A portable TDCR system

Portable oxygen devices simplify and facilitate patient therapy. This study was designed to compare S(pO2) and patient satisfaction with a portable oxygen concentrator or a combined system consisting of a fixed device with continuous-flow oxygen dispensation and a portable device with pulse dispensation for ambulation. This crossover trial assessed 25 subjects with COPD (92% men, mean age of 72.2 ± 7.4 y, mean FEV1 of 34.14 ± 12.51% of predicted) at 4 hospitals in Madrid. All subjects had previously used the combined system, consisting of a fixed oxygenation system and a portable system for ambulation, with 16 (64%) using stationary and portable concentrators and 9 (36%) using a stationary reservoir and portable liquid oxygen bag. Oxygenation settings at rest and while walking were determined at baseline. Subjects were maintained on the previous combined system for 1 week and then switched to the portable oxygen concentrator for 1 week. Mean S(pO2) over 24 h was calculated using the software in the oximeter, and compliance was monitored (Visionox). Low S(pO2) (< 90%) was significantly more frequent during use of the portable concentrator alone than with the combined system (37.1% vs 18.4%, P < .05). The portable system alone was preferred by 43% of subjects, and the combined system was preferred by 36%, whereas 21% were not sure. Subjects preferred using a single portable oxygenation system both at home and during ambulation. Portable systems alone, however, did not supply the same levels of oxygenation as the combination of fixed and portable systems. Before the widespread adoption of portable systems as a single device, additional studies are needed to determine best-practice protocols for adjustment of daytime and nighttime oxygenation settings. (ClinicalTrials.gov registration NCT02079753).

Life cycle assessment of biochar produced from forest residues using portable systems

In recent years, kinematic laser scanning has become increasingly popular because it offers many benefits compared to static laser scanning. The advantages include both saving of time in the georeferencing and a more favorable scanning geometry. Often mobile laser scanning systems are installed on wheeled platforms, which may not reach all parts of the object. Hence, there is an interest in the development of portable systems, which remain operational even in inaccessible areas. The development of such a portable laser scanning system is presented in this paper. It consists of a lightweight direct georeferencing unit for the position and attitude determination and a small low-cost 2D laser scanner. This setup provides advantages over existing portable systems that employ heavy and expensive 3D laser scanners in a profiling mode.A special emphasis is placed on the system calibration, i. e. the determination of the transformation between the coordinate frames of the direct georeferencing unit and the 2D laser scanner. To this end, a calibration field is used, which consists of differently orientated georeferenced planar surfaces, leading to estimates for the lever arms and boresight angles with an accuracy of mm and one-tenth of a degree. Finally, point clouds of the mobile laser scanning system are compared with georeferenced point clouds of a high-precision 3D laser scanner. Accordingly, the accuracy of the system is in the order of cm to dm. This is in good agreement with the expected accuracy, which has been derived from the error propagation of previously estimated variance components.

Experience with Operating and Controlling an In-pit Portable Crushing and Conveying System

The HeartMate left ventricular assist system (LVAS) is now in worldwide use in more than 100 clinical centers. To date, more than 700 implants have been completed, primarily to support patients as a bridge to a biologic heart transplant. Patients have been successfully supported for up to 546 days with a pneumatic-powered device and up to 503 days with an electrically-driven system. These implants have demonstrated the feasibility of this technology. The time has now come to evaluate these systems for permanent, use in the nontransplant category. Patients in this category will tend to be older than the average age of 50 previously evaluated in the bridge category. Analysis of our database indicates that patients in the 61–70-year age group (n = 103) did as well as patients in the overall group of 13–70 years of age (n = 591). Of interest, the 61–70-year age group that received devices did significantly better than the equivalent control patients: 60% transplant rate vs 13%. In the future, patients will be supported for longer and longer periods of time. We will need to develop systems that are smaller, more reliable, quieter, more efficient, and less costly. In addition, portable systems will be of paramount importance to support future patients and to expand the use of this technology. Two clinical trials are being carried out in the USA to demonstrate the safety and effectiveness of our portable pneumatic driver and our portable electric system as a bridge to transplant. A third clinical trial is being carried out to evaluate our electric system as a permanent system in patients who do not qualify for a transplant. The trial consists of studying 65 LVAS patients and 65 randomized control patients receiving the best medical therapy available. All three studies are designed to discharge patients into the home environment.

Portable systems are the trend nowadays, especially during this time that handheld devices have almost the same capability as with most of our computers. Developing a portable system for identifying the specie of a dried sea cucumber would be the focus of this study. Sea cucumber is one of the highest valued marine products of the Philippines. When in dried form, a sea cucumber would be difficult to identify its specie. To correctly identify, the researcher proposed a system that could be use by the traders or collectors. Since most of the collectors and buyers of the dried sea cucumber were from different islands and barangays, having a portable device would be convenient. The prototype of the specie identifier was made up of two layers, the lower box was the base holding the retractable tray while upper box or top cover was the enclosure of most of the electronic components. Raspberry pi was the main controller, processing the data captured by the pi camera and executing different image processing techniques like feature extraction and classification to produce a predicted output. The whole system was powered by 18650 batteries and a power bank. The operation of the system can be controlled through a 7-inch touchscreen Pi display. The portable specie identifier system works properly according to its designed features and functionality. The system was tested using test data employing k-fold cross validation technique, it yields 75.26% overall accuracy in identifying dried sea cucumber specie.

Cycle life of a battery largely varies according to the battery operating conditions, especially the battery temperature. In particular, batteries age much faster at high temperature. Extensive experiments have shown that the battery temperature varies dramatically during continuous charge or discharge process. This paper introduces a forced convection cooling technique for the batteries that power a portable system. Since the cooling fan is also powered by the same battery, it is critical to develop a highly effective, low power-consuming solution. In addition, there is a fundamental tradeoff between the service time of a battery equipped with fans and the cycle life of the same battery. In particular, as the fan speed is increased, the power dissipated by the fan goes up and hence the full charge capacity of the battery is lost at a faster rate, but at the same time, the battery temperature remains lower and hence the battery longevity increases. This is the first work that formulates the adaptive thermal management problem for batteries (ATMB) in portable systems and provides a systematic solution for it. A hierarchical algorithm combining reinforcement learning at the lower level and dynamic programming at the upper level is proposed to derive the ATMB policy.

Commercially available portable metabolic systems have been validated with samples of young, healthy, and well-fit subjects, but use of these systems with a special population, such as healthy but sedentary pregnant women, requires a unique set of considerations. These include a woman's limited testing time necessary for fetal safety, relatively low oxygen consumption, and the unique physiology of pregnancy (woman, the placenta, and the fetus). The purpose of this study was to validate a portable metabolic testing system (VO2000) with healthy sedentary pregnant women. A total of 9 sedentary pregnant women who averaged 30 years of age (SD=3), 93 kg (SD=19) weight, 163 cm (SD=7) height, and at 19 weeks' gestation (SD=5) volunteered to participate. Submaximum fitness tests using the Cornell protocol were conducted once with two systems (VO2000 and CPX/D, a reference) simultaneously, and then subsequently twice with one system (VO2000). The VO2000 consistently overestimated VO2 measurement, compared to the same manufacturer's reference system, by 4.4 +/- 3.6 (SD) ml/kg/min, and when VO2000 was used twice, the mean difference was statistically significant (1.0 +/- 1.8 [SD] ml/kg/min; t(45) = 3.9, p < .001). The results of the study show that although VO2000 is an established and validated portable metabolic system for measurement on adult males and females who are relatively well fit, this portable system consistently overestimates VO2 readings for pregnant women compared to standard full-size system. Measurements, when repeated, were not consistent.

In this paper, an in-line, low-cost, miniature and portable spectrophotometric detection system is presented and used for fast protein determination and calibration in centrifugal microfluidics. Our portable detection system is configured with paired emitter and detector diodes (PEDD), where the light beam between both LEDs is collimated with enhanced system tolerance. It is the first time that a physical model of PEDD is clearly presented, which could be modelled as a photosensitive RC oscillator. A portable centrifugal microfluidic system that contains a wireless port in real-time communication with a smartphone has been built to show that PEDD is an effective strategy for conducting rapid protein bioassays with detection performance comparable to that of a UV-vis spectrophotometer. The choice of centrifugal microfluidics offers the unique benefits of highly parallel fluidic actuation at high accuracy while there is no need for a pump, as inertial forces are present within the entire spinning disc and accurately controlled by varying the spinning speed. As a demonstration experiment, we have conducted the Bradford assay for bovine serum albumin (BSA) concentration calibration from 0 to 2 mg mL(-1). Moreover, a novel centrifugal disc with a spiral microchannel is proposed for automatic distribution and metering of the sample to all the parallel reactions at one time. The reported lab-on-a-disc scheme with PEDD detection may offer a solution for high-throughput assays, such as protein density calibration, drug screening and drug solubility measurement that require the handling of a large number of reactions in parallel.

Abundant study on the hemodynamic response of a brain have brought quite a few advances in technologies of measuring it. The most benefitted is the functional near infrared spectroscope (fNIRS). A variety of devices have been developed for different applications. Because portable fNIRS systems were more competent to measure responses either of special subjects or in natural environment, several kinds of portable fNIRS systems have been reported. However, they all required a computer for receiving data. The extra computer increases the cost of a fNIRS system. What’s more noticeable is the space required to locate the computer even for a portable system. It will discount the portability of the fNIRS system. So we designed a self-contained eight channel fNIRS system, which does not demand a computer to receive data and display data in a monitor. Instead, the system is centered by an ARM core CPU, which takes charge in organizing data and saving data, and then displays data on a touch screen. The system has also been validated by experiments on phantoms and on subjects in tasks.

This study compared the accuracy of three dimensional (3D) mini-optical navigation and accelerometer-based portable navigation systems for cup positioning during a total hip arthroplasty (THA) in the supine position. This retrospective cohort study assessed data for 77 hips using 3D mini-optical navigation (n = 37) and accelerometer-based portable navigation (n = 40). The patients underwent THA through the mini-anterolateral approach in the supine position using a portable navigation system. We assessed the preoperative target angles, recorded intraoperative cup angles, postoperative CT imaging angles, cup angle measurement errors, and other clinical parameters. The mean absolute differences in radiographic inclination were similar between 3D mini-optical navigation and accelerometer-based portable navigation systems during THA in the supine position (2.8° ± 1.7° vs 2.8° ± 1.9°, p = 0.637). The mean absolute differences in radiographic anteversion were also similar (2.6° ± 2.3° vs 2.5° ± 1.9°, p = 0.737). Cup malalignment (absolute difference of inclination or anteversion between postoperative CT and preoperative target angle of > 5°) was significantly associated with body mass index (BMI) in accelerometer-based portable navigation but not in 3D mini-optical navigation. This is the first study to compare the accuracy of cup positioning between 3D mini-optical and accelerometer-based navigations in THA in the supine position. Both portable navigation systems accurately identified the orientation of cup placement. The accuracy of 3D mini-optical navigation is not affected by high BMI and may be preferred over other options in such patients.

There is a growing need of portable ultrasound imaging systems since it can allow clinicians to access and diagnose a patient at the scene of an accident or at the patient's bedside due to their improved accessibility. Portable ultrasound imaging systems have been developed based on application-specific integrated circuits (ASICs). However, this ASIC approach is typically beneficial to well-defined targeted applications such that its usefulness for POC systems would be limited. The recent advance in application processors (APs) and graphics processing units embedded in smartphones can facilitate smartphone-based portable ultrasound imaging systems. In this paper, the feasibility of the smartphone-based portable ultrasound imaging system is demonstrated where the high-end Android smartphone (i.e., Samsung's Galaxy Note II) is used for performing core ultrasound B-mode signal and image processing (e.g., quadrature demodulation and scan conversion). The ultrasound B-mode image reconstructed from the Android smartphone where an 850×800 image is reconstructed and displayed. The total execution time to perform core functional blocks for 128-scanline, 512-sample data is about 520 milliseconds.

A portable fluorescence detection system for use with microchip electrophoresis was developed and compared to a benchtop system. Using this system, six neuroactive amines commonly found in brain dialysate (arginine, citrulline, taurine, histamine, glutamate, and aspartate) were derivatized offline with naphthalene-2,3-dicarboxaldehyde/cyanide, separated electrophoretically, and detected by fluorescence. The limits of detection for the analytes of interest were 50 - 250 nM for the benchtop system and 250 nM - 1.3 μM for the portable system, both of which were adequate for most analyte detection in brain microdialysis samples. The portable system was then demonstrated for the detection of the same six amines in a rat brain microdialysis sample.

Classifying threats with a 14-MeV neutron interrogation system

Electrical grounding is an indispensable part of the power system network. The grounding system is mainly affected by grounding resistance and the nature of the soil. High ground resistance produces the phenomenon of soil ionization, surface arching, and back flashover. A conventional grounding system requires the deep digging of electrodes, thus creating maintenance difficulties. This research work focuses on the safe operation of an electric power system from external and internal impulses arising due to lightning strikes or short circuits. The study proposes an application of mineral samples as grounding materials, and bentonite is used as backfilling material in portable grounding systems. A detailed experimental analysis was conducted under controlled conditions to evaluate the performance of selected materials in high-resistance soil. The problem of a deeply driven electrode is addressed by designing the portable grounding system. The study results demonstrate that the proposed portable grounding system could be installed in troubled environments such as forests, deserts, and rocky terrains. To measure the breakdown voltages of the proposed samples, X-ray Diffraction (XRD) analysis and other laboratory tests were conducted. The electric field intensities are extracted through Finite Element Analysis (FEA). The experimental and simulation findings show the expected performance of mineral samples under various operating conditions. The findings of this study can guide the practitioners for safe and efficient operations of portable electrical grounding systems.