REACTION TIME MEASUREMENT DEVICE
Advisor:
Pablo
Irarrazaval
Mena
Client:
Dr.
Tom
Yin
Team Members (Left to Right):
Darren Klaty-Communicator
Clayton Lepak-BWIG
Nathan Retzlaff-Leader
Hope Marshall-BSAC
Overview of the Presentation
•  Reaction Time Measurement
•  Design Constraints
•  4 Design Alternatives
•  Design Matrix
•  Future Work
Reaction time is highly applicable in daily life.
Reaction time is stimulus dependent.
•  Visual stimulus :
–  190 milliseconds
•  Auditory stimulus:
–  160 milliseconds
•  Difference due to:
–  Audio
•  Hair cells in a fluid
•  Mechanically gated ion channels
–  Visual
•  Chemical cascade
•  Signal amplification
–  Sensitivity vs. Speed tradeoff
A device is desired to demonstrate these
reaction time differences in school settings.
•  Outreach programs
•  Grades 1-8 (ages 6-14)
•  One device initially
•  Grant application
The design is very flexible.
<
20
kg
<
$200
Accuracy + Feedback
Ruler Design Alternative
Light
bulb
Electromagnet
Display
Wiring
Speaker
Ruler
Switch
Circuit
board
The Ruler design has advantages and
disadvantages
Pro:
•  Direct physics correlation to reaction time
•  Reliable-simple concept with falling ruler
Con:
•  Not appealing to kids
•  Bulky structure
The Laser Design
Display
Jewel
Lasers
Infared
sensor
Adjustable
mirrors
Hand
placement
Auditory
s;mulus
The Laser design has pros and cons.
Pro:
•  Visually appealing
•  Fitting for a variety of age groups
•  Game board size=easy transport
Cons:
•  No direct physics correlation
•  Negative moral message about theft
•  Safety and cost concerns of lasers
Rube
Goldberg
Design
Gumball
Release
Mechanism
Light
Timer
Gumball
MoKon
Sensors
Trap
Door
Bell
Trap
Door
Release
BuMon
Gumball
Separator
The Rube Goldberg design is appealing as it…
•  Visually appealing and child friendly product
•  Strong physics correlation
However,
it
is
unappealing
as…
•  Problems exist with its transportability
•  Most expensive design
•  Many separate components
Ambulance
Design
IniKaKng
Switches
A
A
V
B
Both
C
Handlebars
with
Brakes
Ambulance
with
Audio
and
Visual
SKmuli
Scoreboard
Time
Display
Auditory
ReacKon
Time
Visual
ReacKon
Time
Audio
&
Visual
Fastest
Time
Time
The strong parts of the ambulance design are:
•  Its durability and ease of use
•  Simple design
On the other hand…
•  It lacks any physics correlation
•  It doesn’t have much appeal
Design Matrix Point Breakdown
4
6
Manufacturability
Transportability
10
33
Cost
Physics Correlation
20
27
Age Appropriate
Reliability
20
Manufacturability, Transportability, Cost
18
Cost
16
Transportability
14
10
10
Manufacturability
12
7
10
8
6
6
4
2
4
0
Total Points
4
7
6
4
5
2
2
Rube
Goldberg
3
3
Ruler
Laser
4
Ambulance
Physics Correlation
40
Physics Correlation
Cost
Transportability
Manufacturability
35
30
20
25
20
20
15
10
5
6
4
0
7
18
10
4
2
2
Total Points Rube Goldberg
5
10
7
7
4
5
3
3
4
Ruler
Laser
Ambulance
6
Age Appropriate
Transportability
27
Manufacturability
27
40
30
Physics Correlation
Cost
60
50
Age Appropriate
10
25
20
20
20
10
7
6
4
5
7
18
10
0
20
7
10
6
4
4
5
2
2
3
3
4
Ruler
Laser
Ambulance
Total Points Rube Goldberg
100
Reliability
90
80
33
70
24
60
50
27
40
30
27
10
26
31
25
20
20
10
0
29
20
20
10
Reliability
Age Appropriate
Physics Correlation
Cost
Transportability
Manufacturability
6
7
18
4
4
2
2
Total Points
Rube
Goldberg
7
7
4
3
5
3
Ruler
Laser
5
10
6
4
Ambulance
Final Design: Rube Goldberg
•  Very close evaluation
•  Illustrates unique project
•  Technically easy
•  Brainstorming is more important
•  Choice affirmed
•  Original
•  Exciting
Total
100
90
80
70
60
50
40
30
20
10
0
100
77 73 73 76
Future Work
•  Finalize design
•  Work out rough spots
•  Releasing mechanism
•  Electronics
•  Trap door mechanism
•  Add dimensions
•  Energy, velocity, and time calculations
•  Material specs
•  Order materials
•  Build design
•  Testing