In July, I wrote about the Smart Fitness T-shirt that was being developed by a joint collaboration involving the Agency for Science, Technology and Research (A*Star), Singapore-based smart wearables start-up KaHa and home-grown textile company Tex Line.

Touted as the first smart T-shirt conceived in Singapore, it can take the electrocardiography (ECG) readings of its wearer and detect cardiac abnormalities. It can also track physical-activity information, such as steps taken, calories burned and heart rate.

Development has been smooth, with an advanced prototype conducted on a trial group of about 100 participants during the one-north Run early this month. I was given one unit to try.

The first thing you will notice about the Smart Fitness T-shirt is its inner layer that houses the Bluetooth module and the printed carbon electrodes. The outer layer is just like any loose-fitting sports T-shirt.

Its regular fit should encourage more people to wear it. Most smart T-shirts on the market, such as those of Canada-based company Hexoskin, tend to be body-hugging and might not appeal to many who do not have an attractive physique.

The T-shirt also comes in a women's fit. The inner layer of the women's T-shirt is in the form of a sports bra.

The inner layer works like a chest-strap, heart-rate monitor. You place a removable Bluetooth module near the heart area on this layer to track your heart rate.

I found it a tad difficult to wear the shirt. It is tricky to find the arm holes while going through the inner layer.

The inner layer has a velco strap to secure tightly around your chest for more accurate readings.

Pairing the smart T-shirt with my phone was a cinch, as the review unit has a QR code. All I needed to do was download the one-north run app, scanned the QR code and pairing was done.

The app allows you to take ECG readings at any time. You have to remain still for two minutes for the ECG to be taken.

However, it does not show any ECG charts. All you see - after a few readings - is a graph that shows an upward or downward trend of your heart-rate variance.

It would have been better if you can look at the chart of each ECG reading along with warnings about possible atrial fibrillation, like what Apple Watch Series 4 does (in US, ECG not available here yet).

The Apple Health app even allows you to export the ECG readings as a PDF file. This is something I hope to see with the smart T-shirt.

As the heart-rate module does not come with built-in GPS, it uses your smartphone's GPS to record distance.

It is relatively accurate, with readings off the mark by just about 100m on my usual 5km jogging route.

However, its heart-rate readings seem a tad off. During a run, my maximum heart rate was 40 beats per minute less than the readings on my Apple Watch Series 4.

As I was panting heavily after that run, I was more inclined to believe the readings on my Apple Watch.

Hopefully, these issues will be resolved by its targeted commercial availability by the second quarter of next year.

The new Smart Fitness T-shirt will be marketed by Tex Line under a new sportswear brand called Tag.

Pricing of the Tag smart T-shirts is expected to be 20 to 30 per cent higher than conventional running T-shirts, which usually cost between $45 and $60.