Position Sensing Glove Barbara Tuday Nathan Schreppler Lauren McIlwain Michael Nolan Team 6:

For the last 56 years ILC Dover Inc. has been a leader in engineered softgoods products in industry as well as government. They are commonly known for NASA’s spacesuits.

During a hand therapy session, physical therapists must manually measure the angle of each joint in a patient’s hand and wrist. Background

Problem Statement Our goal is to design, develop, produce, and test a prototypic, low-cost, and functional glove that will sense key finger, thumb, and wrist positions using compliant advanced technologies.

Key Joint Positions What joints do we actually need to measure? Thumb Fingers Wrist

Key Motions What motions do we need to measure? Flexion and Extension

Key Motions cont. Abduction & Adduction Pronation & Supination (Wrist Rotation) Total of 41 angles to be measured

Problem Constraints Safety United States Patents FDA 510 K Regulations

Customers ILC Dover Inc.  Engineers  Manufacturers Physical Therapists Patients Hospitals Retailers

Product Breakdown Overall Glove SensorsWiring Glove Material DAQ

Product Wants - Overall

Product Wants - Sensors

Sensor Metrics and Target Values MetricTarget Value Accuracy+/- 2.5 degrees Cost$ Cycles to Failure50,000 Resistance35,000 ohms Radius of Curvature0.1 inches No. of Parts Needed21 Ease of Flexibility (0-5)4 Frequency50 records per second Less Threatening (0-5)4

Product Wants - Wire

Wire Metrics and Target Values MetricTarget Values No. of Flexures before Failure 50,000 Radius of Curvature0.1 in Ease of Flexibility (0-5)5 Diameter0.025 in No. of Washes500

Concept Sensors  Peratech (1 st choice)  Spectra Symbol (used in prototype) Wire  Calmont (1 st choice)  Silver wire (used in prototype) DAQ  LabView Material  Knit, lightweight comfort glove

Modeling Gloves were modeled using acceptable substitutes for our materials  Attachment Methods  Wiring  Various Securing Devices

Modeling – Attachment Methods

Modeling – Wiring

Modeling – Securing Devices

LabView Program Created for individual sensor

LabView Program cont. Convert From Voltage to Degrees Analog In Show Array on A Graph Display Max. & Min. Degrees Obtained

Wiring Sensors

Testing Attachment Method Glue Sensors Directly to Glove

Testing Attachment Method cont. Sensors Held to Glove by Patches

Initial Testing To initially test the sensors, a spring was used as a finger model Cloth was placed around the spring to represent the glove The sensor was attached and tested

Labview Expansion Labview was expanded in order to capture the results of several sensors simultaneously Able to connect five sensors at a time

Testing Position Due to the length of our sensors, a slanted configuration was favorable for close-fitting locations Sensors on knuckles could remain aligned with the joint

Calibrating Sensors Output data was collected for several angles on specific joints Data was not repeatable between tests and oftentimes varied greatly We had to try to understand where the error was coming from

Sensor Error We analyzed the situation and came up with two areas of possible error:  Instability of sensor connections  Absence of a stiff backing to provide support for the sensors

General Sensor Criteria After experiencing difficulty with the sensors we realized that these problems could arise with future sensors We decided to create tests that could analyze the behavior of these and future sensors

Behavior Testing of Individual Sensor Tests were performed, keeping the electrical connection tightly secured, for the following three types of backing on the sensors:  No Backing  Thick Backing (0.01”) – provided by Spectra Symbol  Medium Backing (0.008”) – 3 layers of Scotch Packaging tape

Behavior Testing of Individual Sensor Bend Radius Test

Behavior Testing of Individual Sensor Tension Test

Behavior Testing of Individual Sensor Twist Test

Behavior Testing of Individual Sensor Pressure Test

Stabilizing Connection Since all the tests with the stabilized connections came out with satisfactory results, we felt that the previous problems were at the sensor connection, so we added a connection stiffener The backing on the sensor could help the stability

Testing New Sensors The new backing was then tested for repeatability with and without the connection stiffener This testing showed the backing offers some extra support which improves the repeatability

Calibrating New Sensors The new sensors were then calibrated Blocks were cut to the angles desired so that the calibration procedure could be easily repeated

Results The results from the final calibration came out better then the initial calibration These results, however, were still not accurate enough to meet the needs of the desired product

Cost of Materials

Future Work ILC should use the testing methods devised in this project first test the new Peratech sensors The sensors should then be tested on the actual glove If problems arise, the sensor connection should be addressed as done in this project

Thank You!! Questions?

Schedule

Total Cost

Final Prototype

Initial Calibration

Final Calibration

Final Calibration Data

Sensors Results