BME100 s2017:Group2 W1030AM L3: Difference between revisions

From OpenWetWare
Jump to navigationJump to search
Line 81: Line 81:
Independent: Concentration of photochromic dye in mixture <br>
Independent: Concentration of photochromic dye in mixture <br>
Dependent: Amount of time elapsed for the dye to change color under the sun <br>
Dependent: Amount of time elapsed for the dye to change color under the sun <br>
Controlled: Total quantity of sunscreen mixture; dye used; Percentage composition of supplementary sunscreen material (i.e. oils, waxes, butters).<br>
Controlled: Total quantity of sunscreen mixture, dye used, percentage composition of supplementary sunscreen material (i.e. oils, waxes, butters)<br>


Exp. Control: <br>
Exp. Control: <br>

Revision as of 22:46, 21 February 2017

BME 100 Spring 2017 Home
People
Lab Write-Up 1 | Lab Write-Up 2 | Lab Write-Up 3
Lab Write-Up 4 | Lab Write-Up 5 | Lab Write-Up 6
Course Logistics For Instructors
Photos
Wiki Editing Help

OUR TEAM

Name: Anh Nguyen
Name: Sheridan Hill
Name: Kiryl Sheleg
Name: Thomas Andrews
Name: Skye Russell
Name: Derall Riley

LAB 3 WRITE-UP

Descriptive Stats and Graph

Heart Rate:
Pulse Ox Mean: 98.5218
Pulse Ox Standard Deviation: 23.0305
Spree Band Mean: 98.9538
Spree Band Standard Deviation: 24.8775
Pearson’s r Between the Pulse Ox and Spree Band: 0.6908

Temperature:
Oral Thermometer Mean: 96.6472
Oral Thermometer Standard Deviation: 1.9226
Spree Band Mean: 95.3509
Spree Band Standard Deviation: 0.8704
Pearson’s r Between the Oral Thermometer and Spree Band: 0.1928

Heart Rate Graph
Pearson’s R Graph of Heart Rate
Temperature Graph
Pearson’s R Graph of Temperature

Used the Average, StDev, and PEARSON functions in Microsoft Excel.

Inferential Stats

Paired T test between Pulse Ox and Spree band: The statistical test had a p-value of 0.4271, which is less than 0.95. This means there is a statistical difference between the Pulse Ox and the Spree Band.

Paired T Test between oral thermometer and Spree Band: The statistical test had a p-value of 1.1e-21. This value is essentially zero. Since this P value is less than 0.95, there is a significant difference between the oral thermometer and Spree Band.

Design Flaws and Recommendations

After looking at the results, we can conclude that the Spree Band is not as good as the gold standard for measuring heart rate (pulse ox) and temperature (oral thermometer) because of the large statistical difference between the band and the gold standard. The results of the paired T-test were 0.43 for the heart rate measurement and essentially 0 for the measurement of temperature. Both of these values are too small, so we have to conclude there is a statistical difference between the Spree Band and the gold standards.

The results of the descriptive statistical tests were not much better. Although we observe similar means between the Spree Band measurements and the measurements from the gold standard devices, the standard deviations for the heart rate measurements are quite large. The standard deviation for temperature is much smaller because body temperature should not fluctuate too much. Even so, looking at the Pearson’s r value, we see that the result still points to a statistical difference because the values were too small (0.69 for heart rate and 0.19 for temperature).

After looking at all these numbers, we have to conclude that the claim made by Spree Sports is incorrect. Their device does not accurately measure a person’s heart rate or temperature. This is because of the design flaw of the Spree Band. Because of the placement of the band on a person, it cannot take accurate readings of the heart rate and temperature. As a recommendation, we suggest a new design. Current technologies are not good enough to have the Spree Band give accurate measurements as is.

Experimental Design of Own Device

Statement of problem:
How can the incidence of skin cancer be reduced?

Hypothesis:
The present incidence of skin cancer is partially a result of sun screen application that is not consistent throughout the day. It is estimated that most sunscreens on the market protect against UVB radiation (cancer-causing) within about 2 hours since when they were first applied. Given this data then, it is worthwhile to easily know when to further apply sunscreen, if going out in the sun for long periods of time. Therefore, a bodily indication that prompts the individual to further apply sunscreen may be beneficial, so that more people will remember to put on sunscreen, thereby reducing the incidence of skin cancer in the population.

Variables:
Independent: Concentration of photochromic dye in mixture
Dependent: Amount of time elapsed for the dye to change color under the sun
Controlled: Total quantity of sunscreen mixture, dye used, percentage composition of supplementary sunscreen material (i.e. oils, waxes, butters)

Exp. Control:
The control group will be people using a sample of sunscreen mixture in which no photochromic dye were added. This is done to ensure that the dye are the active ingredients in the coloration after exposure to sunlight and to detect dehydration respectively.

Materials:
solar color dust (photochromic dye), zinc oxide powder (active ingredient in sunscreen), beeswax granules, shea butter, coconut oil, hot plate, stirring rod, six 50-mL beakers, one 100-mL beaker, one 250-mL beaker

Sample Size:
There will be a total of six sample groups (5 experimental and 1 control) with 5 people in each group. This is because we do not have the money to have a large group, but we need at least some people to see if the product works. Sometimes there will be factors that might affect the time of the color change that isn’t accounted for such as different skin reacting to it in different ways. This is why we need more than one person per group. 5 is not many, but the number should stay low for initial testing. The 5 experimental samples involves five different concentrations of photochromic dye: 2%, 4%, 6%, 8%, and 10% of the sunscreen mixture. This is to test how much dye is needed in the sunscreen for it to change color at the appropriate time.

Procedure:
Prepare the sunscreen by heating a mixture of ½ oz. beeswax granules, 2 oz. shea butter, 2 oz. coconut oil, and 1 oz. zinc oxide powder in a 100-mL beaker placed in a 250-mL beaker of water on a hot plate. Stir well until mixture is properly heated (thick white liquid is maintained).
Place 0.5 oz. of the mixture in the six 50-mL beakers to be used as samples (5 experimental and 1 control)
In each of the five experimental groups, change the concentration of photochromic dye that is added to each beaker:
Exp. G1: Add 0.01oz. of dye → to make 2% dye solution
Exp. G2: Add 0.02oz. of dye → to make 4% dye solution
Exp. G3: Add 0.03oz. of dye → to make 6% dye solution
Exp. G4: Add 0.04oz. of dye → to make 8% dye solution
Exp. G5: Add 0.05oz. of dye → to make 10% dye solution
Apply the different sunscreens on different group and stay in the sun for approximately two hours or until dye’s color appears.
Compare results of color change time with results of UV indicating strips. These strips detect the amount of UV absorbed.
Adjust experiment accordingly with results.

Possible Exp. Error:
Error could occur if the dye or dehydration monitor get washed off in the water since some people go swimming when they apply sunscreen.

Inferential Stats:
Do a paired T-test with the time it takes for the dye to change colors and the time it takes for the UV strips to say it has absorbed

Works Cited:
“UV Fastcheck Strips”. http://www.uvprocess.com/product.asp?code=INTS+LBL+B, Accessed

Feb. 21 2017.