Project at a glance
- Client: Birmingham Children’s Hospital (BCH)
- Product: PKU Bite (iOS & Android)
- Classification: Clinical-grade health technology
- Impact: 1,000+ downloads | 1,100+ food database
- Compliance: NHS clinical safety standards
Background: Understanding PKU
PKU is a rare metabolic disorder which prevents the normal breakdown and use of protein-containing foods by the body. It is due to a deficiency of an enzyme (phenylalanine hydroxylase or PAH), which breaks down protein.
Protein is made up of amino acids. One of these amino acids is called phenylalanine and would normally be changed into another amino acid, tyrosine. However, in PKU, because the enzyme is not very active, or is missing, the phenylalanine is unable to be converted into tyrosine and will accumulate in the blood. If left untreated, the build-up of phenylalanine can damage the brain and cause severe learning difficulties. Fortunately, many countries have a newborn screening programme for PKU. This means that PKU is detected in the first few days of life, and treatment can start as soon as diagnosis is confirmed.
What is a low phenylalanine diet?
A low phenylalanine diet is the main treatment for phenylketonuria (PKU). People with PKU must restrict phenylalanine, which is found in protein. However, phenylalanine (protein) cannot be removed completely, so it is given in measured exchange amounts each day.
A low phenylalanine diet can be highly complex, with foods recognised in various groups depending upon their phenylalanine content. Most food labels don’t specify phenylalanine, so protein content is taken as a proxy and a calculation is done on the basis of protein level and food mass to ascertain the “exchange” value of the food.
The engagement: Why Imobisoft?
Imobisoft was asked to design and build a digital application which could fulfil the following requirements:
- Bring to life the coding and labelling system used within a low-phenylalanine diet.
- Create an easy look-up guide for foods to enable patients and carers to know which foods were safe and which need caution or should be avoided.
- Provide a tool which simplified the calculation process for “exchanges” within the low phenylalanine diet.
The solution: What we did
Find your audience: Working closely with the Birmingham Children’s Hospital (BCH) PKU team, we first ascertained the audience for the application. As PKU is often diagnosed at an infant stage, the users of the app would be parents, carers and wider family as well as patients themselves.
Build for everyone: As we needed to ensure that the application was as accessible as possible, we decided that there should be a web browser-based as well as native Android and iOS applications. This means that the app would be accessible and functioning both in online and offline mode and across the most number of devices, whether they were mobile, laptop or tablets.
Design & initial features: We used a very collaborative approach to design with the BCH team, allowing multiple iterations.
The base application included:
- Smart calculator: An inbuilt tool where users enter protein values from labels to automatically calculate exchanges per 100g or per portion.
- Rich food data: A database of over 1,100 foods, including preparation, storage, menu ideas, and recipes.
- Traffic light system: Foods are colour-coded (Green/Amber/Red) using the NSPKU system for instant safety checks.
Continuous development: New functionality
Since the initial engagement in 2020, we have continued to develop and deliver further functionality. We have added two more features to the application:
1. Clinical assessment tool: We have introduced a new clinical assessment section to the application to streamline the process of routine and emergency PKU check-ups for patients. Previously, when patients visited the clinic, they were required to fill out a paper-based form containing around 20 questions related to their condition since their last visit. The form covered various aspects of their health, such as any changes in their medication, whether they were currently taking any medications, if they had developed any comorbidities, and other relevant health details.
This manual process was both time-consuming and inefficient. After the form was filled out, the clinician would review it, often leading to delays and the possibility of errors in data entry. To improve this, we utilised the existing application infrastructure to digitise the process and enhance the workflow.We developed an integrated form system within the application, which allows patients to easily complete their clinical assessments online. The form is accessible to patients through the app, where they can enter their health information and submit it directly.
The backend was enhanced with a user management system that enables clinicians or clinical administrators to manage patients, assign assessments, and track submissions. Once a patient submits the clinical assessment, the clinician receives it electronically through the application. The clinician can then review the submitted form, make any necessary edits, and download the assessment as a Word or PDF document for record-keeping purposes. This improvement has significantly reduced the administrative burden on clinicians, expedited the review process, and minimised the potential for errors, providing a more efficient and effective way to manage patient assessments in the clinic.
2. Blood “Phe” tracking: We added a blood phenylalanine (Phe) level monitoring function to the app, allowing users to track and update their blood Phe levels over time. This feature collects essential details, such as the user’s blood testing frequency, dietary restrictions, and medication status. Users can enter their Phe levels, and with each subsequent visit, they are prompted to update their information if needed.
This function was implemented to help users monitor their Phe levels in a structured, consistent way, improving management of their condition. The ability to track Phe levels over time, alongside key health factors like diet and medication, ensures that clinicians can provide better, data-driven care. Additionally, the feature includes visual charts and historical records, allowing users to review progress and receive timely reminders based on their testing frequency.
Outcomes & governance
From trial to public release: The first iteration was deployed within controlled trials at Birmingham Children’s Hospital. Following successful feedback, PKU Bite was fully released to the public in January 2022. It is now a trusted resource with over 1,000+ downloads and frequent updates (currently version 3.0.3).
Clinical governance & safety: Each stage of development has to not only go through a rigorous testing process, but we also conduct patient and clinician feedback groups. Imobisoft chairs the quarterly clinical safety meeting, ensuring the app meets NHS clinical safety standards and risk management protocols.
