Body Fat MonitorBody Impedance Measuring

Roger TSAI

Apr 25, 2007

Something about Roger (his friend)

Before After

Why Measuring Body Fat?

• Same weight as Michael Jordan? How’bout body fat?– Height 6 ft 6 in (1.98 m)

– Weight 216 lb (98 kg)

• Health Indicator– Prevent from blood related disease

Product Information• Manufacturer: Tanita

• Price: $30

• Function: – Measuring weight

– Measuring body fat

– Two user memory set

– Unit: Lb or kg

How to use it (1)Setting:

How to use it (2)• Switch on and get on !

– (take off your sox first)

Health Standard

Male

Female

How it works electrically

• Theory of BIA (Bioelectrical Impedance Analysis)

– Shots an electron into one side or your body and receive it from the other

side

– Fat generate more resistance(impedance) than muscle do

– BIA: Calculate fat percentage of your body by data of your gender, age,

height, and weight.

What it senses(1)

• Weight – Use balance bridge, malleable metal,

and flex sensor to calculate your weight

What it senses(1)

• Comparing with other weight scale– http://www.howstuffworks.com/inside-scale.htm

What it senses(2)• Impedance

– Shooting electron from left side of food pad, and receive electron from right side.– Measure voltage difference to between two sides.

Data Sheet

• Not much info on data sheet

PCBLED monitor

Connect toUnit switch

Speaker

Connect topower

Connect toFoot pad

Connect to flex sensor

Up Memory DownButtons:

Wiring

Micro controller

NEC SGP (for LCD)

BU4052BCF Dual 4-channel analog multiplexer

Data Value

• Voltage

Availability

• Availability:

– Domestic merchandise, e.g. Bed, Bath, and Beyond

– Pharmacy, e.g. Duane Read

– Internet, e.g. eBay

• Cost:– Price Range: $30~$100

• Industry links:– http://www.tanita.com/

What’s Next

• Advance version of body fat monitor

• Further application