Bl factor is a key system parameter of the resonant blood viscoelastic sensor. In this paper, a dynamic measurement system for the spatial distribution of Bl factor based on velocity amplitude and motional impedance was designed. The system extracted the velocity amplitude and motional impedance of the coil under the dynamic condition of driving the sensor to generate simple harmonic oscillations using laser displacement and impedance analysis combined with in-phase/quadrature demodulation algorithm, and controlled the equilibrium position of the coil by adjusting the direct current component of the excitation current to realize the position scanning. In the position interval of [?240, 240] μm, the maximum coefficient of variation of the measurement results was 0.077 3%, and the maximum relative error to the simulation results was 2.937 9%, with a linear fitting correlation coefficient R2 = 0.996 8. The system can be used to accurately measure the spatial distribution of Bl factor of the resonant blood viscoelastic sensor, which provides a technical support for the verification of the design of the sensor magnetic circuit.
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.
The requirement for unconstrained monitoring of heartbeat during sleep is increasing, but the current detection devices can not meet the requirements of convenience and accuracy. This study designed an unconstrained ballistocardiogram (BCG) detection system using acceleration sensor and developed a heart rate extraction algorithm. BCG is a directional signal which is stronger and less affected by respiratory movements along spine direction than in other directions. In order to measure the BCG signal along spine direction during sleep, a 3-axis acceleration sensor was fixed on the bed to collect the vibration signals caused by heartbeat. An approximate frequency range was firstly assumed by frequency analysis to the BCG signals and segmental filtering was conducted to the original vibration signals within the frequency range. Secondly, to identify the true BCG waveform, the accurate frequency band was obtained by comparison with the theoretical waveform. The J waves were detected by BCG energy waveform and an adaptive threshold method was proposed to extract heart rates by using the information of both amplitude and period. The accuracy and robustness of the BCG detection system proposed and the algorithm developed in this study were confirmed by comparison with electrocardiogram (ECG). The test results of 30 subjects showed a high average accuracy of 99.21% to demonstrate the feasibility of the unconstrained BCG detection method based on vibration acceleration.
Ultra-sensitive and quantitative analysis of proteins, nucleic acid, virus and other biochemical species are critical technologies for effective dianosis of disease, as well as medical studies. Silicon nanowires field-effect transistor (SiNWs-FET) biosensor is one of the most promising powerful platforms for label-free, real-time, ultra-sensitive detection of analyte. Here, the working principle of SiNWs-FET biosensor and the applications of SiNWs-FET biosensors in medicine were introduced. Moreover, the methods for enhancing the sensitivity of SiNWs-FET biosensor were discussed. Lastly, the prospecting of SiNWs-FET biosensor was presented.
Objective To assess the effects and safety of vasodilators for sudden sensorineurial hearing loss (SSHL). Search strategy Electronic databases: MEDLINE from 1966, EMBASE from 1974, the Cochrane Controlled Trials Register, Chinese Bio-medicine Database from 1989. Hand search: Five kinds of Chinese otolaryngology journals were searched. Literature references were checked intensively. Selection criteria Randomized controlled trials comparing vasodilators with placebo or other drugs in patients with SSHL. Data collection and analysis At least two reviewers independently assessed trials quality and extracted data. Main results Thirteen trials with 1 155 patients were eligible and included in the systematic review. Ten of the trials were from developed countries and them were from P. R. China. None of the four trials showed that the effects of vasodilators were better than placebo for SSHL. None of the seven trials showed that the effects of one kind of vasodilators were better than that of the other vasodilators. Two trials showed that other drugs, such as batroxobin and hypaque,were probably better than some vasodilators (dextran, papaverine, 654-2, danshen). Eight trials reported the side effects of vasodilators, such as pruritus, allergy, etc. Reviewers’ conclusions Base on the systematic review of current eligible randomized controlled trials, there is no evidence to prove that vasodilator therapy is better than placebo or other therapies for SSHL, or the effects of one kind of vasodilator are better than that of the other vasodilators. We can’t draw a reliable conclusion about the effects of vasodilators for SSHL at the moment. And we must pay attention to their potential adverse reactions.
The transforming growth factor-β1 (TGF-β1)/Smad3 signal pathway is related to mutiple physiological and pathological generation mechanism of human being. Up to date, however, the spacial and time information on the phosphorylated Smad3 is still unclear. In this study, the process of Smad3 phosphorylation was observed under the physiological state in the living cells. Firstly, the ECFP-Smad3-Citrine (Smad3 biosensor) fusion protein expression vector was constructed and identified. Then the Smad3 biosensor was transfected into 293T cells. The transfection efficiency and the expressions of fusion proteins were observed in 24 hours. Thirdly, Smad3 biosensor flurorescence resonance energy transfer (FRET) was observed with the inversion fluorescence microscope and measured by the MetaFlour FRET 4.6 software. Smad3 biosensor transfection efficiency was nearly 40% and the fusion protein was seen under the fluorescence microscope. The FRET ratio of Smad3 biosensor in living 293T cells was decreased after 10 minutes incubation with the ligand of TGF-β1. The period of decreasing CFP and enhancing Citrine signals was about 300 seconds. With the technology of FRET, the TGF-β1/Smad3 signal pathway could be real time monitored dynamically under the physiological condition in living cells.
ObjectiveTo investigate the effectiveness of free sensate intercostal artery perforator flap for the hand soft tissue reconstruction.MethodsBetween March 2010 and September 2015, 19 cases of hand soft tissue defect were repaired with free sensate intercostal artery perforator flap, including 16 males and 3 females, aged from 18 to 53 years, with an average of 35.2 years. The defect was located in the dorsum of the hand in 15 cases and in the palm in 4 cases. The causes of injury were traffic accident injury in 8 cases, hot crush injury in 5 cases, strangulation injury in 4 cases, and avulsion injury in 2 cases. All of them were full-thickness skin and soft tissue defects of hand with exposure of phalanges, tendons, blood vessels, and nerves. The size of defect was 10.0 cm×7.0 cm to 17.0 cm×8.0 cm. There were 12 cases of emergency operation and 7 cases of selective operation. The thickness of flap was 10-25 mm, and the size of the flap ranged from 10.0 cm×7.5 cm to 17.0 cm×8.0 cm. The vascular pedicle of the flap was anastomosed with the snuff nest branch of the radial artery (12 cases), the main radial artery (7 cases), and there accompanying vein, and the intercostal nerve cutaneous branch of the flap was anastomosed with the lateral cutaneous nerve of the forearm. The donor site was closed directly (14 cases) or repaired with medium thickness skin graft (5 cases).ResultsAll of the flaps and skin grafts survived; the wounds in the donor and recipient sites healed by first intention. All 19 patients were followed up 10- 18 months, with an average of 12.7 months. After operation, the appearance and function of the hand recovered well, and there was no flap bloated. The two-point discrimination of the flap was 7-11 mm, with an average of 8.8 mm. Only linear scars left in the patients with direct closure of the donor site. The sensory function of the donor site was not significantly affected, and the hand function recovered satisfactorily. Conclusion Free sensate intercostal artery perforator flap is a valuable and reliable technique for the hand soft tissue defect.
Artificial prosthesis is an important tool to help amputees to gain or partially obtain abled human limb functions. Compared with traditional prosthesis which is only for decoration or merely has feedforward control channel, the perception and feedback function of prosthesis is an important guarantee for its normal use and self-safety. And this includes the information of position, force, texture, roughness, temperature and so on. This paper mainly summarizes the development and current status of artificial prostheses in the field of perception and feedback technology in recent years, which is derived from two aspects: the recognition way of perception signals and the feedback way of perception signals. Among the part of recognition way of perception signals, the current commonly adopted sensors related to perception information acquisition and their application status in prosthesis are overviewed. Additionally, from the aspects of force feedback stimulation, invasive/non-invasive electrical stimulation, and vibration stimulation, the feedback methods of perception signals are summarized and analyzed. Finally, some problems existing in the perception and feedback technology of artificial prosthesis are proposed, and their development trends are also prospected.
In order to accurately evaluate the similarity of motions during daily rehabilitation training for stroke patients, this paper proposed a novel quantitative assessment method based on dynamic time warping (DTW) algorithm. Firstly, the raw accelerometer signals were preprocessed to eliminate the noise. Secondly, the similarity between the accelerometer signals and four standard task templates was calculated respectively, and then the motion was recognized based on the similarity measurements. Finally, the corresponding quantitative assessment model was used to compute the result. The clinical experimental results showed that there were significant differences in the shortest path distance (R value) of DTW between different tasks, and the classification accuracy could be up to 91% when the R value was selected as the classification feature. Additionally, with the process of rehabilitation, the R value decreased gradually, which means that the R value can be taken as the assessment index to evaluate the quality of designated tasks for stroke patients. It also indicated that the R value could be applied into the scene of automatic prescription generation and interactive gaming to determine whether it is needed to change the rehabilitation plan or adjust the game difficulty level, so as to implement the individualized rehabilitation services.
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.