How the report works

It starts with your pins

You place pins on the body where it hurts, choose how deep and which structure, say what it feels like, and tell the story. Pins that sit along one chain of the body, say the left hip, knee and ankle, are grouped into an episode, and the report reads one episode at a time: the pins, the notes and the history together, as one story rather than a list.

The card before anything runs

Pressing Analyse first shows a short card: what Voodoo is, the signs that should send you to a person today, and one question, whether any of them apply to you right now. “One or more” produces a short report that says to see someone today, and nothing else. “Not sure” lets the report run with a caution at its head. “None of these” lets it run.

The safety screen is code, not the model

Nine rules run before any model is involved. They are ordinary program code: written down, tested, and versioned, so the same inputs always give the same answer. They read your answer on the card and the facts on your pins, for example a calf pin whose own notes say it is swollen, or chest pressure spreading into the left arm. When a rule fires, the report switches to seek-care mode, which explains in plain words why clinicians like to see that combination in person and never names a condition as a fact.

Mapping your pins

Each pin names a structure from a standard anatomical vocabulary, the same names a physiotherapist uses, with everyday names beside them. Voodoo adds the structures around it along the chain and a small, sourced set of facts about each: what it does, what it attaches to, what it tends to be involved in. That is what lets a report connect an outer-knee pin to the outer hip without inventing anatomy.

Drafting the report

A pinned version of Google’s Gemini model, running in Voodoo’s own Google Cloud project, writes the draft from four things: your words, the structures you pinned and their neighbours, the facts about them, and a library of movements. It may only choose movements from that library, and the instructions, the easier versions and the cautions reach you word for word from the library; the model contributes why a movement fits your pattern.

The model is pinned to one version so that a report produced today and the same report produced next month come from the same thing, and every change to the prompts is replayed against a set of recorded test cases before it ships.

Checking the wording

Every analytical sentence has to be conditional: “this pattern could suggest”, “it may be worth checking whether”. A list of banned phrases is checked on every draft, among them “you have”, “diagnosis”, “cure” and “treatment plan”. A draft that uses one is sent back once; if the second draft fails too, you get a safe fallback instead. The number of such phrases that reach a person is counted, and the target is zero.

What the report can tell you, and what it cannot

It can offer:

• patterns between your pins that could be worth a closer look, with the sources they rest on;
• things you can check at home, and what a result would suggest;
• movements to explore, in phases, with the reason each was chosen for you;
• what to track, so that a later report can see what changed.

It cannot offer:

• a diagnosis. Voodoo describes possibilities; it never tells you what you have;
• anything it has not seen. One model reads your words. There is no examination, no imaging, and no history beyond what you wrote;
• certainty. Where the report sounds sure, that is a fault, and we would like to hear about it.

Why the movements say they await review

The library holds 67 movements drawn from published clinical guidance, each with instructions, an easier version, a progression and cautions. A physiotherapist has not yet reviewed them, and until that review is complete every entry says so. Treat a movement as a starting point: start gently, and stop anything that sharpens the pain.

Many movements come with a demonstration, a figure built from recorded human movement. It is a reminder of a movement the report has already described in words, never instruction on its own.

If a report is wrong

Tell us. At the foot of every report there is a link, “Report a problem with this report”, where you can say what was wrong in your own words. We read every one, and each becomes a recorded test case that future versions of the prompts must pass before they ship, so a mistake made once is not made again.

How your data is handled along the way is set out in the Privacy notice; the agreement between us is the Terms of use.