The Problem


Pressure sores are a problem that affect those with limited mobility, such as diabetics, the elderly, and those with spinal cord injuries. It is a condition that can lead to weeks or months of treatment and bed rest, as well as the disruption of daily activities. A sore can form in as little as an hour and a serious one can lead to further disability, infection, and even death - as was the case with Christopher Reeve. Worldwide, pressure injuries affect over 3 million people and result in nearly 60,000 deaths each year and over $15 billion is spent annually on treatment.

It's time for a solution that can help warn a person and possibly prevent a sore from forming in the first place. That's where The Pressure Assistant comes in.


The Pressure Assistant is a small device and sensor that easily mounts to any type of chair and constantly monitors how long a user has been sitting in one place.  A progress bar gives visual feedback and allows a user to see how long they've been sitting.  When a person has been sitting for too long, an alarm sounds and continues until a pressure release is performed.  Once completed, the alarm automatically turns off and the timer resets.    



More than just an alarm

Researchers who have studied the issue of pressure sores have recognized that, while an alarm can adequately warn a patient, it doesn’t lead to the development of good long-term habits. The Pressure Assistant's Natural Use* mode doesn't restrict the user to a rigid pressure release schedule. In this mode, as a user applies pressure, the progress bar increases. The difference between the Natural Use mode and a basic timer is that every pressure release a user does will decrease the level of the progress bar. If a user does routine pressure releases, the progress bar will never reach 100% and the user may go hours without ever hearing an alarm. The hope is that this will encourage users to develop the habit of doing regular pressure releases.

What is a pressure sore?

Impaired sensation can make it difficult to recognize warning signs such as pain and discomfort on areas of the skin that have pressure applied.  When such pressure is applied in a single spot for too long, blood flow is disrupted and tissue is damaged. These areas often include bony prominences such as the heel, the coccyx, and ischial tuberosities (the "sit bones").  If not addressed, a pressure sore can develop into a wound and can kill tissue, eventually exposing muscle, tendons, and bone.



Pressure sore prevention requires education and vigilance, involving regular examinations of skin on areas that receive pressure.  It also requires a routine habit of doing pressure releases (or shifts) to relieve pressure on affected areas.  Current standards of care for wheelchair-bound individuals suggest pressure relief be performed by leaning forward, from side-to-side, or lifting up, every 15 to 30 minutes for 30 to 120 seconds. 

*Patent pending



Multiple Modes

The Pressure Assistant is much more than a simple timer. It has three primary modes - Basic, Natural Use, and Hidden- that can each be further configured to accommodate a variety of use cases. Learn More >

Mobile Integration

The Pressure Assistant settings can be adjusted with a Bluetooth-enabled iOS or Android device using the mobile app. The mobile app also provides real-time feedback, web-integration and more.  Learn More >

Web Management

Working in tandem with a mobile device or Wi-Fi module, the Pressure Assistant can connect seamlessly to the Pressure Assistant Online Portal. On the online portal, a user or seating specialist can review a user's history, recognize trends, and adjust settings remotely.  Learn More >

Transfer Assistant

Impaired sensation can make it difficult for individuals to recognize their positioning, making it difficult and sometimes dangerous to transfer in and out of a wheelchair. The Transfer Assistant function provides feedback, allowing the user to recognize how far out of their chair they are.  Learn More >

Data Logging & Streaming

The data logging and streaming modules allow for the tracking and recording of data, and the monitoring of a users' sitting habits in a research or institutional setting. Learn More >


The Pressure Assistant has a stackable modular design that allows for the addition of extensions that add further functionality. These extensions include a haptic-motor module, a Wi-Fi module that allows for remote monitoring and data collection and more. Learn More >


The Pressure Assistant has the potential to be used in a variety of research settings – especially in the area of pressure sore prevention. The device itself has many modes and setting combinations.  Testing the efficacy of the various modes could form the basis of a research study.  In addition to its own research potential, The Pressure Assistant is a tool that could be used to aid other researchers in other studies. It has the potential to be custom configured to meet the requirements of any study involving pressure, and even – with the addition of other sensors – other conditions, such as temperature.  The Wi-Fi module, in conjunction with The Pressure Assistant Online Portal, allows for the real-time monitoring of your subjects within a facility, and the data logging module allows for the collection and saving of months worth of data at a time to an SD card. Its modular design allows for the addition of other notification devices, such as a vibrating motor or an external speaker, and opens it up to customization for any specific research study.

The Goal

The goal is to get The Pressure Assistant onto as many chairs of the people who could benefit from it the most. To that end, I'm seeking companies, rehab centers and research institutions to partner with. The device still has quite a bit of refinement needed before it could be mass-produced. This refinement involves circuit board design and app development that is currently beyond my abilities. Further development might include incorporating other devices for feedback, such as smartphones and watches.  The current prototype of The Pressure Assistant is functional and has all the features shown above. It is ready for beta testing and I would like to find a rehab center that could get connect me to prospective patients for beta testing. I would also like to partner with research institutions to study the effectiveness of the device and its various usage modes.


About the Developer

The Pressure Assistant is being developed by Herndon, Virginia-based web developer and inventor, Jonathan Campbell. He began developing the device three years ago.  After witnessing the toll that pressure sores and their treatment took on a friend, he set out to build a basic timer that would alert the user when they had been sitting for too long, and reset itself automatically when a pressure release is completed. The device has evolved from a simple box with a speaker and a colored LED, to the device it is today. Jonathan was paralyzed in a bicycle accident in 2004 and is now quadriplegic.   When he's not tinkering with electronics or designing objects to 3D print, Jonathan volunteers with Trauma Survivors Network and mentors newly injured spinal cord patients. He occasionally writes in a blog called A Lighthouse Among the Trees and has recently started a how-to video blog called Building With Idle Hands. In his free time he enjoys spending time with his girlfriend, his dog, Sadie and playing wheelchair rugby.



© 2019 Jonathan Campbell