Medical Apps & Things

Calculating likely gestational age and estimated due date

PregCalc (iOS)

This app is intended to calculate likely due dates of pregnancy.
Adjustment for menstrual cycle frequency can be made, and staging of pregnancy by date of interest is supported.

Simply enter the date of the first day of the last menstrual period, average length of a menstrual cycle (defaults to 28 days), and the date you are interested in finding number of weeks pregnant (defaults to today's date).

The app will provide details of the stage of the pregnancy in weeks for the date of interest, the trimester of pregnancy and the likely due date.

This is based on a modified Naegele's rule, considering the length of gestation to be 280 days from the first day of the last menstrual period, adding or subtracting the difference in cycle length if over or under 28 days.

It is generally accepted that only 4% of pregnancies deliver on the expected due date, with 80% being delivered within 2 weeks either side of this date. This tool is intended as a guide only. There will likely be differences between gestational age and fetal age as measured by ultrasonography as the two models use different methods.


To anticoagulate or not?

The AFAnticoagulation calculator is designed to aid in decision making for anticoagulants in atrial fibrillation.
It utilises the HAS-BLED and CHA2DS2VASc scoring systems.

Screen Shot 2019-10-17 at 8.52.23 pm

When's the next depo contraceptive injection due?

Aimed to shave a few more minutes off your work day.
The DepoProgesterone app automatically calculates a 3 month (84 day) offset from the current system date.
Other reference dates can be chosen easily with the date picker, and the offset from the chosen date is calculated.

Screen Shot 2019-10-13 at 1.41.15 pm

Predict Paediatric Peak Flows

My second app is an implementation of paediatric peak flow formulae in healthy children as given in Acta Paediatr. 1994 Dec;83(12):1255-7.

Screen Shot 2019-10-13 at 12.03.07 pm

An alternative to Framingham

The Framingham study initiated the exploration into the epidemiology of cardiovascular disease. It began in Framingham, Massachusetts, in 1948 with a cohort of 5209 adult subjects and is now on its 3rd generation of participants. Its data has long formed the basis for primary prevention cardiovascular risk calculations.

In May 2018, a study was published in Lancet, "Cardiovascular disease risk prediction equations in 400,000 primary care patients in New Zealand: a derivation and validation study". This large regression analysis study provides a formula for predicting the likelihood of developing cardiovascular disease end points over 5 years in those who have not yet had a cardiovascular event.

My first app is a risk calculator which implements this model with an ergonomic interface.

Buy on the Apple App Store.

Screen Shot 2019-10-13 at 8.00.35 am