​

​

MAE 156B

Tongue Touch Mouse & Keyboard

Final Design Review Presentation

​

Group N8: Jesus Salazar, Punit Aswani, Jiahuan He,

Garrett Almeida, Kwangbok Roh

1

Brief Overview Of Project

• Jason Eldred, our sponsor, is working on a tongue-touch device for our client, Stacy Bibb.
• Previous design is shown on the right.
• The device allows Stacy to click, type and browse on a computer.

2

Stacy with his pre-156B mouse and keyboard system.

Copper Wire- Contact Point

Alligator Clips

Halloween Mask- Chin Strap

Problem Definition - Objectives

• The main objectives we’re focusing on are:
• Headset Comfort
• Current headset: halloween mask
• Device Movement and Rotation
• Current sensor attached to mask by just two zip-ties
• Capacitive Sensor Reliability
• Grabbing the wire causes capacitive interference and false positives
• Number of Capacitive Touch Points
• One touch point -> Multiple Touch points

3

Impact on Society

• Integration of disabled individuals into the realm of technology
• Gives them access to computers and all that it entails (Games, Social Media, Movies, etc)
• Increases the quality of life for disabled individuals
• Provides a source of entertainment and purpose

4

Adafruit CPB

CAT5 Cable

CPAP Strap

Velcro Strap

The Ingenium

Stacy Wearing one of our Prototypes

Final Design - The Ingenium

• Capacitive Contact Point Slots
• Holds 5 Copper tab or Copper wires
• Secured with set screws
• CPAP Strap Anchor Points
• CPAP straps attach here
• Ventilation Holes
• Provides constant airflow to prevent sweat buildup
• Inner Pads
• Serves as extra cushion
• Saliva Channels
• Reduces Saliva Buildup/Bridging

​

​

​

​

​

5

Slots

Saliva Channels

Ventilation Holes

CPAP Strap Anchor Points

The Ingenium

Set Screw Holes

Inner Padding

Final Design - Capacitive Contact Points

• Copper Tabs
• Modifiable to different shapes
• Greater surface area for Stacy to touch with his tongue
• Potential Safety Hazard - May stab Stacy

​

​

​

​

“The Ingenium” with Copper Tabs

“The Ingenium” with Copper Wires

• Copper Wire (Winner)
• Can be bent to a curve
• More accessible and affordable
• Safer to use as it minimizes the possibility of stabbing

​

​

​

​

6

Final Design - Head Straps

• CPAP Strap
• Attaches to the anchor points on “The Ingenium”
• Keeps “The Ingenium” secured to Stacy’s Chin

​

​

​

​

• Velcro Strap
• Added feature on CPAP strap as a forehead strap
• Helps stabilize CPAP strap and “The Ingenium” in the correct position

​

​

​

​

Sponsor Wearing Both Straps�(temporary forehead strap solution)

​

​

​

7

Final Design - CAT5 Cable & Adafruit CPB

8

• Adafruit Circuit Playground Bluefruit (CPB)
• Contains 7 Capacitive Touch Pins
• Compatible capacitive library (touch.IO)�
• CAT5 Ethernet Cables
• Contains 8 wires/multiple signals
• Readily available
• Double Insulation provides some resistance to interferences

Adafruit CPB with highlighted Capacitive Touch Ports

CAT5 Ethernet Cable

Final Design - Food Safe Coating & Silicone Putty

• MAX CLR Food Safe Coating
• Applied to “The Ingenium” and copper tabs for Stacy’s safety
• EasyMold Silicone Putty
• Thick layer bonded to the inner surface of “The Ingenium”
• Conforms to Stacy’s chin
• Elasticity allows adjustment in real time

​

​

​

​

9

MAX CLR Food Safe Coating

EasyMold Silicone Putty

Ingenium with Food Safe Coating

Ingenium with Silicone Putty

Final Design Solution

​

​

​

​

10

The Ingenium

• Chin guard which integrates every other component

Copper Wire Contact Points

• Receives capacitance from user’s tongue
• transmits capacitive signal to Adafruit CPB

Silicone Putty (Yellow)

• Conforms to user’s chin for comfort and stability

CPAP & Velcro Straps

• Keeps “The Ingenium” secured on user’s chin

CAT5 Ethernet Cable

• Receives/transmits capacitive signal

Adafruit CPB

• Synthesizes capacitive signal and executes commands based on its programming

Final Design

Final Design Solution - Demonstration

​

​

​

​

11

Final Design Functional Requirement Recap - Device Comfort & Stability

12

• Velcro Straps:
• Prevents CPAP strap from slipping
• CPAP Strap:
• Attach/Stabilize Ingenium
• Adjustable
• Silicone Putty
• Comfortable padding
• Prevents Ingenium from slipping
• Clasp
• Easy removal and tightening

Garrett

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Switch software from Arduino to CircuitPython
• Contains Touch.IO library for more reliable sensing
• Uses an accelerated sampling rate to help filter out unwanted noise
• Specific Filter - Every 10 signals averaged and printed as 1 signal

13

Exaggerated example of the averaging filter�(not related to the project)

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Add a control wire to filter out interferences
• runs through CAT5 Cable but isn’t connected to device
• Assumption: picks up same interferences (human, etc) as other wires and can “subtract” those �interfering signals from code.
• Ex. Sensor1.value = Sensor1.rawvalue - Control.rawvalue

14

Quantitative Results - Capacitive Reliability

15

Single Touch

Double Touch

Control Wire

Test Interference

Sensor 2 - no control wire

Sensor 2 - with control wire

Quantitative Results - Capacitive Reliability: Pre 156B

16

Test Interference

Single Touch

Quantitative Analysis - Capacitive Results

17

Results:

1. Pre-156B Capacitive Response
1. Test Interference signal was 27.2% of Single Touch Signal
2. Final Design Capacitive Response (using the sensor 2 control wire filter)
• Test Interference signal change of 2.5% of Single Touch Signal�(24.7% improvement)
• Test Interference signal change of 5.7% of DoubleTouch Signal�(21.5% improvement)
• Signal fluctuations remain strong, but well defined thresholds prevent issues

Quantitative Results-Increased Functionality

• Pre-156B device had 3 different actions (move mouse, left click, typing) Stacy could use
• Current code has 10 different actions
• With change mode button, new code can be written to add even more actions to allow Stacy to use more specialized programs - adding a theoretically infinite number of commands
• Mouse movement is much more intuitive now
• Mouse would move in a circle and could be move in a direction radial to circle by tapping again (radial coordinates)
• New device moves cursor up, down, left and right (cartesian coordinates)

18

Design Recommendations for the Future

1. Redesign The Ingenium for comfortable use while laying down.
1. Currently: lower CPAP anchor point makes contact with bed, pushes device away from center
2. Possible Solution:
1. Reduce the arc size of The Ingenium’s lower half
2. Place lower anchor points adjacent to the arc
2. Add detachable connectors to wiring system for easy removal/replacement/maintenance

19

Push Point

Detachable �Connector

Questions?

​

20

Backup Slides -----

21

High Risk Components

• Chin Guard - “The Ingenium”
• Geometry must satisfy comfort requirements and fit the Cat5 Keystone Jacks properly.
• Copper Capacitive Contact Points
• Must be food-safe while producing accurate capacitance readings.
• CAT5 Ethernet Cable and Cat5 Keystone Jacks
• Should easily attach/detach to the chin guard
• Capacitive/Board Program
• Should ensure reliable capacitance signal (no noise)

22

CAT5 Ethernet Cable

Copper Capacitive Sheet Metal

Key Decisions - Food Safe Coating

​

• Current Progress:
• Photo 3: sample coating on a single strip
• Photo 4: Prototype coating with MAX CLR�
• Further Test required
• Determine it’s capacitive sensing property.
• “Taste” issue
• Short cure time

23

1

2

3

4

Key Decisions - CAT5 Cable Choice

​

24

Unshielded Cable

Unshielded CAT5 Cable

• Multiple Wires (8)
• More Flexible
• Thinner
• Shields normal household EMI

Shielded CAT5 Cable

• Multiple Wires (8)
• More Rigid
• Bulkier
• Capable shielding of EMI and some capacitance

Key Decision: Unshielded CAT5 Cable would be our first choice for design/test

Key Decisions - Capacitive/Board Program

​

25

• What Works?
• Strong Direct Signal
• What Doesn’t Work?
• Strong Oscillations to Zero while touching
• Indirect Contact Signal Increase
• Noisy�(many random spikes)

Key Decisions - Capacitive/Board Program

​

26

• What Works?
• Strong Direct Signal
• Unaffected by Indirect Contact
• Controlled Oscillation
• No hints at noise
• What Doesn’t Work?
• Indirect Ground Contact lowers signal

Key Decisions - Capacitive/Board Program

​

27

• Both Tests Given Low, Similar Sampling Rates �(Better matches final product sample rate)
• CircuitPython: 139 samples/sec
• Arduino: 146 samples/sec
• Arduino 2nd test: 5963 samples/sec (fastest) �(Not Shown) - Less Noisy, but still hints
• CircuitPython Wins!!
• Greater Reliability
• Why? Believe it has an accelerated program which either:
• Adjusts sampling rate to avoid noise
• Filters printed/usable capacitance data
• Further Application
• Applying code and setup to Final Design

Capacitive Test Setup:

CAT5 cable and Adafruit CPB

Proof-of-Concept: Results

• Unfortunately, the prototype does not function properly
• Activates action for two tabs when only touching one
• There is crosstalk between channels
• Could be from wires or tabs being too close together or from the keystone jack
• Further testing/troubleshooting is needed
• CAT5 cable hits your chest during downward head movements

28

Cat5 Keystone Jacks

Parts that has been used

• All the parts have been purchased and machined at least once for the current prototype
• Unless something else needs to be purchased to fix the problem

29

CPAP Strap

The Ingenium

Cat5 Cable

Cat5 Keystone Jacks

Garrett

Plastic Set Screws

Final Design - Capacitive Contact Points

• Copper Tabs
• Modifiable to different shapes
• Greater surface area for Stacy to touch with his tongue
• Potential Safety Hazard - May stab Stacy

​

​

​

​

“The Ingenium” with Copper Tabs

“The Ingenium” with Copper Wires

• Copper Wire
• Can be bent to a curve
• More accessible and affordable
• Safer to use as it minimizes the possibility of stabbing

​

​

​

​

30

Final Design - Head Straps

• CPAP Strap
• Attaches to the anchor points on “The Ingenium”
• Keeps “The Ingenium” secured to Stacy’s Chin

​

​

​

​

• Velcro Strap
• Added feature on CPAP strap as a forehead strap
• Helps stabilize CPAP strap and “The Ingenium” in the correct position

​

​

​

​

Sponsor Wearing Both Straps

​

​

​

31

Final Design - CAT5 Cable & Adafruit CPB

32

• Adafruit Circuit Playground Bluefruit (CPB)
• Contains 7 Capacitive Touch Pins
• Compatible capacitive library (touch.IO)�
• CAT5 Ethernet Cables
• Contains 8 wires/multiple signals
• Readily available
• Double Insulation provides some resistance to interferences

Adafruit CPB with highlighted Capacitive Touch Ports

CAT5 Ethernet Cable

Final Design - Food Safe Coating & Silicone Putty

• MAX CLR Food Safe Coating
• Applied to “The Ingenium” and copper tabs for Stacy’s safety
• EasyMold Silicone Putty
• Thick layer bonded to the inner surface of “The Ingenium”
• Conforms to Stacy’s chin
• Elasticity allows adjustment in real time

​

​

​

​

33

MAX CLR Food Safe Coating

EasyMold Silicone Putty

Ingenium with Food Safe Coating

Ingenium with Silicone Putty

Final Design Functional Requirement Recap - Device Comfort & Stability

34

• Velcro Straps:
• Prevents CPAP strap from slipping
• CPAP Strap:
• Attach/Stabilize Ingenium
• Adjustable
• Silicone Putty
• Comfortable padding
• Prevents Ingenium from slipping
• Clasp
• Easy removal and tightening

Garrett

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Switch software from Arduino to CircuitPython
• Contains Touch.IO library for more reliable sensing
• Uses an accelerated sampling rate to help filter out unwanted noise
• Specific Filter - Every 10 signals averaged and printed as 1 signal

35

Exaggerated example of the averaging filter

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Add a control wire to filter out interferences
• runs through CAT5 Cable but isn’t connected to device
• Assumption: picks up same interferences (human, etc) as other wires and can “subtract” those �interfering signals from code.
• Ex. Sensor1.value = Sensor1.rawvalue - Control.rawvalue

36

Timeline for Finalizing Design

37

Huan

High Priority Objectives

Lower Priority Objectives

• Finalize capacitive material and chin cup
• Add QD release for strap (magnetic)
• Manufacture device for Stacy
• Finalize forehead strap design onto current head straps

• Add detachable connector for wiring

Magnetic Clips for CPAP Strap

Quantitative Results - Capacitive Reliability

38

During Test Interference

Results (utilizing mean and standard deviation values):

• Sensor 2 - Raw Signal: 12%-79% increase in capacitive signal
• Sensor 2 - Filtered Signal: 10%-65% decrease in capacitive signal
• Standard deviation (signal fluctuation) had a 22% decrease from raw to filtered signal

Improvements compared to initial, pre-156b design, still under analysis

​

​

MAE 156B

Tongue Touch Mouse & Keyboard

Final Design Review Presentation

​

Group N8: Jesus Salazar, Punit Aswani, Jiahuan He,

Garrett Almeida, Kwangbok Roh

39

Brief Overview Of Project

• Jason Eldred, our sponsor, is working on a tongue-touch device for our client, Stacy Bibb.
• Previous design is shown on the right.
• The device allows Stacy to click, type and browse on a computer.

40

Stacy with his pre-156B mouse and keyboard system.

Copper Wire- Contact Point

Alligator Clips

Halloween Mask- Chin Strap

Problem Definition - Objectives

• The main objectives we’re focusing on are:
• Headset Comfort
• Current headset: halloween mask
• Device Movement and Rotation
• Current sensor attached to mask by just two zip-ties
• Capacitive Sensor Reliability
• Grabbing the wire causes capacitive interference and false positives
• Number of Capacitive Touch Points
• One touch point -> Multiple Touch points

41

Impact on Society

• Integration of disabled individuals into the realm of technology
• Gives them access to computers and all that it entails (Games, Social Media, Movies, etc)
• Increases the quality of life for disabled individuals
• Provides a source of entertainment and purpose

42

Adafruit CPB

CAT5 Cable

CPAP Strap

Velcro Strap

The Ingenium

Stacy Wearing one of our Prototypes

Final Design - The Ingenium

• Capacitive Contact Point Slots
• Holds 5 Copper tab or Copper wires
• Secured with set screws
• CPAP Strap Anchor Points
• CPAP straps attach here
• Ventilation Holes
• Provides constant airflow to prevent sweat buildup
• Inner Pads
• Serves as extra cushion
• Saliva Channels
• Reduces Saliva Buildup/Bridging

​

​

​

​

​

43

Slots

Saliva Channels

Ventilation Holes

CPAP Strap Anchor Points

The Ingenium

Set Screw Holes

Inner Padding

Final Design - Capacitive Contact Points

• Copper Tabs
• Modifiable to different shapes
• Greater surface area for Stacy to touch with his tongue
• Potential Safety Hazard - May stab Stacy

​

​

​

​

“The Ingenium” with Copper Tabs

“The Ingenium” with Copper Wires

• Copper Wire (Winner)
• Can be bent to a curve
• More accessible and affordable
• Safer to use as it minimizes the possibility of stabbing

​

​

​

​

44

Final Design - Head Straps

• CPAP Strap
• Attaches to the anchor points on “The Ingenium”
• Keeps “The Ingenium” secured to Stacy’s Chin

​

​

​

​

• Velcro Strap
• Added feature on CPAP strap as a forehead strap
• Helps stabilize CPAP strap and “The Ingenium” in the correct position

​

​

​

​

Sponsor Wearing Both Straps�(temporary forehead strap solution)

​

​

​

45

Final Design - CAT5 Cable & Adafruit CPB

46

• Adafruit Circuit Playground Bluefruit (CPB)
• Contains 7 Capacitive Touch Pins
• Compatible capacitive library (touch.IO)�
• CAT5 Ethernet Cables
• Contains 8 wires/multiple signals
• Readily available
• Double Insulation provides some resistance to interferences

Adafruit CPB with highlighted Capacitive Touch Ports

CAT5 Ethernet Cable

Final Design - Food Safe Coating & Silicone Putty

• MAX CLR Food Safe Coating
• Applied to “The Ingenium” and copper tabs for Stacy’s safety
• EasyMold Silicone Putty
• Thick layer bonded to the inner surface of “The Ingenium”
• Conforms to Stacy’s chin
• Elasticity allows adjustment in real time

​

​

​

​

47

MAX CLR Food Safe Coating

EasyMold Silicone Putty

Ingenium with Food Safe Coating

Ingenium with Silicone Putty

Final Design Solution

​

​

​

​

48

The Ingenium

• Chin guard which integrates every other component

Copper Wire Contact Points

• Receives capacitance from user’s tongue
• transmits capacitive signal to Adafruit CPB

Silicone Putty (Yellow)

• Conforms to user’s chin for comfort and stability

CPAP & Velcro Straps

• Keeps “The Ingenium” secured on user’s chin

CAT5 Ethernet Cable

• Receives/transmits capacitive signal

Adafruit CPB

• Synthesizes capacitive signal and executes commands based on its programming

Final Design

Final Design Solution - Demonstration

​

​

​

​

49

Final Design Functional Requirement Recap - Device Comfort & Stability

50

• Velcro Straps:
• Prevents CPAP strap from slipping
• CPAP Strap:
• Attach/Stabilize Ingenium
• Adjustable
• Silicone Putty
• Comfortable padding
• Prevents Ingenium from slipping
• Clasp
• Easy removal and tightening

Garrett

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Switch software from Arduino to CircuitPython
• Contains Touch.IO library for more reliable sensing
• Uses an accelerated sampling rate to help filter out unwanted noise
• Specific Filter - Every 10 signals averaged and printed as 1 signal

51

Exaggerated example of the averaging filter�(not related to the project)

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Add a control wire to filter out interferences
• runs through CAT5 Cable but isn’t connected to device
• Assumption: picks up same interferences (human, etc) as other wires and can “subtract” those �interfering signals from code.
• Ex. Sensor1.value = Sensor1.rawvalue - Control.rawvalue

52

Quantitative Results - Capacitive Reliability

53

Single Touch

Double Touch

Control Wire

Test Interference

Sensor 2 - no control wire

Sensor 2 - with control wire

Quantitative Results - Capacitive Reliability: Pre 156B

54

Test Interference

Single Touch

Quantitative Analysis - Capacitive Results

55

Results:

• Pre-156B Capacitive Response
• Test Interference signal was 27.2% of Single Touch Signal
• Final Design Capacitive Response (using the sensor 2 control wire filter)
• Test Interference signal change of 2.5% of Single Touch Signal�(24.7% improvement)
• Test Interference signal change of 5.7% of DoubleTouch Signal�(21.5% improvement)
• Signal fluctuations remain strong, but well defined thresholds prevent issues

Quantitative Results-Increased Functionality

• Pre-156B device had 3 different actions (move mouse, left click, typing) Stacy could use
• Current code has 10 different actions
• With change mode button, new code can be written to add even more actions to allow Stacy to use more specialized programs - adding a theoretically infinite number of commands
• Mouse movement is much more intuitive now
• Mouse would move in a circle and could be move in a direction radial to circle by tapping again (radial coordinates)
• New device moves cursor up, down, left and right (cartesian coordinates)

56

Design Recommendations for the Future

• Redesign The Ingenium for comfortable use while laying down.
• Currently: lower CPAP anchor point makes contact with bed, pushes device away from center
• Possible Solution:
• Reduce the arc size of The Ingenium’s lower half
• Place lower anchor points adjacent to the arc
• Add detachable connectors to wiring system for easy removal/replacement/maintenance

57

Push Point

Detachable �Connector

Questions?

​

58

Backup Slides -----

59

High Risk Components

• Chin Guard - “The Ingenium”
• Geometry must satisfy comfort requirements and fit the Cat5 Keystone Jacks properly.
• Copper Capacitive Contact Points
• Must be food-safe while producing accurate capacitance readings.
• CAT5 Ethernet Cable and Cat5 Keystone Jacks
• Should easily attach/detach to the chin guard
• Capacitive/Board Program
• Should ensure reliable capacitance signal (no noise)

60

CAT5 Ethernet Cable

Copper Capacitive Sheet Metal

Key Decisions - Food Safe Coating

​

• Current Progress:
• Photo 3: sample coating on a single strip
• Photo 4: Prototype coating with MAX CLR�
• Further Test required
• Determine it’s capacitive sensing property.
• “Taste” issue
• Short cure time

61

1

2

3

4

Key Decisions - CAT5 Cable Choice

​

62

Unshielded Cable

Unshielded CAT5 Cable

• Multiple Wires (8)
• More Flexible
• Thinner
• Shields normal household EMI

Shielded CAT5 Cable

• Multiple Wires (8)
• More Rigid
• Bulkier
• Capable shielding of EMI and some capacitance

Key Decision: Unshielded CAT5 Cable would be our first choice for design/test

Key Decisions - Capacitive/Board Program

​

63

• What Works?
• Strong Direct Signal
• What Doesn’t Work?
• Strong Oscillations to Zero while touching
• Indirect Contact Signal Increase
• Noisy�(many random spikes)

Key Decisions - Capacitive/Board Program

​

64

• What Works?
• Strong Direct Signal
• Unaffected by Indirect Contact
• Controlled Oscillation
• No hints at noise
• What Doesn’t Work?
• Indirect Ground Contact lowers signal

Key Decisions - Capacitive/Board Program

​

65

• Both Tests Given Low, Similar Sampling Rates �(Better matches final product sample rate)
• CircuitPython: 139 samples/sec
• Arduino: 146 samples/sec
• Arduino 2nd test: 5963 samples/sec (fastest) �(Not Shown) - Less Noisy, but still hints
• CircuitPython Wins!!
• Greater Reliability
• Why? Believe it has an accelerated program which either:
• Adjusts sampling rate to avoid noise
• Filters printed/usable capacitance data
• Further Application
• Applying code and setup to Final Design

Capacitive Test Setup:

CAT5 cable and Adafruit CPB

Proof-of-Concept: Results

• Unfortunately, the prototype does not function properly
• Activates action for two tabs when only touching one
• There is crosstalk between channels
• Could be from wires or tabs being too close together or from the keystone jack
• Further testing/troubleshooting is needed
• CAT5 cable hits your chest during downward head movements

66

Cat5 Keystone Jacks

Parts that has been used

• All the parts have been purchased and machined at least once for the current prototype
• Unless something else needs to be purchased to fix the problem

67

CPAP Strap

The Ingenium

Cat5 Cable

Cat5 Keystone Jacks

Garrett

Plastic Set Screws

Final Design - Capacitive Contact Points

• Copper Tabs
• Modifiable to different shapes
• Greater surface area for Stacy to touch with his tongue
• Potential Safety Hazard - May stab Stacy

​

​

​

​

“The Ingenium” with Copper Tabs

“The Ingenium” with Copper Wires

• Copper Wire
• Can be bent to a curve
• More accessible and affordable
• Safer to use as it minimizes the possibility of stabbing

​

​

​

​

68

Final Design - Head Straps

• CPAP Strap
• Attaches to the anchor points on “The Ingenium”
• Keeps “The Ingenium” secured to Stacy’s Chin

​

​

​

​

• Velcro Strap
• Added feature on CPAP strap as a forehead strap
• Helps stabilize CPAP strap and “The Ingenium” in the correct position

​

​

​

​

Sponsor Wearing Both Straps

​

​

​

69

Final Design - CAT5 Cable & Adafruit CPB

70

• Adafruit Circuit Playground Bluefruit (CPB)
• Contains 7 Capacitive Touch Pins
• Compatible capacitive library (touch.IO)�
• CAT5 Ethernet Cables
• Contains 8 wires/multiple signals
• Readily available
• Double Insulation provides some resistance to interferences

Adafruit CPB with highlighted Capacitive Touch Ports

CAT5 Ethernet Cable

Final Design - Food Safe Coating & Silicone Putty

• MAX CLR Food Safe Coating
• Applied to “The Ingenium” and copper tabs for Stacy’s safety
• EasyMold Silicone Putty
• Thick layer bonded to the inner surface of “The Ingenium”
• Conforms to Stacy’s chin
• Elasticity allows adjustment in real time

​

​

​

​

71

MAX CLR Food Safe Coating

EasyMold Silicone Putty

Ingenium with Food Safe Coating

Ingenium with Silicone Putty

Final Design Functional Requirement Recap - Device Comfort & Stability

72

• Velcro Straps:
• Prevents CPAP strap from slipping
• CPAP Strap:
• Attach/Stabilize Ingenium
• Adjustable
• Silicone Putty
• Comfortable padding
• Prevents Ingenium from slipping
• Clasp
• Easy removal and tightening

Garrett

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Switch software from Arduino to CircuitPython
• Contains Touch.IO library for more reliable sensing
• Uses an accelerated sampling rate to help filter out unwanted noise
• Specific Filter - Every 10 signals averaged and printed as 1 signal

73

Exaggerated example of the averaging filter

Final Design Functional Requirement - Capacitive Reliability

Design Choices to improve Capacitive Reliability:

• Add a control wire to filter out interferences
• runs through CAT5 Cable but isn’t connected to device
• Assumption: picks up same interferences (human, etc) as other wires and can “subtract” those �interfering signals from code.
• Ex. Sensor1.value = Sensor1.rawvalue - Control.rawvalue

74

Timeline for Finalizing Design

75

Huan

High Priority Objectives

Lower Priority Objectives

• Finalize capacitive material and chin cup
• Add QD release for strap (magnetic)
• Manufacture device for Stacy
• Finalize forehead strap design onto current head straps

• Add detachable connector for wiring

Magnetic Clips for CPAP Strap

Quantitative Results - Capacitive Reliability

76

During Test Interference

Results (utilizing mean and standard deviation values):

• Sensor 2 - Raw Signal: 12%-79% increase in capacitive signal
• Sensor 2 - Filtered Signal: 10%-65% decrease in capacitive signal
• Standard deviation (signal fluctuation) had a 22% decrease from raw to filtered signal

Improvements compared to initial, pre-156b design, still under analysis