Greenworms Thumper

What it does

For individuals with conditions such as Cystic Fibrosis, this device facilitates treatment without incurring the extortionate costs of current HFCWO vests, or requiring a carer. Emulating rythmic manual PT, the device 'thumps' the chest, loosening mucus.

Your inspiration

This project was found in a conversation with my supervisor Soumitri Varadarajan. Whilst working at a hospital, he expressed to me his frustrations towards outdated and costly equipment. We spoke on the injustice that could be felt from the pricing of Cystic Fibrosis related medication and existing airway clearance devices. It felt insensible. Upon further discussion, this project emerged from a designers pride: surely this could be designed in a better way. After considering many means of actuation, I settled on designing this project around solenoid actuators.

How it works

Airway clearance physiotherapy aims to expel mucus from the lungs by first loosening it, then removing it through coughing. Like HFCWO vests, the Greenworms Thumper uses rhythmic percussive impacts to help dislodge mucus. In addition to improving affordability and accessibility, it seeks to introduce greater precision and control to vest-type therapy. The device uses a solenoid as a repeating electromagnetic hammer, mounted to the body and controlled by a handheld dial. It can be repositioned along a garment such as a compression band or vest, delivering targeted impacts with adjustable speed and strength. The current Thumper serves as a proof of concept for a modular system. Its compact size and low cost allow for scalable arrays of multiple units. Future iterations will explore higher frequencies and more advanced impact control across multiple nodes.

Design process

My design process combined academic research, iterative prototyping, expert consultation, and testing. Informed by feedback from cystic fibrosis and physiotherapy professionals, I aimed to design a simple, affordable, self-operable system to support airway clearance. The Greenworms Thumper began with a first principles question: what must a device actually do to help expel mucus? Instead of replicating existing machines, I studied techniques like manual percussion, HFCWO vests, and acoustic therapies. This led to the idea of a localised, body-mounted thumper. After sifting through various designs and actuators I decided to centre the design around the action of a solenoid. Compact, modular, and electronically actuated, it could deliver focused force with control and flexibility. I first attempted to build a solenoid from scratch, but the output was weak and inefficient. Shifting to off-the-shelf solenoids, I prototyped with Arduino control, 3D-printed housings, and evolving mounting systems. Designs improved through repeated testing and expert input, enhancing impact, comfort, and usability. The result is a robust, mountable prototype and a platform for future development including wearable arrays of thumpers, compression modules and smart feedback control.

How it is different

The Greenworms Thumper offers a fresh approach to airway clearance by rethinking what makes therapy both effective and accessible. Unlike bulky, costly HFCWO vests, the Thumper is low-cost, lightweight, and portable, yet still delivers meaningful therapeutic impact. Its single, size-agnostic design also removes the need for replacement as users grow. Rather than relying on rigid systems, the Thumper enables users to target specific chest areas, adjust rhythms, and vary intensity. This flexibility supports more comfortable and responsive treatment. With a streamlined mechanical design and cost-effective components, the Thumper can be manufactured far more affordably than current systems. This opens the door to broader use, including in low-resource and underserved settings. In essence, the Greenworms Thumper makes airway clearance more affordable, adaptable, and inclusive, without losing clinical value.

Future plans

Future development will focus on creating modular thumper arrays for broader chest coverage. Next, a smaller form factor using alternative solenoids will improve comfort and wearability. Enhanced mounting systems, like adjustable vests will secure the device during use. Dual-mode modules will add chest compression to better replicate manual therapy. Integration with Ryobi batteries will enable mobile, untethered operation. App control and sensor feedback will personalise therapy. Clinical testing and low-cost manufacturing will support wide accessibility.

Awards