2015 John Wiley & Sons, Ltd.

ELF-MF exposure levels were no different between laparoscopic and robotic surgeries because the same location was measured. The positions from which surgeons performed surgeries were different; for example, they sat close to the master console during robotic surgeries, but sat close to the operating table in laparoscopic surgeries. We measured patients’ exposure levels to ELF-MFs at the head position because this position was the most suitable due to the low risk of contamination and the low possibility of disturbing an operation. Many studies have also reported ELF-MF hazards to the brain. Jelenkovića et al. Int J Med Robotics Comput Assist Surg (2015) DOI: 10.1002/rcs

Magnetic fields during laparoscopic and robotic surgeries

reported that exposure to ELF-MFs can be especially harmful to the basal forebrain and frontal cortex because of development of lipid peroxidation by ELF-MFs (18). Ciejka et al. reported that ELF-MFs can affect free radical generation in the brain (19). Baldi et al. and Turner et al. also reported the association of ELF-MF exposure and brain tumors (20,21). Other biological effects of ELF-MFs on humans have also been reported. Sastre et al. reported that ELF-MF altered human cardiac rhythm (22). Savitz et al. reported an association between ELF-MF and arrhythmia-related heart disease (23). Several other studies have reported that exposure to ELF-MF is associated with an increase in the risk of breast cancer (24–26). Davanipour et al. reported that MF exposure could increase the risk of cognitive dysfunction (27). Numerous studies have been conducted to assess the health effects of ELF-MFs and have reported various impacts resulting from ELF-MF exposure (10), but there are few reports evaluating ELF-MF strength in hospitals (15). Although patients’ mean exposure levels to ELF-MFs were lower than 0.2 μT in the laparoscopic and robotic surgeries, their exposure levels in the intensive care unit were reported to be higher than 0.2 μT (13). Ubeda et al. reported that the mean exposure levels obtained from spot measurements ranged from a minimum of 0.03 ± 0.01 μT in nurses to a maximum of 0.39 ± 0.13 μT in physiotherapists in a study that also included surgeons, physicians, and radiologists (16). Our previous study reported that the mean ELF-MF exposure of endodontic personnel during working hours was 0.03 ± 0.04 μT (14). Our study has some limitations. First, equipment settings might have been slightly different in each surgery, although every attempt was made to make them the same. Second, the exact sources of ELF-MFs during laparoscopic and robotic surgeries were not evaluated because this study focused on the overall patient exposure to ELFMFs. Moreover, we found that patients’ exposure levels to ELF-MFs were lower than 0.2 μT and therefore there was no need to find the exact devices producing the ELF-MFs. In conclusion, patients’ mean exposure levels to ELF-MFs during laparoscopic and robotic surgeries were lower than 0.2 μT, which is considered to be ‘no hazard’ in many studies (6–9). There was no difference in ELF-MF levels between laparoscopic and robotic surgeries. Although the very weak, long-term effects of ELF-MFs are not understood thoroughly (13), biological effects of ELF-MFs on humans have been reported by many studies (21–27). ELF-MF levels in hospitals should not be overlooked. There are many hospital locations that produce ELF-MFs, including operating rooms. Although we measured patients’ ELF-MF exposure levels during laparoscopic and robotic surgery only, ELF-MF levels in various hospital locations should also be measured and reported to confirm that they represent no hazard. Clinicians’ primary concern is the health of Copyright © 2015 John Wiley & Sons, Ltd.

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patients; therefore, the hospital environment, including exposure to ELF-MFs, should not be overlooked. As a result, it is important that various studies on patients’ ELF-MF exposure levels in a hospital are reported.

Acknowledgements This research was supported by a grant from the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2010-0022374).

Conflicts of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article.

Funding No specific funding.

References 1. California Department of Health Services and the Public Health Institute. Electric and magnetic fields: measurements and possible effect on human health. California Electric and Magnetic Fields Program; 2000. Available from: http://www.ehib.org/ emf/longfactsheet.PDF. 2. California Department of Health Services and the Public Health Institute. Short factsheet on EMF. California Electric and Magnetic Fields Program; 1999. Available from: http://www.ehib. org/emf/shortfactsheet.PDF. 3. Feychting M, Ahlbom A, Kheifets L. EMF and health. Annu Rev Public Health 2005; 26: 165–189. 4. IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Non-ionizing radiation, Part 1: static and extremely low-frequency (ELF) electric and magnetic fields. IARC Monogr Eval Carcinog Risks Human 2002; 80: 1–395. 5. International Commission on Non-Ionizing Radiation Protection. Guidelines for limiting exposure to time-varying electric and magnetic fields (1 Hz to 100 kHz). Health Phys 2010; 99: 818–836. 6. Michaelis J, Schüz J, Meinert R, et al. Childhood leukemia and electromagnetic fields: results of a population-based case-control study in Germany. Cancer Causes Control 1997; 8: 167–174. 7. Schüz J, Grigat JP, Brinkmann K, Michaelis J. Residential magnetic fields as a risk factor for childhood acute leukaemia: results from a German population-based case-control study. Int J Cancer 2001; 91: 728–735. 8. Kroll ME, Swanson J, Vincent TJ, Draper GJ. Childhood cancer and magnetic fields from high-voltage power lines in England and Wales: a case-control study. Br J Cancer 2010; 103: 1122–1127. 9. Rudling J, Nordin H. TCO’06 Media Displays: Ver. 1.2. Sweden: TCO Development, 2006. Int J Med Robotics Comput Assist Surg (2015) DOI: 10.1002/rcs

6 10. Park JS, Chung JW, Kim NK, et al. Exposure of surgeons to extremely low-frequency magnetic fields during laparoscopic and robotic surgeries. Medicine 2015; 94: e539. 11. Rihani A, Van Maerken T, De Wilde B, et al. Lack of association between MDM2 promoter SNP309 and clinical outcome in patients with neuroblastoma. Pediatr Blood Cancer 2014; 61: 1867–1870. 12. World Health Organization. Electromagnetic fields and public health: exposure to extremely low frequency fields, 2007. Available from: http://www.who.int/peh-emf/publications/facts/ fs322/en/. 13. Petrucci N. Exposure of the critically ill patient to extremely lowfrequency electromagnetic fields in the intensive care environment. Intensive Care Med 1999; 25: 847–851. 14. Lee JH, Lee HC, Kim HD, et al. How much are anesthesiologists exposed to electromagnetic fields in operating rooms? Yonsei Med J 2003; 44: 133–137. 15. Roh JH, Kim DW, Lee SJ, et al. Intensity of extremely low-frequency electromagnetic fields produced in operating rooms during surgery at the standing position of anesthesiologists. Anesthesiology 2009; 111: 275–278. 16. Úbeda A, Martínez MA, Cid MA, et al. Assessment of occupational exposure to extremely low frequency magnetic fields in hospital personnel. Bioelectromagnetics 2011; 32: 378–387. 17. Kheifets L, Oksuzyan S. Exposure assessment and other challenges in non-ionizing radiation studies of childhood leukaemia. Radiat Protect Dosimetry 2008; 132: 139–147. 18. Jelenković A, Janać B, Pesić V, et al. Effects of extremely low-frequency magnetic field in the brain of rats. Brain Res Bull 2006; 68: 355–360.

Copyright © 2015 John Wiley & Sons, Ltd.

J. W. Chung et al. 19. Ciejka E, Kleniewska P, Skibska B, Goraca A. Effects of extremely low frequency magnetic field on oxidative balance in brain of rats. J Physiol Pharmacol 2011; 62: 657–661. 20. Baldi I, Coureau G, Jaffré A, et al. Occupational and residential exposure to electromagnetic fields and risk of brain tumors in adults: a case-control study in Gironde, France. Int J Cancer 2011; 129: 1477–1484. 21. Turner MC, Benke G, Bowman JD, et al. Occupational exposure to extremely low-frequency magnetic fields and brain tumor risks in the INTEROCC study. Cancer Epidemiol Biomarkers Prev 2014; 23: 1863–1872. 22. Sastre A, Cook MR, Graham C. Nocturnal exposure to intermittent 60 Hz magnetic fields alters human cardiac rhythm. Bioelectromagnetics 1998; 19: 98–106. 23. Savitz DA, Liao D, Sastre A, et al. Magnetic field exposure and cardiovascular disease mortality among electric utility workers. Am J Epidemiol 1999; 149: 135–142. 24. Kliukiene J, Tynes T, Andersen A. Follow-up of radio and telegraph operators with exposure to electromagnetic fields and risk of breast cancer. Eur J Cancer Prev 2003; 12: 301–307. 25. London SJ, Pogoda JM, Hwang KL, et al. Residential magnetic field exposure and breast cancer risk: a nested case-control study from a multiethnic cohort in Los Angeles County, California. Am J Epidemiol 2003; 158: 969–980. 26. Feychting M, Forssén U. Electromagnetic fields and female breast cancer. Cancer Causes Control 2006; 17: 553–558. 27. Davanipour Z, Tseng CC, Lee PJ, et al. Severe cognitive dysfunction and occupational extremely low frequency magnetic field exposure among elderly Mexican Americans. Br J Med Med Res 2014; 4: 1641–1662.

Int J Med Robotics Comput Assist Surg (2015) DOI: 10.1002/rcs

Patient exposure to extremely low-frequency magnetic fields during laparoscopic and robotic surgeries.

Laparoscopic and robotic surgeries require many electronic devices, and the hazard of extremely low-frequency magnetic fields (ELF-MFs) from these dev...
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