Yuwell YH-450 Review: Reading Your CPAP Data

What Is the Yuwell YH-450?

The Yuwell YH-450 (model number YH450A) is an auto-adjusting CPAP, or APAP. It raises and lowers your pressure through the night within a range you and your clinician set, instead of holding one fixed pressure. Yuwell is one of the larger home medical device makers based in China, and the YH-450 is common across the Asia-Pacific market, where it is often a more affordable alternative to the big Western brands.

Like most modern machines, the YH-450 writes your therapy data to an SD card and pairs with a phone app that shows you one night at a time. What it does not do is open in OSCAR, the free desktop tool many CPAP users rely on to see their full data. That gap is the reason this guide exists.

Why OSCAR Cannot Read It

OSCAR can only read devices that someone has written a loader for, and no one has written one for Yuwell. The YH-450 stores its data in a proprietary binary format (files ending in .bys) that OSCAR simply does not recognize. If you put your YH-450 card into OSCAR, nothing shows up.

CPAP Clarity reads the .bys format directly in your browser. Because there is no OSCAR version of the truth to check against for this device, every number CPAP Clarity shows was matched instead against the YH-450 app's own Detailed Data report, across several real nights, and those values are pinned in our test suite so the mapping cannot drift over time.

What the YH-450 Records

The YH-450 keeps things compact. Rather than a high-resolution flow waveform sampled many times a second, it logs one summary sample per minute. For each minute it stores:

• Your therapy pressure, in cmH2O.
• Your mask leak, in liters per minute.
• A flag for any obstructive apnea or hypopnea that minute.

Each night also carries a small header with your settings and the night's totals: your event counts, your average leak, your pressure range, ramp time, and humidity level.

That summary-level design is why the YH-450 card is small and quick to read. It is also why some metrics you might see on a ResMed simply are not available here. The machine does not record per-breath flow, tidal volume, minute ventilation, snore, or flow limitation, so CPAP Clarity does not show them. We would rather leave a number blank than invent one.

What CPAP Clarity Shows You

Drop your SD card folder onto CPAP Clarity and you get, in your browser and without an account:

• Your AHI, by event type. CPAP Clarity shows the same AHI your Yuwell app does, split into obstructive apneas and hypopneas. We match the app's figure exactly, including the way it rounds the index down, so your number here will agree with the number on your phone.
• Your pressure curve. The per-minute pressure across the night, charted so you can see how the auto algorithm responded, plus the highest pressure you actually reached and your typical pressure.
• Your average leak. The same nightly average the app reports, so you can tell at a glance whether your mask sealed well.
• Your machine settings. Mode, pressure range, ramp, and humidity, read straight off the card so you can confirm what the machine is really set to.
• Multi-night trends. Import regularly and CPAP Clarity builds your history over time, with usage hours, a compliance view against the common 70 percent threshold, and a therapy score, none of which the single-night phone view gives you.

Because everything runs in your browser, your CPAP data never leaves your computer and is never uploaded to a server.

The Honest Limits

A good data tool tells you what it cannot do. For the YH-450:

• No per-breath waveform. One sample per minute is the format's resolution. You can see the shape of the night, not the shape of individual breaths.
• No flow, snore, or respiratory rate. The machine does not record them.
• No central apnea history in this bundle. The format has room for central apneas, but the cards we have validated so far recorded none, so we cannot yet confirm exactly how a central night looks. If you have central apneas flagged by your clinician, treat that part with extra care and verify against your app.
• No SpO2. The YH-450 has no built-in oximeter. If you want overnight oxygen alongside your CPAP nights, a separate pulse oximeter import covers that.

How to Import Your Data

1. Power the machine off and take the SD card out of the YH-450.
2. Plug the card into a USB SD card reader on your computer.
3. Open CPAP Clarity, go to the import page, and drag the whole SD card folder onto the drop zone.

That is it. CPAP Clarity finds the .bys files, reads every night on the card, and shows your dashboard. For a metric-by-metric walkthrough of what you are looking at, see the Yuwell YH-450 device guide, and to understand the headline number, start with what AHI means.

Should You Use It?

If you own a YH-450 and have wanted more than the one-night phone view, CPAP Clarity gives you your full history, trends, and a clear AHI breakdown for free, in a tool that actually reads your machine. It is the closest thing to OSCAR that the Yuwell format allows, and for many users it is friendlier than OSCAR was ever going to be.

Ready to look at your own nights? Import your Yuwell data and see what your machine has been recording. New to reading CPAP data at all? The guide on how to read your CPAP data explains every metric on the dashboard.