Composition simulating the dielectric properties of the human body and use thereof for SAR measurement

Abstract

An oil-in-water emulsion includes an aqueous phase and an oily phase, the aqueous phase including water and a relaxing agent, and the oily phase including an oil and at least one surfactant. The emulsion has dielectric properties simulating dielectric properties of the human body. A device including the emulsion, a simulated human body part filled with the emulsion; and at least one system capable of measuring a local specific absorption rate when the simulated human body part is exposed to an electromagnetic field are also described. A method for conducting specific absorption rate tests of an apparatus radiating an electromagnetic field including using the emulsion, and a process for manufacturing the emulsion are also described.

Claims

1. Oil-in-water emulsion, comprising: water, from 15% to 35% in weight relative to the total weight of the aqueous phase of glycerol, from 0.6% to 1.2% in weight relative to the total weight of the emulsion of CaCl.sub.2; optionally from 0.3% to 2% in weight of the total weight of the emulsion of xanthan, from 15% to 25% in weight relative to the total weight of the emulsion of isopropyl palmitate, and from 6 to 8% in weight relative to the total weight of the emulsion of a mixture of (i) surfactant having polyethylene oxide and chains and at least one aromatic group and (ii) sorbitan esters and/or ethoxylated sorbitan ester.

2. Oil-in-water emulsion according to claim 1, having a viscosity ranging from 0.005 Pa.Math.s to 50 Pa.Math.s at 25 C.

3. Oil-in-water emulsion according to claim 1, having a relative permittivity ranging from 68.09 to 31.2 and a conductivity ranging from 0.68 S/m to 6.60 S/m for frequencies ranging from 30 MHz to 6 GHz.

4. Device comprising: the emulsion according to claim 1, a simulated human body part filled with said emulsion; and at least one system capable of measuring a local specific absorption rate when the simulated human body part is exposed to an electromagnetic field.

5. Device according to claim 4, wherein the simulated human body part is a container in the form of part or all of a human head or part or all of a human trunk.

6. Method for conducting specific absorption rate tests of an apparatus radiating an electromagnetic field comprising: positioning the apparatus on or near the device according to claim 4; and measuring a field strength within the device when the apparatus under test is transmitting.

7. Oil-in-water emulsion, comprising: water, from 2% to 7% in weight relative to the total weight of the aqueous phase of glycerol, from 0.1% to 1% in weight relative to the total weight of the emulsion of CaCl.sub.2; optionally from 0.3% to 2% in weight of the total weight of the emulsion of xanthan, from 10% to 15% in weight relative to the total weight of the emulsion of isopropyl palmitate, and from 6 to 8% in weight relative to the total weight of the emulsion of a mixture of (i) surfactant having polyethylene oxide and chains and at least one aromatic group and (ii) sorbitan esters and/or ethoxylated sorbitan ester.

8. Oil-in-water emulsion according to claim 7, having a viscosity ranging from 0.005 Pa.Math.s to 50 Pa.Math.s at 25 C.

9. Oil-in-water emulsion according to claim 7, having a relative permittivity ranging from 68.09 to 31.2 and a conductivity ranging from 0.68 S/m to 6.60 S/m for frequencies ranging from 30 MHz to 6 GHz.

10. Device comprising: the emulsion according to claim 7, a simulated human body part filled with said emulsion; and at least one system capable of measuring a local specific absorption rate when the simulated human body part is exposed to an electromagnetic field.

11. Device according to claim 10, wherein the simulated human body part is a container in the form of part or all of a human head or part or all of a human trunk.

12. Method for conducting specific absorption rate tests of an apparatus radiating an electromagnetic field comprising: positioning the apparatus on or near the device according to claim 10; and measuring a field strength within the device when the apparatus under test is transmitting.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates the IEC 62209-2 standard requirement for tissue-simulating dielectric properties materials with tolerated +/10% deviations in the 0.03-6 GHz range. (1A) represents the relative permittivity of the material as a function of the frequency. (1B) represent the conductivity of the material as a function of the frequency.

(2) FIG. 2 represents the dielectric properties of emulsion 2 of example 1 compared to IEC standard requirements with tolerated +/10% deviations, from 0.6 GHz to 6 GHz.

(3) FIG. 3 represents the dielectric properties of emulsion 3 of example 2 compared to IEC standard requirements with tolerated +/10% deviations, from 0.6 GHz to 6 GHz.

(4) FIG. 4 represents the dielectric properties of emulsion 5 of example 2 compared to IEC standard requirements with tolerated +/10% deviations, from 0.6 GHz to 6 GHz.

(5) FIG. 5 represents the dielectric properties of emulsion 5 of example 2 compared to IEC standard requirements with tolerated +/10% deviations, from 0.03 GHz to 6 GHz.

(6) FIG. 6 represents the dielectric properties of emulsion 5 of example 2 at 20 C. and 42 C. compared to IEC standard requirements with tolerated +/10% deviations, from 0.6 GHz to 6 GHz.

(7) FIG. 7 represents the dielectric properties of emulsion 7 of example 6 compared to FCC regulatory requirements with +/10% deviations, from 0.15 GHz to 6 GHz.

(8) FIG. 8 is a sectional side view of a device of the invention showing a simulated human body (2) filled by an emulsion of the invention (1), a system capable of measuring the local specific absorption rate (3) when the simulated human body part is exposed to an electromagnetic field, and an apparatus radiating an electromagnetic field (4).

(9) FIG. 9 is a sectional top view of a device of the invention showing a simulated human body (2) filled by an emulsion of the invention (1), a system capable of measuring the local specific absorption rate (3) when the simulated human body part is exposed to an electromagnetic field, and an apparatus radiating an electromagnetic field (4).

EXAMPLES

(10) The present invention is further illustrated by the following examples.

(11) Unless otherwise specified, percentages are given in weight relative to the total weight of the composition.

(12) General Method of Dielectric Properties Measurement

(13) An open-ended coaxial dielectric probe from Agilent Technologies (85070E) was used. This widely-used technique has the advantage to be easy-to-use, available to everyone and applicable up to 6 GHz.

(14) Measurements were carried out with a temperature of the sample under test varying from 20 C. to 40 C., preferably at 25 C.

EXAMPLE 1

Standard Compositions of the Invention

(15) Formulation:

(16) TABLE-US-00001 Composition Emulsion 1 Emulsion 2 water 57.21% 56.48% glycerol 14.57% 14.08% anhydrous CaCl.sub.2 1.13% 1.11% isopropyl palmitate 19.89% 20.39% Triton X-100/Span 80 (79:21) 7.20% \ Tween 80/Span 80 (67:33) \ 7.94%
Process of Manufacturing:

(17) The following steps were followed to manufacture above exemplified emulsions 1 and 2. 1) aqueous phase: weighting of water, glycerol and anhydrous CaCl2; stirring with a propeller stirrer of the mixture to dissolve CaCl2 on a water-bath at 35 C.; 2) oily phase: weighting of oil, Triton X100 or Tween 80 and Span 80; stirring with a propeller stirrer of the mixture to solubilize oil and surfactants, on water bath at 35 C.; 3) emulsification the oily phase is added in the aqueous phase under propeller stirring, on water bath at 35 C.; the mixture is stirred at 600 r/min for 45 minutes; 4) transferring of the resulting emulsion in a closed bottle, at room temperature; 5) the emulsion is then submitted to ultrasounds emitting a power of 30 W in continuous for 1 hour, using an ultrasounds stick plunged in the bottle, on an ice bath to avoid heating of the composition.

(18) Emulsions 1 and 2 have a viscosity of about 6 cP at 25 C.

(19) Dielectric Properties Measurement:

(20) The dielectric properties of exemplified emulsions 1 and 2 were measured using the general method described above. Results are presented in FIG. 2, showing that emulsions meet IEC standards requirements with tolerated +/10% deviations.

(21) Stability:

(22) Dielectric properties are stable for at least 1.5 year.

EXAMPLE 2

Thickened CompositionsXanthan

(23) Formulation:

(24) TABLE-US-00002 Composition Emulsion 3 Emulsion 4 Emulsion 5 water 56.95% 57.10% 58.79% glycerol 14.69% 14.60% 14.50% anhydrous CaCl.sub.2 1.08% 1.10% 1.04% xanthan 0.65% 0.60% 0.56% Germaben II \ \ 0.34% isopropyl palmitate 19.67% 19.70% 18.78 Triton X-100/Span 80 (79:21) 6.96% \ 6.09% Tween 80/Span 80 (67:33) \ 6.90% \
Process of Manufacturing:

(25) The following steps were followed to manufacture above exemplified emulsions 3, 4 and 5: 1) aqueous phase: weighting of water, glycerol and anhydrous CaCl2; stirring with a propeller stirrer of the mixture to dissolve CaCl2 on a water-bath at 35 C.; heating of the water bath at 70 C.; addition of the xanthan powder in rain under mechanical stirring (300 r/min) for 5 minutes; the aqueous phase is then brought back to 35 C. by decreasing the temperature of the water bath; 2) oily phase weighting of oil, Triton X100 or Tween 80 and Span 80; stirring with a propeller stirrer of the mixture to well solubilize oil and surfactants, on water bath at 35 C.; 3) emulsification the oily phase is added in the aqueous phase under stirring with a propeller stirrer, on a water bath at 35 C.; the mixture is stirred at 600 r/min for 45 minutes; 4) transferring of the resulting emulsion in a closed bottle, at room temperature.

(26) All the step of above process of manufacturing may also be performed at 25 C.

(27) Emulsions 3, 4 and 5 have a viscosity of about 30 Pa.Math.s at 25 C.

(28) Dielectric Properties Measurement:

(29) The dielectric properties of exemplified emulsions 3 and 5 were measured using the general method described above. Results are presented in FIG. 3 and FIG. 4 respectively (0.6 GHz to 6 GHz), showing that emulsions 3 and 5 meet IEC standards requirements with tolerated +/10% deviations.

(30) Emulsion 5 has also interesting dielectric properties on a larger band of frequencies, from 0.03 GHz to 6 GHz (see FIG. 5).

(31) Stability:

(32) Dielectric properties are stable for at least 1 year.

EXAMPLE 3

Thickened CompositionsAgarose

(33) Formulation:

(34) TABLE-US-00003 Composition Emulsion 6 water 59.90% glycerol 15.03% anhydrous CaCl.sub.2 0.84% agarose 2.10% isopropyl palmitate 14.49% Tween 80/Span 80 (70:30) 7.64%
Process of Manufacturing:

(35) The following steps were followed to manufacture above exemplified emulsion 6: 1) aqueous phase: weighting of water, glycerol and anhydrous CaCl2; stirring with a propeller stirrer of the mixture to dissolve CaCl2 on a water-bath at 35 C.; changing the water-bath to an oil bath at 80 C.; addition of the agarose powder in rain under stirring with a propeller stirrer for 5 minutes; 2) oily phase weighting of oil, Tween 80 and Span 80; stirring with a propeller stirrer of the mixture to well solubilize oil and surfactants, on oil bath at 80 C.; 3) emulsification the oily phase is added in the aqueous phase under stirring with a propeller stirrer, on an oil bath at 80 C. for 5 minutes; the mixture is stirred at 600 r/min at 35 C. for 30 minutes; 4) transferring of the resulting emulsion in a closed bottle, at room temperature.

EXAMPLE 4

Evolution of Dielectric Properties with Temperature

(36) Dielectric properties of emulsion 5 of example 2 were studied in function of the temperature of the emulsion.

(37) Between 20 to 40 C., dielectric properties required by IEC standards are maintained as evidenced on FIG. 6.

(38) The emulsion can be used from 20 C. to 40 C. during a certain time, according to the limitations of the temperature dependence emulsion stability. The emulsion will be preferably used between 25 C. and 30 C.

EXAMPLE 5

Study of the Rheological Properties of the Composition

(39) Rheological properties of emulsion 5 of example 2 were studied. Measures were performed on emulsion, at 25 C., with a HAAKE RS600 rheometer, with a cone-plate geometry.

(40) Emulsion 5 has a viscosity of about 30 Pa.Math.s at 25 C.

(41) Emulsion 5 was found to be a rheofluidizing, thixotropic and plastic fluid. A fluid with such rheological properties is easy to manipulate, enables the filling of the simulated human body part and limits, if any, leakage of the fluid.

EXAMPLE 6

Composition Approaching American FCC Regulatory Target Values

(42) Emulsions of above examples meet standard requirement defined by the International Electrotechnical Commission under the reference IEC 62209-2 with tolerated +/10% deviations.

(43) Compositions reaching the FCC (Federal Communications Commission) American regulatory requirements may also be interesting for SAR measurement.

(44) Formulation:

(45) TABLE-US-00004 Composition Emulsion 7 water 76.66% glycerol 2.69% anhydrous CaCl.sub.2 0.63% isopropyl palmitate 12.87% Triton X100/Span 80 (79:21) 7.16%

(46) Emulsion 7 was manufactured according to the same process as Emulsions 1 and 2.

(47) Dielectric Properties:

(48) The dielectric properties of exemplified emulsion 7 were measured using the general method described above. Results presented in FIG. 7 (0.15 GHz to 6 GHz), show that the emulsion approaches FCC OET Bulletin 65 Supplement C target values within a +/10% tolerance.