Bioelectric Fat Analyzer

Presented by

P.Sandeep Reddy

B.Santhosh Naik

K.Venkata Rajesh

Guide: Mr.Vennala Kishore Assistant Professor

(Dept of ECE) BVRIT

Presentation Outline

Introduction Hardware used Flow Chart Block diagram Working Existing methods Implementation and Result Future Scope Conclusion

Introduction

• Weight alone is not a clear indicator of good health because it does not distinguish fat and body mass.

• Obesity means an excess of body fat regardless of weight.

Principle

Bioelectric Impedance Analysis

Hardware Procured

• AT89C52• ADC0809• 16*2 Character LCD• Step Down Transformer (Centre Tapped)• External Clock Generator• 12 MHz Crystal Oscillator • Power Supply Circuit• Keypad 4*3• Copper Electrodes

F Flow ChartStart

Accept Inputs (Age, weight)

Adjust Body Peripheral Length

Set electrodes

Apply constant current electrodes

Calculate fat free mass

Calculate body fat by substituting weight , age ,

voltage in regression equation

Set body length by replacing each pair of

electrodes

Find the potential Difference

Calculate body percentage

Display result on LCD Screen

EndNo

Yes

Block Diagram

Working

The measurement is taken when the electrodes are placed at the wrist and the contra lateral ankle.

By injecting an AC current of the order 10uA through one’s body and measuring the voltage across the electrodes and finding instantaneous impedance.

Enter the Age and Weight of the user. Percentage of the Body’s Fat is Calculated by

regression equations.

Males: Bodyfat = 0.0923*weight + 0.1605*age - 0.0263*voltageFemales: Bodyfat = 0.1871*weight + 0.5800*age – 0.0920*voltage

Existing Methods

DEXA (Dual-energy X-ray Absorptiometry) Scan

Underwater Weighing Bod Pod (Whole Body Plethysmography) Skinfold Measurements

Implementation and Result

Step 1: Switch ON the Power Supply Circuit

Step 2: The message “Hold Electrodes” on the 16*2 Character LCD gets displayed.

Step 3:: On seeing the message “Hold Electrodes” on the LCD display, hold it with two figures of your hand as shown in below picture

Step 4: Enter the weight and age of the user using 4*3 keypad present in the Kit and press Go key. After a message “Please enter 1 for MALE or 2 for FEMALE gets displayed” on the display, Enter 1 if the user is 1 or enter 2 if female and press Go key.

Step 5: Fat percentage of the User gets displayed on the LCD screen.

Advantages

Measuring body’s fat with this method is much easier than compared to any other method.

Can be used in any environmental conditions.

Much of reasonable cost.

Future Scope

One extension would be to improve accuracy by implementing multi-frequency bioimpedance analysis.

Another possible extension would be miniaturize the device and making it portable.

Conclusion

For our accuracy goal, we were able to achieve body fat prediction within a 10% error margin for subjects matching our test samples, but we had poor accuracy outside that fairly specific range of weights and body compositions

The device operated at a safe current and did not harm any of our test subjects. Our input signal to the user is approximately 12 μA, which is quite close to our goal of 10 μA, and is still safe to pass through a user’s body mass. 

Thank you