HOCl Wound Irrigation System, per-patient bag and single-use head (Aquaceso variant) — feasibility

The chair: engineering. These are 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-023.md. The number is the claim's position in its ## Claims list. The tag is copied from that claim as it stands at build time and is 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. P1 per-patient HOCl bag has two sub-assemblies, sterilized separately and joined by the user at the point of use.

• The bag: sterile HOCl-preserved saline in a flexible bag, labelled for multiple use within one patient.
• The head: single-use and stored dry, with a hand-squeezed chamber refilled from the bag through a check valve, three nozzles inside an integral splash shield, and no metal in the wetted path.
• No warming and no pump. Warming left the scope with P1 per-patient HOCl bag, and a pump is excluded.

Nothing of either half has been built claim 63unconfirmed. The precedents are strong for the bag's regulatory route and weak for its chemistry. The head has no direct precedent: the only hand-squeezed one cleared is a prefilled bottle.

Slide 1 — What the device actually has to do

Would have to be true:

• Pressure. Fed from the bag by its own hand-squeezed chamber, the head would have to deliver wound-impact pressure within 4-15 psi at its working distance. That would have to hold from the first to the last 10% of the bag and for every operator, including at maximal grip.
• Construction. Three nozzles inside an integral shield, at room temperature, with no metal in any HOCl-wetted part.
• Volume and time. The bag would have to supply a per-session volume V over an in-use period T. V and T are both blank in the file.

Where it stands:

• The range. IWII 2022 recommends 4-15 psi and tabulates 8 psi for a 35 mL syringe with a 19G catheter claim 86verified. K210987 (an FDA 510(k) clearance number)'s summary carries 4-15 psi as a predicate attribute claim 70verified. The 1994 AHCPR guideline itself was not retrieved claim 40unconfirmed.
• This head's delivered pressure across the bag's volume claim 145unconfirmed, and across operators at maximal grip claim 172unconfirmed, are both unmeasured.
• No metal in the fluid path claim 147unconfirmed.
• V, the volume per session: no figure. That a published source reports one is on record from this deck claim 210unverified.
• T, the in-use period: neither cleared HOCl bag's 510(k) (premarket notification) summary states one claim 169verified. P1 per-patient HOCl bag's own in-use period is unknown claim 189unconfirmed.
• Warming: out of scope. The warming question it replaced, claim 50unconfirmed, is marked superseded by P1 per-patient HOCl bag.

What would settle it:

• For V, a literature pull, then literature-detail on whatever source is named.
• For T, the Puracyn Plus product label (REQ-0228 Retrieve the labelled storage condition), a human retrieval because no connector holds labels.
• For the rest, a bench rig on a prototype.

If it's false: A spec with V and T blank cannot size the chamber, the bag, or the cycle-life test. Slide 5's bench plan has no pass line until those two numbers exist.

Slide 2 — The mechanism that has to hold

Would have to be true: A chamber small enough to squeeze in one hand, refilled from the bag through a check valve and splitting its flow across three nozzles, would have to produce at least 4 psi of wound-impact pressure. That is more than a hand-compressed bag reaches. It would also have to stay at or below 15 psi at maximal grip. And irrigation in that band would have to remove slough and debris no less than a 35 mL syringe with a 19G catheter does.

Where it stands:

• Why the head needs its own chamber. A hand-compressed IV bag through a 19G needle gave a median peak of 4 psi (range 2 to 5.5), and a bag in a 400 mmHg (millimetres of mercury) cuff gave 6-10 psi claim 143verified.
• Hand-squeezed bottles reach the band.
  • IRRIGO's 60 mL bottle generates up to 15 psi claim 16verified.
  • IRRISEPT's squeeze bottle with a multi-port splashguard is cleared as jet lavage, and the Verifier's note records 7-8 psi claim 13verified.
  • Both are bottles. Neither is a chamber refilled from a bag through a valve.
• The band works.
  • Saline at 15 psi removed 84.8% of soil infection-potentiating factors claim 88verified.
  • Low-pressure asepto irrigation did not cleanse claim 89verified.
  • 20 psi pulsatile lavage caused myonecrosis that bulb-syringe irrigation did not claim 102verified, which supports the ceiling.
• The threshold is not steep. 1.6 psi and 8.8 psi were equally effective in rat wounds claim 91verified, and the FLOW trial found no pressure effect on reoperation in open fractures claim 92verified.
• For this head, both legs are open claim 145unconfirmed claim 172unconfirmed.

What would settle it: A pressure transducer at working distance, tested with a panel of operators, on a head of defined geometry (REQ-0249 For the P1 head assembly, REQ-0239 For the P1 reference head). The clinical comparison in claim 172unconfirmed comes after and needs funding.

If it's false:

• Below 4 psi, the head is a shielded drip. The fallback is a powered head, and the jet-lavage regulation names an electric roller pump as one means of propulsion claim 15verified. That is a different device, at a different cost.
• Above 15 psi at maximal grip, the tissue-injury findings in claims 90 and 102 apply.

Slide 3 — What the pathway forces you to build

Would have to be true:

• The bag would have to be built to the test plan an HOCl FRO wash already clears on. If the proposed rule is finalized as written, it would also have to meet the Class II (FDA device class II) special controls for a multiple-use wash: worst-case simulated-use preservative effectiveness on three lots, real-time aged to the end of shelf life.
• The head would have to fall inside an existing classification, 21 CFR (Title 21 of the Code of Federal Regulations) 880.5475 or 880.6960, so that it needs bench, sterilization and biocompatibility evidence and no De Novo (De Novo classification request).
• The keyed port would have to be acceptable to FDA (US Food and Drug Administration) within those routes.

Where it stands:

• The bag's route:
  • FDA's proposal accepts a preservative only in a nonsterile wash or a multiple-use single-patient wash claim 119verified.
  • It lists HOCl as low AMR concern, which means Class II claim 120verified.
  • Its special controls would require worst-case simulated-use preservative-effectiveness testing on three real-time-aged lots claim 176verified. That is a proposal, not law.
  • The rule had not been codified as of the eCFR of 2026-09-30 claim 12verified.
• Test plans that have already cleared:
  • Vashe Plus: USP <51> on 9-month-aged samples with a 7-day simulated multi-use period, material compatibility with spike-adapter materials, a GLP porcine wound study, and no clinical data required claim 178verified.
  • Puracyn Plus: stability, biocompatibility, packaging, sterility, endotoxin and preservative-effectiveness testing to named standards claim 125verified.
• P1 per-patient HOCl bag's own bag result is unrun claim 177unconfirmed.
• The head:
  • Its classification is FDA's call claim 180unconfirmed.
  • The nearest precedent cleared on bench, sterilization and biocompatibility testing with no clinical testing reported. But it is a prefilled bottle cleared as a solution product, not a separately sold head claim 179verified.
  • Two separately sterilized sub-assemblies joined at the point of use is a cleared architecture claim 124verified claim 144verified.
• The keyed port claim 195unverified. Its buyer half is in the viability deck, Slide 6.
• The animal study. The Vashe Plus precedent included one. Whether this programme runs one is a Tier 3 decision, and this deck notes the precedent only.

What would settle it: The records search under REQ-0254 Search openFDA 510 for a separately sold, hand-operated, container-fed head cleared under FQH or KYZ, and REQ-0255 P1's mechanism makes the single-use head… for a maker-keyed port. Only FDA settles the head, through a 513(g) request or a Pre-Submission. Either one discloses the project, which makes it the owner's decision.

If it's false: A De Novo for the head changes the evidence package, the timeline and the money (viability Slide 5). If the rule is finalized against HOCl as a preservative, the bag's route changes.

Slide 4 — The hardest unknown

Would have to be true: The opened per-patient bag is HOCl-preserved saline in a flexible bag whose port a new head re-enters at every session. At room temperature, it would have to stay within its free available chlorine, pH and USP <51> specification. Wound organisms introduced at the port would have to not survive in it. The port would have to reseal after the maximum number of connections. All of that would have to hold for an in-use period at least as long as the gap between one patient's sessions, in every setting sold to.

Where it stands:

• The chemistry runs against room temperature.
  • A 200 ppm, pH 6 HOCl solution was unstable at 25 C and above and in light and air; the authors recommend storage below 10 C claim 96verified.
  • Neutral electrolysed water lost almost all its available chlorine over 52 days at 25 C claim 97verified.
  • The only heat-stable result is concentrated alkaline hypochlorite, a different chemistry claim 98verified.
  • Against that, cleared HOCl cleansers carry 12-month stability claim 7verified.
• The precedent stops short of what P1 per-patient HOCl bag needs. The cleared HOCl bag is labelled for multiple use within one patient claim 122verified, but its summary states no in-use period claim 169verified. Vashe Plus showed a 7-day simulated multi-use period, but in PET bottles, not a re-spiked bag claim 178verified.
• Every P1 per-patient HOCl bag-specific leg is open:
  • room-temperature shelf life claim 126unconfirmed;
  • in-use stability with a head connected at each session claim 167unconfirmed;
  • three-lot worst-case simulated use claim 177unconfirmed;
  • microbial challenge at the port claim 174unconfirmed;
  • port reclosure and container-closure integrity claim 168unconfirmed;
  • an in-use period that covers the session gap in all four settings claim 189unconfirmed, and in outpatient clinics specifically claim 163unconfirmed.

What would settle it: First, REQ-0228 Retrieve the labelled storage condition: the Puracyn Plus labelled in-use period and port design, one human retrieval. Then a short in-use run on prototype bags from a candidate filler, which needs a filler request for information that the owner must authorise.

If it's false: If the opened bag cannot be kept, it cannot be labelled for repeated use. FDA's proposal calls a preservative in a sterile single-use wash not appropriate claim 119verified, so the bag would have no label it can carry. P1 per-patient HOCl bag falls, and every slide in the viability deck that counts sessions per bag falls with it.

Slide 5 — Bench evidence before anything lives

Would have to be true: Before any animal or patient is involved, a bench rig on a prototype head of defined geometry would have to show five things:

• delivered pressure within range across operators and across the bag's volume;
• the chamber and check valves surviving twice a session's squeeze cycles after sterilization and ageing, with no leak and no particulate;
• no metal in the wetted path, and solution still in specification after the longest contact time;
• breathing-zone chlorine never above 1 ppm, with droplet concentration no higher with the shield than without it;
• less splatter on the irrigator's face and chest than with an unshielded syringe.

Where it stands:

• Every leg is an unrun test: claim 145unconfirmed claim 192unconfirmed claim 147unconfirmed claim 127unconfirmed claim 191unconfirmed claim 148unconfirmed claim 173unconfirmed. No prototype exists claim 63unconfirmed.
• A materials warning. An FDA recall records an HOCl wound solution that corroded the stainless-steel spring in its sprayer. It was reached by scan only claim 71unconfirmed.
• Aerosol evidence is analogy only.
  • HOCl fog was cytotoxic to cultured cells after repeated 500 ppm exposures, and not at 300 ppm claim 99verified.
  • Sprayed hypochlorite left chlorine below detection claim 100verified.
  • The predicate solution range is 150-330 ppm claim 4verified.
  • The exposure question itself is open claim 51unconfirmed.
• Splatter is measured only for a syringe. A shielded syringe cut face and chest splatter claim 101verified.
• What comes after the bench is Tier 3. No agent here greenlights an animal study.

What would settle it: A contract bench lab, once REQ-0249 For the P1 head assembly fixes the head geometry. That is weeks of work.

If it's false: Each failure sends a specific part back.

• Metal in the path means a valve redesign.
• Breathing-zone chlorine above the ceiling inverts the working-environment premise the desirability deck relies on (desirability Slide 5).
• A chamber that cracks or sheds particulate fails before any clinical question is asked.

Slide 6 — Making it, and using it

Would have to be true:

• The bag. A sterile filler that does not itself sell HOCl wound cleansers in the US would have to fill the bag with a keyed port, with lot release that includes a free available chlorine assay.
• The head. It would have to be made and sterilized as a separate dry sub-assembly.
• Cost. The cost per session would have to clear the price (viability Slide 3).
• Use. On a ward at 3am or in a patient's home, a nurse would have to keep the opened bag with its patient, tell it apart from saline, and squeeze a full session by hand.

Where it stands:

• The filler:
  • a non-competitor filler with a quality agreement is unconfirmed claim 128unconfirmed;
  • a listing search found no contract manufacturer listing a sterile HOCl solution in a flexible bag claim 190unconfirmed.
• Manufacturing precedents exist:
  • the 2026 Puracyn Plus bags are made using aseptic techniques claim 169verified;
  • IRRISEPT pairs an aseptically filled bottle with EO-sterilized accessories claim 124verified;
  • BD Surgiphor's tray is terminally sterilized by gamma claim 144verified.
• How this category fails in the field. Recalls have been for sterility assurance, container integrity, temperature excursion and material incompatibility, reached by scan only claim 130unconfirmed. One sterile saline wound-wash recall was for sterility assurance level claim 75unconfirmed.
• Look-alike risk. A MAUDE (Manufacturer and User Facility Device Experience) narrative relays that an antiseptic wound irrigant was given in place of saline because the packaging was extremely similar claim 73unconfirmed. That bears on an HOCl bag that would sit beside saline bags.
• Cost and schedule: per-session cost claim 188unconfirmed; bag fill as the largest pre-sale cost claim 199unverified; schedule claim 194unconfirmed.
• Human factors, held in the desirability deck: hand fatigue claim 203unverified and bag custody claim 205unverified.

What would settle it: Filler requests for information and quotes, which the owner must authorise. A costed bill of materials. A formative human-factors study on a mock head and bag.

If it's false:

• With no non-competitor filler, the bag goes to an incumbent to fill, which gives away the bag's margin and possibly the keyed fit.
• With cost above price, the rest of this slide is moot.
• A mix-up at the bedside is a use error the label and packaging have to design out.

Slide 7 — What FTO forbids

Would have to be true:

• The head would have to be drawn so that no in-force claim reads on it. That means designing around the Schultz utility claims until about 2032 and its design patents until about 2037 and 2040, Medaxis's protective cover until about 2038, and the unread '811 and '457 patents.
• The bag's formulation would have to fall outside Urgo's stabilized-HOCl claim 1unconfirmed and Sonoma's pH 5.6 claim 1unconfirmed, and still stay within specification.
• The squeeze-chamber and keyed-connector landscape, never searched, would have to hold no blocking patent.

Where it stands:

• Schultz utility patents:
  • '904, '835 and '226 end before 2032-12-31, at about 2032-04-19, 2030-08-05 and 2032-03-14 claim 152verified;
  • their independent claims recite a fluid source connector, a nozzle and a shield, not a squeeze bottle or syringe, so their scope is wider than a bottle claim 181verified;
  • '757 and '356 have expired on their priority chains claim 151verified claim 182verified.
• Schultz design patents run to about 2037-07-05 and 2040-07-22 claim 183verified.
• Medaxis runs to about 2038-09-30. Its independent claims recite a flexible hollow body forming a treatment chamber, a resilient stiffening element and a transparent plate claim 185verified.
• The '811 and '457 patents are in force and their claims are unread claim 186verified.
• Features P1 per-patient HOCl bag does not have. The in-force wound-washing gun's only independent claim recites a battery and a pump claim 184verified; P1 per-patient HOCl bag is non-powered. CareFusion's granted claims each recite a warming component claim 154verified; P1 per-patient HOCl bag does not warm. CareFusion's pending applications are unread claim 187verified.
• The solution claims:
  • Urgo's claim 1unconfirmed is limited to electrolysed HOCl stabilized with added bicarbonate or carbonate, in a CO2- and O2-impermeable container, within stated ranges claim 149verified.
  • Sonoma's claim 1unconfirmed is limited to pH 5.6 with a phosphate buffer and stated chlorine and chloride ranges claim 150verified.
  • That a formulation outside both still holds its specification is on record from this deck claim 212unverified.
  • The tension with Slide 4 is real. The stabilizer in claim 149verified is exactly what keeps HOCl in a container, so the design-around is the harder bag to make.
• The head as drawn:
  • that none of the named live patents reads on a defined head geometry is on record from this deck claim 211unverified;
  • the wider landscape negatives are open claim 155unconfirmed claim 193unconfirmed;
  • the field is otherwise unexamined claim 58unconfirmed;
  • whether the referrer can bring the Aquaceso rights is unknown claim 3unconfirmed.
• Two refuted claims bear here, and both are about the file's own patent lookups.
  • claim 55refuted named the wrong inventor for US 5,941,859 claim 55refuted. Its restatement verifies the patent as lapsed claim 79verified.
  • claim 153refuted described claim numbers and content in two Schultz patents that the grant documents do not contain claim 153refuted. The corrected reading shows their independent claims reach any fluid source connector claim 181verified.
  • Both say that a patent reading in this file has to be checked against the grant text before a head is drawn around it.

What would settle it:

• The head geometry, from REQ-0249 For the P1 head assembly.
• The landscape searches, REQ-0212 Run a recorded and REQ-0248 Run a recorded US landscape.
• Counsel's read of the named families against that geometry, which the owner must engage.
• The referrer's answer on who makes and owns Aquaceso (REQ-0224 Ask the referrer, REQ-0208 Obtain from the referrer).

If it's false:

• If a live Schultz or Medaxis claim reads on the head, the head is redesigned, licensed, or held back until those terms end.
• If no formulation can avoid claim 149verified and still hold its specification, the bag needs an Urgo licence. That is the incumbent-fills route, and it gives away the bag's margin.

Slide 8 — Where this deck outruns the file

Every condition above with nothing verified behind it that supports it. Most verified claims on this deck are precedents, ranges, or the patent terms and claim scopes that set the constraints. They describe what P1 per-patient HOCl bag has to meet. None of them shows that P1 per-patient HOCl bag meets it.

• The head delivers 4-15 psi across operators and across the bag (Slides 1, 2 and 5) — claim 145unconfirmed claim 172unconfirmed. Settled by a bench rig on a prototype.
• V, the per-session volume (Slide 1) — claim 210unverified. Newly on record from this deck. Settled by a literature pull and literature-detail.
• T, the in-use period (Slides 1 and 4) — claim 189unconfirmed claim 163unconfirmed. Settled first by REQ-0228 Retrieve the labelled storage condition, then an in-use run.
• The head falls under an existing regulation, and the keyed port is acceptable (Slide 3) — claim 180unconfirmed claim 195unverified. Settled by REQ-0254 Search openFDA 510 and REQ-0255 P1's mechanism makes the single-use head…, and finally by FDA through a 513(g) or Pre-Submission, which is the owner's decision.
• The P1 per-patient HOCl bag bag passes three-lot worst-case simulated use (Slide 3) — claim 177unconfirmed.
• The opened bag holds at room temperature, kills port-introduced organisms, and its port reseals (Slide 4) — claim 126unconfirmed claim 167unconfirmed claim 174unconfirmed claim 168unconfirmed. A project-cost study on prototype bags.
• Cycle life, no metal, breathing-zone chlorine and splatter (Slide 5) — claim 192unconfirmed claim 147unconfirmed claim 127unconfirmed claim 191unconfirmed claim 148unconfirmed claim 173unconfirmed. Settled by bench work.
• A non-competitor filler, cost per session, and schedule (Slide 6) — claim 128unconfirmed claim 190unconfirmed claim 188unconfirmed claim 199unverified claim 194unconfirmed. Settled by filler quotes and a costed plan.
• Hand fatigue and bag custody (Slide 6, held in the desirability deck) — claim 203unverified claim 205unverified.
• No live claim reads on the head as drawn (Slide 7) — claim 211unverified claim 155unconfirmed claim 193unconfirmed claim 58unconfirmed. Newly on record from this deck. Settled by counsel, once a geometry exists.
• A formulation outside the Urgo and Sonoma claims still holds its specification (Slide 7) — claim 212unverified. Newly on record from this deck. Settled by counsel's read plus the Slide 4 stability work.
• Aquaceso rights (Slide 7) — claim 3unconfirmed. Settled by the referrer.

Slides 2 and 3 carry verified claims that support part of their condition. Slide 2 has the experimental evidence that irrigation in the 4-15 psi band cleanses. Slide 3 has the bag's FRO route and a test plan that has already cleared. Nothing verified supports Slides 1, 4, 5, 6 or 7. Of seven conditions, five have nothing verified behind them.

Slide 9 — The load-bearing condition

If only one thing from this chair could be checked: whether the opened per-patient bag, re-entered by a new single-use head at every session and kept at room temperature, stays within its free available chlorine, pH and USP <51> specification, with no survival of wound organisms introduced at the port, for an in-use period at least as long as the gap between one patient's sessions in every setting sold to claim 189unconfirmed claim 174unconfirmed claim 167unconfirmed.

Why this one rather than the head's pressure:

• The head has a fallback; the bag does not. If hand pressure fails, a powered head is a known if costlier device (Slide 2). If the opened bag fails, P1 per-patient HOCl bag has no label for its preserved bag (claim 119verified), and the original single-use shape was set aside for exactly that reason.
• The verified chemistry runs against it (claims 96, 97). The one cleared bag precedent states no in-use period P1 per-patient HOCl bag could borrow (claim 169verified).
• The viability deck depends on it. T sets sessions per bag, which sets the cost of every session (viability Slide 3).
• The first step is one retrieval. The Puracyn Plus labelled in-use period (REQ-0228 Retrieve the labelled storage condition) says whether any HOCl bag has ever been labelled for a period that covers a wound-care visit gap.

Naming it is not a recommendation, a gate, or a kill.