Medical Equipment Buying Checklist: ResMed AirSense 11, Patient Monitors, Fundus Cameras, and Microplate Readers

When you get a purchase request for a ResMed AirSense 11 CPAP machine, a patient monitor, a fundus camera, or a microplate reader, your first instinct is probably to compare prices. I get it. I've been the admin buyer for a private clinic for five years, and I used to do the same thing. Then a $2,400 expense rejection taught me that a quote is not a cost.

When to use this checklist

Use this when you are the person who has to turn a clinical request into a purchase order without being a clinician yourself. It works for sleep medicine equipment, diagnostic imaging, patient monitoring, and lab instruments. I manage roughly $300,000 a year in equipment and supply orders across 12 vendors, and I built this checklist after a few requisitions took the wrong path.

There are eight checkpoints. Start at number one, and don't skip ahead to pricing.

Step 1. Start with the clinical workflow, not the product brochure

The first question is not which model. It's what this device is supposed to do for the patient, the nurse, or the lab tech.

For a ResMed AirSense 11 CPAP machine, you need to know whether the patient needs fixed pressure or auto-adjusting pressure, whether they need a heated humidifier, and whether the unit must connect to remote monitoring. A respiratory therapist or sleep physician has to make those calls. I make sure the requirement is written down before I talk to a supplier.

Patient monitors are the same. One requisition for a patient monitor might actually mean a simple SpO2 monitor. Another means a full multiparameter unit with ECG, NIBP, and EtCO2. Those are different budgets, different cables, and different training requirements.

For a fundus camera, define whether you need a mydriatic or non-mydriatic unit first. That decision changes the camera design, the patient experience, and the price.

For a microplate reader, ask the lab what type of assays they run. If a lab team asks how does a microplate reader work before they have defined the assay, that is a red flag. Here is the short answer: it measures light in a sample well. For absorbance, light passes through the sample and a detector measures what is left. For fluorescence, the reader excites the sample at one wavelength and reads another. For luminescence, it simply detects emitted light. Different assays call for different detection modes, and the right mode matters more than the brand.

Step 2. Build a total cost model, not a quote comparison

Once the clinical need is clear, calculate the total cost of ownership. I know TCO sounds like consultant language, but it saved me from one of my worst buying mistakes.

Total cost formula: purchase price + installation + training + first-year service + consumables + disposables + downtime risk.

In my first year, I chose a patient monitor because the quoted unit price was $400 lower than the other one. The low quote didn't include a mounting bracket. The bracket was $300. The nurse-call cable was another $240. The installation visit that the more expensive vendor included free would have cost $450. So the cheap monitor was actually $590 more expensive before anyone touched it.

Now I put every cost line into a spreadsheet before contacting a supplier. If a vendor won't give an itemized quote, that tells me something.

Step 3. Verify the source and the support chain

This is the checkpoint I skipped when I bought through a reseller. I found a good price on an AirSense 11, but the unit turned out to be a customer return. It worked for about a week and then displayed ResMed error 006. I'm not a technician, so I didn't try to fix it myself. But the seller couldn't service it and wouldn't take it back. We had to rent a machine at urgent rates while the replacement arrived.

Here's what I now do before paying: ask for the serial number, ask if the unit is new or refurbished, ask for the original invoice, and confirm the seller is an authorized distributor for that exact model. ResMed publishes user guides and service information on its website. Download the guide for the AirSense 11 and look at the error-code section before you buy, so you know what error 006 means in the vendor's service context.

Standard troubleshooting may be as simple as unplugging the machine, checking the filter, and restarting. But if the error persists, you need an authorized service path. That service path is part of the purchase.

Step 4. Write a short spec list for the exact model

Don't buy a category. Buy a specific set of requirements. For an AirSense 11 CPAP machine, the list might include fixed or auto pressure, heated humidifier, heated tubing, cellular data, and mask compatibility. For patient monitors, list the parameters, battery life, alarm settings, EMR export, and cable requirements. For fundus cameras, list field of view, mydriatic or non-mydriatic, image resolution, and export format. For microplate readers, list detection modes, wavelength range, plate type, and software.

A short spec list is a sanity check. When someone tries to upsell you to a bigger model, you can say it doesn't meet the requirement.

Step 5. Ask for references from a department like yours

Sales reps are not a reliable source of truth. Ask for two or three accounts that run the same model in a similar setting. If you're buying a patient monitor for a 12-bed clinic, don't talk only to a hospital that has a tech team for everything. Call the clinic. Ask how long service really takes. Ask what broke, and what the vendor did about it.

During our 2024 vendor consolidation project, the lowest-priced provider was also the worst referenced. One phone call saved us six months of pain.

This is especially important for devices that need ongoing support. A ResMed error 006 call is not the same as a routine question. You want to know that the vendor will pick up the phone and route you to a person who can help.

Step 6. Run a demo with the person who will use it

Don't make the usability decision alone. Schedule a demo with an actual respiratory therapist, nurse, ophthalmic tech, or lab tech. Give them 20 minutes with the device. Let them create a test patient, change a setting, and export a report.

I once saw a technically excellent patient monitor lose out to a simpler one because nurses hated the menu. That is not employee preference; it's a training cost. A device people resist will create more support tickets, fewer logged measurements, and more time in the budget.

Step 7. Price the consumables before you sign

Skip this step and your total cost model will betray you. For each device, list every item it consumes in two years.

For a ResMed AirSense 11, that includes masks, headgear, tubing, filters, and humidifier chambers. The AirSense 11 works with a range of ResMed masks, but compatibility still has to be verified for each patient. For a patient monitor, SpO2 sensors, NIBP cuffs, and ECG lead wires are often proprietary and priced separately. For a fundus camera, check software upgrades, calibration, and print supplies. For a microplate reader, you need microplates, filter sets, calibration plates, and cleaning supplies.

I add a two-year consumables estimate to every comparison. It changes the ranking in roughly 40% of the quotes I compare. If a vendor won't quote consumables, it's usually because consumables are where they make their margin.

Step 8. Get the service response in writing

Before you sign a PO, get the service commitment in writing. What happens when the device fails at 6 p.m. on a Friday? Who do you call? Is there a loaner unit? How long until a technician is on site?

For a CPAP machine, patients can't wait weeks for a replacement. The vendor's willingness to write down response within 24 hours matters more to me than a discount. For a patient monitor, ask about loaner equipment during repair. For a fundus camera or microplate reader, ask about calibration visits and firmware updates. If a salesperson says they will work something out, that is not a service plan.

Three mistakes I won't make again

1. Buying the spec sheet instead of the workflow. A microplate reader with the right detection mode is worth more than one with a bigger brand name.
2. Believing we support it without a written service path. That's how a ResMed error 006 phone call gets bounced between three different people.
3. Asking how does a microplate reader work after the check has been signed. If you can't explain what a device does, you'll buy the wrong one.

That's the checklist. It's not clever. Every checkpoint is boring, and it works.