{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"8e3d8855e8fc699c0f158a32cf2c91b6e6080bdf2083acbd80971332e09cbc88","created":"2026-10-03T07:18:06Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"001c91b32ecf0dab43cd1de0993de8a051248b5256ad85bc852604ba4f0d6f35","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"med.focused-ultrasound.histotripsy-predictability","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Very short, very intense sound pulses tear tissue apart mechanically by creating clouds of bubbles. Where and when those clouds form is only partly predictable.","posed_since":"2004","precise":"Predict the threshold and spatial extent of histotripsy bubble-cloud formation from the incident pressure waveform, with peak negative pressures of $10^8\\text{ to }3 x 10^8\\,\\mathrm{dyn}/\\mathrm{cm}^2$ and microsecond pulses, including nucleus distribution in tissue, shock scattering from earlier bubbles, and tissue mechanical properties. An answer is a predictive model giving the treated volume boundary to within $1\\,\\mathrm{mm}$.","problem_ref":null,"references":"","settled_by":"High-speed imaging and acoustic measurement of cloud formation across pressure and tissue type, compared with the model prediction and the resulting lesion.","status_note":"","title":"Predicting and controlling histotripsy bubble clouds","topic_ref":"8f240ebd4ecd5f8e303bb3f92d02a60c846c51e2ff4c97cf08dac7930e62b3b4"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"bb59506fc5b983170be3f7aef24e7ff1738a058777d40d6d2eeb811410202b2b","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"aee675f0a6e12fa76d8f6efab6a5c4908398fb54ec54b9dd285dac25c3199a8b","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"VnqU-38Yi02Vuac0X3bXcBsr8tkyu41y5wmwVxXUwQKLkanQg8C22aSiRKxRjFnim5X7PU-zcUzUw9kqA7yvBg"},"schema":"pubphys.envelope/1"},"record_hash":"bb59506fc5b983170be3f7aef24e7ff1738a058777d40d6d2eeb811410202b2b","leaf_index":1686}