A Wearable Ultrasound Transducer Array for Neuromodulation Applications in the Treatment of Diabetic Foot Disease

Diabetic foot is regarded as one of the most serious chronic complications of diabetes. Numerous studies have shown that diabetic neuropathy is one of the primary risk factors, occurring of almost 85% of diabetic feet. Ultrasound neuromodulation method has performed a remarkable therapeutic efficacy in neuropathic diseases such as Alzheimer’s disease owing to its non-invasiveness and high spatial resolution and illustrates the potential on treating the diabetic neuropathy. However, prevailing studies on ultrasound neuromodulation utilize commercial water-immersed ultrasound transducers or 2-D ultrasound arrays which are rigid, bulky, and unsuitable for daily use by diabetic foot patients. In this study, we design and fabricate a flexible and wearable spiral focused phased ultrasound transducer array composed of 41 PZT-4 micromachined elements (1.2 mm × 1.2 mm), serpentine electrodes and flexible encapsulation. The whole size of the wearable array is 2 cm × 2 cm, and the driving frequency is 1.4 MHz. The measured focal distance and the beam size are 7 mm and 4.8 mm × 1.1 mm × 1.1 mm, respectively. The array is capable of generating acoustic pressure up to ~ 1.0 MPa which is sufficient for ultrasound neuromodulation applications.