body fat% measurement

8/3/2019 Body Fat% Measurement

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MEASUREMENT OF BODYFAT % USING DIRECT

SEGMENTAL BIO-ELECTRICAL IMPEDANCEANALYSIS



OBJECTIVE

To measure and display

• Body fat %

•

Extra cellular fluid (ECF)component.

• Body mass index



EXISTING METHODS.EXISTING METHODS.

• Near-infrared interactanceNear-infrared interactance

• Dual energy X-ray absorptiometryDual energy X-ray absorptiometry

•

Body average density measurementBody average density measurement• Anthropometric methodsAnthropometric methods

• Skin fold methodsSkin fold methods

• Bioelectrical impedance analysisBioelectrical impedance analysis



PRINCIPLE

The basic principle behind this project isBIO – ELECTRICAL IMPEDANCE analysis.

• BIA determines the opposition to the

flow of an electric current through bodytissues.

• Human body consist of lean tissue andfat.

• Fat offer high resistance to current as itcontains only 3 – 13% of water.



BLOCK DIAGRAM

Powersupply

Right wrist

50/100 KHZOscillator

LCD Display

Right ankle

Microcontroller

Level converter

PC

AC Amplifier

Bridge rectifier

ADC



WORKINGPOWER GIVEN TO ALL

MODULES

OSCILLATOR DELIVERS PULSES TO THE BODY THROUGHELECTRODES

VOLTAGE IS GIVEN TO O/P ELECTRODES BASED ON BIO-IMPEDENCE

ALTERNATING VOLTAGE IS CONVERTED USING BRIDGERECTIFIER

IT IS CONVERTED TO DIGITAL FORM BY AN ADC

THE O/P FROM THE ABOVE STAGE IS PROCESSED BY AµCONTROLLER

O/P IS OBTAINED AS VOLTAGE IN LCD

THE SETUP IS INTERFACED TO PC THRO’ RS232 &O/P IS VIEWED



ELECTRODE PLACEMENT

Tetrapolar electrode system is used.

• A pair of patch electrodes on rightwrist & other pair on right ankle.

• This type of placement is reliable ,convenient & accurate than othersystems.

• Also, extremities have an increasedflow of voltage when compared withother parts.



A Quick Glance

• Power Supply: Linear Power Supplythat uses a constant Voltage source .

• Oscillator: 555 Timer .

• Electrodes: 4 Patch electrodes.

• AC Amplifier: IC 741 in non inverting

mode



Cont…………

• Bridge Rectifier: Converts the a.c tod.c.

• ADC: 0809 ADC.

• Micro Controller: 89s52 μC.

• LCD Display: FET Display.

•

Level Converter: Max232



TABLE FOR CALIBRATION



Software used in our Project

• We use VB in our Project forconverting the Voltage to Fat

• We establish a relation between BMIand Fat thereby finding a constant tofind out the value.



Flowchart for micro-controllerprogramming

START

IINITIALISE THE MEMORY LOCATIONS FORSTORING

MOVE THE HEXADECIMAL DATA TO p2, p1 ,p3,p4

SET THE DELAY FOR LCD

DISPLAY

A

CLEAR ALL THE ADC PORTS



CONT..... A

CALL LCD DELAYS TILL ALL THE DATAS AREDISPLAYED

CONVERT HEXADECIMAL DATAS TOBINARY

MOVE DATAS TO 11,12,13 ROMLOCATIONS

B

SET ALE



CONT…. B

CLEAR OE,CLK,AND SETCLK

MOVE THE DATAS FROM ADC TO MEMORYLOCATION

STORE THEM INACCUMULATOR

SEND THE DATAS TO PC THROUGHSERIAL PORT

SEND THE DATAS TO LCD

STOP



FLOWCHART FOR VBPROGRAMMING

START

GET THE VALUES OF THE VOLTAGE FROM THE KIT THROUGH RS232 PORT

CALCULATE THE BMI FOR AN AVERAGE NUMBER OF

PERSONS

ESTABLISH A RELATION BETWEEN BMI AND VOLTAGEWHAT WE OBTAIN AT THE OUTPUT

HAVE A CONSTANT THROUGH THE PREVIOUSSTEP IN THE INBUILT PROGRAM

C

RUN THE PROGRAM REAL TIME AND CHECK THEOUTPUT



CONT……C

GET THE VALUE OF O/P ANDCONSTANT

IFCONST=CO

NST OFAGES

DISPLAY THE VALUE AND RESULT ASNORMAL OR POOR

DISPLAY THE VALUE AND SHOW ASOBESE

STOP

yes

no



OVERALL SETUP



Some rules to be followedwhile measuring

• Should not take food before 4 hoursof undergoing the test.

• Should be in a stable position onceafter the electrodes are connected.



Our Contribution

• We measure Fat using DirectSegmental Bio Impedance which is

more reliable and accurate thanconventional techniques.(50KHz)

• We also measure ECF by allowing

discrete frequencies(100KHz)



RESULTS

SL NO SUBJECT

AGE WEIGHT(Kg)

HEIGHT(meter)

SEX BODY FAT%

1 A 19 55 1.54 F 26.69

2 B 20 38 1.52 F 18.88

3 C 21 55 1.57 F 26.19

4 D 21 42 1.57 F 19.83

5 E 22 60 1.68 M 14.3

6 F 22 58 1.56 M 17.42

7 G 36 68 1.61 F 34.32

8 H 47 70 1.73 M 22.57

9 I 49 68 1.66 M 24.59

10 J 38 61 1.69 M 18.1



REFERENCE

• Al Libke, and Richard G. Wooten (2004) ‘System for bodyimpedance data acquisition’ (www.patentstorm.com)

• Auguste Louis Thomasset (1999) ‘Apparatus and methodsfor the measure of the electrical impedance of livingorganisms’(www.patentstorm.com)

• D.Roy Choudhury and Shail B. Jain – “Linear IntegratedCircuits”- chapter 3, pp.104-111 . Chapter 8- pp. 311-312 ;318-321

• Harry Shizgai and Dollard Des Orneaux (1996) ‘ Method for

measuring total body cell mass and total extracellular massby bio electrical resistance and reactance ‘(www.patentstorm.com)

• P. Pecoraro, B. Guida, M. Caroli, R. Trio, C.Falconi, S.Principato, A. Pietrobelli (2003) ‘Body mass index and

skinfold thickness versus bioimpedance analysis : fat massprediction in children’-Acta Diabetol 40: pp 278- 281.



THANK YOU……………

body fat% measurement

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