Ergonomics and Human Factors

This project for ME115B was an exploration into ergonomics and how human factors shape design. Our task was to create an ergonomically correct wireless stethoscope that had to include a 4 cm by 6 cm cylindrical sensor. The design goals of this project were to create a comfortable and easy to use tool that fits a variety of people, looks professional, and is improved upon by user testing and feedback. 

Ideation and Sketching 

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Initial sketches and ideations of different grips, handle shapes and features. 

Anthropometrics and Ergonomics 

 An ergonomic analysis table detailing the various tasks required of the product and the related anthropometric information. 

An ergonomic analysis table detailing the various tasks required of the product and the related anthropometric information. 

Initial Prototypes 

After sketching and anthropometric research, I created two different prototype models out of modulan. Using a bandsaw, belt and oscillating sanders, files, rasps, and sand paper I shaped two different forms for initial user testing. 

 Two initial prototypes.

Two initial prototypes.

 Using the orthographic projection to shape my model. 

Using the orthographic projection to shape my model. 

 Checking for fit. 

Checking for fit. 

 Using a rasps to create an indent on the top of one prototype. 

Using a rasps to create an indent on the top of one prototype. 

 Model A

Model A

 Model B

Model B

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User Testing and Feedback 

After creating my two models, I set out to do user testing by having potential users interact with both prototypes and perform the task of listening to a patients heartbeat as if they were a doctor. The models were marked A and B, and I had each user fill out a survey asking feedback about each of the models, as well as asking questions and jotting down quotes as the testing progressed. 

The diameter of the grip [B] feels either a little too big or a little too small. The taper fits nicely.
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It seems like there are a number of different ways to hold this [grip A], how did you intend it?

Final Model

Based on user feedback, I decided to move forward and iterate on model A. Users preferred the finger slide grip of A to the wrap around grip of B. In addition, model A allowed a more comfortable range of motion in the user's wrist and more easily allowed the user to take reading on both the chest and back of the patient without wrist discomfort or having to readjust their grip. In order to inform the user as how the model is supposed to be held, I rounded down one side as to allow a hand to slide in and to signify where one's hand should go. This also widened the gap space, allowing for people with bigger fingers to have a comfortable mount of space in the gap while still being snug enough to grip the stethoscope and perform the task. Finally, I rounded down slightly where one's pointer and middle finger rest allowing for a more comfortable grip with a larger corner radius. 

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