BME100 s2017:Group2 W1030AM L3

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. We used the paired T-test because there are two readings from the Spree Band and the pulse ox/oral thermometer. The two values side by side are readings from the same person at the same time. It makes sense to use a paired T-test in this situation. 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 Experiment 1: photochromic dye (UV indicator) Experiment 2: bromocresol purple (pH indicator) Statement of problem: One of the most common healthcare issues is that of skin cancer, specifically squamous cell carcinoma and melanoma. Both of these result from overexposure to the UV radiation which often occurs when people forego the recommended time in between reapplying sunscreen. 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. This idea can also be applied to dehydration. Many people get dehydrated because they forget to drink water. A lot of times when they are out in the sun, they will be partaking in activities that increase dehydration. Having a different indicator that monitors dehydration will also help people stay hydrated. Variables: Independent: Experiment 1: Concentration of photochromic dye in mixture Experiment 2: Concentration of bromocresol purple indicator Dependent: Experiment 1: Amount of time elapsed for the dye to change color Experiment 2: How well the pH correlated with actual dehydration We can change the independent variable to see how accurate the product is when measuring the dependent variables to compare to their respective gold standards. Exp. Control: The control group will be people using a sample of sunscreen mixture in which no photochromic dye and no bromocresol purple were added. This is done to ensure that the dye and the bromocresol purple 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, bromocresol purple 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. For the experimental sample in dehydration, again, 5 experimental and 1 control. The experimental samples will also have varying concentrations of the bromocresol purple indicator. The groups in the two experiments will overlap. This will test how much bromocresol purple is needed to accurately change color for dehydration. Procedure: (UV): 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. (pH): Subject the pH indicator to a variety of pHs in its range, using a standard pH system to create an effective marker for what the dye looks like in its mixture (which should be the same as the photochromic dye mixture). More dehydrated skin is more basic skin, around a pH of 7, as opposed to hydrated skin around approximately a pH of 5, which should shift the color of the pH indicator dye between yellow and purple. Use Total Body Weight Loss as a measure of dehydration: have a person drink water until they are well-hydrated (by physiological indicators), weigh them, and then use the indicator mix to create a standard colour for them. Continue to do so over the course of the day, measuring their body weight against the apparent pH demonstrated by the indicator. More dehydrated skin is more basic skin, around pH7, as opposed to hydrated skin around approximately pH5, which should shift the colour of the pH indicator dye between yellow and purple. Allow each person one day to set themselves a standard, in which they try to keep their body weight the same just by drinking as they normally would, one in which they allow a constant decrease of body weight water to dehydrate themselves, and one where they try to adjust water intake according to the indication of the bromocresol purple. 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. It will be hard to measure a qualitative thing, like color, and apply it to a chart for the pH monitor. 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. While dehydration is hard to measure to a gold standard due to how different people will change at different rates, etc, marking the change in color against the change in body weight should provide a basis for linear correlation, which, if above .7 or .8, should be definitely tested more thoroughly. A RGB/Hexcode colour assessment could be used to determine exactly the colour presented in the indicator. Works Cited: Armstrong, Lawrence. "Assessing Hydration Status: The Elusive Gold Standard". Human Performance Laboratory, Departments of Kinesiology and Nutritional Sciences, University of Connecticut, Storrs, Connecticut. "Sunscreen FAQs". American Academy of Dermatology, https://www.aad.org/media/stats/prevention-and-care/sunscreen-faqs Accessed Feb. 21 2017. “UV Fastcheck Strips”. http://www.uvprocess.com/product.asp?code=INTS+LBL+B, Accessed Feb. 21 2017.