The Fun Cane

Designers: Ben Hoover, Aishu Nag, Michelle Wang, David Williams

Advisors: Brandi McDaniel, Quashanna Glass

Supervising Professors:  Kevin Caves, Chelsea Salinas

Abstract

Infants learn more about the world by exploring their surroundings on their own. Young children with visual impairments use mobility devices such as pre-canes to independently navigate their environment, and when they are older they use a white cane. Most pre-canes are made out of polyvinyl chloride (PVC) pipes with a rectangular or T-shaped structure and are simply pushed forward. If our 3 year-old client, Harry, used such a device, he would be able to explore public places and the outside of his classroom with minimal supervision. Harry does not enjoy using any of the pre-canes currently on the market and refuses to use them. However, our client needs to learn to explore his surroundings with a mobility device instead of using his outstretched hands. This will allow him to successfully transition into using a white cane when he is older. We created a customized pre-cane for our client that incorporates both music and lights. These features successfully capture Harry’s interest in the device and also allow his care team to use the pre-cane as a training tool.

Introduction

Our client, Harry, is a 3-year-old boy with a congenital visual impairment. He is able to see lights, including both natural light and artificial light, and bright colors, such as red, orange, and yellow. He also has well-developed hearing skills and greatly enjoys listening to music.

Like many blind or significantly visually impaired children, Harry learned to use a mobility device, or a pre-cane, to probe the area around him to check for obstacles when he was first learning to walk [1]. However, once Harry felt confident enough to move around on his own, he lost interest in his pre-cane and stopped using it. Currently, Harry is able to walk independently, but holds his hands out to explore his surroundings and avoid running into obstacles. His parents and classroom teacher monitor him constantly to ensure that he avoids injury.

Harry will eventually need to learn how to use a full-sized cane. However, these canes are more difficult to learn how to use, so he needs to further practice and master using a pre-cane first. Due to Harry’s dislike of using pre-canes, the device would need to attract his attention and motivate him to use it. If this is accomplished, he will be able to navigate different environments with minimal supervision. Harry needs a device that he would be willing to use to explore his environment as safely and independently as possible.

There are many commercially available mobility devices. Some of these devices, such as the “Roller”, “Wheeler” and “T-Wheeler” from SpecialEd Solutions, Inc., consist of PVC pipes connected in different configurations and are physically similar to the pre-cane device that Harry is no longer interested in using [2]. More technologically advanced products such as the “SmartCane” or the “Light Stick” are available. However, these devices use vibrational feedback and contain multiple detachable parts that may be too complex for our client to use without supervision [3, 4]. Despite the availability of an array of commercial products, they all seem to share the same drawback: the inability to hold the attention and interest of our client.

Project Goals

The goal of this project is to create a device that will motivate Harry to use a pre-cane to independently and safely navigate his surroundings. Harry’s parents and care team have mentioned that he responds most enthusiastically to bright lights and music, so both a light component and a musical component will be incorporated into our project to act as motivating tools. These components will be designed so that they can be easily controlled by the client’s care team. This will allow them to use the device as a training tool, as they will be working with Harry to help him develop the skills he needs to navigate the world with a full-sized cane. The device will also need to be safe and easy to use with minimal to no supervision.

Design and Development

Our design consists of four components: the “I” shaped frame, the wheels, the electrical components, and the housing for the electrical components. The device functions similarly to a conventional pre-cane when detecting objects. This allows Harry to safely navigate his environment, as the cane will hit any obstacles before he does. Harry will be engaged with the device through the bright lights and music that his care team can control with an infrared sensing remote control. The “I” shaped frame, the wheels, the electrical components, and the housing for the electrical components will be further discussed in the following sections.

I. “I” Shaped Frame

The overall frame of this device is comprised of 3 PVC pipes connected in an “I” shape with T-connectors, as seen in Figure 1. The overall height of the cane is 27 inches, which is slightly shorter than the 28.5-inch height of Harry’s original pre-cane. The pressure couplings above and below the electronic housing allow the handle of the cane to be detached form the housing and protect the main housing in the event the device falls to the ground. The I-shape was chosen because of the additional stability that having a two-handed handlebar provided. Using this shape instead of the rectangular shape of Harry’s original pre-cane device decreased the likelihood of Harry tripping over the device or getting caught inside it, which was an issue with his original pre-cane. With this design, Harry is able to step towards the middle of the device without it wrapping around his legs. The device is painted in a Spiderman design at the specific request of Harry’s mother.

II. Wheels

At the bottom of the frame are the wheels. Rotacaster wheels (Magnus Mobility Systems, R2-0484-90/D07) were attached to each end of the base of the device, as in Figure 2. The wheels are connected to each other through a threaded stainless steel rod that runs through the length of the base PVC pipe. This threaded rod acts as an axle that alleviates the force being exerted on the end caps of the base when the device is being pushed across the ground. These wheels help Harry push the device across different surfaces and also protect the bottom of the device from any damage when used over rougher surfaces. They also allow for multidirectional movement.  The gray wheels are moved forwards and backwards, while the red rollers allow for a sweeping side-to-side motion.

III. Electrical Components

At the top of the frame is the two-handed handlebar. Clear PVC was used to make the handlebar, seen in Figure 3, to allow for increased visibility of the embedded lights and for more precise sensing of the infrared remote, which controls both the lights and the music incorporated into the device. These components will be further discussed in the following subsections.

A. Lights

A 1-meter-long Neo-Pixel SMRT LED light strip (Embedded Adventures, SMRT-ST60-1M) was embedded into the handlebar of the pre-cane, shown on in Figure 3. The LED lights are controlled by an Arduino Nano microcontroller that has been coded to display a rainbow that slowly cycles through the strip over time. The LED light strip appeals to Harry’s love of bright lights and bright colors and therefore, acts as a motivating tool that allows Harry to engage with the device.

B. Music

Two small speakers are attached to the device inside the housing unit, seen in Figure 4. The speakers output audio files that are saved on a micro SD card. The audio files on the memory card are read by an SD card reader, the DFPlayer Mini (DFRobot, DFR0299), controlled by a second Arduino Nano microcontroller. The speakers appeal to Harry’s love of music and act as a second motivating tool that encourages Harry to train with a pre-cane.

C. Remote Control

Both the LED light strip and the music being outputted by the speakers are controlled by an HX1838 NEC infrared wireless remote control (Royfee Electronics, VS1838), displayed in Figure 6. The infrared signal sent by pressing a button on the remote control is sensed by an infrared receiver located in the handlebar of the cane, also displayed in Figure 5. Each button sends a different signal to the receiver, which is programmed by the second Arduino Nano microcontroller to recognize each signal as a different function, such as LIGHTS ON, LIGHTS OFF, MUSIC ON, and MUSIC OFF. This control system can be easily used by Harry’s care team. This allows the care team to either motivate Harry to accomplish different tasks while using the device or to reward different behaviors. In this way, the pre-cane can be used as a long term training tool as Harry progresses in his cane training.

D. Electrical Housing

The electrical components of this device are enclosed inside a 5.1”x4.6”x2” PVC junction box embedded in the main shaft of the cane, as seen in Figure 6. The wires from the SMRT light strip inside the handlebars are fed down from the handlebars through the vertical connector attached to the main shaft of the cane and into the enclosure. An ethernet connector was placed inside the pressure coupling to ensure easy connecting and disconnecting of the handlebar wires to the rest of the electronic housing if one needed to look at the housing off the box. The device only falls forward so rubberized housing foam was glued to the front of the box to ensure minimal damage will be done to the circuit. The purpose of this box is to safely house all the electrical components so no wires are exposed. The housing also allows the device to withstand any accidental splashes of liquids, thereby making the device safer for Harry to use.

IV. Conclusion

The components of this device work in conjunction to produce a motivational pre-cane training tool that our client and his care team can use for long term can training. Each component is designed to help facilitate Harry’s mobility, encourage and reward his pre-cane use, and optimize his safety. This design provides Harry with a tool that can help him feel more comfortable walking independently and can help him further develop his proprioceptive skills [5].

Evaluation

The device was evaluated to test its durability, ease of maintenance, reliability of operation, and safety. The Fun Cane significantly increased Harry’s desire to walk with a mobility device, accomplishing the primary goal of the project. The device was tested with the client to evaluate specific features against the design specifications and performance criteria. This consisted of the project team verifying the performance criteria and the client validating that all features met the criteria. The Fun Cane was brought to the client’s school, where Harry and his vision instructor used it for a full cane training session. This routine involved using the device in the school hallways, dropping it several times, using the buttons on the remote to change the music, and cleaning it with a wet rag. The device performed successfully under each of these conditions. Harry’s vision instructor and mother completed a survey on their levels of satisfaction with different aspects of the device. They both reported that working with the device has improved Harry’s desire to walk with a mobility device.

Discussion and Conclusions

The components used to construct this pre-cane worked in conjunction to create a training tool that meets all of our design specifications and successfully engages our client’s interest. The pre-cane is made of PVC, which is a lightweight and durable material that Harry can easily lift. All of the electrical components are housed within a box along the main shaft of the device, ensuring that it is safe to use. The design includes lights and music that our client greatly enjoys and can be easily controlled by the care team through the use of a remote. The final device cost $355.45 to build.

References

[1] Mobility Devices for Young Children. (n.d.). Retrieved September 20, 2016, from http://www.afb.org/info/living-with-vision-loss/getting-around/mobility-devices-for-young-children/235

[2] SpecialEd Solutions, Inc. (n.d.). Retrieved September 20, 2016, from http://www.specialed.com/orientationmobility.html

[3] Smartcane. (n.d.). Retrieved September 20, 2016, from http://www.abledata.com/product/smartcane

[4] Light Stick. (n.d.). Retrieved September 20, 2016, from http://www.abledata.com/product/light-stick

[5] Hudson, L. J., & Kosior, P. R. (n.d.). Anticipators for Young Children with Visual Impairments: Push Toys, Pre-Canes and Long Canes. Retrieved November 15, 2016, from http://www.wonderbaby.org/articles/anticipators

Acknowledgements

We would like to acknowledge the following for their assistance in completing this project: Duke University’s BME Department, Professor Kevin Caves, Dr. Chelsea Salinas, Amitha Gade, Matt Brown, and the client’s care team.

First Author Contact Information

Ben Hoover

103 Summerwinds Dr., Cary, NC 27518

919-345-3107

benjamin.hoover@live.com

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