Test Equipment

Home Potassium Monitoring:

The PPA is aware of two devices for home potassium monitoring

  • Cardy ion meter
    The Cardy meter is not approved as a clinical laboratory device altogether.
  • i-STAT
    The i-STAT is FDA-approved for use by physicians and other CLIA-certified individuals but was not intended for home use by individual patients.

The PPA has no vested interest in any company mentioned in this letter. We simply want you to be aware that there is a way to accurately know your potassium levels in the comfort of your own home. The PPA endorses neither product, but we provide information about them here as it may be of interest to our membership.Click for speech

Cardy Ion Meter

  • For more information, go to here.
    This device is not FDA approved for blood potassium measurements. Some members have found a way to make this useful for them.
  • A nice video on how to calibrate the Cardy Ion Meter can be found here.
Horiba, the company that makes the Cardy Ion Meter, reported to the PPA in February 2013 that the Horiba C-131 Cardy meter is discontinued and replaced with a B-731. Click for speech


  • The i-STAT is a handheld analyzer that provides reliable blood test results in just minutes, using as little as two drops of blood and a test cartridge (CHEM8+).
  • The i-STAT® 1 handheld system performs a comprehensive panel of critical tests. Utilizing self-contained test cartridges, along with the Precision PCx™ and PCx Plus™ glucose test strips, the i-STAT 1 system delivers lab-accurate testing for Blood Gases, Electrolytes, Chemistries, Coagulation, Hematology, Glucose, and Cardiac Markers (cTnI).
  • Easy To Use: Cartridges are self-contained and the system is simple to learn and operate
  • Lab-Accurate Results: Advanced biosensor technology and real time quality assurance provides extremely accurate testing
  • Small Sample Size: Just a few drops of blood per cartridge
  • Ready When You Need It
  • Test results in as little as two minutes
The i-STAT is made by Abbott Laboratories and is a very expensive testing device. However, it tests potassium, sodium, hematocrit, hemoglobin and glucose to the exact (possibly more accurate) degree as a laboratory. It is about the size of a shoe and is easily transported anywhere you travel. It utilizes testing cartridges also made by Abbott which must be kept refrigerated to preserve quality. It is easy to use and gives a totally accurate reading of blood potassium levels whenever the need arises without leaving your bed let alone your house.

The PPA recognizes the fact that this device could be incredibly important to our patients who are trying to manage Periodic Paralysis. It is a device that is recognized by the medical profession as being accurate and for human use. It is used extensively in hospitals – especially ICU units – where test results need to obtained immediately.

In order to obtain an i-STAT, you must have a CLIA-waiver. Anyone can apply for a CLIA waiver and then Abbott can sell to that individual. It entails filling out a two-page form and paying a fee of $150 good for two years. To get this waiver, complete the application: APPLICATION FOR CLIA-WAIVER<

A sample of a completed application is provided here: SAMPLE APPLICATION.

It is possible for CLIA-waived individuals to buy this device if you are financially able to assume the cost. As far as we know there is no insurance coverage offered but we encourage you to contact your carrier and ask.

If you buy an i-STAT on e-Bay or through some non-regulated third party site, Abbott will not support it, and it probably will not have updated software. To be able to use the machine, it would cost an estimated additional $4K ($2K to update the software and $2K to send it back to Abbot for them to inspect the device to ensure proper functioning).

Each potassium measurement requires the use of a cartridge. Each cartridge costs anywhere from $7-14, depending on the type of cartridge you use. Testing twice daily at $14/cartridge is $28/day or $10.000+/year. Cartridges need to be refridgerated. If you take them out of the refridgerator, you have 14 days in which to use them provided they are not exposed to extreme heat (i.e., don’t leave them in the car on a summer day).

Blood tested with the i-STAT was meant to be obtained from a venous draw, like the kind done in a doctor’s office or blood laboratory center. Fingersticks cause falsely elevated potassium, especially if the finger is milked. Some members heat up their hand prior to the stick, which improves circulation to the hand. As such, when you do the stick, the blood flows freely. Using the above method, some members have used the following lancets with what they feel to be reasonable accuracy: Tenderlett, incision depth of 1.75mm, obtained at: www.itcmed.com

If you are interested in the i-STAT, you may find some answers regarding purchase at the website below.Click for speech