Bioelectrical Impedance
Analysis and Vasoconstriction
Taylor Guffey
Lauren Morgan
Harry Han
Shelby Hassberger
Daniel Kim
Elizabeth Morris
Rachel Patel
Radu Reit
Problem Statement
• The purpose of this study is to evaluate
whether the temperature of the room can
affect the body fat percentage reading for an
individual.
Sample Size
• Sample size derived from pilot study
• 23 estimated for statistical significance
• 24 used in experiment
Exclusion/Inclusion Criteria:
• Only students in BMED1300 will participate in this study as
part of a class project.
Hypothesis
Null Hypothesis
• There will be no difference in the readings of
body fat percentage from 24oC to 4oC as
measured by the bioelectrical impedance
analysis.
Alternative Hypothesis
• There will be a statistically significant increase in
body fat percentage when the readings are taken
from 24oC to 4oC as measured by the bioelectrical
impedance analysis.
Materials
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Instruction Sheet
Name tags
Consent Form
Data Card
Survey
Jackets
Scale
Meter Stick
Omron HBF-360 Fat Analyzer
Thermometer
Space Heater
A room at 24o C
A room at 4o C
http://image3.examiner.com/images/blog/wysi
wyg/image/omron_HBF-306.jpg
Methodology
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2 groups of 12 subjects each
Read and sign consent form
Assign subject IDs and handout Data Card
Height and weight were measured
Subjects fill out survey
BIA measured after 10 minutes
Subjects transferred to Cold Room
BIA measured again after 10 minutes
Simulation
Waiting Area
Door
Height
Heate
r
Ten Minutes Later
Ten Minutes Later
Waiting Area
Survey
& Time
Table
Chair
Time & BIA
Reading Station
Weight
BIA Reading
Station
Door
Warm Room 24oC
Cold Room 4oC
Data
Subjects
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
Height
6' 2"
5' 8.5"
5' 2"
5' 11"
5' 5"
5' 8"
5' 9.75"
5' 4.75"
5' 8.25"
5' 8"
6' 0"
5' 11.5"
6' 2"
5' 5.25"
5' 10"
6' 4"
5' 10.75"
6' 1"
6' 2"
5' 10"
6' 0"
5' 11.75"
6' 1.5"
5' 10.5"
Weight (lbs)
184
148
137
179
141
165
166
139
135
155
164
182
166
148
151
211
153
186
163
170
175
138
171
195
Gender
Male
Male
Female
Male
Female
Male
Male
Female
Female
Male
Male
Male
Male
Female
Male
Male
Male
Male
Male
Male
Female
Male
Male
Male
Age
19
18
19
19
19
20
19
18
19
19
18
19
19
19
19
20
18
18
18
20
19
19
19
19
Hot BIA
13.5
15.9
26.35
16.65
29.7
18.25
17.25
25.1
17.7
15.9
13.2
19.45
11.95
29.15
7.5
13.95
14.7
18.05
13.7
11.3
24.5
9.65
10.35
18.6
Cold BIA
17.35
17.65
27.55
16.7
30.5
19.05
18.25
26.35
18.7
17.25
15.6
20.6
13.65
29.3
9.85
14.6
16.95
18.9
14.4
13.1
25.6
11.05
11.75
19.95
Statistical Analysis
•Student’s Dependent One-Tailed T-test
Statistics
t-score
p-value
9.608
1.2423E-09
Standard Deviation
0.617402438
Mean of Difference
1.237
T-Score Calculation
XD
n
23
t
 XD
 1.237
 9.608
SD
SD
0.617
n
XD = Mean of the differences
SD = Standard Deviation of the differences
n = Sample size
Analysis
T-value Needed= 1.72 for 95% confidence
Distribution of the Mean of the
Differences
T-score = 9.608
P value = 1.24 x 10-9
Null Hypothesis is rejected
Normal Density
2.5
2
1.5
1
0.5
0
0
0.5
1
Mean of Differences
1.5
2
Outliers
Box and Whisker Plot
-0.5
0
0.5
1
1.5
Difference in Body Fat %
2
2.5
3
Discussion
• Null hypothesis is rejected
• Statistically significant increase in BIA readings
• Data supports the alternative hypothesis
• Strong correlation
Improvements
• Less subjects
• Smaller groups
• Multiple devices
• More time in each room
• Specific groups
– (e.g. gender, weight class, etc.)
Questions?