3D Suture v2

The prompt

Build a suturing trainer you look at from the side, with a wound that sits open because the skin was already tight. The skin has a thin surface, a tougher dermis, and soft fat under that. Some wounds are straight, some curve, some have a flap, some have one edge longer or thicker, and some are on thin shin skin or are too old or too dirty to sew.

Before a stitch I pick a thread, a size, a needle, and where I hold the needle. I should hold it around the middle. On skin the needle is curved and its cutting edge faces away from the wound. I put the stitch in the middle of the wound first, then in the middle of what is left. The bite should go deeper than it is wide, and the loop should be a bit wider underneath, so the edge rolls out a little and the two sides meet at the same height. I tie a square knot, more throws when the thread is slippery, and I leave short ends that are still long enough not to slip.

Some wounds want a different plan. A pointed flap is stitched inside the skin so the tip does not lose its blood. A deep wound is closed underneath first, with thread the body can absorb, then the skin. A tight wound can use a mattress stitch, but not pulled so hard the edge goes white. Thin shin skin should get strips or glue, because a stitch cuts through it. A dirty wound or one that has waited too long is left open.

When I say I am finished, score whether the wound is actually closed, whether the bites and knots would hold, and whether I chose the plan that wound needed. A pretty row of stitches on the wrong wound should not score well. Show the field under a lamp, the thread in its own colour, the knot, and a small side view of the layers. Say that this is a teaching model.

# AI : shared Action contract — the page posts {"move": "..."}; keep this shape.
from pydantic import BaseModel


class Action(BaseModel):
    move: str