The variation in blood flow in time and space contains abundant information regarding a person’s cardiovascular situation.
The wearable Doppler device has the potential to enhance the quality of care of patients after reconstruction surgery. Experimental studies on ultrasound phantoms and human subjects demonstrate accurate measurement of the flow velocity. When the dual-beam Doppler method is used, the influence of the Doppler angle on the velocity measurement is avoided. The device is thin (1 mm), lightweight (0.75 g), and skin conforming. Here, we introduce a flexible Doppler ultrasound device for the continuous monitoring of the absolute velocity of blood flow in deeply embedded arteries based on the Doppler effect. Techniques based on photoplethysmography or thermal analysis provide only relative changes in flow volume and have a shallow detection depth. Conventional ultrasound probes are rigid, particularly for postoperative patients with fragile skin. Thrombosis and restenosis after vascular reconstruction procedures may cause complications such as stroke, but a clinical means to continuously monitor vascular conditions is lacking.
