Designing for "No Hands Free"
■ The courage not to guess "that" in one shot
"Grab that — that thing!" In a sterile field, the doctor can only point with words. Most systems commit to a single top candidate. Hakobukun didn't — it laid out "gauze / forceps / antiseptic / scalpel" and waited. Ambiguous references fail most when you rush them. Laying out the options is the shortest path to the right answer.
■ Multimodal input when both hands are full
With candidates on screen, the doctor still can't touch it — hands sterile. All that's left is voice, chin, and a nod. Hakobukun narrowed it by gaze — "Gauze?" — and took the nod as yes. A UI built on "tap with a finger" collapses when hands are gone. Input channels can't be designed after they're taken away.
■ Conclusion
constraints sharpen design The doctor asked to "register chin + nod as a confirmation action." A sterile field is an extreme constraint, yet design reasoned backward from "no hands" works even when hands are free. The harshest setting brings the most universal answer. Constraints don't bind design — they hone it.
