| Specifications of the device |
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| The EIS equipment, with a computer forms an electro medical system in the sense of norm EN60601. |
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| It is assumed that the computer is external to the patient environment and complies with its own norm, in this case EN60950/ EC 60601-1-1 / EC 60601-1-2 |
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| Configuration of the computer necessary for the correct operation of the device : |
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| EIS is a programmable electro medical system (PEMS) including |
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| 1. The hardware |
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| The hardware is configured in mode "plug and play", the power supply of the box is transmiting via the USB port of the computer, the recognition of the hardware by the computer is carried out by the driver fdt2xx.dll incorporated in the disc, then copied in repertory WINDOWS/SYSTEM. |
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| Each time the hardware is connected to the PC it will appear on the list of USB installations and each time that it will be disconnected, it will disappear from the list. |
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| Technical specifications : |
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| Accessories : |
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| The structure of the hardware is composed of a receiving USB circuit and a circuit of converters placed on the same chart and separated by a galvanic decoupling. |
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| This chart is installed in the black box . |
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| The front panel included : |
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- 1 green LED of PC control / hardware recognition
- 1 yellow LED of PC control / hardware recognition
- 1 green LED of control of the power supply
- 1 connector RCA "HEAD".
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| The back panel included : |
- USB-A port
- 3 RCA "HAND" "FOOT" "TEST"
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| 2. The software |
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| The data-processing program includes 4 parts : |
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| A. Control correct operation of the black box |
- Test of the power supply
- Test of the channels
- Test of laterality and correspondence of volumes
- Test of the cables
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| B. Tension control , sequence and time of measurementB. Tension control , sequence and time of measurement |
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Each examination make 3 measurements in 1min and 50s:
For the first measurement (22 s): the software control the hardware for send beetween the electrodes hands and feet right and left an imposed intensity of 600µA with a frequency 250KHz , then 50KHz. |
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| For the second (22s) and third measurement(66s) : the software control the hardware for send between 2 electrodes an imposed tension of 1.28V during in D.C ,1 second per volume and then 3 seconds per volume |
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The tension while DC current is sent in a chronological way of a negative electrode towards the positive electrode and according to a programmed sequence: 2, 10, 4, 11, 6, 14, 7, 16, 17, 19, 22, 1, 9, 3, 12, 5, 13, 8, 15, 18, 20, 21
Thus, the electrodes will be alternatively cathode then anode and will record 22 tissue volumes located between the electrodes. |
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| The hardware transmits via USB port measurements of intensity (32 measurements in 1 seconds and 255 measurements in 3 seconds) in numerical form to the data-processing program. |
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| C. Application of the mathematical formulas |
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| The program transforms the measurements of intensity provided by the hardware in numerical form and according to several aspects : |
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| Analysis of the direct method of conductivity measurements by applying Maxwell's equation |
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- Working of conductivity measurements after calculation of item 0 according to the formula of the body volume's equation (v=H2/R) , a scale of - 100 to +100
- Application of the inverse problems algorithms (results of STATISTICA program version 7.0 with the patients databases)
- Estimate of acid base balance (Cottrell's equation )
- Estimate the body composition after calculation of the total water body (1MHz) ,the extracellular water (50KHz) and interstitial water (DC) .
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| D. Analysis and statistical program |
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| This program incorporates the whole of informations in order to carry out : |
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- Conductivity graphics in order to carry out a electro scan gram (ESG)
- Modeling and synthesized images
- Statistical graphic of functional risks by application of the results of external program: STATISTICA
- Body composition graphic
- Decision-making aid therapeutic : regulate target supplementary examinations
- Decision-making aid therapeutic: contributes to the nutrition
- Measurements Control by simultaneous visualization of 2 visits of the same patient on different dates
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| E. Specifications of the program |
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| Language C++ |
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| External program used |
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Compilers:
1) Borland C++ 5.0
2) Microsoft Visual C++ (Visual Studio 2003) |
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3D design program:
AutoDesk Inc. 3D Studio MAX 7.0
STATISTICA version 7.0 |
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