Hybrid nanogenerator based closed-loop self-powered low-level vagus nerve stimulation system for atrial fibrillation treatment

Atrial fibrillation is an “invisible killer” of human health. It often induces high-risk diseases, such as myocardial infarction, stroke, and heart failure. Fortunately, atrial fibrillation can be diagnosed and treated early. Low-level vagus nerve stimulation(LL-VNS) is a promising therapeutic method for atrial fibrillation. However, some fundamental challenges still need to be overcome in terms of flexibility,miniaturization, and long-term service of bioelectric stimulation devices. Here, we designed a closedloop self-powered LL-VNS system that can monitor the patient’s pulse wave status in real time and conduct stimulation impulses automatically during the development of atrial fibrillation. The implant is a hybrid nanogenerator(H-NG), which is flexible, light weight, and simple, even without electronic circuits,components, and batteries. The maximum output of the H-NG was 14.8 V and 17.8 μA(peak to peak). In the in vivo effect verification study, the atrial fibrillation duration significantly decreased by 90% after LLVNS therapy, and myocardial fibrosis and atrial connexin levels were effectively improved. Notably, the anti-inflammatory effect triggered by mediating the NF-κB and AP-1 pathways in our therapeutic system is observed. Overall, this implantable bioelectronic device is expected to be used for self-powerability,intelligentization, portability for management, and therapy of chronic diseases.

A wearable noncontact free-rotating hybrid nanogenerator for self-powered electronics

Self-powerability is a new trend in the development of portable devices.Harvesting biomechanical energy to power personal information electronics is of great significance.In this work,we report a wearable noncontact freerotating hybrid nanogenerator(WRG),which is constituted by a triboelectric nanogenerator and an electromagnetic generator.A continuous output over 2 seconds can be achieved during one instantaneous incentive by external force,which is improved by two orders of magnitude compared to other wearable nanogenerators due to its unique mechanical energy storage design.The WRG can be integrated into shoes to generate an output energy of 14.68 mJ in each stepping,which meets the power requirements of most personal information electronics.The wireless sensor,GPS,and smartphone can be powered by the WRG continuously.The WRG is expected to be applied in self-powered information electronics extensively in the future.

Piezoelectric wearable atrial fibrillation prediction wristband enabled by machine learning and hydrogel affinity

Atrial fibrillation(AF)is a common and serious disease.Its diagnosis usually requires 12-lead electrocardiogram,which is heavy and inconvenient.At the same time,the venue for diagnosis is also limited to the hospital.With the development of the concept of intelligent medical,a wearable,portable,and reliable diagnostic method is needed to improve the patient’s comfort and alleviate the patient’s pain.Here,we reported a wearable atrial fibrillation prediction wristband(AFPW)which can provide longterm monitoring and AF diagnosis.AFPW uses polyvinylidene fluoride piezoelectric film as sensing material and hydrogel as skin bonding material,of which the structure and design have been optimized and improved.The hydrogel skin bonding layer has good stability and skin affinity,which can greatly improve the user experience.AFPW has enhanced signal,strong signal-tonoise ratio,and wireless transmission function.After a sample library of 385 normal people/patients is analyzed and tested by linear discriminant analysis,the diagnostic success rate of atrial fibrillation is 91%.All these excellent performances demonstrate the great application potential of AFPW in wearable device diagnosis and intelligent medical treatment.