Note:
Standard deviation and standard error in this data set are reported with units of beats per minute.
Temperature:
Note:
Standard deviation and standard error in this data set are reported with units of degrees Fahrenheit.
Results
Heart Rate
The error bars were found using the standard deviations of the data set.
Temperature
The error bars were found using the standard deviations of the data set.
Use of T-Test
For both the heart rate and the temperature readings, T-tests were used for inferential analysis. This is because both tests only relied on two variables: the measurements collected from the Spree device and those of the gold standard. Had the temperature and heart rate readings been analyzed within a single test, ANOVA would have been appropriate; however, the two tests were run separately and thus necessitated separate T-tests.
Analysis
Analysis of Significant Differences
In the test producing heart rate measurements, the p-value obtained from the T-test between the Spree device readings and the gold standard was significantly larger than 0.15. Thus, there is no significant difference between the two sources of measurement, and from this information it can be concluded that there is no statistical difference between heart rate measurements from the Spree device and from the gold standard.
In the test producing temperature measurements, the p-value obtained from the T-test was incredibly small (much smaller than 0.15), suggesting significant difference between the two sources of measurement.
Analysis of Pearson's R Correlation
The Pearson's R values for the heart rate test and the temperature test are roughly 0.82 and 0.89, respectively. This suggests that there is a fairly strong, positive correlation between both the heart rate and the temperature measurements as related to their respective gold standards.
Conclusion
Overall, the data shows that the Spree obtained measurements of heart rate relatively similar to that of the gold standard but was not so accurate in terms of temperature readings. Although both tests show a fairly positive correlation between the Spree device measurements and the gold standards, the measurements of temperature from the Spree device were significantly different from the gold standard temperature measurements.
Summary/Discussion
Discussion
From the experiment with the Spree band the test subject found several issues with the overall Spree design. For instance, in order to get an accurate measurement of heart rate and temperature, the Spree had to be extremely tight on the subject's head and as the experimental testing continued, it began hurt the subject's head. Another issue that occurred was the Bluetooth nature of the system. Bluetooth connections only last for a certain distance, and then they get weak and fail. This is an issue because you can lose the connection easily, which defeats the purpose of the band in the first place.
Statistically, the measurements of temperature between the Spree device and the gold standard may be so different because the device only vaguely reported temperature as having four different, qualitative, levels total as opposed to actual measurements in degrees with the gold standard.
Recommendations
It is recommended that at least three main improvements be made to the Spree device for better accuracy and usability. Firstly, temperature readings should be quantitative with definable units. Next, the Bluetooth system used for connectivity between the device and the phone app should be either improved for distance and identification of the proper Bluetooth network (knowing whose Bluetooth network was whose posed an issue) or the app should utilize an entirely different system for connecting to the device. Lastly, the band itself should be less constricting and less harsh on the skin in order to allow extended use.
The Spree band is not recommended for consumer use without at least these improvements.
LAB 3B WRITE-UP
Target Population and Need
The target population for the Fit Patch is athletes and people that wish to track their body temperature, heart rate, and distance traveled during a workout, a practice, a game, or simply throughout their day. This target group needs the Fit Patch because tracking body temperature, heart rate, and distance traveled throughout a workout or throughout the day will help a person improve their workout and track their progress. Being able to improve a workout and track progress is important to the target population because athletes and work out enthusiasts are always trying to improve their workouts and watch their progress. The 20% of America's population that actively works out, or participate in sports, are the base of the target population that would purchase the Fit Patch, however it is assumed that more people outside of the 20% would purchase the Fit Patch. These are encouraging numbers because twenty percent of the US population is about 64 million people that will be a target population plus additional customers.
BME 100 Fall 2015
