BME100 s2015:Group6 12pmL3

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Name: Justin Blommer
Name: Ethan Mathew
Name: Spencer Cobb
Name: Sarah Jones
Name: Abigail Rene


What are the design flaws of the Spree headband? How valid is it in comparison to the current gold standard devices?

Descriptive Statistics

Body Temperature

Gold Standard (Oral Thermometer)

Mean: 97.39 degrees F

Standard Deviation: 2.95 degrees F

Standard Error: 0.16 degrees F


Mean: 98.74 degrees F

Standard Deviation: 0.54 degrees F

Standard Error: 0.03 degrees F

Heart Rate

Gold Standard (Pulse Oximeter)

Mean: 95.06 bpm

Standard Deviation: 22.58 bpm

Standard Error: 1.24 bpm


Mean: 94.62 bpm

Standard Deviation: 20.63 bpm

Standard Error: 1.13 bpm



Inferential Statistics

Body Temperature

Pearson's R: 0.0086

T. Test: 1.14*10^-15

The Pearson's R Coefficient indicates that there is very little correlation between the temperature recorded by the Spree and the oral thermometer. The fact that the t-test produced a p value less than .05 means there was a statistically significant difference between the two temperature groups. There should not be a difference if the Spree device measured the temperature accurately.

Heart Rate

Pearson's R: 0.57

T. Test: 0.69

The Pearson's R for heart rate indicated that there was a positive correlation between the Spree and pulse oximeter measurements. A complete correlation would produce a 1.0 Pearson's R value, so the measured value of 0.57 for the heart rate implies a partial positive correlation. Because the p-value was so much higher than the threshold value of 0.05, there was not a statistically significant difference.


The Spree headband had an abundance of design flaws. The temperature sensor only assigned a rating of 1-4, but did not measure the actual temperature. The entire device would also power off if there was not enough movement, such as when the user was at rest. This could be easily remedied by modifying the device so it will not turn off at rest. It lacked unique identification, which made it difficult to differentiate between multiple devices in a close proximity. An option to add custom device ID's to each device would resolve this. The wireless connectivity was also very unreliable. It disconnected multiple times after initially pairing with the mobile device. The band materials are not effective in handling sweat. An easy solution to this would be wrap the forehead piece with a polyester/nylon cover. The headband itself is not aesthetically pleasing, which could be resolved by offering multi-colored polyester/nylon wraps.


Based upon the observed flaws of competing industry devices, design an improved body monitoring device.

Target Population and Need

The SmartCrib is targeted towards any parents with a baby that sleeps in a crib. With over 3.9 million babies born annually in the United States alone, there is a huge demand for this type of product. With approximately 2,500 infant deaths per year attributed to SIDS in the United States alone, the SmartCrib would be highly sought after. SIDS is a major concern for many new parents because there are no warning signs or prevention methods. In order to be put at ease, parents need a "guardian" watching over their infant while they sleep. New parents will also benefit from the reduced occurrences of having to get up during the night to comfort their crying baby.

Device Design

The SmartCrib is ideally designed to put parents of newborn babies at ease during the night. Its innovative spherical shape allows your baby to be cradled, imitating a parent holding a baby. Functioning as a rocking chair, the crib detects discomfort in your baby and gently rocks it back to sleep. In addition, the crib can identify the cause of discomfort and efficiently sends a text message to the parents, alerting them if the baby needs to be fed or changed, or for any other given reason.

The SmartCrib also addresses a fear many parents have of sudden infant death syndrome, or in short, SIDs. In the wire-free mobile attached to the top of the crib is a hidden camera and a micro laser doppler vibrometer. The camera provides a visual of the baby, that you can easily pull up on your phone with the SmartCrib app, to use for safety, and has an extra feature that takes pictures of your cute sleeping baby, ready to post to any social media. The micro laser doppler vibrometer monitors and alarms you if your babies breathing becomes abnormal or changes drastically. The wrist band worn by the baby monitors heart rate and is also synchronized to the monitor.

Furthermore, the SmartCrib has a facial recognition software that you can switch on that warns you if something unrecognizable approaches the crib, preventing intruders, as well as, cats. The SmartCrib also adapts to your growing baby and is able to tilt reactively so that the baby cannot roll or crawl out of the crib. Finally, the SmartCrib is easy to assemble with basically two steps: attach the mobile to the crib, and download the complimentary SmartCrib app.

Data & Statistics

Experimental Data

SmartCrib Wristband

Mean: 102.75 bpm

Std. Deviation: 6.80 bpm

Std. Error: 1.29 bpm

Pulse Oximeter

Mean: 103.18 bpm

Std. Deviation: 7.00 bpm

Std. Error: 1.32 bpm

Inferential Statistics

T. Test: 0.167

Pearson's R: 0.974

P-Value: 3.15071*10^-18

SmartCrib Laser Doppler Vibrometer

Mean: 27.5 breaths/min

Std. Deviation: 3.34 breaths/min

Std. Error: 0.63 breaths/min


Mean: 27.46 breaths/min

Std. Deviation: 3.25 breaths/min

Std. Error: 0.61 breaths/min

Inferential Statistics

T. Test: 0.713

Pearson's R: 0.988

P-Value: 7.4498*10^-23