Technology and development
3D limb volume measurement with an iPhone
LimbVolScanner is being developed to capture a leg’s surface in 3D and calculate volume from the resulting model. This page explains the concept and the questions that still need answering.
From surface capture to a volume estimate
The planned workflow starts with a guided iPhone scan of the leg from the upper thigh to the ankle, excluding the foot. The surface capture is used to create a 3D model. The app then calculates the volume represented by that model.
- Scan: move the iPhone around the leg while following on-screen guidance.
- Review: inspect the captured model and calculated volume before saving the measurement.
- Track: compare saved measurements to explore changes over time.
The workflow preview shows illustrative screens. The model, scan time, quality indicator and volume changes on the homepage are examples, rather than measured performance results.
3D capture and tape measurements
Circumference-based methods measure selected points along the limb and use a simplified geometric model to estimate volume. LimbVolScanner’s proposed approach uses the captured 3D surface instead.
| Aspect | Tape-based estimate | Planned 3D approach |
|---|---|---|
| Input | Circumferences at selected points | Captured leg surface |
| Model | Simplified geometry between measurements | A reconstructed 3D shape |
| Workflow | Measure and calculate | Scan, review and compare saved models |
Capturing a surface does not, by itself, establish greater accuracy or clinical usefulness. A fair comparison needs a defined reference method, consistent scan boundaries and documented measurement conditions.
What needs to be validated?
The development work needs to establish volume error against an appropriate reference, repeatability across repeated scans, and the effect of different operators and capture conditions. Tracking changes also requires a consistent definition of the leg segment being measured.
A scan-time target of less than one minute appears on the homepage. It is a development target, not a demonstrated result. Supported iPhone models and a validated capture protocol are not specified on this website yet.
Areas for future evaluation
The intended areas for exploration include limb-volume tracking in research into lymphedema and lipedema, comparisons before and after treatment, and longer-term monitoring. These are proposed evaluation areas; the website does not provide a diagnostic or treatment tool.
The homepage identifies Dr. med. Jeremias Schmidt as providing clinical input. This does not establish validation results or hospital endorsement.
Discuss a structured evaluation
Clinics and researchers can contact the developer to discuss the approach and evaluation requirements. An inquiry does not enroll anyone in a study or authorize patient use.