초록 ▼

The present invention is a magnetic field warning device suitable for protecting fetal health by alerting the mother whenever she or her fetus is exposed to alternating magnetic field levels which exceed predetermined levels. The device may also be used by anyone concerned about exposure to excessiv

The present invention is a magnetic field warning device suitable for protecting fetal health by alerting the mother whenever she or her fetus is exposed to alternating magnetic field levels which exceed predetermined levels. The device may also be used by anyone concerned about exposure to excessive alternating magnetic fields. The device comprises a magnetic field sensor for sensing alternating magnetic fields of arbitrary orientation, a detector for obtaining the magnitude of the sensed magnetic field, a filter for reducing the possibility of false alarms, a comparator for comparing the magnitude of the sensed field to a predetermined magnitude, and an alarm mechanism. The predetermined magnitude may optionally be adjustable, and the alarm mechanism is designed to minimize unwanted coupling of vibration to the user\s abdomen. The device may be made small enough to be easily clipped on a belt so as to be worn by pregnant women at the abdominal level to monitor magnetic field exposure at the abdomen. With the preferred circuitry, magnetic fields may be measured in the range of 0.5-200 mGauss over a frequency range of 4 Hz-50,000 Hz.

대표청구항 ▼

A portable magnetic field detection device to alert a person when an ambient low-frequency magnetic field of arbitrary orientation has a magnitude exceeding a predetermined value, said value being adjustable, the portable magnetic field detection device comprising: (a) magnetic field detection means

A portable magnetic field detection device to alert a person when an ambient low-frequency magnetic field of arbitrary orientation has a magnitude exceeding a predetermined value, said value being adjustable, the portable magnetic field detection device comprising: (a) magnetic field detection means responsive to the ambient low-frequency magnetic field irrespective of the magnetic field\s orientation for generating a first electrical signal representative of the magnitude of the magnetic field, said magnetic field detection means comprising: (i) three orthogonally placed coils, fitted inside the magnetic field detection device, for simultaneously detecting orthogonal components of the ambient low-frequency magnetic field and for producing outputs indicative of the magnitude of the orthogonal components of said magnetic field, and (ii) means for combining the outputs indicative of the magnitude of such orthogonal components of said magnetic field to generate the first electrical signal; (b) comparator means responsive to the first electrical signal for comparing the first electrical signal with a second electrical signal representative of the predetermined value, and for generating a third electrical signal when the first electrical signal exceeds the second electrical signal; and (c) alarm means, comprising visual and acoustical alarm means, responsive to the third electrical signal for alerting the person when the magnitude of the ambient low-frequency magnetic field exceeds the predetermined value; (d) means for placing the device at the level of and in proximity to the person\s abdomen to accurately detect the exposure of a fetus and abdominal organs of the person to the low-frequency magnetic field; (e) a switch means for controllably switching the alarm means on and off; wherein the detection device protects the person\s fetus and abdominal organs from over-exposure to the low-frequency magnetic field while isolating vibrational effects of the acoustical alarm means from the person\s fetus and organs, the alarm means comprising: A. means for generating an audible alarm; B. an enclosure for the alarm means having a frontal audible alarm emission point; and C. means for minimizing acoustical coupling of vibrations and sounds placed between the means for generating the audible alarm and said enclosure, to reduce coupling of vibrations and sounds from the alarm means to the person\s fetus and organs through said enclosure at said frontal audible alarm emission point; wherein the enclosure for the alarm means is worn in a pocket or is used in conjunction with a clothing material comprising one of a drape, a belt, and pairs of slacks such that said clothing material is placed between the enclosure and the person\s skin and thus does not contact the person\s skin, therefore additionally reducing exposure of the person\s fetus and organs to the sounds and vibrations generated by the portable magnetic field detection device.