BME100 s2015:Group18 12pmL3
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Lab Write-Up 1 | Lab Write-Up 2 | Lab Write-Up 3
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LAB 3A WRITE-UP
Designing a device (process of biomedical engineering (bme)) requires five stages/phases: identifying/understanding the problem, investigating solutions, designing a prototype, testing the prototype in the target population, and finalizing the prototype and making it available. "The Spree Sports headband is a wearable fitness management tool that uses a biosensor to measure body temperature, heart rate, and movement." Our team re-enacted and re-did step four of the bme design process in order to find out if the Spree Sports headband is reliable when compared to the temperature reading of a thermometer and the heart rate reading of an oximeter which are proven, reliable tools.
The purpose of this experiment is to assess how valid the Spree is and identify any design flaws by comparing data collecting from the temperature and heart rate readings on the device to those of an oral thermometer (gold standard) and pulse oximeter (gold standard).
Our group collected five initial measurements of heart rate and temperature at two minute intervals for ten minutes, using all of the devices presented. Then, data was collected while walking,jogging and running around campus every five minutes for an hour. Finally, we collected the same data every two minutes for ten minutes total (five readings) while walking slowly inside the classroom as a 'cool down'. All collected data from the experiment was used to create two T-Tests; one for the heart rate data and another for the temperature data. We collected the same data from the other seventeen groups and combined it all together. The mean, standard deviation and standard error was calculated for both variables. We also used Pearson's R to measure the linear correlation (dependence) between the oral thermometer's temperature and the Spree band's temperature as well as the pulse oximeter's hear rate and the Spree band's heartrate.
Heart Rate Data
Our team used the T-Test to investigate the differences between the two groups; temperature and heart rate.
The mean of the temperature for all 390 data was 1.5 degrees higher for the Spree than for the thermometer. The standard deviation for the thermometer was 2.3 higher than the Spree. The standard error for the thermometer was 0.115 higher than the Spree. The temperature T-Test was a number way smaller than the 0.05 p-value we use to compare the two. The Pearson's R for temperature was a -0.053.
The mean of the heart rate for all 332 data was only 0.18 beats per minute (bpm) higher in the pulse oximeter than in the Spree. The standard deviation of the pulse oximeter was about 2.5 bpm higher than in the Spree device. The standard error for the pulse oximeter was 0.14 higher than the Spree. The heart rate T-Test was slightly bigger than the 0.05 p-value. The Pearson's R for hear rate was 0.57.
We decided to use the T-Test on both the temperature and heart rate trials because we were comparing two groups in each trial. We compared thermometer to Spree data in the temperature trial and we compared pulse oximeter to Spree in the heart rate trial.
Since the T-Test p value for temperature was way smaller than the p value of 0.05 this told us that there was a statistical difference (significance) between the two groups. The -0.053 Pearson's R for temperature meant that there was negative linear correlation between the two groups. The slightly larger T-Test p value for the heart rate trial tells us that there is no statistical difference (insignificant) between the two groups. The 0.57 Pearson's R value for heart rate meant that there was a slight linear correlation between the two groups.
The standard deviation is a measure used to quantify the amount of variation/dispersion of a set of data values. In both trials the Spree had a lower standard deviation mainly because it only had four possible temperature settings or choices (1 for blue/cool, 2 for yellow/slightly warmer, 3 for red1/warm, 4 for red2/hot). The negative correlation for body temperature is not really a correlation because the Spree only used three out of a possible four choices whereas the thermometer used a lot bigger range of settings. You need a range of numbers but the Spree only provides four and really only uses the first 3.
We tested the Spree Fitness headband and found some positives and negatives about it.
The great things about it was that it was light weight, it was not uncomfortable and it actually gave a pretty good accurate measure of temperature as compared to our gold standard which was the thermometer. The three settings for temperature is meant to tell you if you are cold, warmed up ready for exercise or you are overheated. This was a nice feature. Another positive is that you don't have to buy the receiving unit which could be an expensive watch or so. The receiving unit is a free app that you download to your smart phone. When we tested it the Android app was not available and this was a bummer because there are slighlty more Android phones than iPhones. Just after our trials and testing we had heard that the Android app was now available for download.
Some of the negatives were that the setup of the Spree was a little difficult at first in trying to sync the blue tooth. There is no specific name for your Spree and its signal interferes with another Spree if they are in close proximity to each other. So, if others around you are using the Spree as well, it is difficult to find your device. We had a hard time getting the blue tooth to communicate with the headband unit sensor. Once we got it to work than it was fine and all was good. In order to fix this, each device could have its own name, such as one that the user provides for their device. The connection kept failing even when the phone and the Spree were fairly close together. This would happen when our test subject stopped moving. To solve this issue Spree Fitness would need to design a newer, improved head band unit sensor. Another negative is that Spree did not have the app for the Android smart phones. The results of this test could have turned out somewhat differently if we could have tested an Android app vs an Apple app. The solution to this is to have designed the Android app with as much importance as the Apple app and in addition there needs to be a Blackberry app too. Another flaw is that the Spree would stop working if the user stopped moving so if one wanted to take a break while working out, they would lose connection. The Spree did not give the user a specific number for temperature, it provided qualitative feedback in terms of three color settings which to their credit actually would turn out to be accurate due to the big range in temperature each setting would have but it would not be something that the user is used to because when someone wants to know temperature they don't want to know if they are cold, warm or hot. They want to know the exact number. Spree should use quantitative feedback and design the device to display actual temperature numbers so the user can have an easier time understanding their approximate temperature. The spree might not feel very attractive to some when you have the band on your forehead even though it is light weight and after time you get used to it. To fix this problem, one could make a Spree band that went on the user's wrist and not the head. If the Spree was on the wrist it would not interfere with caps and fleece headbands. Another suggestion for improvement of the design is to add a built-in timer into the headband so users can set a timer for their workout.
In summary the Spree was accurate in heart rate but the temperature settings are not what people are used to and it might have been or not have been accurate. It is hard to say on the temperature because the range of temperatures was so big for each setting it is hard to tell if the temperature was accurate. It had some quirks that took some time to pan out and get used to.
LAB 3B WRITE-UP
Memory loss affects everyone regardless of gender, age, occupation, etc. While memory loss can be a result of a concussion, old age, Alzheimer's disease, dementia or alcoholism, it is prevalent to healthy non-diseased young people as well. From kids in elementary school to way old great grandparents everybody suffers from memory loss each and every single day. Alzheimer's disease affects 35 million people around the world, and that number is expected to double within the next 20 years (News Medical) so this portion of the population would benefit from a revolutionary break through invention that magically restores your memory to double its power. Similarly, students in all grades including pre-school, medical school and anything in between are victims of memory loss due to lack of sleep, excessive stress, extreme workload and just being a normal human automatically causes memory loss. People with head injuries from sports or other accidents are also susceptible to memory loss. Memory loss is a natural occurrence with age, therefore everyone is affected.
Needs and Target Population
People of all ages have a huge demand for better memory whether they are in school taking difficult exams and learning new material, whether they are young adolescents in the beginning stages of primary education, or whether they are old and can't remember anything due to the natural fact of brain degeneration. Everybody benefits with the new Memory Life patch. Even people out of school and in the workforce won't be missing deadlines or tasks due to forgetting or just because of having a lackluster day. Our product is designed to protect everybody from the damaging effects of memory loss including people who have suffered from traumatic brain injury and terminal amnesia. The need of our customers is to be able to not forget important things and boost their memory brain power two fold as well as prevent memory loss. The target population is directed towards all economic backgrounds, all genders, all ages, all races, all religions, all cultures, and to people of all belief systems. The Memory Life patch also works on burn victims, amputees, the deaf, the blind and the mute. Basically the only thing a person needs for our patch to work is a brain and a beating heart.
Problem Understanding Form
-sensor accuracy is important because the device must be able to accurately measure brain waves
-size and weight are important because it is strongly correlated to the customer needs of something being attractive
-effective injection is very important to the health of the customer, as to not under or overdose
-drug supply is important because without the drug the device is obsolete
-low cost is important to the customer because they don’t want to spend a lot of money
-attractiveness is important to the customer because they want their device to be discreet, and not be embarrassed by the device
-portability is important so customers can take this device with them easily
-effectiveness is important because they want to get what they paid for
-memory is important because this is what the device is for— for improving memory
-durability is important because customers don’t want to keep purchasing this device too often
Diagram of the Device
Descriptive Statistics and Graph
Memory Life Patch Data Set, Statistics and Graph
Twenty groups of 100 people (aged 3 to 123 yrs old) in each group were taken as sample subjects from around the world (every continent except Antarctica where we found no humans but only penguins). We performed within group testing where we tested the group before the intervention (no Memory Life Patch) and after the intervention (with the Memory Life Patch). Individually within each group, subjects were given a story to read and then asked twenty memory-based questions pertaining to it. The number (#) of questions answered correctly was recorded for each member in the group and then the mean (average) was taken for all 100 subjects in the group. This was repeated for another 19 groups giving a total of 20 groups of 100 subjects in each group. Fifteen years later, the same 2000 subjects were tested with the same story and questions but this time the subjects were given the revolutionary Memory Life Patch on their arm. We told them we wanted to see if placing a sticker on their upper arm would affect the results from their previous answers 15 years ago and if they did well they would get a gift card. The mean of the correctly answered questions was again taken for each subject and subsequently for the whole group and then subsequently for all 20 groups combined. Statistics were taken after the Memory Life Patch's effects and compared with before the patch.
The standard deviation and standard error of the "before" patch results for all 2000 subjects was slightly larger than the standard deviation and standard error for the "after" patch results.
The t-test p value for all 2000 subjects (for paired within group testing) came out to 4.33*10^(-20) which was way smaller than 0.05 which told us that there was significant statistical difference between the before and after patch test results.
The "before" Memory Life Patch mean results were 9.2 questions answered correctly and the "after" Memory Life Patch mean results were 18.4 questions answered correctly. These results from this carefully given and thought out experiment overwhelmingly shows the advantages, benefits and impact of wearing the Memory Life Patch has on greatly increasing the memory of the subjects tested.