|20||ZZZ-Mate : Pulse Driven White Noise Generator
|Team Members: Sanjana Chunduri (sc65) / Vakaris Ragauskas (vragau2) / Haruya Kamitani (hkamit2)
According to the CDC, about 70 million Americans suffer from sleep deprivation. Lack of sleep causes various issues in our daily lives such as tiredness, lack of concentration, and in extreme cases, heart failure, diabetes, and various serious conditions.
Some of us rely on external sound sources for falling asleep. Currently, there are various white noise machines out in the market. However, most of these devices output a single, continuous signal. According to one article (https://krisp.ai/blog/background-noise-impact/), “the continuous background noise also known as white noise which comes from machines and other appliances, can harm your brain, it does so by overstimulating your auditory cortex”. According to one Healthline article (https://www.healthline.com/health/parenting/white-noise-for-babies#cons), a 2014 study concluded that “regular exposure to these sound pressure levels may be damaging to infant hearing and auditory development.”
White noise is typically beneficial during the earlier sleep stages, when people are more likely to be awoken by distracting noises or thoughts. However, rather than continuously playing background noise through the night and overstimulating the auditory cortex, our design aims to combat typical sleep deprivation issues by supporting users through all stages of their sleep cycle: Wake, light sleep, deep sleep, REM, and repeat. By taking pulse rate measurements as an indicator of the user’s current sleep stage, our sound generation device will adjust the volume of the white noise. A wristband with a photo sensor and green LEDs will be used to detect the user’s heart rate and will wirelessly relay the information to the white noise generator to adjust the volume as necessary.
-Subsystem 1(Noise Source):
Power Supply Section: Noise source unit will be powered by 9-15VDC voltage. AC/DC adapter cable will be used. This power supply will provide a necessary power for MPU and if necessary, for speaker power amplifier as well as noise source.
MPU: ESP32 or related with built in Bluetooth/WiFi. This will be used to communicate with another ESP32 which will be built into the wearable band. The pulse rate data received from the wearable band will be used to control the output level of the noise source.
Speaker: Speaker with a wideband output frequency range (100Hz - 20kHz) will be used as white noise has an even power level across the full frequency spectrum. We may implement a power amplifier circuit with a simple transistor topology.
Noise Source: If it is manageable through ESP32, this will be programmed in MPU. Otherwise, transistor/opamp based white noise source will be implemented.
-Subsystem 2 (Wearable band):
MPU: another ESP32 microcontroller to send the pulse data to the main speaker/source unit.
Heart rate sensor: MAX30100 or MAX30102 or SEN11574
Battery: Lithium ion 3.3/5VDC
#Criterion For Success
One high-level goal of our project is to have wireless communication between a heart rate sensor wristband and a white noise machine. This wristband should be able to detect the heart rate of the user and differentiate between the four sleep stages of the user and differentiate between slight increases in heart rate to detect unrest. With software implementation, the WNG should decrease in volume when transitioning between sleep stages and after detecting an increase in heart rate.