Löwenstein Prisma Smart CPAP Review

What Is the Löwenstein Prisma Smart?

The Löwenstein Prisma Smart is an auto-titrating CPAP (APAP) machine manufactured by Löwenstein Medical, a German device maker best known in continental Europe for hospital-grade ventilation equipment. The Prisma Smart is the consumer-facing member of Löwenstein's wider Prisma range, which also includes the prismaLINE machines described below and adaptive variants sold into sleep clinics.

Outside the United States, the Prisma Smart is a common prescription. You will see it in Germany, Austria, Switzerland, the Netherlands, Belgium, Croatia, the Czech Republic, and across Scandinavia. Distributors in the UK (Intus Healthcare among them) sell it to private-pay patients. In the US it is not a mass-market device, which is why most online CPAP communities are ResMed-dominated and most data tools historically ignored it.

If you received a Prisma Smart from your sleep clinic and wondered why the usual apps (myAir, SleepHQ) do not speak to it, the answer is simple: those apps are tied to ResMed hardware. Löwenstein ships its own patient app (the prisma APP) and clinician software (prismaTS), but neither gives you the kind of deep-dive a data-curious user wants on your own screen.

CPAP Clarity now fully reads Prisma Smart SD card data client-side, free, with no account. Your data never leaves your browser. The Prisma Smart device page has the quick version of what you get and how to import.

A note on the prismaLINE machines

This page is about the Prisma SMART. If yours is a prisma 20A, 25S, 25ST or 30ST, that is the prismaLINE family, and CPAP Clarity cannot read those yet. They write a different card layout, so rather than failing with a generic error the import recognizes the family and tells you by name. If you own one, sending a card is what makes support possible, and we use what you send only to build support for your device.

Who Is the Prisma Smart For?

The Prisma Smart is a solid mid-range APAP for adults diagnosed with obstructive sleep apnea. It is a typical prescription when your sleep clinic either carries the Löwenstein line or ran a specific trial that pointed at this device. Clinicians praise it for the SoftPAP pressure-relief algorithm (Löwenstein's equivalent of ResMed EPR) and its quiet operation.

If you live in continental Europe and your clinic asked you to use the Prisma Smart, you are getting a machine that is functionally equivalent to a ResMed AirSense 10 AutoSet or a Philips DreamStation 2 Auto. All three devices do the same core job: detect apneas and hypopneas, adjust pressure to respond, and log everything for review.

Never change your own pressure settings based on anything you read in a data tool. Prescription adjustments are a conversation for your clinician, who has access to the clinical data view and your medical context.

The prisma APP, prismaTS, and What the SD Card Adds

Löwenstein's own patient app is the prisma APP. It pairs over Bluetooth with the plus and max variants of the Prisma Smart, and with the base variant through an optional wireless module. It shows a nightly summary (therapy duration, AHI, leakage, and a sleep quality rating, with a diary and a PDF report), and it can also adjust comfort settings such as humidification and start or stop therapy from your phone. On the max variant, a built-in modem also sends data once a day to prisma CLOUD, which is a portal for your care provider rather than for you.

The full record is a different thing. Every event with its timestamp, the pressure and leak waveforms, and the respiratory signals are written to the SD card, and that level of detail is normally read only by clinicians using Löwenstein's prismaTS software. If you searched for a Löwenstein app hoping to see more than the nightly summary, the SD card is where the detail lives, and CPAP Clarity reads that same card in your browser, free, without an account.

What the Prisma Smart Records

Every night, the Prisma Smart writes a structured bundle to its SD card. The root of the card contains a plain-JSON configuration file (config.pscfg), a binary summary (statistic.psstat), a cloud-upload envelope, and a per-device logs directory. Inside a serial-numbered folder, each date gets its own subdirectory with one or more sub-session pairs: an XML event file (event_NNN.xml) and a companion waveform file (signal_NNN.wmedf) in a Löwenstein variant of the European Data Format.

CPAP Clarity parses the JSON configuration and the XML events right now. You see:

Apnea-Hypopnea Index (AHI): Events per hour of usage, the headline therapy number.

Event counts: Obstructive apneas, central apneas, unclassified apneas, hypopneas, and RERAs (respiratory effort related arousals), mapped to Löwenstein's event taxonomy via the same ID scheme the OSCAR project uses. The card also records vibratory snore and flow-limitation event markers; CPAP Clarity does not display those markers yet, and charts a continuous flow-limitation index derived from the breathing signal instead.

Pressure set-points: Minimum and maximum APAP pressure from your prescription, plus the SoftPAP relief floor (PSoft and PSoft minimum).

Therapy mode: APAP (standard), CPAP, or other modes the device supports.

Usage duration: Total nightly usage in hours and minutes, summed across sub-sessions when you take the mask off and put it back on.

Machine settings: Tube diameter, ramp behavior, auto start, SoftPAP mode.

Waveforms and respiratory metrics: CPAP Clarity decodes the Löwenstein .wmedf signal files directly, so you also get the pressure and leak curves, and respiratory rate, tidal volume and minute ventilation derived breath by breath from the respiratory flow channel. The EPAP and IPAP envelopes are decoded too, but they are not charted today. The breath-by-breath flow waveform is charted, and it is sample-checked against OSCAR.

How the Numbers Were Validated

Every Prisma Smart metric was cross-checked against OSCAR on real contributor data: the comparison covered 29 rows across AHI, event counts, pressure, leak, and the respiratory metrics, with zero out of tolerance, and the waveforms were diffed at the sample level. The .wmedf format is a Weinmann variant of EDF with per-channel sample widths; decoding it took its own engineering pass, which is why early versions of CPAP Clarity showed only the headline numbers for this device.

How to Read Your Prisma Smart SD Card

Power off the Prisma Smart and unplug it from the wall. Remove the humidifier chamber if you have one attached.
Eject the SD card from the side of the machine. Newer Prisma Smart units ship with a card labeled in hundreds of megabytes; if you ever need a replacement, any standard SDHC card up to 32GB works.
Plug the SD card into your computer (a USB SD reader or the built-in card slot on most laptops).
Open cpapclarity.com and drag the entire SD card folder onto the import zone on the home page. Select the whole SD card, not just the serial-numbered therapy folder inside it. The import needs the root-level config.pscfg to identify your device.
The dashboard loads. You will see a "Löwenstein Prisma Smart" label in the machine-settings card, your AHI for the most recent night, and a list of every session CPAP Clarity found on the card.

If your browser cannot read the folder, try a different SD reader or a different browser. iOS users: the whole-folder import works on iOS 17 and newer Safari. Android users: Chrome handles Löwenstein bundles the same way it handles ResMed and BMC bundles.

What the Numbers Mean

AHI under 5.0 is the range the AASM associates with well-controlled CPAP, a figure that comes from its in-lab titration guideline rather than a home therapy target. A residual number well above that, or a clear change from your own normal, is worth raising with the clinician who manages your therapy. The mild, moderate and severe bands you may have been given at diagnosis are a different thing: they describe untreated sleep apnea, so they do not map onto what your machine reports on therapy. See What Is AHI? for the full clinical framing.

RERA events show up in Prisma data because the firmware detects respiratory-effort arousals separately from apneas and hypopneas. RERAs do not contribute to the AHI number but they do count toward the respiratory disturbance index if your clinician uses that.

Pressure range (for example, 6 to 14 cmH2O) is the window your prescription allows the machine to auto-titrate inside. A night that sits at a fairly steady pressure usually means the algorithm found a comfortable working range; one pinned near your upper limit is worth showing your clinician.

SoftPAP Standard with a PSoft of 6 means the machine drops pressure by a small amount when you exhale, to make the therapy feel less like breathing against a wall. This is a comfort feature, not a clinical parameter.

Settings Explained

Therapy mode. APAP is the default. The Prisma Smart can also run in fixed-pressure CPAP mode if your clinician prescribed it.

Pressure min and max. The boundary of the auto-titration window. Your clinician sets these based on your sleep-study titration results. One label note: Löwenstein documents pressure in hPa rather than cmH2O, and the two units are close enough to treat as interchangeable for reading your own data. What Is cmH2O? covers the conversion.

SoftPAP. The Löwenstein equivalent of ResMed's EPR. "Standard" means a gentle pressure drop on exhale; "Off" means constant pressure.

Soft start / ramp. The machine starts at a lower pressure and climbs to the therapy range over the configured ramp time (typically 30 minutes). Used by people who need to fall asleep before full therapy pressure arrives.

Auto start. When on, the machine begins therapy automatically when you breathe into the mask. When off, you press the power button.

Tube type. Recorded in centimeters of internal diameter. A 2.2 cm tube is the standard Löwenstein heated tube; a 1.9 cm is the slim hose variant.

None of these should be changed without your clinician's involvement.

Mask Compatibility

The Prisma Smart uses a standard 22 mm heated-tube connector at the machine end, which means it works with essentially any mass-market CPAP mask. Popular choices that pair cleanly include:

ResMed AirFit P10 nasal pillow cushion for side sleepers who want minimal mask contact
ResMed AirFit P30i nasal pillow cushion with hose-on-top routing for active sleepers
ResMed AirFit F30i full face cushion for mouth breathers or higher-pressure nights
Fisher & Paykel Brevida / Simplus and Philips DreamWear (DME-only in most US markets)

If you are new to CPAP and want help picking a mask style, try the Mask Finder Quiz to narrow down pillow, nasal, or full-face by breathing pattern and sleep position.

How the Prisma Smart Compares

Feature	Prisma Smart	ResMed AirSense 11	BMC G3 A20
Therapy modes	APAP, CPAP	APAP, CPAP, VAuto (11)	APAP, CPAP
Pressure relief	SoftPAP	EPR (Easy-Breathe)	Reslex
SD card format	JSON + XML + EDF variant	Proprietary EDF	Proprietary binary
Home market	Germany / EU	US / UK / EU	China / EU
Data in CPAP Clarity	Full (waveforms, timeline)	Full (waveforms, timeline)	Full (waveforms, timeline)
Native app	prisma APP (prismaTS for clinicians)	myAir	None
US availability	Limited	Primary	Limited

If you live in the US and have a choice, most sleep clinics prescribe ResMed because the US supply chain is easier. If your European clinic prescribed the Prisma Smart, it is a good device and CPAP Clarity now gives you the same browser-based data workflow other brand owners have had for years. For a broader comparison including BMC, Luna G3, and Philips, see our CPAP machine comparison.

Where to Buy

The Prisma Smart itself is not a consumer direct-purchase device in most markets. You get one through a sleep clinic or a licensed DME provider. If a clinician pointed you toward Löwenstein for a private-pay purchase, the manufacturer's patient portal has product information, the official clinician locator, and a list of regional distributors:

Löwenstein Medical (patient portal)

When to Talk to Your Doctor

Bring your data to your clinician if you notice any of the following trends across multiple nights:

AHI consistently above 5 despite therapy hours above 4.
Max pressure hitting your prescribed ceiling every night.
Frequent central apneas (if the Prisma Smart starts reporting them, your therapy may need an adaptive-servo device instead).
Daytime sleepiness returning even though therapy numbers look normal.

CPAP Clarity is a data-visibility tool, not a diagnostic tool. Anything above is a conversation starter, not a prescription change.

Frequently Asked Questions

Is there an app for the Löwenstein Prisma Smart?

Yes, the prisma APP, which pairs over Bluetooth with the plus and max variants (the base variant can add it with a wireless module) and shows a nightly summary: duration, AHI, leakage, and a sleep quality rating. The detailed record (every event with its timestamp, plus the pressure, leak, and breathing waveforms) is written to the SD card instead, and CPAP Clarity reads that card in your browser for free.

Can I read my Prisma Smart SD card myself?

Yes. Power the machine off, take the card out of the slot on the side of the device, plug it into your computer, and drag the whole card folder onto CPAP Clarity. Everything is processed in your browser; nothing is uploaded anywhere.

Can I use prismaTS to read my own data?

prismaTS is Löwenstein's desktop software for reading the card's full record, and it is built for clinicians and sleep labs rather than patients. Some data-curious owners do track it down, but if you just want to see your own detail, CPAP Clarity reads the same card in your browser with nothing to install and nothing uploaded.

Is the Prisma Smart a good CPAP machine?

It is a solid mid-range auto-titrating machine: quiet, with SoftPAP exhale relief, and functionally comparable to the mainstream APAP machines from ResMed and Philips. The practical catch is distribution: it is common in continental Europe and scarce in the US, so US-based apps and supply channels mostly ignore it. Your data is fully readable either way.

Get Started with CPAP Clarity

Drop your Prisma Smart SD card folder into the home page to get your first dashboard. No account, no upload, no data leaves your browser. If you have questions or if something in your data does not look right, the feedback page goes to a real person.

Further reading:

What Is AHI?
CPAP Mask Finder Quiz
BMC E-20A and G3 A20 data guide, fellow non-US machines with a similar data-access story

Primary Sources

Kushida CA, Chediak A, Berry RB, et al. Clinical Guidelines for the Manual Titration of Positive Airway Pressure in Patients with Obstructive Sleep Apnea. J Clin Sleep Med. 2008;4(2):157-171. PubMed 18468315 (opens in new tab). The AASM guideline behind the under-5.0 figure quoted above.