The Startup Teaching Ventilator Patients to Breathe on Their Own Again

A ventilator is one of the most reassuring machines in a hospital and one of the most quietly damaging. It keeps a critically ill patient alive by pushing air into the lungs when they cannot do it themselves. What it does not do is use the diaphragm - the broad sheet of muscle under the lungs that ordinarily powers every breath. Leave that muscle idle for days or weeks, and it does what any unused muscle does: it weakens. That weakening has a clinical name, ventilator-induced diaphragm dysfunction, and it is one of the reasons some patients get stuck on the machine far longer than anyone wants.

XN Health, a small medical device company founded in 2021, is built around that single, overlooked problem. Its device, the Phlex Diaphragm Stimulator, is designed to keep the diaphragm working while the ventilator does its job - so the muscle does not atrophy in the first place, and the patient has a better shot at breathing on their own sooner. The company sums up the idea in three words on its website: "Muscle through the ICU."

01 / The ProblemThe muscle you forget you have

Most people never think about the diaphragm until something goes wrong with it. In healthy breathing, the diaphragm contracts and flattens, creating a vacuum that pulls air into the lungs - what physiologists call negative pressure ventilation. A mechanical ventilator works the opposite way: it pushes air in under positive pressure. That reversal keeps people alive, but it also means the diaphragm can sit unused for the duration of a long ICU stay.

The consequences compound. A weakened diaphragm makes it harder to wean a patient off the ventilator, which extends time in the ICU, which raises the risk of further complications. XN Health's framing is that the standard of care spends enormous effort breathing for the patient and comparatively little keeping the patient's own breathing apparatus in shape.

This is not a fringe concern. Roughly 1.6 million Americans are placed on mechanical ventilation each year, and the patients who need it longest - those with severe respiratory failure, complex surgeries, or extended ICU stays - are exactly the ones whose diaphragms have the most time to deteriorate. The muscle that should be doing the hardest work is the one most likely to have gone quiet. XN Health's thesis is that the earlier you intervene, the less catching-up the patient has to do later.

02 / The ProductWhat Phlex actually does

The Phlex Diaphragm Stimulator takes a deliberately indirect route to the diaphragm. Rather than opening the chest or implanting a lead surgically, it delivers what the company calls transtracheal phrenic nerve stimulation - electrical stimulation of the phrenic nerve delivered through the respiratory tract, the same airway that already holds the breathing tube. The phrenic nerve is the wiring that tells the diaphragm to contract. Stimulate it, and the diaphragm pulls down, generating the natural negative-pressure breath a ventilator normally replaces.

The company describes the device as minimally invasive, and lists a stack of intended benefits that all follow from the same mechanism: it keeps the diaphragm strong, lowers the pressure needed to inflate the lungs, and aims to shorten the time patients spend being weaned. In other words, it is less a replacement for the ventilator than a companion to it - something that runs in parallel to protect the muscle the machine tends to sideline.

The choice to go through the airway is the clever part. Other approaches to phrenic nerve stimulation reach the nerve surgically or through the veins, which raises the stakes of the procedure. By working through the respiratory tract that already contains the breathing tube, XN Health is trying to lower the barrier to using the device at all - the fewer new lines and incisions a critically ill patient needs, the easier it is for a care team to justify adding a therapy. It is the difference between asking a busy ICU to adopt a new operation and asking it to adopt a new attachment.

03 / The FoundersA lab scientist, a flight surgeon, and a 40-year operator

XN Health's team is small but pointedly credentialed. CEO and co-founder Elizabeth Jaworski holds a PhD in biochemistry and came up through a biodesign fellowship at TMC Innovation, the innovation arm of Houston's Texas Medical Center. Before medical devices, she co-founded a genomics tools company, ClickSeq Technologies - an unusual path into the ICU, from the sequencing bench to the bedside.

Her co-founders round out the gaps. Lance Black, the chief medical officer, is a physician and former U.S. Air Force flight surgeon who has contributed to more than two dozen medical devices. Mehdi Razavi, a cardiologist tied to the Texas Heart Institute, is listed among the founding team, and the company has pulled in critical-care and physiology advisors from institutions including Mayo Clinic and Texas Children's Hospital. For a four-person company, that is a lot of clinical firepower pointed at one muscle.

04 / The TractionPrizes, animal data, and Mayo Clinic in the corner

XN Health is still early, and it does not pretend otherwise. The milestones to date are the ones you would expect from a serious pre-commercial device company. In 2022 it completed animal studies showing that transtracheal phrenic nerve stimulation could in fact generate negative pressure ventilation - the core scientific claim the whole company rests on. That same year it was accepted into Creative Destruction Lab and joined the HAX hard-tech accelerator run by SOSV.

The pitch-competition record is unusually strong. XN Health took a top prize at the Texas A&M New Ventures Competition in 2022, and Jaworski went on to win the TiE New Jersey Women's Pitch Competition in 2023. The company was named to the SOSV Human Health 100 the same year, and closed a seed round whose backers included UCeed, Princeton Alumni Angels, Atlanta Technology Angels, and Mayo Clinic. A convertible note followed in early 2024.

Bars indicate progression of milestones, not funding amounts. XN Health has not publicly disclosed round sizes.

05 / The MarketA big market with a blind spot

The mechanical ventilator market is large - measured in the billions of dollars annually and growing steadily - but most of that spending is aimed at the machine that breathes for the patient. XN Health is betting on the adjacent, less crowded question: what happens to the patient's own muscles while the machine runs. That places it near a small set of companies working on diaphragm and phrenic nerve stimulation, such as Lungpacer Medical and Stimdia Medical, rather than against the ventilator makers themselves.

Its real competition, in a sense, is the current standard of care - the accepted routine of ventilate, then wean, then rehabilitate. XN Health's argument is that keeping the diaphragm active during ventilation could shrink the wean and rehab that follow. Whether that holds up in human trials is the open question every early device company faces, and the honest answer for now is that the human data does not yet exist.

The business model follows the shape of the market. XN Health is a business-to-business hardware company: the eventual customer is the hospital, and the eventual user is the ICU clinician, not the patient. That is a slow, deliberate sale - hospitals adopt new critical-care devices only after evidence, regulatory clearance, and reimbursement line up - which is why an early-stage company in this space lives on grant money, accelerator backing, and angel and strategic investment rather than revenue. The presence of Mayo Clinic on the cap table is as much a signal to future hospital buyers as it is a check.

It is worth being clear-eyed about where the company sits geographically, too. XN Health was born out of Houston's Texas Medical Center ecosystem, but it has also spent time in the HAX hard-tech program's Newark, New Jersey hub - a reminder that a modern device startup often lives in more than one place at once, chasing the accelerators, clinical partners, and investors that fit its stage.

06 / The TakeawayChasing the muscle, not the machine

There is a tidy lesson in XN Health for anyone building in a mature market: the crowded fight is usually over the obvious device, and the opening is often one layer down, in a problem the incumbents created but never owned. Ventilators saved millions of lives; they also introduced diaphragm dysfunction as a side effect that nobody's core product was designed to fix. XN Health simply decided that side effect was a company.

The caveats are real. It is a four-person, pre-revenue company whose central promise still has to survive human trials and a long regulatory road. Plenty of physiologically elegant ideas fail there. But the premise is easy to grasp and hard to argue with: if a patient is going to be on a ventilator for weeks, keeping their diaphragm awake the whole time is a better starting point than rebuilding it afterward.