Project Proposal

Abstract:

Many individuals often experience trouble sleeping which causes tiredness to arise upon awakening. There are currently products on the market that allow consumers to track his/her sleeping patterns, however these devices are not very accurate. Instead of using only  accelerometers, this design proposes using a mask with inlaid EOG sensors along with an accelerometer on the wrist to record not only REM cycles but also NREM stages. The EOG sensors measure potential differences to determine the direction of the eye and the accelerometer will measure movement during sleep.

This design idea aims to provide an common individual with the ability to analyze his/her own sleeping patterns without needing to visit a doctor. Although the purpose is for personal use, the data can easily be shown to a doctor if needed. This aspect allows for quicker diagnosis of possible sleeping problems. Furthermore, this device is to be easily applied and relatively comfortable for the user. The group possesses the knowledge and expertise needed to complete this design. The group has experience with programming and research, which are the two largest components of this design.

1         Introduction

The goal of this design project is to design a device and accompanying software that can record and analyze sleeping patterns by use of electrooculography (EOG) sensors and accelerometers. The device needs to be easily applied by the user. The intended target group for this device includes any common citizen looking to examine his/her sleeping patterns. There are devices on the market currently that have the same goal, however, most of these devices only use accelerometers, either in a smartphone or in a device attached to the wrist. This method of using only an accelerometer to measure human sleep states does not yield as accurate results as does using EOG sensors along with an accelerometer.  The latter method, which includes the combination of an accelerometer and EOG sensors, allows the computer to accurately track additional sleep stages that EOG sensors are unable to do.  The proposed deliverable includes a wearable mask that allows for easy placement of the EOG sensors. as well as an accelerometer for added accuracy and information about sleep patterns. The intangible component of the deliverable includes software that analyzes and outputs the collected sensor data to the user. This serves as a platform for viewing sleeping trends for an individual. The software not only displays graphs but also gives recommendations for better sleep (determined through research).

The design is heavily focused on software development and therefore will include nine weeks of literature study since the output is based on research. In addition, the device needs to be fabricated and this will require research to find the best method for easy application night after night. It is proposed that a semi-rigid plastic could be used for a mask that the user would wear and would be comfortable. The mask will have the EOG sensors built into it, with its electrodes  sitting sturdily on the surface of the mask. Also the user will be wearing a wristband with an accelerometer built into it. The group has experience in programming and a large amount of experience in extensive research which allows this design to be possible.

The motivation for this design stems from the inaccuracy and inefficiency of current sleep pattern measurement methods. Sleep is an important part of life and provides the brain and body with a period of relaxation and regeneration. Measuring patterns of sleep gives the user the ability to examine quickly his/her sleep patterns and alter actions that can improve sleep periods. This feedback is given by the computer software part of the project. Upon waking, the computer allows the user to see visuals such as graphs and trends of the sleep characteristics during the night and previous nights. The program also gives feedback in the form of recommendations for changing components of life such as diet in order to aid in more constructive sleep.

2         Deliverables

2.1 Physical Component

The final product that will be delivered will be both hardware and software based. The first component is an EOG/EMG device that will attach easily to the user’s face in combination with an accelerometer attached to the wrist This device will be re-applicable and be both easy to apply and be comfortable to wear. As of right now, the device that will be used is a semi-rigid sleeping mask that will be modified for easy sensor application (holes will be drilled into mask).

2.2 Software Component

This design is largely software/research based in that research will allow for detailed feedback in the form of graphs and different time period trends as well as recommendations for increased sleep health. The device will collect data that will be transmitted to an attached computer. The computer will collect the data in order to analyze it and compare data from different days, weeks, or longer. Additionally, the user will use a manual notification such as an on/off switch in the computer program to begin data collection just before the user falls asleep.

2.2.1 Software Output

When the user wakes up in the morning, he will be able to view the collected data from the night’s sleep. This data will be compiled and organized in a comfortable and easily viewed format. The screen that the user will view will display a graph of movement from the night as well as a graph indicated the sleep cycles reached and at what time during the night. Additionally, as more night’s data are collected, the information will be compared against all other data collected previously. This will most likely be a tabbed view that displays graphs indicating nights with most movement, most REM cycles, et cetera. Other information will also be displayed including sleeping duration.

Furthermore, the user will have the ability to log notes about the day before and how they feel in the morning. Along with notes, the user will be prompted in the morning with questions regarding aspects such as the consumption of alcohol the day before and the last meal eaten. Additionally, simple questions such as, “Is your sleep environment loud quiet?” will be asked. The answers from theses various questions will be used to output canned responses that offer recommendations to encourage healthier sleeping habits.

3         Technical Activities  

3.1 Research of Sleep

In order to understand the data collected by EOG/EMG sensors and accelerometers, the group must have a general understanding of the science of sleep. This information will then allow for the group to formulate a basic idea of how the device will need to be designed and thus programmed. This will also help refine the main goals of the product itself. The more the group understands sleep, the more refined the ideas will become for the product. Considering that there are two stages of sleep, NREM and REM, the goal is to retrieve information that provides proof that the user is in REM sleep or in a stage of NREM sleep (N1, N2, N3). With this, the software can monitor how long the subject is in each level of sleep to see whether he is having healthy sleep. Since the deepest level of NREM sleep (N3) can only be seen with an EEG, this is the only time that the sensors will not be retrieving significant data. However, this lack of information identifies the deepest sleep state for use in output. Furthermore, the research will serve as the background for giving feedback to the user, after sleeping.

3.2       Device Specifications:

The quantity of the EOG/EMG devices, accelerometers and other necessary parts needed to perform the desired tasks must be determined. Subsequently, it is very important to find the most logical way to assemble the parts on the test subjects so that it fits properly, retrieves information accurately, and can be worn by any person comfortably. On top of its physical design, the electrical design needs to set up properly so that the data successfully transfers from the sensors to a computer. Since the sensors do not produce data that is untranslatable, amplifiers will need to be implemented.

3.3       Software Creation

The heart of this project lies in the software programming. Without being able to organize the data so that it can be easily understood by the average person, the device would be useless. The team must collaborate with knowledge of the fundamentals of sleep and programming skills so that the data can be translated ultimately into a consumer-based output.

3.4       Testing

When the device has been constructed and a basic program has been made, the group can begin to test the prototype and troubleshoot any issues that arise. The majority of the work that has to be completed early in the term is identifying thresholds for differentiating the different stages of sleep. As testing continues the program can continue to evolve by becoming more accurate in tracking the different phases of sleep. The consistency of the device is entirely dependant on how accurate it can become from continued testing. The longer that the device is tested, the more consistent and accurate the program will become. Since another large portion of the project is research, the program can change based on new information gathered. The longer amount of time allowed for testing, the greater chance the group has of designing a better prototype--and this is why the group is allotting six weeks for testing.

4         Project Timeline

	Week
Task	1	2	3	4	5	6	7	8	9	10
Literature study	x	x	x	x	x	x	x	x	x
Electrical design			x	x	x	x
System integration				x	x	x	x	x
Mask						x	x
Testing				x	x	x	x	x	x
Final report preparation							x	x	x

Table 1: Project Timeline ***Since the output is largely dependent upon research, 9 weeks have been allotted for literature study.

5         Facilities and Resources

There will be many resources that may be needed in order to complete the project in the given timeline. The first resource that will definitely be utilized is the ECE Labs. The ECE Labs can provide valuable resources for the group. Physical resources include an oscilloscope, printed circuit boards, and tools from the machine shop. Additionally, the ECE labs can provide help with wiring and software integration if needed. Lastly, the machine shop may be used for very limited tasks including light metal working, however this is a slight possibility.

6         Expertise

Specialized skills demonstrated by the group members include:

• Computer programming experience
• Familiarity with C++ Programming language
• Familiarity with Matlab
• Data acquisition
• Data projection (organized output)
• Familiarity with circuitry
• Soldering components to a PCB
• Wiring
• Insulating components
• Knowledge of human physiology
• Familiarity of human sleep habits
• Familiarity of human sleep disorders
• Use of tools
• Design of headgear
• Light metalworking and fabrics(materials)

7         Budget

Category	Projected Cost
Electrodes Mask Circuit Board	$15 $10 $5
Batteries	$10
Amplifier	$10
Wire/Alligator Clips/Resistors/Capacitors	Free
TOTAL	$50.00

7.1       Circuitry Components

One of the largest parts of this design is the circuitry. The EMG and EOG pads need to be attached to the circuit using alligator clips, since it is a less permanent solution. The pads will be connected to a printed circuit board (PCB) in which there will be an attached amplifier. This will all be connected to two 9V batteries that are attached via two 9V battery leads. Once powered, the data will be transmitted to a Data Acquisition Board that is attached to a computer to log all of the information.

7.2       Amplifier

The amplifier is needed to increase the strength of the EOG/EMG signals to a suitable level for data acquisition. The amplifier works by amplifying the difference between the two inputs on the integrated circuit (IC) while using a common ground.

7.3       EMG/EOG Pads

The EOG pads are used to track eye movement through measuring changes in potential difference around the eyes. The EMG pads measure the potential difference in muscles which is used to track any movement of the arms. When the person enters REM sleep the EOG pads track the length of movement while the EMG tracks how much a person is moving in their sleep.

7.4       Mask

Since the device is intended for consumers, it is best to design it as one solid piece rather than several individual wires.  The mask will consist of an eye mask identical to the ones used during sleep to block out light, but with EOG sensors built into it. The sensors will be on the inside of the mask with the electrodes going through holes drilled in it. The electrodes will be connected to the leads through these holes, which will help hold them in place comfortably. The wires on the connections to the electrodes will need to be at least five feet long so that the user has room to move around while sleeping without ruining any data received by the sensor.