No abstract

Therapeutic applications of auricular vagus nerve stimulation (VNS) have drawn recent attention. Since the targeted stimulation process and parameters depend on the electrode-tissue interaction, the lack of structural anatomical information on innervation and vascularization of the auricle restrain the current optimization of stimulation paradigms. For the first time, we employed high-resolution episcopic imaging (HREM) to generate histologic volume data from donated human cadaver ears. Optimal parameters for specimen preparation were evaluated. Anatomical 3D vascular and nerve structures were reconstructed in one sample of an auricular cymba conchae (CC). The feasibility of HREM to visualize anatomical structures was assessed in that diameters, occupied areas, volumes, and mutual distances between auricular arteries, nerves, and veins were registered. The selected region of CC (3 × 5.5 mm) showed in its cross-sections 21.7 ± 2.7 (mean ± standard deviation) arteries and 14.66 ± 2.74 nerve fibers. Identified nerve diameters were 33.66 ± 21.71 µm, and arteries had diameters in the range of 71.58 ± 80.70 µm. The respective occupied area showed a share of, on average, 2.71% and 0.3% for arteries and nerves, respectively, and similar volume occupancy for arteries and nerves. Inter-centroid minimum distance between arteries and nerves was 274 ± 222 µm. The density of vessels and nerves around a point within CC on a given grid was assessed, showing that 50% of all vessels and nerves were found in a radial distance of 1.6-1.8 mm from any of these points, which is strategically relevant when using stimulation needles in the auricle for excitation of nerves. HREM seems suitable for anatomical studies of the human ear. A 3D model of CC was established in the micrometer scale, which forms the basis for future optimization of the auricular VNS. Obviously, the presented single cadaver study needs to be validated by additional anatomical data on the innervation and vascularization of the auricle.

Percutaneous auricular vagus nerve stimulation (pVNS) is a novel approach of treating cardiovascular and inflammatory diseases, as well as pain and neurological conditions. The treatment can be optimized by using biosignals as objective measures and feedback-control. One suitable biofeedback could be the use of pulse rate and pulse rate variability (PRV) derived from optical pulse plethysmography (PPG) instead of heart rate and heart rate variability (HRV) derived from electrocardiogram (ECG). For this purpose, a single-lead ECG on the thorax and a PPG on the earlobe were measured simultaneously on 10 healthy subjects for 420 s during three different respiratory phases. The data was analyzed and compared with scatterplots, the Pearson correlation coefficient and a Bland-Altman analysis. The outcomes show a very high correlation of heart rates from PPG and ECG (= 0.9663) and SDNN values (= 0.9791). Comparison of RMSSD values showed a high positive correlation (= 0.7963) but a mean overestimation of 10 ms in RMSSD values measured with the PPG. The results presented suggest that PRV could be and alternative biofeedback used in pVNS.

The current study explored how Vietnamese EFL high school teachers self-assessed their current English proficiency. It also compared teachers’ self-ratings with the results they obtained in the Project 2010 test, which was  used to assess English level of EFL teachers across Vietnam as part of the implementation of the National Foreign Language Project 2020. The data were drawn from 15-item online questionnaire with 94 teacher participants. The findings revealed that teachers perceived themselves as being more proficient in skills of writing and reading, compared to listening, spoken production (e.g., making presentations) and spoken interaction (e.g., making conversations). Most of them rated their current English proficiency level lower than the level they achieved in the Project 2020 test.  The findings offer information  about the language aspects that teachers were least proficient, which can be used to specify what support they actually desire from in-service training courses.  Also, as teachers are at the centre of the Project 2020, their perceptions of their own English proficiency provide insightful input to enhance the effectiveness of this educational reform.

Background: Chronic low back pain is a global health problem having a tremendous effect on the quality of life of patients. Objectives: An online therapy management system (TMS) is developed for comprehensive management of chronic low back pain patients. Methods: A smartphone and a web app are built based on the Keep-In-Touch Telehealth Platform. The smartphone app allows entering patient reported outcomes and connection to third party devices to monitor physiological data and parameters of therapy. Results: The TMS has been realized and a wearable auricular vagus nerve stimulation device has been integrated. The TMS is currently evaluated in a randomized clinical trial.