Project description:During the COVID-19 pandemic, a shortage of mechanical ventilators was reported and ventilator sharing between patients was proposed as an ultimate solution. Two lung simulators were ventilated by one anesthesia machine connected through two respiratory circuits and T-pieces. Five different combinations of compliances (30-50 mL × cmH2O-1) and resistances (5-20 cmH2O × L-1 × s-1) were tested. The ventilation setting was: pressure-controlled ventilation, positive end-expiratory pressure 15 cmH2O, inspiratory pressure 10 cmH2O, respiratory rate 20 bpm. Pressures and flows from all the circuit sections have been recorded and analyzed. Simulated patients with equal compliance and resistance received similar ventilation. Compliance reduction from 50 to 30 mL × cmH2O-1 decreased the tidal volume (VT) by 32% (418 ± 49 vs. 285 ± 17 mL). The resistance increase from 5 to 20 cmH2O × L-1 × s-1 decreased VT by 22% (425 ± 69 vs. 331 ± 51 mL). The maximal alveolar pressure was lower at higher compliance and resistance values and decreased linearly with the time constant (r² = 0.80, p < 0.001). The minimum alveolar pressure ranged from 15.5 ± 0.04 to 16.57 ± 0.04 cmH2O. Cross-flows between the simulated patients have been recorded in all the tested combinations, during both the inspiratory and expiratory phases. The simultaneous ventilation of two patients with one ventilator may be unable to match individual patient's needs and has a high risk of cross-interference.
Project description:Lack of access to high-frequency, high-volume patient-derived data, such as mechanical ventilator waveform data, has limited the secondary use of these data for research, quality improvement, and decision support. Existing methods for collecting these data are obtrusive, require high levels of technical expertise, and are often cost-prohibitive, limiting their use and scalability for research applications. We describe here the development of an unobtrusive, open-source, scalable, and user-friendly architecture for collecting, transmitting, and storing mechanical ventilator waveform data that is generalizable to other patient care devices. The system implements a software framework that automates and enforces end-to-end data collection and transmission. A web-based data management application facilitates nontechnical end users' abilities to manage data acquisition devices, mitigates data loss and misattribution, and automates data storage. Using this integrated system, we have been able to collect ventilator waveform data from >450 patients as part of an ongoing clinical study.
Project description:ObjectiveTo develop a simple, robust, safe and efficient invasive mechanical ventilator that can be used in remote areas of the world or war zones where the practical utility of more sophisticated equipment is limited by considerations of maintainability, availability of parts, transportation and/or cost.MethodsThe device implements the pressure-controlled continuous mandatory ventilation mode, complemented by a simple assist-control mode. Continuous positive airway pressure is also possible. The consumption of compressed gases is minimized by avoiding a continuous flow of oxygen or air. Respiratory rates and inspiration/expiration time ratios are electronically determined, and an apnea/power loss alarm is provided.ResultsThe pressure profiles were measured for a range of conditions and found to be adjustable within a ± 2.5cmH2O error margin and stable well within this range over a 41-hour period. Respiratory cycle timing parameters were precise within a few percentage points over the same period. The device was tested for durability for an equivalent period of four months. Chemical and biological tests failed to identify any contamination of the gas by volatile organic compounds or microorganisms. A ventilation test on a large animal, in comparison with a well established ventilator, showed that the animal could be adequately ventilated over a period of 60 minutes, without any noticeable negative aftereffects during the subsequent 24-hour period.ConclusionThis ventilator design may be viable, after further animal tests and formal approval by the competent authorities, for clinical application in the abovementioned atypical circumstances.
Project description:During embryogenesis, the musculoskeletal system develops while containing within itself a force generator in the form of the musculature. This generator becomes functional relatively early in development, exerting an increasing mechanical load on neighboring tissues as development proceeds. A growing body of evidence indicates that such mechanical forces can be translated into signals that combine with the genetic program of organogenesis. This unique situation presents both a major challenge and an opportunity to the other tissues of the musculoskeletal system, namely bones, joints, tendons, ligaments and the tissues connecting them. Here, we summarize the involvement of muscle-induced mechanical forces in the development of various vertebrate musculoskeletal components and their integration into one functional unit.
Project description:BackgroundDespite the increased use of home mechanical ventilation (HMV), data on home care services for HMV users in Asian countries are scarce. This study investigated the current status of HMV use in the Seoul metropolitan area.MethodsThis cross-sectional study involved three university-affiliated hospitals. Subjects who were receiving HMV at home for >3 months were included, and door-to-door visits were done to collect data (e.g., on devices, caregivers, and healthcare service use) from the subjects or their families.ResultsAmong the 140 individuals who were initially screened, 38 adults and 26 children were finally enrolled; the duration of HMV use was 14.5 (8.8-37.5) months and 20.5 (7.0-28.0) months, respectively. Tracheostomy ventilation was performed in 36.8% of the adults and 61.5% of the children, and life-support ventilator in 55.3% and 96.2%, respectively. Regarding ancillary devices, 42.1% of the adults and 80.8% of the children had an oxygen monitoring device, while only one member of each group had a cough assist device. Among those with a tracheostomy, 64.3% of adults and 81.3% of children had an AMBU-bag. Reliance on a family member for care was determined in 65.8% of adults and 88.5% of children, but a home visit by a hospital nurse during the previous year occurred in only 26.3% of the adults and 3.8% of the children. Emergency incidents at home occurred in 39.5% of the adults and 50.0% of the children, with dyspnea being the most common cause. Out-of-pocket expenses tended to be higher in the tracheostomy (vs. non-tracheostomy) group and in children (vs. adults).ConclusionsOur study highlights the challenges faced by adults and children dependent on HMV, and their families. There is an urgent need for nationwide standardization of care for patients receiving HMV at home.
Project description:BackgroundPersonal logbooks are universally applied for monitoring and evaluation of surgical trainees; however, the quality and accuracy of such logbooks in low income countries (LICs) are poorly examined. Logbooks are kept by the individual trainee and detail every surgical procedure they perform and their role during the procedure. The aim of this study was to evaluate the quality of such a logbook system in Sierra Leone and to identify areas of improvement.MethodsThe last 100 logbook entries for students and graduates participating in a surgical task sharing training programme were compared with hospital records (HRs). The logbook entries were categorized as matching, close matching or over-reported. Moreover, HRs were checked for under-reported procedures. Semi-structured interviews were conducted with the study participants on logbook recording routines. The results were analysed using mixed effects logistic regression models.ResultsThree thousand one hundred sixty-nine database entries from 35 participants were analysed. Of that amount, 62.2% of the entries matched the HRs, 10.4% were close matches and 26.9% were over-reported. 20.7% of the investigated HRs were under-reported.ConclusionsInformation gathered from surgical logbook systems must be applied with care, and great efforts must be made to ensure that the logbook systems used provide reliable data. Based on analysis of the logbook data and interviews, focus areas are suggested to ensure reliable logbook data in LICs. Clear instructions and proper training should be provided when introducing the logbook system to the users. The importance of logging all procedures, including minor ones, should be emphasized. The logbook system should be user friendly and only as extensive as necessary. Lastly, keeping the logbooks exclusively digital is recommended, combined with sufficient IT equipment and training.