Assessment of Statistical Distribution of Exposure to Electromagnetic Fields from Social Alarm Devices

Social alarm devices are used to assist patients, elderly and disabled people in distress situations. Environments equipped with such wireless, sensitive and responsive devices are referred to as being Ambient Assisted Living (AAL). The use of such devices and transmission sources based on short range wireless technologies involves the increase of levels of electromagnetic (EM) fields in residential environments. Laboratory measurements have been carried out to characterize and analyze the radiofrequency emissions of one of the more extended models of social alarm devices. The electric field (E-field) strength has been measured to examine the compliance with exposure guidelines. The maximum value obtained is much lower than the 3 V/m that is established in the International Electrotechnical Commission Standard of Electromedical Devices. Results show a high correlation in terms of E-field cumulative distribution function (CDF) with the most typical statistical distribution in indoor environments. Keywords—.social alarm devices, electric field, exposure threshold, near field exposure.