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 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.
0bjective To evaluate the efficacy of FEV6 and FEV1／FEV6 as surrogates for FVC and FEV1／FVC in the spirometric diagnosis of airway obstruction，and to determine the fixed cut-off point of FEV1／FEV6 which can be used as an alternative for FEV1／FVC lt; 70％.Methods Spirometry measurements were perform ed in 128 participants．FEV1，FEV6，FVC，FEV1％pred，FVC％pred，FEV1／FVC and FEV1／FEV6 were measured and analyzed.FEV1／FVClt;70％ was used as the“gold standard”。Severity of obstruction was based on FEV ％ pred．From ROC curve analysis，the FEV1／FEV6 ratio，which corresponded to optimal combination of sensitivity and specificity，was determined．Correlation between FEV1／FVC and FEV1／FEV6 was studied．Results Of 128 participants，there were 65(51％)with FEV1／FVC ≥70％ ．Of the 63 participants with FEV1／FVC lt;70％ ，there were 5 with FEV1／FEV6 between 70.09％ to 71％。There was no significant difference between the mean value of FVC and that of FEV ．Lifear correlation was revealed between FEV1／FVC and FEV1／FEV6 with the value close to 1(r=0.9979，Plt;0.0001)．From ROC curve analysis，the FEV1／FEV6lt;71.14％ was the best cut-off point coresponding to FEV1／FVC lt;70％ ．Conclusion These results suggest that FEV1／FEV6 is a valid alternative to FEV1／FVC for spirometric diagnosis of airw ay obstruction．There is a b corelation between FEV1／FEV6 and FEV1／FVC．
Objective To systematically review the effectiveness of forced air warming for the maintenance of perioperative core temperature, so as to provide clinical evidence for an appropriate warming plan during the perioperative period. Methods We electronically searched PubMed, The Cochrane Library, EMbase, Web of Science, CBM and CNKI from 2000 to 2012, so as to comprehensively collect randomized controlled trials (RCTs) about the effectiveness of different warming methods for the maintenance of perioperative core temperature (including forced air warming, resistive-heating blanket/electric heating pad, circulating water mattress, and infrared ray radiant heating system) for maintenance of perioperative core temperature. References of the included studies were also retrieved. Two reviewers independently screened literature according to the inclusion and exclusion criteria, extracted data and assessed the quality of the included studies. Then, meta-analysis was performed using RevMan 5.1 software. Results Eleven RCTs involving 577 patients were included. The results of meta-analysis indicated that, in the maintenance of core temperature during the perioperative period, forced air warming was superior to resistive-heating blanket/electric heating pad (SMD= –0.40, 95%CI –0.73 to –0.06), circulating water mattress (SMD= –1.10, 95%CI –1.55 to –0.66), and infrared ray radiant heating system (SMD= –0.69, 95%CI –1.06 to –0.32). In the incidence of hypothermia during the perioperative period, the group of forced air warming was lower than the group of blanket/electric heating pad (RR=1.76, 95%CI 1.15 to 2.69), but it was the same as the group of infrared ray radiant heating system (RR=1.37, 95%CI 0.83 to 2.27). In the incidence of shivering during the perioperative period, the group of forced air warming was the same as the group of blanket/electric heating pad (RR=0.75, 95%CI 0.18 to 3.21) and the group of infrared ray radiant heating system (RR=0.8, 95%CI 0.19 to 3.36). Conclusion Compared with resistive-heating blanket/electric heating pad, circulating water mattress, and infrared ray radiant heating system, forced air warming maintains patients’ core temperature better during the perioperative period, with a lower incidences of hypothermia. Due to the limited quantity and quality of the included studies, more high quality RCTs with large sample size are needed to verify the above conclusion.
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.
In resting platelets, the 17th domain of filamin a (FLNa17) constitutively binds to the platelet membrane glycoprotein Ibα (GPIbα) at its cytoplasmic tail (GPIbα-CT) and inhibits the downstream signal activation, while the binding of ligand and blood shear force can activate platelets. To imitate the pull force transmitted from the extracellular ligand of GPIbα and the lateral tension from platelet cytoskeleton deformation, two pulling modes were applied on the GPIbα-CT/FLNa17 complex, and the molecular dynamics simulation method was used to explore the mechanical regulation on the affinity and mechanical stability of the complex. In this study, at first, nine pairs of key hydrogen bonds on the interface between GPIbα-CT and FLNa17 were identified, which was the basis for maintaining the complex structural stability. Secondly, it was found that these hydrogen bonding networks would be broken down and lead to the dissociation of FLNa17 from GPIbα-CT only under the axial pull force; but, under the lateral tension, the secondary structures at both terminals of FLNa17 would unfold to protect the interface of the GPIbα-CT/FLNa17 complex from mechanical damage. In the range of 0~40 pN, the increase of pull force promoted outward-rotation of the nitrogen atom of the 563rd phenylalanine (PHE563-N) at GPIbα-CT and the dissociation of the complex. This study for the first time revealed that the extracellular ligand-transmitted axial force could more effectively relieve the inhibition of FLNa17 on the downstream signal of GPIbα than pure mechanical tension at the atomic level, and would be useful for further understanding the platelet intracellular force-regulated signal pathway.
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.
Objective To observe the changes of force bearing area and pressures of the rabbit tibiofemoral contact area and the biomechanical reconstruction level of joint after meniscal allograft. Methods A total of 28 Japanese rabbits were involved, weighing 3.0-3.5 kg, male or female. Of 28 rabbits, 7 were selected as meniscus donors, the remaining 21 rabbits were randomized into group A (n=7), group B (n=7), and group C (n=7). Group A underwent single knee opening and suturing, group B underwent medial meniscus excision and suturing, and group C underwent medial meniscus allograft after medial meniscus excision and suturing. The rabbits were sacrified at 12 weeks after operation for biomechanical observation through biomechanical machine and color imaging system. The meniscus tissue specimens were harvested from groups A and C to perform histological and immunohistochemical staining. Results After operation, all rabbits in 3 groups survived to the end of experiment. There were significant differences in the force bearing area and pressures at 0-90° flexion between group B and groups A, C (P lt; 0.05) at 12 weeks, showing no significant difference between group A and group C (P gt; 0.05); and there were significant differences in the force bearing area and pressures at 120° flexion among 3 groups (P lt; 0.05). The histological observation showed that the number of cartilage cells and collagen fibers returned to normal in group C, and the immunohistochemical staining showed that transplanted meniscus of group C contained large amounts of collagen fibers consisting of collagen type I and collagen type II. After 12 weeks of operation, the collagen type I contents were 0.612 5 ± 0.059 8 in group A and 0.587 2 ± 0.063 9 in group C, showing no significant difference (t=0.765, P=0.465); the collagen type II contents were 0.772 4 ± 0.081 5 and 0.814 3 ± 0.051 7, respectively, showing no significant difference (t= —0.136, P=0.894). Conclusion The allograft of rabbit meniscus can significantly increase the force bearing area of the tibiofemoral contact area and reduce the average pressure. Therefore, biomechanically speaking, the meniscus allograft can protect the articular cartilage and reconstruct the biomechanical balance.
Objective To evaluate if the difference between slow vital capacity ( VC) and forced vital capacity ( FVC) could be used to predict severity of airflow limitation in patients with stable chronic obstructive pulmonary disease ( COPD) . Methods VC and FVC were measured in 200 patients with COPD [ 159 males;mean FEV1 , ( 49.31 ±15.75) % of predicted] and 114 healthy controls [ 64 males; mean FEV1 , ( 99.67 ±13.62) % of predicted] . Results The difference between VC and FVC ( VC - FVC) , which showed a negative correlation with FEV1 of predicted ( r=- 0.412, Plt;0.001) , was significantly larger in the COPD patients than that in the controls [ ( 145.40 ±157.50) mL vs. ( 21. 10 ±61. 30) mL, Plt; 0. 001] . The FVC/VC ratio was significantly lower in the COPD patients than that in the controls [ ( 93. 61 ± 7. 10) % vs. ( 99.27 ±2.24) % , P lt; 0.001] , and was positively correlated with FEV1 of predicted in the COPD patients ( r =0.517, P lt;0.001) . There was significant difference in VC - FVC in the COPD patients with FEV1≥50% of predicted ( 5 patients in GOLD level 1 and 74 patients in GOLD level 2) and those patients with FEV1 lt;50% of predicted ( 106 patients in GOLD level 3 and 15 patients in GOLD level 4) [ ( 78.23 ±108.26) mL vs. ( 189.26 ±169.21) mL, P =0.003] . Conclusion The difference between VC and FVC and the FVC/VC ratio, which are more easily obtained from spirometric test, are able to detect severity of airflow limitation in patients with stable COPD.