Self-powered wearable piezoelectric sensing devices demand flexibility and high voltage electrical properties to meet personalized health and safety management needs. Aiming at the characteristics of piezoceramics with high piezoelectricity and low flexibility, this study designs a high-performance piezoelectric sensor based on multi-phase barium titanate (BTO) flexible piezoceramic film, namely multi-phase BTO sensor. The substrate-less self-supported multi-phase BTO films had excellent flexibility and could be bent 180° at a thickness of 33 μm, and exhibited good bending fatigue resistance in 1 × 104 bending cycles at a thickness of 5 μm. The prepared multi-phase BTO sensor could maintain good piezoelectric stability after 1.2 × 104 piezoelectric cycle tests. Based on the flexibility, high piezoelectricity, wearability, portability and battery-free self-powered characteristics of this sensor, the developed smart mask could monitor the respiratory signals of different frequencies and amplitudes in real time. In addition, by mounting the sensor on the hand or shoulder, different gestures and arm movements could also be detected. In summary, the multi-phase BTO sensor developed in this paper is expected to develop convenient and efficient wearable sensing devices for physiological health and behavioral activity monitoring applications.
Flexible conductive fibers have been widely applied in wearable flexible sensing. However, exposed wearable flexible sensors based on liquid metal (LM) are prone to abrasion and significant conductivity degradation. This study presented a high-sensitivity LM conductive fiber with integration of strain sensing, electrical heating, and thermochromic capabilities, which was fabricated by coating eutectic gallium-indium (EGaIn) onto spandex fibers modified with waterborne polyurethane (WPU), followed by thermal curing to form a protective polyurethane sheath. This fiber, designated as Spandex/WPU/EGaIn/Polyurethane (SWEP), exhibits a four-layer coaxial structure: spandex core, WPU modification layer, LM conductive layer, and polyurethane protective sheath. The SWEP fiber had a diameter of (458.3 ± 10.4) μm, linear density of (2.37 ± 0.15) g/m, and uniform EGaIn coating. The fiber had excellent conductivity with an average value of (3 716.9 ± 594.2) S/m. The strain sensing performance was particularly noteworthy. A 5 cm × 5 cm woven fabric was fabricated using polyester warp yarns and SWEP weft yarns. The fabric exhibited satisfactory moisture permeability [(536.06 ± 33.15) g/(m2·h)] and maintained stable thermochromic performance after repeated heating cycles. This advanced conductive fiber development is expected to significantly promote LM applications in wearable electronics and smart textile systems.
OBJECTIVE: To investigate the characteristics and the pathologic classification of electrical-injury nerve using somatosensory evoked potential(SEP) technique. METHODS: SEP were detected and evaluated in 12 cases with electrical-injury nerve during operation, electrical stimulation was commenced from distal side of nerve where the structure of nerve looks normal under operating microscope, up to proximal side until evoking out a stable SEP predeterminate virtual value. Pathological examination and the following functional evaluation were compared with the values of SEP. RESULTS: At the site of nerve looking normal under operating microscope, perineurium appears normal or slightly thicken. But there are obvious fibrosis and fibrotic proliferation between fascicular and intrafascicular. Vessel plexus is not seen. At SEP stabilizely evoked site, nervous construction is normal, there are visible interfascicular vessel plexus and connective tissue appears loose. Comparing SEP values with pathological section, amplitude and latency of SEP is positively correlative with the quality of nerve. Eight cases repaired with SEP technique to select the anastomosis site for nerve transplantation were followed up, two-point discrimination reached grade III (America hand surgery association criterion) within 62.5% cases. CONCLUSION: SEP technique is valuable method for functional evaluation of electrical- injury nerve which has a complicated pathology. The pathology of electrical-injury nerve can be classified into 4 types, type A: fibrosis of nerve; type B: nerve looking normal under operation microscope, perineurium appears thicken, and there are obvious fibrosis and fibrotic proliferation between fascicular and intrafascicular, vessel plexus is rarely to see; type C: nerve looks normal, lymphocyte infiltration exists and it is obvious that there are many physalis-like, retrogressive construction in the section; type D: nervous construction is normal, there are visible interfascicular vessel plexus, and connective tissue appears loose, SEP always can be stably evoked.
Objective To investigate the relationship between graded spinal cord ischemia/reperfusion injury and somatosensory evoked potentials(SEP),neurologic function score（NFS）and the histopathological changes of spinal cord. Methods Forty rabbits were randomized and equally divided into 4 groups: shamoperation group, ischemia for 30min, 45min and 60min groups. The spinal cord ischemiareperfusion injury model was created by occlusion of the abdominal aorta in rabbits. SEP was monitored before ischemia,5,10minutes after ischemia, 15, 30 minutes, 1,2, 24 and 48 hours after reperfusion. NFS was evaluated at 6,12,24 and 48 hours after reperfusion.The pathological changes of spinal cord were observed after reperfusion 48 hours. Results The pathological characters with mild,moderate and severe spinal cord ischemia/reperfusion injury could be simulated by declamping after 30， 45 and 60 minutes infrarenal aorta crossclamping. SEP amplitude returned to normal after reperfusion 15 minutes（Pgt;0.05）and SEP latency returned to normal after reperfusion 30 minutes（Pgt;0.05）during mild spinal cord ischemia/reperfusion injury.SEP amplitude returned to normal after reperfusion 30 minutes（Pgt;0.05）and SEP latency returned to normal after reperfusion 60 minutes（Pgt;0.05）during moderate spinal cord ischemia/reperfusion injury. SEP latency increased and SEP amplitude decreased during severe spinal cord ischemia/reperfusion injury,compared with other groups, there were significant differences in SEP latency and SEP amplitude by clamping the infrarenal aorta for 60min（Plt;0.01）. With graded spinal cord ischemia/reperfusion injury, compared with shamoperation group, spinal cord ischemiareperfusion groups had significant differences in NFS（Plt;0.01）. Conclusion SEP is much quicker in the recovery of amplitude than latency during spinal cord ischemia/reperfusion. SEP is a sensitive and accurate index for spinal cord function during ischemia/reperfusion injury. SEP monitoring spinal cord ischemia/reperfusion injury during operation provides experimental basis for clinical application.
Cardiovascular disease has caused a huge burden of disease worldwide, and the rapid advancement of smart wearable devices has provided new means for early diagnosis, real-time monitoring, and event prevention of cardiovascular disease. Smart wearable devices can be classified into various categories based on detection signals and physical carrier types. Based on an overview of the composition of such devices, this article further introduces the current cutting-edge research and related market products related to smart blood pressure monitoring, electrocardiogram monitoring, and ultrasound monitoring. It also discusses the future development and challenges of such devices, aiming to provide evidence support for the research and development of smart wearable devices in the diagnosis and treatment of cardiovascular diseases in the future.
Motor imaging therapy is of great significance to the rehabilitation of patients with stroke or motor dysfunction, but there are few studies on lower limb motor imagination. When electrical stimulation is applied to the posterior tibial nerve of the ankle, the steady-state somatosensory evoked potentials (SSSEP) can be induced at the electrical stimulation frequency. In order to better realize the classification of lower extremity motor imagination, improve the classification effect, and enrich the instruction set of lower extremity motor imagination, this paper designs two experimental paradigms: Motor imaging (MI) paradigm and Hybrid paradigm. The Hybrid paradigm contains electrical stimulation assistance. Ten healthy college students were recruited to complete the unilateral movement imagination task of left and right foot in two paradigms. Through time-frequency analysis and classification accuracy analysis, it is found that compared with MI paradigm, Hybrid paradigm could get obvious SSSEP and ERD features. The average classification accuracy of subjects in the Hybrid paradigm was 78.61%, which was obviously higher than the MI paradigm. It proves that electrical stimulation has a positive role in promoting the classification training of lower limb motor imagination.
Objective To observe the therapeutic effect of autologous neurosensory retinal transplantation in repairing unhealed giant macular hole after pars plana vitrectomy (PPV). MethodsA prospective clinical study. From July 2022 to December 2023, 12 patients (12 eyes) with refractory large macular hole who received autologous neurosensory retinal transplantation treatment in Department of Ophthalmology of the First Affiliated Hospital of Zhengzhou University were selected for the study. The macular hole in affected eyes still did not close after PPV combined with inner limiting membrane removal or tamponade, and the diameter of macular hole were greater than 600 μm. All affected eyes received best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examinations. The BCVA examination employed the international standard visual acuity chart, with results converted to logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. During the surgery, a piece of healthy retinal neuroepithelial tissue, approximately 0.3 optic disc diameters larger than the macular hole, was removed from the upper retinal periphery and used as a graft. The graft was inserted into the macular hole with the aid of intraoperative OCT. Post-surgery, the vitreous cavity was filled with silicone oil or sterile air. The follow-up period after surgery was 6 months. The thickness of the retinal grafts was measured using the same equipment as before surgery at 3 days, 1, 3, and 6 months post-surgery. The primary focus was on observing the macular hole closure rate and changes in BCVA at 6 months post-operation. A paired t-test was used to compare BCVA before and after surgery. Results In the sample of 12 cases (12 eyes), there were 5 males with 5 eyes and 7 females with 7 eyes. The mean age was (50.4±12.6) years. The mean macular hole diameter was (1 085.6±344.0) μm; The mean eye axis length was (27.64±4.19) mm. At 6 months after surgery, all affected eyes showed macular hole were completely closed (100.0%, 12/12). The thickness of the retinal graft was measured as (206.8±21.0), (170.8±23.3), (165.6±31.6), and (157.9±31.1) μm at 3 days, 1, 3, and 6 months post-surgery, respectively. At before and 6 months after surgery, the logMAR BCVA of the affected eyes was 1.28±0.39 and 0.95±0.22, respectively. The difference in logMAR BCVA before and after surgery was statistically significant (t=3.40, P＜0.05). Conclusion Autologous neurosensory retinal transplantation could effectively improve the closure rate of refractory large macular hole and improve or stabilize vision in the short run.
Objectives To investigate the correlation between blood total cholesterol (TC) and prognosis of idiopathic sudden sensorineural hearing loss (ISSNHL) and to provide references for clinical treatment and prognosis assessment. Methods We included 232 ISSNHL patients with total deafness in Wenzhou Central Hospital from June 2015 to March 2017 using a prospective cohort design. Recording information including age, gender, hypertension, diabetes mellitus, vertigo, level of blood total cholesterol (TC), level of triglyceride (TG), level of low-density lipoprotein (LDL-C) and LDL/HDL ratio (LDL-C/HDL-C) were collected. Correlation between the prognosis of ISSNHL and blood total cholesterol were analyzed by univariable and multivariable logistic regression analysis. Results The clinical effective rate of patients with TC ranging from 5.2 mmol/L to 6.2 mmol/L was higher than that of patients with TC lower than 5.2 mmol/L (univariable: RR=6.49, 95%CI 3.16 to 13.30, P<0.001; multivariable-adjusted covariates: RR=6.15, 95%CI 2.66 to 14.3,P<0.001) with significant difference. No significant difference was found between patients with TC lower than 5.2 mmol/L and patients with TC higher than 6.2 mmol/L (univariable: RR=1.02, 95%CI 0.52 to 2.00,P=0.960; multivariable-adjusted covariates: RR=1.61, 95%CI 0.55 to 4.73, P=0.386). Gender-specific analysis showed for both male and female groups, the effective rates of patients with TC ranging from 5.2 mmol/L to 6.2 mmol/L were significantly higher than those of patients with TC lower than 5.2 mmol/L. There was no significant difference between patients with TC lower than 5.2 mmol/L and patients with TC higher than 6.2 mmol/L (P>0.05) in either male group or female group. Conclusion The current study suggests that patients with levels of TC ranging from 5.2 mmol/L to 6.2 mmol/L predicts the best prognosis.
The current quantitative methods of bilirubin have disadvantages such as high cost and low sensitivity. Due to the negative correlation between the level of serum bilirubin and the risk of cardiovascular diseases, a fluorescent ratiometric film sensor was developed aiming at bilirubin detection at low level concentration. Blue-emitting and red-emitting gold nanoclusters were assembled into the same film using layer-by-layer self-assembly technology. Detection of bilirubin was achieved based on the intensity ratio of the two nanoclusters. Bilirubin exposure causes fluorescent quenching of the film. The fluorescence intensity ratio of the two cluster probes had quantitative relationship versus bilirubin concentration. Based on this film sensor, a portable fluorescence detection system was designed for the ratiometric sensing of bilirubin. The hardware of the system was mainly composed of main control chip STM32F407, TSL237 and TSL238T optical frequency sensor. A light-avoiding dark room and detection light path were designed through three-dimensional printing to reduce the interference from ambient light and improve detection accuracy. Experimental results showed that the proposed detection system had strong anti-interference, good stability and accuracy. The linear coefficient of bilirubin detected by this system was 0.987. The system presented good results in reproducible experiments and possessed a good linear relationship with the data obtained by standard spectrofluorometer. The portable system is expected to detect serum bilirubin at low levels.
The main magnetic field, generated by the excitation coil of the magnetic induction phase shift technology detection system, is mostly dispersed field with small field strength, and the offset effect needs to be further improved, which makes the detection signal weak and the detection system difficult to achieve quantitative detection, thus the technology is rarely used in vivo experiments and clinical trials. In order to improve problems mentioned above, a new Helmholtz birdcage sensor was designed. Stimulation experiment was carried out to analyze the main magnetic field in aspects of intensity and magnetic distribution, then different bleeding volume and bleeding rates experiments were conducted to compared with traditional sensors. The results showed that magnetic field intensity in detection region was 2.5 times than that of traditional sensors, cancellation effect of the main magnetic field was achieved, the mean value of phase difference of 10 mL rabbit blood was (–3.34 ± 0.21)°, and exponential fitting adjusted R2 between phase difference and bleeding volumes and bleeding rates were both 0.99. The proposed Helmholtz birdcage sensor has a uniform magnetic field with a higher field strength, enable more accurate quantification of hemorrhage and monitored change of bleeding rates, providing significance in magnetic induced technology research for cerebral hemorrhage detection.