Designing a Single Handed Keyboard Input Solution

Project Overview

Client: NASA

Team members: 5

Personal Role: Experience Design

Personal Skills Used: Ideation, Problem Solving, Circuit Building, Usability testing

Presented at NASA Symposium, Houston- Texas

Project Duration: January - May 2014


The goal of this project was to create a device that functionally allows one-handed alphanumeric data entry for a heads up display. An effective solution would allow human-machine communication without impeding the user completing their task. Constraints to our problemincluded :
1. Single- handed keyboard entry
2. Presence of an external EVA glove
3. Small screen size for keyboard display


Two main components needed to be addressed in our device design: the method of input with the spacesuit, and the organization and representation of characters on a small screen was a concern.

Method of Input

1. Gesture Based
2. Trackpad


Use of an external unobstrusive camera, memorization of gestures
Location on spacesuit

Character Representation mock-ups:

While designing the character representation format for the GUI, we were having problems with the occupation of the screen space in our initial designs. With several iterations, we came down to a method of character input with minimal usage of the screen space.


The design of the system is composed of two main parts:

1. A glove with 12 attached buttons

2. A heads up display GUI

Our prototype successfully lets the users enter characters using the Glove based buttons. The GUI for our prototype is designed for a headsup display and is functional across a desktop.

The hardware for our system is designed using tactile buttons and arduino. The GUI for our system is designed using processing.


The Glove

The user activates the glove with a switch on the rear- side of the glove. Upon activation, the user utilizes attached buttons to enter respective characters which are seen via the GUI designed for a heads-up display.
We have used wires to build the circuit in our prototype. For our future iterations, we propose the use of conductive threads and smaller buttons to enhance the comfort of the system.


Screen 1

Screen 2

The first two row of buttons on the glove are mapped to 8 broad character catgories displayed to the right corner of the GUI. Upon selection of a category, the user can select the desired character from the menu on the top corner of the GUI. It takes the user two steps to type any character on the GUI. The GUI provides feedback to the user at each step taken to type a character.

Usability Testing

We asked 8 users to test our prototype to identify areas that needed improvement in our current design. Users put on the glove and were told the goal of our project and had the mapping explained to them by a team member. The users typed a couple of words to get adjusted, and were then asked to type a pangram, a sentence containing all letters of the alphabet (A QUICK BROWN FOX JUMPS OVER THE LAZY DOG). Time taken to type the sentence and the number of errors were recorded for each of the sentences. Following the typing, users were asked to rate their experience using the prototype on a 5-point Likert scale, with three questions measuring comfort, ease of use, and learnability. After the typing tests were done, users were asked to write a quick note using a pen, and to pick up a water bottle, to observe any interference of the device while carrying out regular tasks.

5/10 users found it hard to use the little finger to type.
All our users said that they can use the system without having to look at the glove, with practise.
60% of the users found the mapping of the buttons to the GUI logical.
Most of the system commented that the system is faily easy to use and they can improve their typing speed with time and practise.


Based on the inputs we received from our users, we have redesigned the GUI to have the characters represented vertically on the second key press, as opposed to the horizontal representation used in our previous prototype. We also used two columns of four buttons each to represent the information so as to map the characters to the tactile buttons more intuitively. This helps users identify the button on the hand that they must press without trying to guess which button number they were pressing. The vertical alignment addresses the problems mentioned in the previous section. Also, in the new GUI, the overall aspect ratio was modified to imitate the screen display of google glass.