Bioimpedance
Encyclopedia
In biomedical engineering
, bioimpedance is a term used to describe the response of a living organism to an externally applied electric current. It is a measure of the opposition to the flow of that electric current through the tissues, the opposite of electrical conductivity[1]. The measurement of the bioimpedance (or bioelectrical impedance) of the humans and animals has proved useful as a non-invasive method for measuring such things as blood flow (often referred to as bioimpedance plethysmography) and body composition (known as bioelectrical impedance analysis
or simply BIA).
In bioimpedance plethysmography, the measure is sometimes based on pulsatile blood volume
changes in the aorta
. Bioimpedance is relevant to the development
of devices to measure cardiac output
and circulating blood volume. Electrical conductivity can vary as a result of breathing. Because of this and other sources of variability, the reliability of bioimpedance for obtaining accurate data has been called into question. Nevertheless, the technique is used in both routine clinical medicine and research.
BIA has found a much sounder footing and is the basis of a number of commercially available body composition analysers. See Bioelectrical impedance analysis
for more details.
Biomedical engineering
Biomedical Engineering is the application of engineering principles and design concepts to medicine and biology. This field seeks to close the gap between engineering and medicine: It combines the design and problem solving skills of engineering with medical and biological sciences to improve...
, bioimpedance is a term used to describe the response of a living organism to an externally applied electric current. It is a measure of the opposition to the flow of that electric current through the tissues, the opposite of electrical conductivity[1]. The measurement of the bioimpedance (or bioelectrical impedance) of the humans and animals has proved useful as a non-invasive method for measuring such things as blood flow (often referred to as bioimpedance plethysmography) and body composition (known as bioelectrical impedance analysis
Bioelectrical impedance analysis
Bioelectrical impedance analysis is a commonly used method for estimating body composition. Since the advent of the first commercially available devices in the mid-1980s the method has become popular owing to its ease of use, portability of the equipment and its relatively low cost compared to...
or simply BIA).
In bioimpedance plethysmography, the measure is sometimes based on pulsatile blood volume
Blood volume
Blood volume is the volume of blood in the circulatory system of an individual.-Humans:A typical adult has a blood volume of approximately between 4.7 and 5 liters, with females generally having less blood volume than males....
changes in the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
. Bioimpedance is relevant to the development
New product development
In business and engineering, new product development is the term used to describe the complete process of bringing a new product to market. A product is a set of benefits offered for exchange and can be tangible or intangible...
of devices to measure cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
and circulating blood volume. Electrical conductivity can vary as a result of breathing. Because of this and other sources of variability, the reliability of bioimpedance for obtaining accurate data has been called into question. Nevertheless, the technique is used in both routine clinical medicine and research.
BIA has found a much sounder footing and is the basis of a number of commercially available body composition analysers. See Bioelectrical impedance analysis
Bioelectrical impedance analysis
Bioelectrical impedance analysis is a commonly used method for estimating body composition. Since the advent of the first commercially available devices in the mid-1980s the method has become popular owing to its ease of use, portability of the equipment and its relatively low cost compared to...
for more details.
| tissue | Ω.cm |
|---|---|
| blood | 150 |
| urine | 30 |
| muscle | 300-1600 |
| lung | 1275 |
| fat | 2500 |