Traditional manual testing of ventilator performance is labor-intensive, time-consuming, and prone to errors in data recording, making it difficult to meet the current demands for testing efficiency in the development and manufacturing of ventilators. Therefore, in this study we designed an automated testing system for essential performance parameters of ventilators. The system mainly comprises a ventilator airflow analyzer, an automated switch module for simulated lungs, and a test control platform. Under the control of testing software, this system can perform automated tests of critical performance parameters of ventilators and generate a final test report. To validate the effectiveness of the designed system, tests were conducted on two different brands of ventilators under four different operating conditions, comparing tidal volume, oxygen concentration, and positive end expiratory pressure accuracy using both the automated testing system and traditional manual methods. Bland-Altman statistical analysis indicated good consistency between the accuracy of automated tests and manual tests for all respiratory parameters. In terms of testing efficiency, the automated testing system required approximately one-third of the time needed for manual testing. These results demonstrate that the designed automated testing system provides a novel approach and means for quality inspection and measurement calibration of ventilators, showing broad application prospects.
Objective To design a novel stentless porcine aortic bioprosthesis and test the feasibility and its function in vitro after the valve was implanted by a modified method. Methods Six stentless porcine aortic bioprosthesis were divided into two groups according to different implantation, single layer suture group: new improvement stentless porcine aortic bioprosthesis sutured with single layer was implanted; double layer suture group: stentless porcine aortic bioprosthesis developmented by our laboratory used double layer suture was implanted. Each group contained three scales: 23 mm ,25 mm and 27 mm. Analogue ex vivo aortic valve replacement was performed , the feasibility of the new implantation was detected. Effective orifice area, transvalvular pressure gradient and regurgitation ratio were recorded at the cardiac output of 2.0 L/min, 3.5 L/min, 5.0 L/min and 7.0 L/min under the guideline of International Organization for tandardization （ISO）5840. Results The average aortic valve implantation time used for single layer suture and tradition double layer suture were 50 min and 70 min respectively. The transvalvular pressure gradient in the single layer suture group were significantly lower than those in double layer suture group under the flow of 5.0 L/min in 23 mm valve and 27 mm valve （13.51±0.51 mm Hg vs. 14.44±0.99 mm Hg, 7.36±0.19 mm Hg vs. 7.53±0.28 mm Hg；P＜0.01）;and the effective orifice area in the single layer suture group were larger than those in double layer suture group in the same case(1.87±0.06 cm2 vs. 1.76±0.08 cm2, 2.26±0.07 cm2 vs. 2.16±0.05 cm2；P＜0.01). There was no statistically difference in other parameters between both groups. Conclusion The novel design of new improvement stentless porcine aortic bioprosthesis used single layer suture has good hemodynamic characteristics as the nature structure . The modified suture method decrease the implantation time.Nemerical data of the evaluation in vitro show that the difference between single layer suture group and double layer suture group in effective orifice area,transvalvular pressure gradient and regurgitation ratio haveno statistical significance. This experiment is the foundation of the animal and clinical experiment in the future.
Finger tapping test is a common testing item for patients with Parkinson's disease (PD) in clinical neurology. It mainly evaluates the fine motor function of patient's hand in three aspects:amplitude, speed and regularity of the movement. This paper focused on the quantitative assessment of regularity of finger tapping movement for PD patients. The movement signals of thumb and index finger were recorded by using inertial sensor unit in the process of tapping test. Two nonlinear dynamic indexes, approximate entropy (ApEn) and sample entropy (SampEn), were calculated, and then the values were statistically analyzed. The experimental results indicated that both indexes had significant differences between patient group and control group. Moreover, the indexes had relatively high correlation with the scores of corresponding unified Parkinson's disease rating scale (UPDRS) item rated by clinical clinician, which illustrated that these two indexes could reflect the injury level of the repetitive finger movement. So, as a reliable method, it can be provided to the clinical evaluation of hand movement function for PD patients.
Neuromuscular disease (NMD) encompasses a group of disorders that affect motor neurons, peripheral nerves, neuromuscular junctions, and skeletal muscles, potentially leading to respiratory muscle impairment and decline in respiratory function, significantly impacting patients' quality of life. In March 2023, clinical practice guideline titled Respiratory Management of Patients with Neuromuscular Weakness was released by the American College of Chest Physicians. This article summarizes, categorizes, and interprets the contents and key points of the guideline, aiming to provide more targeted guidance for clinical healthcare professionals and ultimately enhance the effectiveness of respiratory management for patients with NMD.
With the advancement of research on rare ocular diseases such as inherited retinal dystrophy (IRD) has advanced in recent years, especially breakthroughs in therapeutic approaches represented by cell and gene therapy, potential intervention strategies have emerged for these conditions. Establishing standardized endpoints and evaluation methods for visual function in patients with IRD has become crucial for assessing disease progression, safety, and therapeutic efficacy of innovative treatments. Best corrected visual acuity (BCVA) is widely recognized as one of the primary endpoints for assessing visual function. However, for IRD patients with severe rod photoreceptor dysfunction, who often present with profound low vision or even legal blindness, the applicability of BCVA as a traditional visual function indicator is limited. The multi-luminance mobility test (MLMT) has emerged as a functional visual assessment tool that evaluates the ability to navigate obstacle courses under varying illumination levels. By establishing graded evaluation standards, MLMT objectively quantifies the impact of lighting conditions on patients’ nobility and spatial orientation, providing a novel quantitative tool for assessing visual function in IRD clinical trials. Currently, there is a lack of unified and standardized guidelines for the use of MLMT in China, posing challenges to its implementation in practical clinical research. To address this, Ocular Fundus Disease Society of Chinese Medical Association and Chinese Medical Doctor Association convened a multidisciplinary team comprising clinical experts in genetic retinal diseases, statisticians, and optical specialists to investigate the current applications and technical characteristics of MLMT, ultimately formulating consensus recommendations for its use as a clinical trial endpoint for IRD gene therapies. This consensus aims to provide a set of MLMT operating norms applicable to China's national conditions, guide clinical practice and research in ophthalmology and related disciplines, and promote the standardization process of IRD clinical trials in China, so as to better serve the IRD patient population and promote the development of related fields.
The performance of intelligent prosthetic knee has an important effect on the realization of physiological gait of transfemoral amputees. A new type of single axis hydraulic damping knee prosthesis was designed based on the analysis of physiological gait. The training methods of the stance and swing phase were proposed. Knee prosthesis test was done through simulation and measurement device. The control target of peak flexion angle during swing of knee prosthesis is chosen to be 60–70°. When the damper valve closure was 0%, maximum swing-phase knee flexion angle of knee prosthesis were (86±2)°, (91±3)° and (97±3)° with the speed of 0.8 m/s, 1.2 m/s and 1.8 m/s, respectively. Once the valve closure was changed, maximum swing-phase knee flexion angle with different speeds could be adjusted between 60° and 70° and the required valve closure percentage were separately 25%, 40% and 70%. The damping adjustment law of intelligent knee prosthesis to achieve physiological gait was revealed.
ObjectiveTo observe the changes of visual acuity and fixation properties of eyes with idiopathic macular hole (IMH) before and after surgery. MethodsA prospective clinical study. From September 2019 to December 2020, 25 patients with 25 eyes of IMH diagnosed in Department of Ophthalmology of The Fourth People's Hospital of Shenyang were included in the study. All patients underwent pars plana vitrectomy (PPV) combined with internal limiting membrane stripping. All eyes underwent best corrected visual acuity (BCVA), optical coherence tomography (OCT), and microperimetry before and after surgery. The BCVA examination was carried out using the Snellen visual acuity chart, which was converted into logarithmic minimum resolution angle (logMAR) visual acuity during statistics. The 12° macular sensitivity (MS) and bivariate contour ellipse area (BCEA) were measured by MP-3 microperimetry. The minimum diameter (MIN) and base diameter (BASE) of the macular hole were measured by OCT; the distance between the preferred retinal location (PRL) and the center of the fovea was measured by Image-proplus 6.0 image processing software. At 1 and 3 months follow-up after surgery, the same equipment and methods as before surgery were used to conduct related examinations. The changes of BCVA, PRL distance from the fovea, MS, BCEA, and macular hole shape before and after surgery were compared and observed. One-way analysis of variance was used to compare the indicators before and after surgery. Pearson correlation analysis was used for the correlation between BCVA and preoperative BCVA, PRL and foveal center distance at 3 months after surgery. The correlation between MIN, BCVA, PRL and foveal center before surgery distance, MS, BCEA and BCVA at 3 months after surgery were analyzed by multiple linear regression. ResultsAmong 25 eyes of 25 cases, 1 male had 1 eye, and 24 females had 24 eyes. The macular hole in stage Ⅲ and Ⅳ were 11 eyes and 14 eyes, respectively. MIN and BASE were 537.68±200.09 and 905.48±278.79 μm, respectively. One month after surgery, the hiatus was closed. Before surgery and 1 and 3 months after surgery, the logMAR BCVA of the affected eyes were 0.80±0.17, 0.70±0.21, 0.60±0.25, and the MS were 22.20±3.86, 23.60±3.14, 24.38±2.68 dB, the distances between PRL and the center of the fovea were 537.72±426.05, 402.00±395.06, 236.80±219.54 μm, and BCEA were 7.90±3.43, 6.40±2.67, 4.80±2.32 deg2. Compared with before operation, BCVA (F=7.047, 20.104) and MS (F=1.980, 5.390) were significantly improved at different time after operation, the distance between PRL and fovea center (F=1.265, 9.530), BCEA (F=2.762, 13.617) were decreased, the difference were statistically significant (P＜0.05). The results of correlation analysis showed that BCVA at 3 months after surgery was significantly associated with preoperative MIN (r=0.810), BASE (r=0.664), BCVA before surgery and 1 month after surgery (r=0.854, 0.940), preoperative and surgical MS at 1 month after surgery (r=－0.548, －0.578), distance between PRL and foveal center before surgery and at 1 month after surgery (r=0.833, 0.915), BCEA before surgery and at 1 month after surgery (r=0.636, 0.732) were significantly correlated (P＜0.05). The results of multiple linear regression analysis showed that the distance between PRL and foveal center before surgery and BCVA were risk factors for poor prognosis of BCVA at 3 months after surgery. ConclusionsThe BCVA and MS of eyes with IMH are significantly improved after surgery, and the distance between PRL and foveal center and BCEA decreased. BCVA, PRL and foveal center distance before surgery are risk factors for poor visual acuity after surgery.
Acute zonal occult outer retinopathy (AZOOR) is an acquired retinal diseases. The majority of patients who develop AZOOR are women characterized by an acute onset of visual blurred and scotoma with photopsias. The fundus examination is often normal or appeared mild abnormal. The RPE atrophy of fundus is similar with white syndrome. Although FFA and ICGA features are either unremarkable or unrelated to AZOOR, there are still important in differential diagnosis. The characteristic abnormalities appearance of FAF (complicated and varied), OCT (regional anomaly of ellipsoid zone), visual field (visual field defect) and ERG (decreased amplitude and prolonged latency of rod reaction, maximum reaction, cone reaction and scintillation reaction) are considered critical examinations to the diagnosis of AZOOR. Although there is no effective therapy for AZOOR, it has some self-limitation.
ObjectiveTo observe the changes of macular visual function after myopic foveoschisis (MF) and pars plana vitrectomy (PPV) combined with internal limiting membrane peeling and air filling. MethodsA single-center, retrospective study. From October 2018 to October 2019, 29 MF inpatients (32 eyes) in Tianjin Eye Hospital were included in this study. There were 3 males (4 eyes) and 26 females (28 eyes). The age was 63.00±3.45 years old. Equivalent spherical lens degree was －14.16±2.54 D, and axial length was 29.14±1.04 mm. Among them, 3 patients (3 eyes) had lamellar macular holes. All eyes underwent standard pars plana three-channel 25G PPV combined with internal limiting membrane peeling and air filling. Before surgery and at 1, 3, and 6 months after surgery, macular microperimetry was performed with a macular integrity assessment instrument, and the mean retinal sensitivitie (MS) within 10° of the macula, fovea 2° and 4° fixation rates (P1, P2), 63% and 95% bivariate contour ellipse area (BCEA) were recorded. The comparison of MS, P1, P2, 63%BCEA and 95%BCEA at different times before and after surgery was performed by paired t test; the comparison of fixation stability rate was performed by χ2 test. ResultsCompared with before surgery, there were significant differences in the improvement of MS in affected eyes at 1, 3 and 6 months after surgery (t=－2.208, －3.435,－4.919; P=0.038, 0.002, 0.000). In the pairwise comparison at different times after surgery, only 6 months after surgery and 1 month after surgery were significantly different (P=0.036). Compared with the preoperative P1, P2, 63%BCEA and 95%BCEA, the P1 and P2 of the eyes gradually increased after surgery, while the 63%BCEA and 95%BCEA gradually decreased, however, the difference was not statistically significant (P1: t=－1.595,－1.698,－1.966; P=0.125, 0.104, 0.062. P2: t=－1.622,－1.654,－1.707; P=0.119, 0.112, 0.102. 63%BCEA: t=1.410, 1.409, 1.553; P=0.172, 0.173, 0.135. 95%BCEA: t=1.412, 1.408, 1.564; P=0.172, 0.173, 0.132). Six months after surgery, all the eyes underwent anatomical repositioning of the macular area, and no serious complications such as full-thickness macular hole and macular hole retinal detachment were found. ConclusionsPPV with internal limiting membrane peeling and air filling is an effective and safe method for MF, and the macular function improved significantly within 6 months postoperatively.
Objective To investigate the control level in asthmatic patients who were members of asthma association in the People’s Hospital of Peking university.Methods 76 asthmatic patients attended the Third Meeting of asthma association and asthma test was conducted.The patients self-evaluated the state of illness，filled the questionnaire of asthma control test（ACT） while peak expiratory flow（PEF） was measured.The steroids usage was also investigated.Results The average age of the patient investigated was（60.6±11.5）year old.The percentage of well control by self-evaluation was 89.5%（62/76）；75%（48/64） by ACT questionairs.50.8%（31/61）of the patients fell in green region and 36.1%（22/61）fell in yellow region of PEF.The coincidence rate of self-evaluation with ACT was 40.6%.ACT scores comparable to green region，yellow region and red region were 21.33±3.44，21.12±3.24 and 17.43±4.47 respectively.There were no significant difference of ACT score between green region group and yellow region group，or yellow region group and red region group.Conclusions Most of asthma association members could achieved well control which could be ascribed to asthma education and management program on the basis of partner relationship between doctors and patients.