Engineering for Access 2020 shortlist: Matthew Lillywhite

This design is for a haptic metronome to be held in each hand or strapped to each wrist, providing Parkinson’s sufferers with tempo and rhythm for walking.

Parkinson’s disease affects the part of the brain which controls movement.

The NHS says that the 3 main symptoms of Parkinson’s are:

• involuntary shaking of parts of the body
• slow movement
• stiff and inflexible muscles

I have family members who suffer from Parkinson’s, so I was compelled to try and design a product which would help them.

After speaking with people who have Parkinson’s, I learnt of a common piece of advice to listen to marching band music and that keeping a steady rhythm can help while walking other actions such as use a walking stick to give the same effect. Researching further I learned that there was no product currently available made specifically to help in this situation and listening to the music and using a walking stick come with their own complications.

Listening to music would require occupying your hearing, potentially leaving somebody at risk and a walking stick can be cumbersome and annoying to carry. A haptic metronome would be able to provide rhythm without forcing the user to encumber themselves.

There does not exist currently any product or design made to provide a haptic metronome for people with Parkinson’s. Haptic metronomes do exist, but they are aimed entirely at musicians. Therefore, specific aspects of this design, such as the alternating pulses on either side, which are specifically aimed at aiding walking do not exist on the market in any form.

The design utilizes two vibrating discs which will pulse alternatively to a set bpm. They are designed for one disc to be on each side of the body and a range of peripherals will allow for the disc to be strapped to the wrist like a watch, or held in the hand, as gripping something is also suggested to help with walking and movement. The discs themselves can be interchanged into both sets of peripherals easily.

The sizes of the disc and the peripherals have been considered to provide an ergonomic and comfortable experience for the user. The advantage of using the peripherals for each configuration and not a separate unit for each way of using the device is that for those who may need smaller sizes or even want to have the device on them in a different form. Personalised peripherals can then be designed to fit these needs at a later point. For example one potential configuration from the research would be the ability to slot a disc in the handle of a walking stick.

The discs will be controlled via a mobile app and the pulse bpm and the strength of pulse can be adjusted to allow for personal preference and comfort.

The disc casing will be produced and made of brushed stainless steel as it gives a good clean look to the disc. Practically it will also provide the internals with good protection and not break under any impacts it could face in day to day life due to it being a strong material.

The peripherals will be produced using a silicone rubber, this will be comfortable to hold and strap as the rubber is flexible. It will also provide extra protection to the discs once in the peripheral. This material is proven for this kind of use as it is commonly used in watch straps and watch casings for different watches but in particular, sport watches. Silicone rubber is more expensive that other rubbers but as shown by its use in sport watches and other devices its properties are very desirable in the day to day environment that this product will be used in

The dimensions of the disc and peripherals:

Figure 1-Outer Casing of the vibrating disc from 3 angles.

Figure 2-Peripheral Designed to be held (Note round slot for disc to be inserted)

Figure 3-‘Watch Strap’ Designed for disc to be strapped to the wrist

In order to produce the timed pulses, the disc will contain a vibration motor, to create the pulses, and a control board. The control board would be small, and coin shaped. It has a small piezoelectric resonator which will control the digital clock. This resonator will allow the device to time the sending of a current to the vibration motor, allowing the user to effectively change the bpm of the pulses. The small control board will also be able to adjust the strength of the current to the motor allowing the user to change the intensity of each pulse.

In order to alternate pulses from one disc to another the discs will utilize Bluetooth chips on the board. Then we can use a button that alternates between pre-sets. For the pulses to be timed the two discs must be synced together. To do that a master-slave connection will be used. One board is the master and it sends a “go” signal to the slave, then the other board starts a given delay later.

Figure 4-Block diagram of system.

The cost of one unit of this product (2 discs, 2 straps, 2 holders) comes to approximately £50. Much of this cost is spent of the electric components and machining and assembly costs. Due to the design being small and handheld the materials cost (stainless steel and silicone) are low. This price places this product in line with other health devices such as fitbits. So will remain affordable for any potential customer.