The Quantum II BIA Analyzer

The hand held Quantum II offers clinics, hospitals and research facilities a way to monitor changes in fat mass, fat free mass, and total body water. Scale weight alone provides little information regarding body composition. The results of testing with the Quantum II system yields beneficial information that illustrates changes of body composition in a variety of populations.

The Quantum II comes with the BC software, which performs body composition analysis and also has a diet and exercise wizard. 

A variety of clinics and facilities currently use the Quantum II system to aid in the management of an overall health plan. The ability to know when fat, fat-free mass, and fluids are lost or gained is important for improved body composition in relation to health issues.

Measurement of whole body bioelectrical impedance analysis with a Quantum II is quick and repeatable. The Quantum II measures whole body resistance and reactance. These measurements are then entered in the body composition software. The software and Quantum II create an efficient system for revealing and monitoring changes in body composition.

The Quantum II system provides the patient a method of monitoring and historically tracking body composition.

Bioelectrical impedance analysis is the study of the electrical properties of biological material and its change over time. This includes humans, animals, fish, plants, vegetables, fruits and anything living. Even human circulation and breathing can be quantified with a real-time BIA instrument that has enough sensitivity and a short sampling interval[1].

The most popular application for BIA is predicting human body composition as a total body measurement from hand to foot where resistance and reactance is evident from a biological circuit that conducts alternating current. The source electrodes introduce an alternating current (50 Khz) at the base of the toes and fingers. The detecting electrodes measure the voltage drop due to this circuit at the anatomical land marks of the ankle and wrist bones. This is a four electrode or tetrapolar measurement, which is essential to eliminate electrode and field distribution problems associated with two electrode measurements. The conducting media has a resistive and capacitive electrical path. These two values are independently measured and resolve the cellular and ionic components of the material. The cellular volume is measured as capacitive reactance and the resistive volume is ionic resistance, both are expressed in ohms. Modeling these two values as their series or parallel equivalent circuits is important when comparing them to criterion methods.

1. Nyboer, J.: Electrical Impedance Plethysmography. Second Edition. Charles C. Thomas, Springfield, IL, 1970.

The first application of BIA occured on Mount McKinley, Alaska in 1981. Dr. William Mills MD, an Admiral in the US Navy, initiated a study to assess the hydration status of soldiers in high altitude cold weather environments. There was one reference paper by Hoffer[1] in 1969 that indicated a hand to foot whole body BIA measurement could predict total body water. With the encouragement of Jan Nyboer MD Dsc the Mount McKinley soldier hydration project was started.

Four BIA instruments were ordered by the US Navy from RJL Systems that had to be designed and built to handle the cold weather on top of Mount McKinley. The instruments were applied to soldiers along with analyzing samples of blood and urine at approximately 10,000 feet. Electrode placement was the same as is used today. The dollar amount of the Navy contract was enough to put months of research and development in designing an accurate, dependable and safe instrument that could be used on humans.

The results of BIA measurements compared to blood and urine analysis were very encouraging. This inspired RJL Systems to build additional instruments for scientific research. Shortly thereafter Hank Lukaski[2] at the USDA in Grand Forks, ND was one of the first to publish a paper on BIA and body composition. Today there are thousands of papers and abstracts on BIA to predict body composition.

1. Hoffer, E.C., Meador, C.K. and Simpson, D.C.:Correlation of whole body impedance with total body water volume. J. Appl. Physiol., 27: 531, 1969.

2. Lukaski, H.C., Johnson, P.E., Bolonchuk, W.W., Lykken, G.I.: Assessment of fat free mass using bio-electrical impedance measurements of the human body Am. J. Clin. Nutr., 41: 810-817, 1985.