idea-009 · 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 specify an inelastic strap assembly and a printed tension indicator, show on a bench that it produces a gradient, make it in lots that all calibrate the same, and get it through whatever FDA (US Food and Drug Administration) route the device actually lands on.
How to read this: every slide is a condition, not a conclusion. A bracketed claim reference points at a numbered line of the ## Claims list in knowledge-base/candidates/idea-009.md (numbered by position) and carries the tag that line carries there, copied and never adjusted here. [no claim] would mean nothing in the file speaks to a condition. No pressure figure, tolerance, cost or lead time appears here that is not in a claim. See docs/deck-spec.md.
What moved since the last build: two things. First, the design target moved out from under the file: the earlier bench condition located the pressure band as "the 30-50 mmHg (millimetres of mercury) band named in the A6583 (a HCPCS code for a supply) descriptor"; that descriptor names no band, and the condition is refuted on that ground. The performance question — does a patient-applied wrap produce a gradient at all — is not what was refuted, and is restated on Slide 1 against a band the design team would have to choose. Second, an earlier build of this deck on the same date cited the single-tension condition and the strap-aid labelling condition under each other's claim numbers. This build cites them by position as the file numbers them: the single-tension condition on Slides 4, 5 and 8, the labelling condition on Slides 3 and 8.
Would have to be true: Applied by the patient with every strap at its indicator mark, the wrap would have to produce a distal-to-proximal decreasing sub-bandage pressure gradient within a resting pressure band that the design team chooses and states in the labelling — a band not yet chosen, because nothing outside the design now sets one.
Where it stands: The earlier form of this condition is refuted: it tied the target to a 30-50 mmHg band in the A6583 descriptor claim 36refuted, and the descriptor carries no pressure band claim 44verified, claim 8refuted. The restated condition, with the band left as a design choice, is on record claim 70unverified. The file carries one bench lead that constrains the choice: in six commercially marketed wraps on healthy subjects, inelastic wraps did not exceed roughly 30 mmHg at rest while higher-stretch wraps went above 60 mmHg claim 48unconfirmed. No target band number is on this slide because none is in a claim.
What would settle it: A design decision on the labelled band, then a bench rig — a leg form with sub-bandage pressure sensors at ankle and calf — with the wrap applied by untrained users to indicator alignment. No connector answers device performance; this is bench work.
If it's false: No gradient at indicator tension means no product, on any route. If an inelastic wrap cannot reach the band the design team wants, the choice is a lower band (and a clinical conversation) or a higher-stretch material — which reopens Slide 3's elastic-material question from the other side.
Would have to be true: An inelastic short-stretch strap assembly would have to hold its applied tension across a full labelled wear period without being re-tensioned more often than the labelling says — the property the product's whole therapeutic premise depends on.
Where it stands: Untested; no test data exist claim 37unconfirmed. That sustained gradient compression is established maintenance therapy is itself unverified in this file claim 21unconfirmed.
What would settle it: A wear-period bench test on a leg form with cyclic loading, logging sub-bandage pressure decay from indicator-aligned application; a Tier 3 clinical review of the consensus documents for the therapy premise.
If it's false: Tension that decays faster than the label allows means the indicator reports a tension that held at donning and not after, and the desirability deck's reproducibility premise (its Slide 2) is measuring the wrong moment.
Would have to be true: FDA would have to read an inelastic, strapped wrap indicated for lay self-application without a fitter into 21 CFR (Title 21 of the Code of Federal Regulations) 880.5780(b) — despite the regulation identifying the device as "constructed of elastic material" and § 880.9 requiring a premarket notification for lay use where the prior use was professional-only — and the tension indicator would have to be labelled as a strap aid, never a pressure measurement.
Where it stands: The generic type is verified: § 880.5780 exists claim 1verified, paragraph (b) is Class I, premarket-exempt and exempt from part 820 except records and complaint files claim 2verified, product code FQL maps to it claim 4verified. The venous route is also verified — paragraph (a), Class II (FDA device class II), code DWL, without the part 820 exemption claim 3verified, claim 5verified — which is why a line of "venous circulation" marketing copy is an engineering constraint on labelling. This device's membership in that generic type is not established: both paragraphs say "elastic material" against an inelastic mechanism, and the lay-use trigger in § 880.9 reads on this indication claim 6unconfirmed. Whether human-factors testing alone would then carry the self-application indication claim 38unconfirmed is open. Whether labelling the indicator as a strap self-application aid, with no mmHg measurement claim, keeps the device within § 880.5780(b) rather than under a pressure-measurement regulation is recorded, unchecked claim 72unverified. If the exemption does not hold, no predicate has been identified and no prior De Novo (De Novo classification request) grant matches claim 56unconfirmed.
What would settle it: A 513(g) Request for Information to FDA, or Tier 3 regulatory-counsel review of the draft labelling — the two routes the file names; neither is an agent action. A human browse of FDA's product-code database by regulation 880.5780 and panel HO supplements it.
If it's false: The engineering programme changes shape: a premarket submission with a predicate question, a human-factors validation built for FDA review rather than for labelling confidence, and full quality-system design controls rather than records and complaint files. The viability deck's Slide 4 becomes a different business.
Would have to be true: One design strap tension, marked by a single indicator setting per strap, would have to yield a sub-bandage pressure inside the labelled band across the whole labelled below-knee circumference range — and the printed window would have to align at that tension within a stated tolerance across that range and across production strap lots.
Where it stands: Both halves are assumptions with no data behind them. That one tension and one indicator setting serve every circumference in the range is recorded, unchecked claim 71unverified. That the window aligns at the design tension within tolerance across the circumference range and across production lots is untested, with no lot data claim 39unconfirmed.
What would settle it: Bench measurement of sub-bandage pressure at indicator alignment on leg forms spanning the labelled circumference range; the same measurement on straps drawn from several production lots. Bench work; no connector.
If it's false: If pressure at a fixed strap tension varies with limb size beyond the band, a single indicator mark is right for one leg and wrong for another — the indicator becomes a sizing problem (several windows, or size-specific straps), and the product's one differentiator stops meaning what the label says.
Would have to be true: The wrap, its hook-and-loop closures and its printed indicators would have to keep gradient performance and indicator calibration over the labelled service life, including repeated home laundering — shown on the bench before a patient wears one.
Where it stands: Untested; no test data exist claim 40unconfirmed. The minimum bench list this deck implies is Slides 1, 2, 4 and 5 together — gradient at indicator tension claim 70unverified, tension retention claim 37unconfirmed, one tension across the circumference range claim 71unverified, window calibration across circumference and lots claim 39unconfirmed, and durability here.
What would settle it: Laundering and closure-cycling protocols followed by a repeat of Slide 1's pressure mapping and Slide 4's calibration check.
If it's false: An indicator that drifts with washing reports the wrong tension late in service life; a closure that loses grip loses the gradient. Service life in turn sets how often a wrap is replaced, which meets the unread quantity limits on the viability deck's Slide 2 claim 45unconfirmed.
Would have to be true: The wrap would have to be manufacturable at a landed unit cost below the wholesale price incumbents charge suppliers, and its labelling would have to carry an arterial-insufficiency contraindication that prescribers actually act on before a self-applied device is used.
Where it stands: Unit cost against incumbent wholesale is recorded, unchecked claim 63unverified; the wholesale price it is measured against is itself unchecked claim 62unverified. On the (b) route the quality-system burden is narrower than "QMS (quality management system) compliance" suggests — records and complaint files only claim 2verified — but only if Slide 3 holds. The labelling content (peripheral arterial disease contraindication, ankle-brachial-index statement) is clinical reasoning, unverified claim 21unconfirmed, and whether prescribers will document arterial status is the desirability deck's Slide 3 claim 28unconfirmed.
What would settle it: A costed bill of materials and textile-converter quotes, compared with supplier purchase prices a supplier shares; a Tier 3 clinical and regulatory labelling review.
If it's false: A wrap that costs more to land than incumbents sell for has no margin under the $160.13 allowable claim 11verified. A contraindication nobody screens for leaves the file's named harm pathway open on a device with no fitter in the loop.
Would have to be true: No unexpired US patent — held by the four named incumbents or by any other assignee — would have to claim a strap tension or elongation indicator on a limb compression wrap; and for the indicator to be protectable, no prior art would have to anticipate it.
Where it stands: The field is unexamined, not clear claim 19unconfirmed. A patent sweep of the four incumbents has run and returned leads, never a tag: the closest is an Essity application titled "Compression garment with indicator", found only as a Canadian filing claim 41unconfirmed. The same sweep found elongation- and extension-indicator art from unrelated assignees in the class; that no such holder has an in-force US claim on the indicator is recorded, unchecked claim 73unverified. Patentability of this indicator is recorded, unchecked claim 66unverified. The moat this would protect is the viability deck's Slide 5 claim 20unconfirmed.
What would settle it: A patent professional reading the Essity family's claims and searching for any US counterpart, and the class sweep's other indicator art read claim by claim; a Tier 3 FTO (freedom to operate) opinion at Stage 7.
If it's false: A blocking claim on a strap tension indicator removes the one feature that distinguishes this wrap — the rubric's only automatic-kill factor sits on it — and design-around means a different indicator mechanism, which reopens Slides 4 and 5.
Every condition above with nothing verified behind the part that decides it. On this deck that is all seven. Slides 3 and 6 carry verified operands — the generic type's class and exemptions, and the $160.13 allowable — and are listed for their open halves.
Claims 70, 71 and 72 were appended by an earlier build of this deck on the same date; claim 73unverified was appended by this one. The verified claims on this deck are all about the regulation and the code — the generic type, its class, its exemptions, the descriptor, the payment rule. None is about the device.
If only one thing from this chair could be checked: whether FDA reads an inelastic adjustable-strap wrap, indicated for lay self-application without a fitter, into 21 CFR 880.5780(b) — or whether the elastic-material identification or the § 880.9 lay-use trigger puts it on a premarket route claim 6unconfirmed.
This one rather than the bench questions because it decides which engineering programme exists at all: records-and-complaint-files manufacturing with labelling-grade human factors, or design controls, a submission and a predicate question claim 56unconfirmed. Every bench condition on Slides 1-5 is needed either way; this one sets their evidentiary grade and the calendar around them.
Naming it is not a recommendation, a gate, or a kill. It is the answer to "check what first."
_shared/plain-language.md