The Cue Covid-19 Test Cartridge | Hacker News Reader

The Cue Covid-19 Test Cartridge

danrl.com

26 pointsdanrl19 comments

Probably a loop mediated isothermal amplification (LAMP) based diagnostic like the Lucira test. The time-frame is about right, as is the cost.

For those unfamiliar, it's an alternative to pcr. pcr requires alternating heating cooling cycles, whereas lamp can induce sample replication with just heating.

The main device almost certainly uses fluorescence detection to quantify sample counts.

Might also be colorimetric.

That is correct. From the FDA Emergency Use Authorization: "Your product is an automated assay that utilizes isothermal nucleic acid amplification technology for the qualitative detection of SARS-CoV-2 viral nucleic acids." Also interesting: "Heating, mixing, amplification, and detection take place within the cartridge. The current flow from the electrodes is converted to a positive or negative result (based on a pre-determined cutoff)." https://www.fda.gov/media/146467/download

I'm glad we can test, but I was already appalled by the wastefulness of the small "manual" quick-tests, they have way more plastic than needed.. Then I see this, and.. there's no excuse for humanity to produce something like this just to get thrown out.

The EEPROM is likely not as much for DRM but for serial number / batch number. That way if they recall a batch, the app can tell you right away by pulling down a list of recalled batches, and comparing to yours.

I bet it has calibration details, too. No two cartridges are exactly alike, but with calibration they can give like results.

strange use for a microswitch, must've had access to dirt cheap switches; IR diodes tend to be cheaper and less faulty for that kind of use.

all the microfluidic/lab-on-a-chip stuff is neat, i'm thankful that someone decided to tear something like this apart and show us.

microswitches are like $0.05 or less in large quantities, I don't think you can find an LED/phototransistor pair cheaper than that.

Under $0.02 @2K: https://lcsc.com/mobile/product-detail/Phototransistors_XING...

Plenty more as well and no shortage of LEDs at $0.01ea @ 2K.

Why does it need an app for that? A basic red/green indicator would suffice.

It needs the phone's battery to hear up the reagents and sample. It's also not clear to me what processing is occurring within the cartridge and cue device.

it doesn't use the phone's battery at all, have you ever used a Cue before?

Agreed. The app stuff is nonsense. We have one of these and they could very well have used a small display or light patterns to indicate test progress and test results without a mobile phone.

In the app you can choose a patient (useful for families and recordkeeping), optionally have a doctor virtually supervise the test, and then it walks you through the test. You can also view a history of all your prior tests.

Honestly, out of all the phone-connected medical devices I've used (most of which suck), Cue has been the best by far.

This. The virtual supervision by a doctor part is necessary for it to be considered a valid test for international travel per CDC guidelines:

https://www.cdc.gov/coronavirus/2019-ncov/travelers/testing-...

This is one of the rare cases where having an app and Bluetooth is indeed useful.

Wonderful way of wasting our precious resources on more e-waste.

Nice touch to recommend dumping it in household waste instead of offering a recycling option.

Is it really that hard to drip a few drops on a standard antigen card and read the stripes 15m later?

> Is it really that hard to drip a few drops on a standard antigen card...

To be fair, this is an NAAT test[1], which identifies the RNA sequences of the virus, so it is (allegedly) much more precise and sensitive than the cheap antigen test. The real comparison is with laboratory-based PCR tests.

But I agree that antigen tests are much more convenient, cheaper and less wasteful than the Cue.

[1] https://www.cdc.gov/coronavirus/2019-ncov/lab/naats.html

Ah I see. Fair enough. Though it's still a very wasteful way to do it IMO. A human could open those liquid capsules and save all the plastic. I hope the big labs don't do it like this?

But there was another covid test in the press lately that was really just a $2 lateral flow test with a bluetooth module attached ready to be disposed. I incorrectly assumed this was the same idea. Apologies.

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