The Quantum II BIA Analyzer
On April 2nd, 2008, an RJL Systems Quantum-II was featured in a Health Watch segment on CBS News titled "Fatter Than They Look." Click here to watch that video. Also, click here to learn how the BIA is used to help one achieve a longer life span.
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
The Quantum II system provides the patient a method of monitoring and historically tracking body
What is Bioelectrical Impedance Analysis (BIA)
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
Even human circulation and breathing can be quantified with a
real-time BIA instrument that has enough sensitivity and a short
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
1. Nyboer, J.: Electrical Impedance Plethysmography. Second
Edition. Charles C. Thomas, Springfield, IL, 1970.
The history of Bioelectrical Impedance Analysis (BIA)
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 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 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,