A Client Story

Ohio WillowWood

LimbLogic® iOS & Android App

WillowWood is a prosthetics designer and manufacturer with a unique history. Over 110 years ago, their founder survived a tragic accident in which, he lost both legs; one below the knee and one above. He refused to settle for the painful and burdensome prosthetics available to him and began carving and curing wood from willow trees to build his own. From then on, he was determined to advance the comfort and performance of prosthetic limbs and the quality of life for those who need them.

Over a century later, WillowWood remains a beacon in the amputee community. Their core mission is to empower their patrons to live a more seamless and simple life by combining groundbreaking prosthetic design with sophisticated technology that gives greater control to the patient and clinician.

To carry out this mission, WillowWood invented The LimbLogic product line, which consisted of a LimbLogic® Vacuum System (i.e. pump) that could be controlled by patients and clinicians using a small key fob controller. Additionally, clinicians had access to a Windows-based software package named the LimbLogic® Communicator, which assisted in the monitoring and management of each patient’s prosthetic experience.

Project Purpose

As time passed and WillowWood observed user behavior with this solution, it became evident that the key fob controller wasn’t as intuitive and simple to use as they’d like. Committed to the notion that true innovation never relents; never settles, they set out to completely reinvent their solution and asked k2d for help.

K2d helped WillowWood eliminate their key fob controller and LimbLogic® Communicator, and replace these technologies with two powerful new smartphone applications; one designed for patients and one designed for practitioners.

The Patient Mobile App enables patients to communicate with their LimbLogic® Pump using Bluetooth LE on iPads and popular smartphone devices. The app is simple to navigate and empowers patients by allowing them to:

  • Easily monitor and control one or two prosthetic pumps
  • Monitor pump charge level
  • Manage and monitor vacuum levels in real time
  • Monitor Bluetooth connection status
  • Manage pump modes
  • Manage pump alerts

The Practitioner Mobile App includes all the same functionality as the patient mobile app combined with all the features of WillowWood’s LimbLogic® Communicator. Using this application, clinicians can communicate with and manage multiple patient pumps, set and lock optimal settings, and assess usage data over time for an unprecedented degree of personalized care.


k2d jumped right into technical discovery and solutions planning, and suggested that WillowWood create a UX and UI process that prioritizes the user. We also recommended a process method that enabled stakeholders to actively participate in the design and development of this new solution. Lastly, we created a rapid prototyping process to quickly assess design concepts and cost/time efficiency to better manage the scope of the project, minimize errors, and ensure quality.

UX/UI Design

Creating a simple but powerful tool for patients and clinicians required that k2d dive deep into the existing user experience.

UX: We investigated LimbLogic® use cases and evaluated how users interact with the existing Key Fob and LimbLogic® Communicator. After extensive research, k2d provided recommendations for how to develop an intuitive and efficient solution that met all user expectations for utility, performance, and value.

UI: After determining how users wanted and needed to interact with this tool, we designed a user interface that puts patients and clinicians in clear control. The interface reduces the amount of memorization users require to navigate different functions and provides visual consistency throughout the software interface that beautifully personifies the WillowWood LimbLogic® brand.


In production, we made all developers well acquainted with user stories and recommended that all assets for the project be organized in a way that was accessible to the entire team. k2d provided comprehensive prototypes that represented all functional requirements, and produced and delivered application specifications, assets and guidelines to ensure a smooth handoff to the development team. We also created design standards for use in future expansions.

Quality Assurance

At k2d, we believe that quality assurance directly impacts user experience. If the applications we develop doesn’t work properly, users question their understanding and create workarounds that disrupt efficient workflows. To prevent this from happening, we review all text and visuals, test all functions, and enact key scenarios based on use cases to trigger errors and validate error usage. As user behaviors evolve over time, our quality assurance coverage will ensure that LimbLogic® for iOS and Android adapts and continues to support user requirements.