Bioimpedance‐BIA• Early detection of malnutrition the
measured Phase angle, the body cell
mass (BCM) and the ratio between body
cell mass and extracellular mass (ECM)
as well as the nutrition index (R/Xc ) ,
extra and intracellular water (ECW,ICW) ,
total body water (TBW) Lean body mass
(FFM) , Resting energy expenditure
(REE)are the most meaningful body
Body composition‐Hydration‐Nutritional status
Resistance (R), Reactance (Xc), Phase angle (φ)
Is the real part of impedance; a device with a purely resistive impedance exhibits no phase shift
between the voltage and current.
Is the imaginary part of the impedance; a component with a finite reactance induces a phase shift
between the voltage across it and the current through it.
A purely reactive component is distinguished by the sinusoidal voltage across the component being in
quadrature with the sinusoidal current through the component. This implies that the component
alternately absorbs energy from the circuit and then returns energy to the circuit. A pure reactance will
not dissipate any power.
Capacitive reactance o Capacitance
Has a purely reactive impedance which is inversely proportional to the signal frequency.
A capacitor consists of two conductors separated by an insulator, also known as a
• LEAN BODY MASS (FFM)
1. Cell mass (BCM), is the most active metabolic compartment of the body and one of
the most important keys to determine a subjects nutritional status measured in the
NUTRITIONAL INDEX (R/ Xc).
2. Extracellular mass (ECM), another component of lean mass, contains all the
metabolically inactive parts of the body including extracellular water (ECW).
• TOTAL BODY WATER (TBW) composed by intra and extracellular water.
1. These two fluid compartments are tightly regulated. It has been shown that cellular
hydration (ICW) is an important regulator for protein catabolism.
2. An increase in extracellular water (ECW) may indicate disturbance in the cellular
membrane and is a typical sign of malnutrition, even if weight stays the same and
body fat is within a normal range.
EDA = Electrodermal activity
• Property of the human body that causes continuous
variation in the electrical characteristics of the skin .
• Known as skin conductance, galvanic skin response
(GSR), electrodermal response (EDR), psychogalvanic
reflex (PGR), skin conductance response (SCR), and skin
conductance level (SCL).
• Skin resistance varies with the state of sweat glands in
the skin. Sweating is controlled by the sympathetic
nervous system, and skin conductance is an indication of
psychological or physiological arousal.
If the sympathetic branch of the autonomic nervous system is highly aroused, then sweat gland activity also
increases, which in turn increases skin conductance.
Systems that influence the EDA
• Locomotor system:
* controlling brain structures = frontal lobe motor processing areas and motor areas in the brain
stem (medulla & pons)
* function = an anticipatory increase in EDA that allows for a response to potentially dangerous
stimuli that requires a motor response
• Orienting‐arousal system:
* controlling brain structures = prefrontal areas of the frontal lobe, hippocampus, amygdala, RAS
* function = part of the orienting response produced by the limbic system that is seen in response
to dangerous or novel stimuli
• Thermoregulatory system:
* controlling brain structures = hypothalamus
* function = not so related to cognitive functions, a response by this system is generated either in
order to maintain normal homeostasis or in response to physical trauma
GSR= Galvanic skin response
GSR, standing for galvanic skin response,
is a method of measuring the electrical
conductance of the skin. Strong emotion
can cause stimulus to your sympathetic
nervous system, resulting more sweat
being secreted by the sweat glands.
Grove – GSR allows you to spot such
strong emotions by simple attaching two
electrodes to two fingers on one hand
Extended to eating habits
Extended to Glucosae
NIR glucometer by Arduino
InGaAs photodiode, 8 LEDs(2 x Green, 2 x NIR @ 1550nm, 1 IR @ 960nm, 1 Red)
an Atmega328p, and the circuits required to run those. Also it contains a small
LiPo in order to be able to test, or take training data. Two separate circuit boards
and the ADC is channeled through an MCP3421 and then i2c goes across a
connector at the bottom which also supplies the regulated 3.3V
NIR glucometer – Open source
• green LED, a red LED, IR LED, and a 1550nm NIR LED. The
green is used to determine how much skin is in the way, the
Red and IR are used to determine the volume of blood being
measured, and with the volume of blood you can use the
1550nm NIR LED to determine the amount of glucose.
NIR gluc – GlucoNIR™‐VivaScan ™ ‐
LighTouch Medical ™
using three kinds of technologies: ultrasound,
electromagnetic, and thermal. You just clip
the GlucoTracksensor onto your earlobe
and within a minute, it sends your BG data
through a headphone‐style cord to a
smartphone‐sized handheld controller. And
that's where the glucose reading is displayed
or even verbally announced.
• unique sensor and a nano‐film
• passing low‐power radio waves through the body
• Electromagnetic waves at specific frequencies can be used to detect blood glucose
• The metamaterial technology was initially developed to enable a novel diagnostic
imaging technique, using safe radio waves instead of ionizing x‐rays.
• Metamaterials make it possible to bend light around an object making it seem
that it’s not there, so these seemingly preposterous sci‐fi scenarios are in fact
within the realms of probability
• Raman spectra, a unique Raman “fingerprint”
• belt around the waist. Rather than puncturing the skin, the sensor sits close
against the skin, and small drop of gel helps to seal any air gaps. The technology
behind the HG1‐c is complicated, but in a nutshell: a special camera, called a
Golden temporal tatoos