Body Functional Capacities Variation and Its Relation with ECG Parameter

Tresna P Soemardi, Mechanical Design and Biomechanics Laboratory, Dept.of Mechanical Engineering, University of Indonesia, Kampus UI Depok 16424, Indonesia. Tel. +62-21-7270032 ext.245. E-mail: tsoemardi@eng.ui.ac.id. Yossita Wisman, Physical , Health and Recreation Study Program, Faculty of Education, University of Palangka Raya. Central Kalimantan 73111.Indonesia. Tel.+62-563-3227111. E-mail: yossita@fkip.upr.ac.id

Abstract

There’s electrical and mechanical activity in each human body.  So there’s also electrical and mechanical activity in the human hearts. In the other side, human body are considered as a volume conductor for the alectrical activity in the body. Based on this event, human are searching a way for representing the heart activity and therefore electrocardiography (ECG) is invented. Each human has its own fitness level and this level can be represented by bodies functional capacity. Regarding this matter, this report will analyze the correlation between bodies functional capacity with the heart wave (ECG). In this matter, the sample are MAPALA UI member.

Analysis will be done by calculating the heart wave with BIOPAC Student Lesson Pro software and then finding the correlation to the bodies functional capacity with simple liner regression analysis. The results are expected to be information in developing the Biomechanics and Medical Equipment area in Indonesia especially in Mechanical Engineering Department University of Indonesia.

1. Introduction

ECG invention was one of many great contribution to medical world from biomechanical area. Biomechanical studied how body works as a system in human mechanical movement. This can be done by taking that human body works the same way as machine. Beside that, biomechanical also involving biomaterial. That means all subtances in this world can be manipulated and used as a subtitute for human organ.

In Biomechanic, human body has three major component [1]:

  1. Supply System

In the supply system, Heart take role as a blood pump so blood can distribute important substances to other organs.

  • Movement System

The main function of this system is to translate instruction from central nervous system to body in form of muscle and bone movement.

  • Control System

This system control every mechanical activities of human organ. It acts as a command center for your body.

Figure 1. Human Mechanical Movement

(source : college material dr. Dangsina Moeloek)

Basically ECG only record potential electrical diference between two electrodes that placed in certain places on the human body. This potential difference describes algebra sum of miocardium tissue activities that recorded. In the recording process, we will find many phenomena and anomalies that happen. As an example : electrode placing position in the body, type of lead, P-R Interval, QRS Interval, amplitude difference, etc.

 Beside that, every kind of body activities will affect the electrical potential value that produced by the heart. So the ECG result will be different for each person.  It depends on what activity the person do while recording the ECG of his/her heart.

Every parameter in ECG will be studied so we will know the correlation between activities of the hearth with its ECG result.

Therefore experiment is needed. The experiment will be in form of functional body capacity test and correlate its result with the ECG result so we will know what or how strong the correlation value between every parameter in the body functional capacity with the ECG wave pattern.

2. Objectives

The objectives are :

  1. Find correlation between body functional capacity with ECG wave pattern.

This experiment involving measurement of body functional capacity asnd try to find the correlation value between correlation every parameter in the body functional capacity  with the ECG wave pattern. Microsoft excel is used as a helping tool to find the correlation value.

  • Study electrical and mechanical activity of the heart.

ECG used to record electrical and mechanical activity of the heart. This include study every part of the heart like sinoatrial node (SA node), atrioventricular node (AV node), bundle of His, branches, Purkinje fiber, etc and understand heart terminology such as ventricular systole, ventricular diastole, etc

3. Basic Theory

    Mechanical activities on the heart depends on electrical activities produced from the nervous system. The heart has specialized pacemaker cells that start the electrical sequence of depolarization and repolarization. This property of cardiac tissue is called inherent rhythmicity or automaticity. The electrical signal is generated by the sinoatrial node and spreads into the ventricular muscle via particular conducting pathways: internodal pathways and atrial fibers, the atrioventricular node, the bundle of his, the right and left bundle branches, and purkinje fibers. When the electrical signal of depolarization reaches the contractile cells, they contract. When the repolarization signal reaches the myocardial cells, they relax. Thus, the electrical signals cause the mechanical pumping action of the heart. [2]

The electrical events of the heart usually recorded on the ECG as a pattern of a baseline broken by a P wave, a QRS complex and a T wave. In addition to the wave components of the ECG, there are intervals and segments.

  • Baseline (isoelectric line)
    • The baseline is a straight line on the ECG. It is a point of departure of the electrical activity of depolarizations and repolarizations of the cardiac cycles.
  • P waves
    • The P wave results from atrial depolarization.
  • QRS complex
    • QRS complex is a result of ventricular depolarization and initiates ventricular contraction
  • T waves
    • T wave result from ventricular repolarization.
  • Intervals
    • Intervals is a part of ECG containing at least one wave and a staright line.
  • Segment
    • A segment is a period of time from the end of one wave to the beginning of the next wave.

Figure 2. Standard ECG Wave

(source : ECG Modul Lesson 5, BIOPAC)

R-R interval in ECG shows hearts beat per minute (BPM). BPM is used as a cardiac output from the subject.

Body functional capacity shows physical ability of a man/woman. This can be known with body functional capacity test. This experiment included test of body mass index, cardiac output , muscle power, muscle exposive power, muscle endurance, reaction time, coordination, and running speed [3].

4. Research Methodology

This experiment use Biopac Studen Lab software for extracting data and Biopac Student Lab Pro software for analyzing data. And as for the body functional capacity test, many equipment are needed like hygrometer, automatic blood pressure monitor, height-weight scale  and stopwatch. 

4.1 ECG Recording

This experiment using equipment package from Biopac :

  1. Biopac MP35 (Data acquisition)

MP35 used as data acquisition unit. There are four channel that can be used as an input channel (trigger).

Figure 3. Data Acquisition MP35

  • SS2L Biopac Electrode lead set

These cables are used to connect disposable electrode on the skin surface with MP35 data acquisition unit.

Figure 4. Unit SS2L

  1. Disposable vinyl electrode

These kind of electrodes are common electorodes used in medical world.


Figure 5. Disposable Electrodes EL 500 series

  1. Software Biopac Student Lab Lesson version 3.7

This Software read electrical current from the data acquisition unit and display it in a form of ECG wave

4. 2 Data Procedure

ECG data extracted from subject in sit and relax condition and not yet doing the body functional capacity test. However, step for extracting ECG data are not necessary to be explained. In the picture below, you can see that Limb Leads are used in this experiment. 

Figure 6. Electrodes Configuration

4. 3 Body Functional Capacity Measurement

Measurement include cardiac output, body mass index, anthropometry, muscle endurance and explosive power, Leg and back test, reaction time, 2,4 km run, 50 m sprint, body coordination and color blind test. From ten test item, only few that required for this experiment. The test that required are :

  1. Cardiac output

This test include heart sistole/diastole measurement and heart beat measurement. Subject are tested before and after running test so tester can be assured that subject is in the resting state and can differentiate cardiac output before and after running test.

  1. BMI (Body Mass Index) and anthropometry

BMI was measured with weight and height scale.  Anthropometry include just leg and waist measurement.

Figure 7. Anthropometry measurement

  1. 2,4 km Run

2,4 km running take places in the running track 6 x 400 m. Besides measuring track record per subject, a few subject was taken as a sample for blood pressure and BPM change between before and after running. This test must be done in 90ºF temperature and 70% humidity limitation.

This test objective is to measure VO2max capacity through cooper method but this method not too accurate because this not a direct measurement. The VO2max value come from this equation below.

  1. 50 m Sprint

This test measured subject 50 m sprint record. BPM and heart pressure was also measured from the subject before and after sprint.

Figure 8. 50 m Sprint test

5. Results & Discussion

5. 1. ECG Parameter Analysis

Table 1. Sample age

UmurJumlah
18-2130
22-256
>252

    Table below shows that 38 subject are taken as a sample. Age range from 18 to 21, this shows us the data that collected has a little variance value and this means it has homogenic property. This property eventually will affect the outcome results.

Compared to the normal standard value, the experiment results shows no big difference in value except for ST segment  (there’s some exception to judge ST segment value). The comparison is in the table below.

Table 2. Comparison ECG parameter with standard

PARAMETERMAPALA UINORMAL STANDARD
BPM7670 – 80
Interval PR0,150,12 – 0,20
Interval QRS0,080,08 – 0,09
Interval QT0,350,33 – 0,37
Segmen ST0,100,13 – 0,15

This standard is taken froom book : Travis Winsor, The Electrocardiogram in Myocardial Infarction  (USA: Ciba Pharmaceutical Company, 1977)

5. 2. Relations between Body Functional Capacities and ECG

Comparison that taken are based on existing theory and previously taken body functional capacity test. The goal of this comparison is to find any relationship between the parameter with the used of regression and corelation chart. These following charts will shows the relationship between ECG and body functional capacity parameters.

Figure 9. R-R interval Vs Sprint Correlation

Figure 9 shows that for longer R-R interval times, the subject running time will be faster. This relationship is the same as the existing theory that stated bigger heart stroke volume is to adjust to bodies blood need so with the same or less beat per minute, the body will move more efficiently and in this case is the running ability of the subject.

Figure 10. BMI vs 50 m Sprint Correlation

Comparison in figure 10 shows that for bigger BMI value, the subject running time will be longer. This can be proven from daily life that the bigger someone, the harder him/her to do all kind activities like jumping, running, etc. As for the other comparison, the chart below will show complete list of comparison that tested in the experiment.

Table 3. Correlation summary

CorrelationrError (%)
R-R interval vs 50 m sprint0.3310.9
R-R interval vs VO2max0.1818.64
R-R interval vs 2,4 km run0.2213.48
BMI vs 50 m sprint0.648.92
BMI vs VO2max0.5715.01
BPM before run vs 50 m sprint0.0911.26
BPM before run vs 2,4 km run0.3312.16
Hip size vs 50 m sprint0.126.08
Leg length vs 50 m sprint0.1511.1

6. Conclusion

  1. VO2max was measured by indirect method not by direct method. So the data results is not too acurate
  2. Correlation coefficient value still too far from one. This could be happen because the population sample are homogenic in age range and body condition.
  3. From the correlation cofficient value, we can concluded that ECG wave pattern is more like a control parameter for the test subject. ECG wave pattern are better being used as a screening test for decide whether normal or not normal the subjects are.

7. Suggestion

  1. Experiment should use more variate population sample so the the data range is more adequate.
  2. VO2max measurement should use direct measurement method rather than indirect methode so the result is more accurate cause the indirect methode is predictive measurement.

References

[1]  College material from Dr. Dangsina Moeloek

[2] Richard Planzer, et al., Modul Biopac Student Lab Lesson 5: Electrocardiography I (California: Biopac System Incorporation, 2003) p.4

[3] A. Purba, et al., Pedoman Kesehatan Olahraga (Jakarta: Depkes RI, 2002) p.15-19

[4] John M. Brown, Introduction to Biomedical Equipment Technology (New Jersey: Prentice Hall & Technology, 1993)  p.126

[5] Leslie Cromwell, et al., Biomedical Instrumentation and Measurements (New Jersey: Prentice-Hall,1980) p.66

[6] John M. Brown, Introduction to Biomedical Equipment Technology (New Jersey: Prentice Hall & Technology, 1993) p.130

 [7] Tim Penyusun Naskah Modul Pelatihan Tenaga Medis Kesehatan Olahraga, Modul Pelatihan Tenaga Medis Kesehatan Olahraga (Jakarta: Depkes RI, 1994) p.5 – 14

[8] Tim Penyusun Naskah Modul Pelatihan Tenaga Medis Kesehatan Olahraga, Modul Pelatihan Tenaga Medis Kesehatan Olahraga (Jakarta: Depkes RI, 1994) p.25

[9] Jacqueline M. Green, Anthony J. Chiaramida, EKG-12 Sadapan Terpercaya, terj.A. Samik Wahab (Jakarta: EGC, 2003) p.38

[10] Jacqueline M. Green, Anthony J. Chiaramida, EKG-12 Sadapan Terpercaya, terj.A. Samik Wahab (Jakarta: EGC, 2003) p.61

[11] Travis Winsor, The Electrocardiogram in Myocardial Infarction (New Jersey: CIBA, 1977) p.12

[12] Youlian Hong (2006). Sport Science & Physical Education.

http://www.cuhk.edu.hk/

[13] Michael (2005). VO2 Testing. 

http://www.wellnesswithinu.com