One unique feature of echocardiography as an imaging modality is the integration of both anatomical and flow data to make complex assessments of cardiac structures. To assess a stenotic aortic valve, for example, requires an appreciation of the concept of the conservation of mass with regards to flow as well as the structure of the valve and LV outflow tract. A lot can be derived about the heart based on Doppler assessment of flow and 2D structural measurements.
As such, echocardiography is riddled with formulas.
Given their relatively narrow scope, these formulas are rarely found in your typical medical calculator app or even calculator apps aimed at cardiologists.
For that reason, we took a look at Echo Lab, a calculator app designed specifically for this niche purpose.
Not only does it accomplish what it sets out to do, EchoLab is also a great example for other enterprising clinicians and developers of a how a decision support tool should be designed.
The app opens to a listing of categories organized alphabetically. At the top is a prominent No Data header – more on that in a moment. At the bottom is a navigation bar that offers another option for viewing the available calculators (Alphabetical) and a Favorites section for frequently used calculators. We’ll come back to the last two, Data and My Library.
We’ll use the task of calculating an aortic valve area as an example of how the app works. Navigating to the Aortic Valve category then to the Aortic Valve Area gets to our desired calculator. Note the star at the bottom of each calculator which allows us to mark favorites.
Part of the calculator includes calculating the BSA. Tapping on that line, we are taken to a linked BSA calculator. After inputting the data, the previously dull gray header and footer bars now turn bright green.
That change highlights one of the most unique and exceptional features of the app. When any value is calculated, it is saved and can be used in any other formula where it is needed. Now that we have done the BSA calculation for the AVA index, it will be automatically input into any other formula we select that requires a BSA. All active data being stored by the app can be reviewed in the Data section found on the navigation bar.
This feature reflects the insight of someone who understands the practicalities of their end-user. In this case, that someone interpreting an echo will often want to do multiple calculations on the same patient. Formulas being utilized by each calculator are available by tapping the Formula option at the bottom left of each calculator screen. References for the formula are also available there.
An additional feature of the app is the My Library category which lets users import a variety of documents into the app to help centralize relevant resources. This includes relevant papers, guideline documents, or even textbook chapters. Finally, there is a fairly lengthy users’ guide available by tapping the information icon on the top right of the screen – a feature we have not come across often.
One question any user considering using this app should ask is regarding quality control and testing. We contacted the developer, a practicing cardiologist, to find out more. He advised us that each formula is verified (after programming) by manual checks to ensure accuracy. He also notes additional safety features including the prominent green banner indicating active data as well as the clearance of all data each time the app is closed. These features were implemented to reduce the risk of inadvertently mixing data from different echos.
- Comprehensive selection of calculators
- Simple design and features like nesting of calculators make app very usable
- Excellent referencing
- Thoughtful attention to quality control and safety
- Would benefit from a search function
- Would include links to relevant resources like ASE Guidelines as part of My Library
- EchoLab is an outstanding resource for anyone who interprets echocardiograms. It is additionally an excellent example of a well-designed clinical decision support tool for anyone interested in designing resources for other niche areas of medicine.
Type of device used--iOS