Alivecor Kardia

Alivecor make products that read your EKG. The Kardia Band was previously reviewed and although convenient as it's always on your wrist (it's an Apple Watch add-on) it's extremely susceptible to movement, external interference and lots of other constraints so it's not always easy to get an accurate reading. It also takes a while to process the result as a lot of noise has to be filtered out.

The Kardia Mobile is much easier to use. It's a unit with two electrode pads on it (underneath there's a battery compartment which holds a CR2016 coin cell) which should give about 12 months of use.

Download the free iOS or Android Kardia app and then set-up an account. Then take a reading and the app will search for the Kardia Mobile device and pair with it (it uses Bluetooth 4 so a recent'ish iOS or Android phone must be used with a recent OS).

The app will wait a while, while you put your first and second fingers from both hands on either pad, then relax and the app will record your EKG. It needs to read about 30 seconds to get a sensible heart rate reading.

After the reading is saved it will tell you if there are any abnormalities or anything. As the pads are large and the signal is being received from across the body, the results are much cleaner and less susceptible to interference (compared to the Watch version).

The EKG Characteristics are single lead ECG, 10 mV peak-to-peak input dynamic range, 30 second to 5 minute recording duration, 300 samples per second sampling rate at 16 bit resolution.

There are extra features such as unlimited storage and history, summary reports for your doctor, blood pressure monitoring and tracking weight and medication (though the last two need manual intervention) that are available through the premium service which is available as an in-app purchase.

There's also a phone attachment strip that allows the Kardia Mobile to be carried with the phone (glues on to the phone).

The Kardia Mobile costs £99 direct from Alivecor.

Xiaomi Huami AMAZFIT A1603 Smartband

Xiaomi make lots of stuff, but they also work with partners and specifically Huami who make wearables (under the AMAZFIT brand). In the US it's known as the Amazfit ARC.

Though the functionality is almost identical to the Xiaomi Band 2, it looks much nicer and the silicon strap has a 'hatch' effect on it which is very comfortable to wear. The actual unit is permanently attached to the strap and has a soft 'brushed' metal feel. Underneath there's an optical heart rate sensor and charging pins and the top is a UV coated scratch resistant OLED display.

Like most trackers it measures steps but also sleep (you obviously have to wear it at night), distance and active calories. The battery life is VERY good (Huami claim 20 days). It can also display notifications from your phone (currently iOS and Android are supported).

As a bonus it's also water proof and can be used when swimming, though it doesn't track swimming.

There's a USB charging cable that is magnetically polarised so it 'snaps' on to the charging pins on the bottom of the unit, this also stops you getting it the wrong way around.

There is an Amazfit app available and through it's pretty basic, it does support all the devices features and notifications, alarms etc can be set through it. However, it the ARC also works with the Xiaomi Mi Fit app, which has a lot more features and links with Apple Health and Android Fit on the relevant platforms. The Mi Fit app also seems to have a few more advanced features like being able to track heart rate when sleeping which give more accurate results (though reduces battery life).

It's definitely a cut above the Mi Band2 in terms of looks and comfort and on a par with traditional fitness trackers from established US companies, though at a very competitive price. However, the apps of more expensive western vendors are generally quite a bit better with more functionality.

The list price is $99 from the US Amazfit site, but various Asian sites have it available for around £30 including shipping.