Printing - University of Utah
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Introduction Results Fluid flowing through tubing around forearm creates angular momentum: Metrics Simulations Irsyad Badri, Kory Cross, Mikaela Hayward, Hyrum Peterson, Quincy Stevens Advisor: Dr. Andrew Merryweather – Department of Mechanical Engineering Essential tremor (ET) is the most common movement disorder in adults age 65 and older with a prevalence of up to 9.0%, nearly 2.5% of the US population [1] . Conclusion Characteristic ET Control Difference Amplitude 1 mm 0.1 mm 1000% Acceleration 1 m/s 2 - - Frequency 6 Hz 5 Hz 120% Project Scope: Design a mechanical device to reduce the severity of ET across multiple daily activities. Factor Low (-) High (+) Number of coils 4 10 Wrapping pattern 1-way 2-way Tube diameter 6.4 mm 15.8 mm Flow speed 0.2 L/s 0.3 L/s Number of coils Wrapping pattern Tube diameter Flow Rate Torque (Nm) 10 1-way 6.4 mm 0.3 L/s 3.47 Simulation in SOLIWORKS was used to determine the best configuration of factors to produce the highest torque from a 2 k factorial design. 16 configurations were analyzed. Prototype Testing Baseline tremor Device Operating with Tremor Device Operating without Tremor The device increased and reduced acceleration by 0.31 m/s 2 . Though the concept of coils to produce angular momentum could be utilized in situations other than ET to dampen unwanted movement or vibration, the feasibility for damping ET is low. Future Improvements By having the device operate at the same frequency of the tremor and 180º out of phase, we can eliminate the constructive interference. Ideally, this would achieve a 0.31 m/s 2 reduction in acceleration. References [1] M. Zappia, et al., J. Neurol., 260 (2013), pp. 714-740 Unbiased test apparatus • Tremor created using rumble motor powered by Arduino • Springs are used to simulate joint compliance • Bucket is used to remove air bubbles in tubing • Pump moves fluid through tubing • Data collected using Shimmer IMU accelerometer ET can be highly disabling, affecting a person’s ability to complete Activities of Daily Living (ADLs), leading to physical limitations and emotional issues. Current devices used to address ET primarily focus only on a single activity. Metric Target Value Achieved Value Tremor reduction 0.25 m/s 2 ± 0.31 m/s 2 Range-of-motion > 90% 100% Weight < .454 kg 0.068 kg 2 k Factorial Design Parameters Best Configuration Average Tremor Characteristics [L = Iω] = Water reservoir Coils Pump Spring Rumble motor Arduino (power) Design Reducing the tremor acceleration by 0.25 m/s 2 would enable the individual to reduce the severity level by one, based on a 0 (mild) -10 (extremely severe) scale. A 90% range of motion and a weight of 0.454 kg would not inhibit the user’s mobility. Vibration from the device with the tremor created a change of ± 0.31 m/s 2 . This was due to wave interference. The differences in frequency caused destructive and constructive interference. Tremor Only (8 Hz) Device Only (15 Hz) Tremor + Device #1159885
Transcript of Printing - University of Utah
Printing:
Introduction
Results
Fluid flowing through tubingaround forearm creates angular
momentum:
Metrics
Simulations
Irsyad Badri, Kory Cross, Mikaela Hayward, Hyrum Peterson, Quincy StevensAdvisor: Dr. Andrew Merryweather – Department of Mechanical Engineering
Essential tremor (ET) is the most commonmovement disorder in adults age 65 and older with aprevalence of up to 9.0%, nearly 2.5% of the USpopulation[1].
Conclusion
Characteristic ET Control DifferenceAmplitude 1 mm 0.1 mm 1000%
Acceleration 1 m/s2 - -Frequency 6 Hz 5 Hz 120%
Project Scope: Design a mechanical device to
reduce the severity of ET across multiple daily
activities.
Factor Low (-) High (+)
Number of coils 4 10
Wrapping pattern 1-way 2-way
Tube diameter 6.4 mm 15.8 mm
Flow speed 0.2 L/s 0.3 L/s
Number of
coils
Wrapping
pattern
Tube
diameter
Flow
Rate
Torque
(Nm)
10 1-way 6.4 mm 0.3 L/s 3.47
Simulation in SOLIWORKS was used to determinethe best configuration of factors to produce thehighest torque from a 2k factorial design. 16configurations were analyzed.
Prototype Testing
Baseline tremor
Device Operating with Tremor
Device Operating without Tremor
The device increased and reduced acceleration by0.31 m/s2. Though the concept of coils to produceangular momentum could be utilized in situationsother than ET to dampen unwanted movement orvibration, the feasibility for damping ET is low.
Future ImprovementsBy having the device operate at the samefrequency of the tremor and 180º out of phase, wecan eliminate the constructive interference. Ideally,this would achieve a 0.31 m/s2 reduction inacceleration.
References[1] M. Zappia, et al., J. Neurol., 260 (2013), pp. 714-740
Unbiased test apparatus• Tremor created using rumble motor powered by Arduino• Springs are used to simulate joint compliance• Bucket is used to remove air bubbles in tubing• Pump moves fluid through tubing• Data collected using Shimmer IMU accelerometer
ET can be highly disabling, affecting a person’s abilityto complete Activities of Daily Living (ADLs), leadingto physical limitations and emotional issues. Currentdevices used to address ET primarily focus only on asingle activity.
Metric Target Value Achieved Value
Tremor reduction 0.25 m/s2 ± 0.31 m/s2
Range-of-motion > 90% 100%Weight < .454 kg 0.068 kg
2k Factorial Design Parameters
Best Configuration
Average Tremor Characteristics
[L = Iω]
𝛴𝜏 =𝑑𝐿
𝑑𝑡
Water reservoir
Coils
Pump
SpringRumble motor Arduino
(power)
Design
Reducing the tremor acceleration by 0.25 m/s2
would enable the individual to reduce the severitylevel by one, based on a 0 (mild) -10 (extremelysevere) scale. A 90% range of motion and a weightof 0.454 kg would not inhibit the user’s mobility.
Vibration from the device with thetremor created a change of ± 0.31m/s2. This was due to waveinterference. The differences infrequency caused destructive andconstructive interference.
Tremor Only (8 Hz)
Device Only (15 Hz)
Tremor + Device
#1159885
