See helmet therapy progress in numbers
Enter the diagonals from the start of treatment and from a follow-up visit; see how much CVAI changed, the monthly rate and the CHOA level shift.
Baseline measurement
Follow-up measurement
For brachycephaly follow-up, enter width and length in both measurements.
Change
Enter the diagonals of both measurements.
Does not make treatment decisions
This tool only calculates the change between two measurements. Decisions to continue, adjust or end treatment belong to the doctor and orthotist who examine the baby.
Who are you?
Run this measurement automatically from a scan in your clinic
In a 30-minute demo we'll show the same calculation on a 3D scan, with your own case. Your result is added to the form automatically.
Result added to the form
No calculated result yet — you can still send the form.
Frequently asked questions
How is progress measured in helmet therapy?
The most common approach is to compare CVAI (and cephalic index in brachycephaly) at the start of treatment and at follow-up visits. The difference between two values taken with the same method shows how much the asymmetry has reduced.
How should a drop in CVAI be read?
It is expressed in two ways: the absolute drop in percentage points (for example 9.0% to 5.5% is 3.5 points) and the relative drop from baseline (about 39% in the same example). The change in CHOA scale level is also a useful summary.
Why should measurements use the same method?
A tape measure, calipers and a 3D scan can give different values on the same head. Comparing measurements taken with different methods can make progress look better or worse than it is. Use the same method, and ideally the same person, at every visit.
Does this calculator decide whether treatment is finished?
No. It only calculates the change between two measurements. Decisions to continue, adjust or end treatment belong to the doctor and orthotist who examine the baby.