idea-019 · feasibility deck
Every slide states a condition that would have to be true, then reports where it stands using the candidate file's own claim and its own confidence tag. A deck never upgrades a tag, invents a number, or recommends anything, and there is no ask slide.
The chair: engineering. The people who have to build it, test it, manufacture it, and produce the evidence a reviewer will ask for.
How to read this: every slide is a condition, not a conclusion. A bracketed claim reference points into knowledge-base/candidates/idea-019.md: the number is the claim's position in its ## Claims list, and the tag is copied from that claim as it stands at build time, never adjusted here. A [no claim] marker means nothing in the file speaks to the condition. Where another lens holds a condition, this deck points at that deck rather than restating it. See docs/deck-spec.md.
What the file looks like from this chair. The device does not exist claim 8unconfirmed. What exists is an investigational analog, manually activated, studied on single study days. The technology and operations chairs have stated quantified engineering conditions — inflation latency, vent time under fault, a false-upright rate, garment sizing, battery — and every one is unconfirmed, because nothing measurable has been built. The regulatory classification facts are the only verified ground under this lens.
One thing reached this chair from the money side since the last build: the compressor family is paid once, as a purchase, not as a rental claim 117refuted. That makes cost of goods a design input rather than a later optimisation (Slide 6).
Would have to be true: On a detected sit-to-stand transition, a unit worn under clothing would have to inflate an abdominal bladder to 90% of a 40 mmHg (millimetres of mercury) set pressure within 15 seconds, hold that pressure under closed-loop control while the wearer is upright, and vent to zero when the wearer sits or lies down — and 15 seconds would have to be earlier than orthostatic symptoms begin in this population.
Where it stands:
What would settle it: A bench rig with a sit-to-stand fixture and a pressure transducer measures claim 109unconfirmed directly. For the budget, a named beat-to-beat or tilt time-course paper in nOH, then a Verifier literature-detail run (claim 142unverified); the trial in claim 77verified is the obvious first read.
If it's false: If the bladder is still filling when symptoms begin, the posture trigger — the candidate's defining feature — delivers less than manual pre-inflation did in the analog, and Slide 2's mechanism has to hold without the timing the published result had.
Would have to be true: Posture-triggered splanchnic compression worn through a normal day would have to reproduce the symptom-burden effect seen when the analog was pre-inflated manually on a study day, at a set pressure the wearer tolerates through every upright period.
Where it stands: Direction is evidenced on an analog; magnitude under this device's use pattern is not.
What would settle it:
If it's false: If the effect needs pre-inflation the trigger cannot deliver, or a pressure patients will not wear all day, the therapeutic claim has nothing under it. Factor 6, scored 2/5 on class-1 evidence, has no device-level support to rise on, and the desirability deck's Slide 6 loses its only evidence.
Would have to be true: FDA (US Food and Drug Administration) would have to classify the device Class II (FDA device class II) through De Novo (De Novo classification request) with special controls, not Class III (FDA device class III), and the build spec would then have to carry an IDE clinical investigation of sham-controlled design, biocompatibility testing on garments conditioned through the labelled cleaning regimen, IEC 60601-1, 60601-1-2 and 60601-1-11, IEC 62304 software life-cycle evidence, and IEC 62133-2 battery safety.
Where it stands:
What would settle it: A Q-Sub pre-submission, human-run and months long, settles class, IDE and trial design in one meeting. FDA's Recognized Consensus Standards database for claim 94unconfirmed is a lookup.
If it's false: Class III means a PMA (premarket approval), and the evidence and calendar the viability deck's Slide 5 already cannot cost grow further. A 510(k) route through 870.5800 shortens the build but leaves the candidate without a De Novo of its own.
Would have to be true: A posture classifier on a single torso-worn inertial sensor would have to class a recumbent wearer as upright in fewer than 1 in 1,000 recumbent periods, with no false-upright call lasting over 60 seconds, in adults with Parkinson disease, MSA (multiple system atrophy) or PAF (pure autonomic failure) including camptocormia and dyskinesia — and its decision would have to be unaffected by the co-located bladder inflating or venting, or by the garment migrating on the torso over a day.
Where it stands: Nothing is measured for this device. The specification is the technology chair's claim 108unconfirmed, as is stability under inflation and migration claim 113unconfirmed; the general form is claim 48unconfirmed. The population makes it harder: camptocormia in 15.6% of one large MSA cohort claim 84verified. The nearest precedent used three body-fixed sensors, not one, and reported "high" sensitivity and specificity for lying with no numeric figures claim 85verified.
What would settle it: A video-referenced, home-like validation in the target population, including stooped and dyskinetic patients, with enough recumbent periods to bound a 1-in-1,000 rate. Stage 7 bench and clinical-engineering work; no connector reaches it.
If it's false: The clinical-risk case rests on zero supine exposure "by construction" (claim 31unconfirmed). A classifier that inflates on a recumbent patient with supine hypertension — common in this population (claim 82verified, desirability deck) — removes the design's stated advantage over pressor drugs, and the whole safety case moves to Slide 5's independent vent and interlock.
Would have to be true: Before any patient wears it, a bench rig would have to show the bladder venting below 5 mmHg within 10 seconds under each single fault (pump runaway, sensor failure, loss of posture signal, firmware lock-up) through a normally-open de-energise-to-vent valve and an independent mechanical relief valve; an independent second posture channel venting within 60 seconds of recumbency whenever the primary classifier has failed; and a battery of 20 Wh or less running a 16-hour day of at least 60 cycles with continuous holding at 40 mmHg.
Where it stands: All three are technology-chair conditions on an unbuilt device: vent under fault claim 110unconfirmed, interlock claim 111unconfirmed, battery claim 114unconfirmed; the general vent condition is claim 49unconfirmed. The nearest cleared architecture has a software-pressure failure history: Kendall SCD recalls cite "Incorrect software logic may cause frequent E1 errors (system high pressure)", root cause "Software change control" claim 56unconfirmed, and the JOW recall count is on record claim 95unconfirmed. Both are scan-derived and unconfirmed.
What would settle it: Fault-injection bench work with a pressure log per fault, and a duty-cycle battery test; both need a prototype. openFDA recall detail for Z-1917-2025 to Z-1919-2025 is a Verifier run once the scan-supported question is decided. No agent here greenlights an animal or human study; that sits immediately downstream and is Tier 3.
If it's false: If a single fault can hold pressure on a recumbent wearer, the device has no safety case and Slide 4's classifier would have to be perfect. If the battery cannot last a waking day, the desirability deck's daily-wear condition gains a mid-day recharge.
Would have to be true: No more than three stock garment sizes would have to hold splanchnic skin-interface pressure within 5 mmHg of set pressure across this population's waist range; the pump, vent valve and pressure sensor would each need two independent suppliers; the controller would have to survive at least three years and repeated patients; and the controller plus the garments it consumes would have to be built for less than the one-time purchase allowable of the code it bills under.
Where it stands: All unmeasured.
What would settle it: A sizing study with interface-pressure mapping on the population's body habitus; accelerated wear-and-launder testing of garment prototypes; supplier RFQs against a draft bill of materials, which also gives the viability deck its cost side. All Stage 7 engineering work, except the desk-costed BOM (bill of materials), which an engineer can draft before a prototype.
If it's false: Custom-fit garments or frequent replacement push cost of goods above a one-time allowable with no rental tail to recover it. A single-source pump is a supply risk to a Class II device whose design is fixed at clearance.
Would have to be true: In a summative human-factors validation, patients with Parkinson disease, MSA or PAF, or their caregivers, would have to complete the critical tasks — positioning the garment and sensor, connecting and charging the controller, responding to a fault alarm — without a use error that leads to compression while recumbent or no compression on standing.
Where it stands: Unconfirmed; the study does not exist claim 134unconfirmed. The behavioural premise under it is the desirability deck's load-bearing condition claim 28unconfirmed. The adjacent verified finding that older users reject stockings over the practicalities of applying them claim 71verified describes a different garment.
What would settle it: A formative usability round on a prototype, then a summative validation. Human-run; no connector reaches either.
If it's false: A use error that inflates a recumbent wearer defeats Slides 4 and 5 from outside the electronics, leaving a residual risk that hardware alone cannot close.
Would have to be true: Posture-triggered inflation and closed-loop pressure control of an abdominal bladder would have to be free to practise — because the Vanderbilt family has no granted claim in force covering them, or because an exclusive licence is available — and no other live patent could claim the same combination.
Where it stands:
What would settle it: USPTO (United States Patent and Trademark Office) file history and INPADOC family status for US2015313608, free and hours. A landscape search of posture-sensing compression and servo pneumatic-control art, and an FTO (freedom to operate) opinion, outside counsel work and Tier 3.
If it's false: If granted claims cover posture-triggered abdominal inflation and no licence is available, the workaround is manual or timed activation — the analog's mode, not this candidate's defining feature. The design survives only as a compromise of itself.
Every condition above with nothing verified behind it that supports it. On this deck the verified claims are regulatory-classification facts and analog-device findings; nothing verified is about this device, because it has not been built.
Slides 1, 2 and 3 carry verified claims that bear on their condition in part: the analog's set pressure and inflation time, the analog's symptom result, and the regulation's non-limb codes. Slides 4 to 8 carry none that supports the condition.
If only one thing from this chair could be checked: whether a single torso-worn posture classifier can keep false-upright inflation of a recumbent wearer below 1 in 1,000 recumbent periods in Parkinson disease, MSA and PAF patients, including those with camptocormia and dyskinesia claim 108unconfirmed.
It is this one because the candidate's reason to exist, set against pressor drugs, is zero supine pressure exposure "by construction", and the classifier is the construction.
The purchase-model change on Slide 6 tightens the cost envelope but does not displace this: a cheap device that inflates on a recumbent patient has no safety case to price.
Naming it is not a recommendation, a gate, or a kill.
_shared/plain-language.md