A sock to detect diabetic, CV complications?

A study presented at EHRA 2024 demonstrated the potential of a sock fitted with a ballistocardiogram (BCG) sensor to predict diabetic complications by identifying foot pressure distribution patterns, as well as to detect cardiovascular issues.

“Diabetes can affect the way people walk [ie, gait]. Patients with diabetes tend to put pressure on the metatarsal area of the foot, rather than the heel. This way of walking encourages ulcers, which can become infected and lead to amputation,” stated study author Dr Ki Hong Lee from The Heart Center Chonnam National University Hospital, Chonnam National University Research Institute of Medical Sciences, Gwangju, Republic of Korea, in a press release.

“Identifying walking issues early using an electronic sock would enable patients to learn a healthy walking style and prevent serious foot problems,” Lee continued.

Lee and his team sought to develop self-powered wearable bio-signal sensing arrays for diagnosing and continuous monitoring of diabetic and cardiovascular complications. Of the 20 participants, 10 individuals had diabetes while the other 10 did not. [EHRA 2024, Moderated ePosters 1]

Participants wore the BCG sock for 40 seconds while standing and for another 40 seconds while walking to measure heart rate and evaluate pressure distribution on the foot. While wearing the sock, heart rate was simultaneously measured with an electrocardiogram (ECG) via a small patch attached to the wrist and a single electrode attached to the chest.

Compared with those without diabetes, the subgroup of individuals with diabetes exerted greater pressure in the metatarsal area of the foot, as reflected by the mean pressure distribution while walking (103.22 vs 99.02 kPa; p<0.001).

When stratifying diabetic patients by ankle brachial index (ABI), those with abnormal ABI (>1.3 vs <0.9) exerted substantially greater mean pressure while standing + walking than those with normal ABI (1.1–1.3), in both the metatarsal (121.11 vs 111.32 kPa; p<0.001) and the heel areas of the foot (36.74 vs 23.55 kPa; p<0.001). Mean pressure while walking was also greater on the heel among those with abnormal vs normal ABI (41.47 vs 27.52 kPa; p<0.001).

According to Lee and colleagues, the “pressure distribution pattern and gradient analysis in diabetic patients by wearable BCG sensor arrays might predict diabetic complications.”

The wearable BCG sensor was also able to accurately measure heart rate, as the measurement generated from the BCG sock was similar to that seen with the ECG, yielding an intraclass correlation coefficient of 0.99 (95 percent confidence interval, 0.99–1.00).

Takeaways

“The pressure measurements showed that the sock could identify patients with diabetes and could also pinpoint patients with diabetes and poor circulation,” said Lee. “The novel BCG sock produced accurate measurements of heart rate as indicated by the nearly identical values as ECG.”

“Taken together, the results suggest that the electronic sock could be an easy, noninvasive way to find patients with diabetes who could benefit from gait remedial training to prevent [diabetic foot] complications,” Lee concluded.