The Development of a Wi-fi Enabled, Wireless Medical Alarm Device

One of Public Invention’s most prominent projects, the General Purpose Alarm Device, or GPAD, which was recently published in HardwareX, has developed into a wireless version called the Krake. Both versions aim to be used in a medical setting as a peripheral annunciator, connecting to medical devices and alarming personnel to changing patient states or other shifting variables.

The original GPAD design, developed between the summer of 2022 through 2024, utilized either a serial port or an RJ12 cable to connect with a device and monitor fluctuations. However, the Krake offers both cable and wireless capabilities, extending the possible distance between the monitored person or device, and the monitoring physician, in any given situation. 

The device’s developers, Public Inventor Nagham Kheir and Invention Coach Forrest “Lee” Erickson similarly connected over a long distance while working on the project. Despite Kheir being located in Lebanon while Erickson lives in Tennessee, they both collaborated, learned, and continue to successfully develop this important technology.

Kheir began working on the project in early 2024. She decided to volunteer with Public Invention after connecting with its mission to support the wider community through independent engineering projects.

“I remember going to the website for Public Invention, and there was a comment [that said] ‘You can have the ideas that you want, and keep having them, and not bring them to the world,’” Kheir said. “‘If you don’t work on it, someone else might, or it might not come to life and no one will benefit from it.’ They continued to say, ‘This is a space where you can find a volunteering opportunity, and get these ideas into life.’ And that was exactly what I needed.”

After meeting with Volunteer Coordinator Miriam Castillo, Kheir was drawn to the GPAD, which connected with her interests and experience from university. She began developing software that would enable it to connect with devices through wi-fi, a task which required her to program an ESP32 microcontroller. Kheir remembered the exact moment the Krake first became wireless.

“I remember jumping off my seat when my code first worked, and I was able to hook it to the wi-fi and control it through my PC,” Kheir said. “Then Rob [Read] introduced me to Lee, and we started from there.”

Lee Erickson, a retired embedded system designer, began volunteering with Public Invention in 2022. He connected most with its Invention Coach role, which aimed to provide mentorship for younger volunteers.

He was given the opportunity to mentor Kheir as the Krake project took shape. Originally part of the early GPAD development team, Erickson joined after seeing Kheir’s initial progress. He provided mentorship, resources, and his own expertise to expedite the development of both the project and Kheir’s electrical skills. He also reflected that this project was becoming an entirely different device compared to its predecessor.

“I made the argument that it needed its own name,” Erickson said. “That gave me the inspiration that maybe we needed to find an animal in Lebanon that makes noise. That turned out to be a bird, and it’s a crake.”

This change in name to the wildlife-based ‘Krake’ set the device apart from its parent the GPAD, and opened the door to more changes from the original. Erickson encouraged Kheir to ruggedize the Krake’s breadboard onto a wooden board, and they fabricated assemblies of this second PCB for both Lebanon and Tennessee. These “Home Work 2” assemblies approximated some of the Krake’s prototype functionality, and led to more confident evaluation of design ideas. “Home Work 2” also anticipated the team’s creation of pseudo-medical devices, which would send alarm messages to the Krake for further system development and demonstrations.

“Nagham [Kheir] added two connectors,” Erickson said of the assemblies. “The connectors enabled us to connect to a liquid crystal display as well as to an audio circuit that can play audio files. So, this is approximately the Krake. In addition, I added a rotary encoder.”  

The creators have integrated the Krake into their everyday work on the project. They use their “Home Work 2” devices to facilitate meetings and send short messages to each other over their crystal displays, from Lebanon to Tennessee and vice versa, through the internet. These messages alert each owner about whether the other has joined Discord or wants to set up a meeting, gaining their attention through flashing LEDs or alarm sounds. This current use of the device, spanning a distance of over 6,000 miles and seven time zones, already demonstrates its utility and broad possible applications.

Erickson and Kheir are optimistic about the continued development of the Krake, and hope to spread the word about its uses through open-source publications and outreach once it is complete. Both Public Inventors have invested over a year of work and many hours on this project, but valued the new technologies it has enabled them to learn, the community of open-source engineering and their relationship as collaborators. Erickson reflected on his experience as a mentor, and what the role has taught him.

“You’ve got to listen to [your mentee], try and figure out what their capabilities are, and how to take them to the next step each time. You need to not take too big a step for fear of demotivating them. And it has been fun showing Nagham [Kheir] some of the next steps,” Erickson said. “There’s a very gratifying thing that happens as you’re mentoring someone, and that is that, as they begin to really understand what you’re doing, they eventually reach a point where they are anticipating you or even finding your mistakes. That’s already happened with [Kheir].”

Kheir also reflected on her experience with Public Invention and the Krake project. She appreciated the organization’s support while working with Erickson on the project, and the opportunity to learn from his guidance and feedback. 

“It’s like a treasure we have here. It’s so rare to find someone who’s been doing this his whole life,” Kheir said. “It makes it really easy for people to just get in there, because they will get the help needed.”

Public Invention continues to provide leadership and structure to support independent projects like the Krake, and connects teams like Erickson and Kheir to bring their ideas to life. It aims to help the wider community through open-source medical projects, while providing development for its volunteers and opportunities for those looking to mentor the next generation of inventors.