Plantar pressure distribution can reflect the force of several key points on foot while standing and walking. A comprehensive understanding of the plantar pressure distribution makes great sense in the following aspects:the understanding of the normal foot biomechanics and function, clinical diagnosis, measurement of disease extent, postoperative efficacy evaluation, and rehabilitation research. A simple plantar pressure measurement device was designed in this study. This paper uses FlexiForce flexible sensor to pickup plantar pressure signal and USB A/D board to do data acquisition. The data are transferred into a laptop and processed by a VB-based software which can display, remember and replay the data. We chose patients with hallux valgus and normal people to measure the pressure distribution and make contrast analysis of plantar pressure with this device. It can be concluded that people with hallux valgus have higher pressure on the second metatarsophalangeal joint and the distribution move outward. The plantar pressure of patients postoperative could be greatly improved compared to the preoperative. The function of this device has been confirmed.
Objective To determine the efficacy of forced expiratory volume in six seconds( FEV6 ) as an alternative for forced vital capacity( FVC) in the diagnosis for mild-moderate chronic obstructive pulmonary disease( COPD) .Methods A total of 402 mild-moderate COPD and 217 non-COPD patients’ spirometric examinations were retrospectively analyzed. The correlation between FEV6 and FVC, FEV1 /FVC and FEV1 /FEV6 was evaluated by the Spearman test. Considering FEV1 /FVC lt;70% as being the ‘golden standard’ for airway obstruction, a ROC curve was used to determine the best cut-off point for the FEV1 /FEV6 ratio in the diagnosis for COPD. Results The Spearman correlation test revealed the FEV1 and FEV6 , FEV1 /FEV6 and FEV1 /FVC ratios were highly correlated ( r = 0. 992, 0. 980, respectively, P = 0. 000) . Using FEV1 /FEV6 lt; 70% as the diagnosis standard, 12. 69% of the 402 patients could not be diagnosed as COPD. The FEV1 /FVC ratio of these patients was very close to 70% . The best cut-off point for the FEV1 /FEV6 ratio in the diagnosis of mild-moderate COPD was 72% while the sensitivity and specificity were 94. 7% and 92. 2% , respectively. Conclusions There is a b correlation between FEV1 /FVC and FEV1 /FEV6 . The FEV6 can be a valid alternative for FVC in the diagnosis for mild-moderate COPD, although it may result in false negative. The best cut-off point for the FEV1 /FEV6 ratio is 72% .
Objective To observe the decline ratio of FEV1 after inhaling 0. 9% saline to the baseline, and to explore its relation to the result of bronchial provocation test ( BPT) with methacholine.Methods 115 patients with chronic cough or chest tightness were collected in Shougang Hospital, Peking University from March 2008 to September 2009. They were all performed pulmonary function test and the decline ratio of FEV1 after inhaling 0.9% saline to the baseline( ΔFEV1 ) was measured. Then they were allperformed BPT with methacholine. The predictive value of ΔFEV1 measurement for BPT results was evaluated. Results 49 cases yielded positive results in methacholine BPT, with ΔFEV1 gt; 3% in 35 cases and gt;5% in 20 cases. 66 casess yielded negative results in methacholine BPT, with ΔFEV1 gt; 3% in 6 cases. The sensitivity and specificity were 71% and 91% respectively when ΔFEV1 gt;3% was set as a cutoff,and which were 40. 8% and 100% respectively when ΔFEV1 gt;5% was set as a cut-off. All the patients didn’t show any serious adverse reaction. Conclusion ΔFEV1 gt;3% after inhaling 0. 9% saline is a good predictor for BPT results. More caution should be paid to these patients when performing BPT.
To address the challenges of capturing micro-strains in detecting esophageal motility disorders and the limitations of existing high-resolution manometry and functional intraluminal imaging probes in directly measuring esophageal tissue electrical impedance, this study proposes a novel flexible balloon sensor structure that integrates a piezoelectric film assembly with a distributed impedance electrode array. Using the electrical analysis module in the finite element analysis (FEA) software, simulations of the forward problem for esophageal impedance detection were conducted to optimize the excitation source parameters, and a physical prototype was fabricated. Under a relative excitation mode with a voltage sensitivity of 2.059%, the voltage output characteristics of the impedance electrode array were analyzed during linear changes in the balloon filling volume. Based on the performance variation of the piezoelectric film assembly, 80% was selected as the optimal filling volume. Force-electric coupling tests were conducted on the balloon sensor using a pressure testing platform, revealing that both the piezoelectric film assembly inside the balloon and the impedance electrodes outside the balloon exhibited significant load differentiation characteristics as the force application point shifted. In summary, this balloon sensor facilitates the localization of force application while simultaneously analyzing esophageal tissue properties, offering a novel diagnostic approach and objective tool for esophageal disease detection.
Currently, transcranial magnetic stimulation (TMS) has been widely used in the treatment of depression, Parkinson’s disease and other neurological diseases. To be able to monitor the brain’s internal activity during TMS in real time and achieve better treatment outcomes, the researchers proposed combining TMS with neuroimaging methods such as magnetic resonance imaging (MRI), both of which use Tesla-level magnetic fields. However, the combination of strong current, large magnetic field and small size is likely to bring physical concerns which can lead to mechanical and thermal instability. In this paper, the MRI static magnetic field, the TMS coil and human head model were built according to the actual situations. Through the coupling of the magnetic field and the heat transfer module in the finite element simulation software COMSOL, the force and temperature of the TMS coil and head were obtained when the TMS was used in combination with MRI (TMS-MRI technology). The results showed that in a 3 T MRI environment, the maximum force density on the coil could reach 2.51 × 109 N/m3. Both the direction of the external magnetic field and the current direction in the coil affected the force distributions. The closer to the boundary of the external magnetic field, the greater the force. The magnetic field generated by the coil during TMS treatment increased the temperature of the brain tissue by about 0.16 °C, and the presence of the MRI static magnetic field did not cause additional thermal effects. The results of this paper can provide a reference for the development of the use guidelines and safety guidelines of TMS-MRI technology.
In existing vascular interventional surgical robots, it is difficult to accurately detect the delivery force of the catheter/guidewire at the slave side. Aiming to solve this problem, a real-time force detection system was designed for vascular interventional surgical (VIS) robots based on catheter push force. Firstly, the transfer process of catheter operating forces in the slave end of the interventional robot was analyzed and modeled, and the design principle of the catheter operating force detection system was obtained. Secondly, based on the principle of stress and strain, a torque sensor was designed and integrated into the internal transmission shaft of the slave end of the interventional robot, and a data acquisition and processing system was established. Thirdly, an ATI high-precision torque sensor was used to build the experimental platform, and the designed sensor was tested and calibrated. Finally, sensor test experiments under ideal static/dynamic conditions and simulated catheter delivery tests based on actual human computed tomography (CT) data and vascular model were carried out. The results showed that the average relative detection error of the designed sensor system was 1.26% under ideal static conditions and 1.38% under ideal dynamic stability conditions. The system can detect on-line catheter operation force at high precision, which is of great significance towards improving patient safety in interventional robotic surgery.
ObjectiveTo explore the serum concentrations of complement C1q tumor necrosis factor related protein 5 (CTRP5) in patients with acute exacerbations and stable stage of chronic obstructive pulmonary disease (COPD), and analyze the correlation of CTRP5 with high sensitivity C-reactive protein (hs-CRP) and FEV1/FVC and FEV1%pred.MethodsThirty hospitalized patients with acute exacerbation of COPD and 30 outpatients with stable COPD according with diagnostic criteria and inclusive criteria were sampled successively. At the same time 30 healthy volunteers were selected as normal control. All subjects were measured the concentrations of CTRP5 and hs-CRP in serum and lung function test was performed.ResultsThe serum CTRP5 and hs-CRP concentrations of the acute exacerbation group was higher than those in the stable group and the control group. The serum CTRP5 and hs-CRP concentrations of the stable group was also higher than those of the control group. The FEV1/FVC of the acute exacerbation group was lower than those of the stable group and the control group; and the FEV1/FVC of the stable group was lower than that of the control group. The FEV1%pred of three groups by analysis indicated the difference was statistically significant. Further pairwise comparisons demonstrated that the FEV1%pred of two COPD groups were lower than that of the control group but the FEV1%pred of the acute exacerbation group and stable group was not significantly different. The correlation analysis of the acute exacerbation group and the stable group demonstrated that the levels of serum CTRP5 and hs-CRP were postively correlated and the level of serum CTRP5 was negatively correlated with FEV1/FVC and FEV1%pred.ConclusionsThe level of CTRP5 in serum of COPD patients is increased. No matter in acute exacerbation or stable phase, the level of serum CTRP5 is positively correlated with hs-CRP and negatively correlated with FEV1/FVC and FEV1%pred, which suggests that CTRP5 is involved in the pathogenesis of COPD but the exact mechanism needs further study.
Objective To study the influence of in vitro force-vascularization on in vivo vascularization of porous polylactic glycolic acid copolymer(PLGA) scaffolds with internal network channels (PPSINC). Methods After the in vitro forcevascula ization of PPSINCs covered with microvessel endothelial cells (MVEC) of mice, they were divided into two groups: the force-vascularization group (group A) and the control group with only PSINCs (group B). All the PPSINCs were planted in the mesentery of 12 mice for 2 and 4 weeks, the PPSINCs were cut out, the vascular ization of PPSINCs was investigated by histology and immunohistochemistry, and the vascularization area of the histologic section of the PPSINCswas measured with the computer-assistant image analysis system. Result After the in vitro forcevascularization of PPSINCs, the MVEC of the mice sticking on the channel wall could be seen. After the scaffold was im planted into the mice for 2 weeks, the vascularization area of the histologic section of PPSINCs (VA) in group A (2 260.91±242.35 μm2) was compared with that in group B (823.64±81.29 μm2)，and the difference was sig nificant in statistics（P＜0.01).The VA for 4 weeks in group A (17 284.36 ±72.67 μm2) was compared with that in group B (17 041.14±81.51 μm2), and the difference was not significant in statistics（P＞0.05）.The area of the actin positivestaining (AA) in the histologi c section of PPSINCs for 2 weeks’ implantation in group A (565.22±60.58 μm2) was compared with that in group B (205.91±16.25 μm2), and the difference was signi ficant in statistics（P＜0.01). After the implantation for 4 weeks, the VA in group A (4 321.09±19.82 μm2) was compared with group B (4 260.28±27.17 μm2), and the difference was not significant in statistics（P＞0.05）. Conclusion The PPSINC is a good simple scaffold model of vasculariazation. The in vitro force-vascularization can increase the in vivo vascularization of PPSINCs in the early stage.
Objective Since 2009, assessment of asthma control in Global Initiative for Asthma (GINA) includes current clinical control and future risk. " Current clinical control” is replaced by " symptom control” in GINA 2015, and lung function is excluded from assessment of current clinical control. This study was designed to investigate the agreement in current asthma control assessment between GINA 2009 and 2015, and to explore whether FEV1 monitoring plays an important role in this context. Methods A cross-sectional study was conducted among patients with stable asthma (n=138). The levels of asthma control were graded by GINA 2009 and GINA 2015, respectively. Demographic data, spirometry, exacerbations in the past 12 months, peripheral blood cells, induced sputum were collected. Kappa coefficient was used to measure the agreement of the two asthma control tools. Association of the asthma control levels using the two tools with the exacerbations in the past 12 months was examined by Spearman correlations. Additionally, associations of lung function with the exacerbations in the past 12 months were analyzed. Results Agreement in assessing current asthma control between GINA 2009 and 2015 was moderate (Kappa=0.595, P<0.001). Compared with GINA 2009, the patients with well-controlled asthma assessed by GINA 2015 had worse FEV1%pred [(89.9±12.9)% vs. (79.9±18.2)%, P=0.013], the partly controlled subjects assessed by GINA 2015 had worse asthma control scores in ACQ-6 score (0.8±0.7 vs. 1.1±0.7, P=0.028) and ACT score (20.7±2.5 vs. 19.4±2.5, P=0.007). Furthermore, asthma control levels assessed by either GINA 2015 or 2009 were related to exacerbations in the past 12 months and stronger relationship was presented in GINA 2015 (r=–0.268 for GINA 2015 vs. r=–0.212 for GINA 2009, respectively). In addition, there were no differences in cell counts in induced sputum or peripheral blood or IgE level in peripheral blood in patients with different asthma control levels assessing by GINA 2009 and 2015. Conclusions Our study indicates that it has a moderate agreement of assessing current asthma control between GINA 2015 and 2009. Compared with GINA 2009, absence of FEV1 monitoring from GINA 2015 would result in worse lung function in well-controlled asthma and worse asthma control scores in partly controlled asthma. Addition of FEV1 monitoring to GINA 2015 would weaken the relationship between current asthma control and future asthma outcomes, although it didn't reach statistical significance. Our study supports that GINA 2015 lacking lung function monitoring in current asthma control assessment is applicable in clinical practice.
The master manipulator is a crucial component in enabling interactive perception between the physician and the guidewire/catheter; however, the lack of real-time haptic feedback increases the difficulty of hand–eye coordination. This paper designed and developed a master manipulator for a vascular interventional surgery robot with haptic feedback to provide the physician with high-accuracy force feedback. Using a two-degree-of-freedom decoupling mechanism combining key transmission and bearings, the master manipulator captured the physician’s push–pull and rotational actions accurately and synchronously. The haptic feedback module adopted dual-channel independent control: axial resistance was generated by three springs evenly distributed at 120° and driven by a linear motor, while circumferential resistance was produced directly by a brushed direct current motor. To enhance the fidelity and accuracy of force feedback, inherent friction within the mechanical structure was identified as a critical non-negligible factor. Consequently, a feedforward compensation strategy grounded in the Stribeck friction model was developed and implemented to proactively counteract friction forces. The performance of the axial force module and the circumferential torque module was evaluated, and the displacement acquisition resolutions reached 1 μm and 0.087 9°, respectively. The average error for axial force feedback was 0.11 N, and that for circumferential torque feedback was 0.154 mN·m. The master manipulator was constructed using a combination of custom 3D-printed photosensitive resin parts and machined aluminum alloy, resulting in a lightweight, low-friction structure. It provides an immersive force-interaction experience for the physician, improving operational precision and radiation safety in vascular interventional surgery and enabling coordinated “vision–hand–force perception”.