The utility model discloses a human body impedance measuring device which comprises a microcontroller an orderly connected measuring circuit an electronic switch gating device an alternating current amplifier a cymoscope and an ad converter. Measurement seem to indicate that the internal impedance also has a small capacitive component.
Figure 5 From New Equivalent Electrical Circuit Model And A
Body impedance measurement circuit. 1 circuit diagram for the impedance of the human body. The population bia can prove to be an effective tool for quantifying ones body composition in clinical studies more specifically studies whose population consists of individuals from developing countries 3 due to its low cost portability ease of use and reliability 4. Most body water is stored in muscle. Bio impedance circuit design for body worn systems august 7 2014 jose carlos conchell table 2electrode skin typical impedance 24. From the body to both the transmitter and receiver sides are high. A precision voltage reference and voltagecurrent control loops are essential and a microcontroller is typically required to process data and obtain the real and imaginary parts of the impedance.
The vectorsum of the internal impedance of the human body and the skin impedance is called total impedance of the human body which is shown in figure 1. The impedance measurement requires a voltagecurrent source and a currentvoltage meter so dacs and adcs are commonly used. Quantitatively the impedance of a two terminal circuit element is the ratio of the complex representation of the sinusoidal voltage between its terminals to the complex representation of the current flowing through it. Conceptual block diagram of the signal chain sbaa181 february 2011 respiration rate measurement based on impedance pneumography 3. In practice however the capacitors are chosen to be large enough so that the carrier is not significantly attenuated. Correlations between whole body impedance measurements and various bioconductor volumes such as total body water and fat free mass.
To measure impedance the circuit connects to 2 electrodes placed at the wrist and 2 placed at the ankle b 8. The paper proposes a method for body or bioelectrical impedance bi measurement based on voltage measurement and analysis at different frequencies with a four electrodes configuration and the principles of virtual instrumentation. It is often useful to express the impedance of this circuit in. The output terminal of the ad converter is connected with the input terminal of the microcontroller. Bioelectrical impedance analysis bia is a commonly used method for estimating body composition in particular body fat and muscle massin bia a weak electric current flow through the body and the voltage is measured in order to calculate impedance resistance of the body. Iec6060 1 the iec 60601 is a series of technical standards for the patientwearer safety and effectiveness of.
In electrical engineering electrical impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied.
Gallery of Body Impedance Measurement Circuit
