A Stylet That Does Not Have To Come Out Two Half Millimetre Holes in a 3.18 mm Disc

This application covers a very thin feeding tube with a stiffening wire permanently seated inside it, for use when surfactant is delivered into the windpipe of a premature baby who is breathing on their own. The novelty is a small disc on the top end of the wire: it is too wide to slide down the tube, so the wire cannot poke out of the far end, and it has channels bored through it so the fluid can flow past it without the wire being withdrawn first. It was filed by BLES Biochemicals Incorporated of London, Ontario, and names Harold Nigh as sole inventor. The application is a divisional of Australian application 2020268126.

The Problem

Babies born very early often have lungs that have not yet made enough pulmonary surfactant, the substance that lowers surface tension inside the air sacs and stops them collapsing at the end of each breath. The resulting condition is neonatal respiratory distress syndrome, and the established treatment is to instil replacement surfactant directly into the trachea.

The older way to do that was to pass a breathing tube, which means the baby is then on a ventilator. Over the last fifteen years the practice has moved toward giving the surfactant through a thin catheter while the baby keeps breathing spontaneously on continuous positive airway pressure, an approach known as less invasive surfactant therapy or LIST, and elsewhere as LISA or MIST. The specification lists the outcomes that have been associated with it: reductions in early CPAP failure, in the need for invasive ventilation, in bronchopulmonary dysplasia, and in the combined outcome of death or bronchopulmonary dysplasia. It also notes, plainly, that endotracheal intubation is recognised as a difficult procedure even for experienced physicians.

That leaves a mechanical problem. A catheter thin enough for a premature airway is too floppy to steer, so clinicians stiffen it. The specification cites published work showing that stylet guided catheters shorten the procedure compared with alternatives such as manoeuvring a plain feeding tube with Magill forceps. But a stiffening wire inside a tube is dangerous if it can slide forward and emerge from the tip, so the usual fix is to put a handle or loop on the back end that is too big to enter the tube. That handle then blocks the syringe port, so the stylet has to be pulled out before the surfactant can be given. The specification’s statement of the need is exact: a stylet stiffened feeding tube that stops the stylet protruding from the distal end but does not require the stylet to be removed before instillation.

What This Invention Does

Claim 1 describes a flexible feeding tube with an integrated stylet. The tube has a distal end, a proximal end and an adapter at the proximal end. The stylet sits inside the tube and carries an anchor at its proximal end. Two requirements do the work. The anchor is configured to seat removably within the adapter so that it cannot enter the tube. And the anchor has one or more channels running through it, so that fluid can flow from the adapter, through those channels, and down the tube while the anchor stays seated.

That is the whole invention: move the stop from outside the adapter to inside it, and drill holes through it. The wire still cannot advance, because the disc is caught on a shoulder, but the fluid path is no longer blocked, so the syringe goes straight on and the stylet stays where it is.

The dimensions in the description are what make the constraint real. A typical tube for this procedure is 18 to 23 cm long with an inner diameter under 1 mm, and the preferred figures are 20.5 cm and 0.91 mm. The stylet is about 2 cm shorter than the tube, preferably 18.5 cm, and 0.48 to 0.54 mm in diameter, preferably 0.51 mm. The anchor is a disc 3.15 to 3.21 mm across, preferably 3.18 mm, seating against a shoulder inside the adapter inlet that is described as substantially 90 degrees. The channels through the disc are 0.45 to 0.55 mm, preferably 0.50 mm, and there are preferably two of them, one on either side of the wire.

There is one more detail that shows the design has been thought through rather than sketched. Because the disc seats flat against a flat shoulder, the shoulder would sit over the channel outlets and choke them. So the underside of the disc carries an annular recess around the wire, preferably 0.50 mm deep, into which the channels open. Fluid leaves the channels into that recess and then spreads into the annular gap between the 0.51 mm wire and the 0.91 mm bore, which is a clearance of about 0.2 mm on each side. Dependent claims 4, 5 and 6 pick up the recess, the annular space and the complementary shoulder respectively, and claim 7 makes the disc round and the shoulder annular.

It is worth being precise about the difference between the claim and the rest of the document. The abstract says only that the anchor is configured to seat within the adapter. Claim 1 says seat removably. The description goes further in the other direction, noting at paragraph [0021] that the anchor may alternatively be permanently attached or formed integrally with the tube or adapter. The granted scope, if this divisional proceeds, will cover the removable version only.

Key Features

• An anchor that seats inside the adapter. Rather than a handle or loop sitting outside the syringe port, a disc wider than the tube bore seats on a shoulder inside the adapter inlet, which mechanically prevents the stylet from advancing into the tube.
• Channels bored through the anchor. One or more passages, preferably two of 0.50 mm on either side of the wire, run through the thickness of the disc so that surfactant flows past the seated anchor rather than being blocked by it.
• An annular recess to stop the shoulder sealing the channels. A groove about 0.50 mm deep on the underside of the disc collects the flow from the channels and feeds it into the space around the wire, so seating the anchor does not close the fluid path.
• A stylet deliberately shorter than the tube. At preferably 18.5 cm against a 20.5 cm tube, the wire ends about 2 cm short of the tip even before the anchor is taken into account, giving a second margin against protrusion.
• A removable stylet, by claim. Claim 1 requires the anchor to seat removably, so the wire can still be taken out if wanted, although the point of the design is that it does not have to be.
• Shape agnostic seating. The description allows spherical, dome, cone or prismatic anchors provided the shoulder is shaped complementary to them, with the disc and annular shoulder of claim 7 being only the preferred case.

Who Is Behind It

BLES Biochemicals Inc. is a privately owned Canadian pharmaceutical company at 60 Pacific Court, London, Ontario, incorporated on 5 March 1992. Its product is BLES, a bovine lipid extract surfactant supplied as a 27 mg phospholipid per millilitre suspension for intratracheal instillation, approved by Health Canada in 2002 and, by the company’s account, the market leading pulmonary surfactant in Canada. The science behind it came out of work by Fred Possmayer at the University of Western Ontario beginning in the early 1970s on collecting surfactant by intact lung lavage.

The inventor named on this application, Harold Nigh, is not an outside consultant. The company’s own history page describes Drs Possmayer, David Bjarneson and Harold Nigh as the team whose combined research produced the surfactant itself.

This is one of the relatively few applications in this batch with a product already on the market. BLES Biochemicals sells a device called BLEScath, launched in 2022 as a Health Canada approved single use intratracheal catheter with an integrated stylet, for giving BLES by the LISA or MIST technique. Both company sites place their content behind a medical professional declaration, so a general reader will meet a gate before the product pages load.

On the paper trail, this specification is more careful than most. Its RELATED APPLICATIONS paragraph states that it is a divisional of Australian application 2020268126, which is the national phase entry of PCT/CA2020/050599, published as WO 2020/223805. It makes no convention priority claim anywhere in the body. From the published family record rather than from this document, that PCT application claims priority from United States provisional application 62/843,673 filed 6 May 2019, which is what puts United States in the priority country row below. The Australian parent is published as AU 2020268126.

Why It Matters

The value of this device is measured in seconds and in steps, not in any new chemistry. The surfactant is the same surfactant. What changes is that the clinician does not have to unseat and withdraw a 0.51 mm wire from a 0.91 mm tube, one handed, while the far end of that tube is sitting in the trachea of a baby who may weigh under a kilogram, before attaching the syringe. Removing a step at that moment is the entire argument, and it is a reasonable one: a 2024 review in Neonatology, Less Invasive Surfactant Administration for Preterm Infants, State of the Art, sets out how much attention the field now pays to procedural detail of exactly this kind.

It also explains why a surfactant manufacturer is filing a device patent. The specification cites published evidence that the catheter used affects how well the procedure goes, so the delivery hardware is now part of how a surfactant competes. A company whose only product is the drug has a direct commercial reason to own the thin catheter that the drug is given through, and BLEScath is that product.

Two caveats for a reader of the document. First, the specification cites its key reference as Rigo et al., Devices for less invasive surfactant, Acta Paediatrica 2017; 106: 1091-1096. The volume, year and pages match a paper by Rigo and colleagues, but its published title is Rigid catheters reduced duration of less invasive surfactant therapy procedures in manikins, so the citation as printed is abbreviated or simply wrong. Second, the document is silent on a good deal that a clinician would want to know: it reports no trial, no bench flow rate through the two 0.50 mm channels, no instillation time, and no material for either the tube or the wire beyond calling the stylet a semi rigid length of wire. The final paragraph of the description also states that the device may be used wherever a stylet stiffened feeding tube needs to pass fluid without the stylet being removed, so the claims are not limited to neonatal use even though the whole document is written around it.

Related Concepts

• Preterm birth – the circumstance that produces the surfactant deficient lungs this device is used to treat.
• Bronchopulmonary dysplasia – the chronic lung injury that less invasive surfactant delivery is intended to help avoid.
• Catheter – the general class of thin tube the device belongs to, here at an inner diameter under one millimetre.
• Luer taper – the standard fitting convention for the syringe to adapter connection the anchor has to sit inside without blocking.
• Neonatal intensive care unit – the setting where the procedure described in the specification is carried out.
• Feeding tube – the everyday device this one is adapted from, repurposed here for tracheal rather than gastric use.

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AU 2026202235 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.