Low-cost Mesh Research Articles

Performance Evaluation of an IEEE 802.15.4-Based Thread Network for Efficient Internet of Things Communications in Smart Cities

The increasing demand for Internet of Things (IoT) applications has resulted in vast amounts of data, requiring the utilization of big data analytics. The integration of big data analytics in IoT-based smart cities can greatly benefit from the development of wireless communication protocols, among which the Thread protocol has emerged as a promising option. Thread is IEEE 802.15.4 based and has advanced capabilities like mesh networking, IPv6 support, and multiple gateways providing no single point of failure. This paper presents the design and evaluation of a low-cost mesh network using Raspberry Pi, nRF52840 dongle, and OpenThread 1.2 (i.e., an open-source software implementation of the Thread protocol stack). The research elaborates on the hardware and software solutions used, as well as the network topologies adopted. To evaluate the performance of the developed system, extensive real-time tests are performed, considering parameters, such as jitter, packet loss, and round trip time. These tests effectively demonstrate the effectiveness of the Thread network. Furthermore, the impact of varying payload size and bitrate on the network is analyzed to understand its influence. The behavior of the multi-hop network is also examined under link failure scenarios, providing insights into the network’s robustness. Our findings provide valuable insights for researchers interested in designing low-cost and efficient mesh networks for various IoT applications, including home automation, building/campus monitoring systems, distributed industrial IoT applications, and smart city infrastructure.

Hernioplasty using low-cost mesh compared to surgical mesh in low- and middle-income countries: a systematic review protocol.

This review aims to assess the differences in surgical outcomes between hernioplasty using low-cost mesh and surgical mesh in adults undergoing elective hernioplasty in low- and middle-income countries. The use of untreated mosquito netting in inguinal hernioplasty in low- and middle-income countries has been well described in the literature, with two recent limited systematic reviews finding equivalent postoperative surgical outcomes. This comprehensive review, across a wider set of databases and gray literature, will assess a broader set of outcomes including patient and surgeon preference and sterility, report more granular complication outcomes, and include other low-cost mesh alternatives such as resterilized surgical mesh and indigenous products, alongside mosquito net mesh. Adult patients undergoing elective inguinal hernioplasty with mesh in low- and middle-income countries. Electronic bibliographic databases (PubMed, Embase, Scopus, Web of Science and the Cochrane Library) and gray literature databases and trial registers will be searched for experimental studies, either randomized or quasi-randomized controlled trials, comparing hernioplasty with surgical mesh versus low-cost mesh, published in any language from 2000 to the present. Two independent reviewers will conduct the literature search, screen titles and abstracts, assess full-text studies for inclusion, assess methodological quality using the Cochrane Risk of Bias 2 tool, and extract data using a custom extraction tool. Synthesis will involve pooling for statistical meta-analysis with either a random-effects or fixed-effects model, as appropriate, and where this is not possible, findings will be presented in narrative form. PROSPERO CRD42019136028.

Advanced Wireless Sensor Networks for Sustainable Buildings Using Building Ducts

The communication technology ZigBee has been widely adopted in wireless sensor networks (WSNs) for a wide range of industrial applications. However, although ZigBee provides low-power, low-cost mesh networking, it cannot guarantee steady and predictable network performance as channels are time-variant and highly attenuated by man-made obstacles. The networks also suffer from interference, especially in the important 2.4 GHz industrial, scientific, and medical (ISM) band. These degraded channel characteristics increase the number of hops, thus increasing both the packet error rate and transmission delays. In this paper, we report the deployment of a ZigBee-based WSN inside an existing building duct system utilized for intelligent waste collection in an industrial environment. The Received Signal Strength (RSS) and path losses were measured, revealing that the duct communication channel acts as a very effective waveguide, providing a more reliable and consistent network performance than conventional free space channels.

International guidelines for groin hernia management

International guidelines for groin hernia management

Our Experience with the Use of Low Cost Mesh in Tension-Free Inguinal Hernioplasty in Northern Ghana.

To describe our experience and success in the use of low cost mesh for the repair of inguinal hernias in consenting adult patients. A prospective study was carried out from August 2010 to December 2013 in ten district hospitals across Northern Ghana. The patients were divided into four groups according to Kingsnorth's classification of hernias. Low cost mesh was used to repair uncomplicated groin hernia. Those hernias associated with complications were excluded. We assessed the patients for wound infection, long term incisional pain and recurrence of hernia. The data collected was entered, cleaned, validated and analyzed. One hundred and eighty-four patients had tension-free repair of their inguinal hernias using non-insecticide impregnated mosquito net mesh. The median age of the patients was 51 years. The male to female ratio was 7:1. Using Kingsnorth's classification, H3 hernias were (62, 33.7%), followed by the H1 group (56, 30.4%). Local anaesthesia was used in 70% and less than 5% had general anaesthesia. The cost of low cost mesh to each patient was calculated to be $ 1.8(GH¢7.2) vs $ 45(GH¢ 180) for commercial mesh of same size. The benefit to the patient and the facility was enormous. Wound hematoma was noticed in 7% while superficial surgical site infection was 3%. No patient reported of long term wound pain. There was no recurrence of hernia. Low cost mesh such as sterilized mosquito net mesh for use in hernioplasty in resource-limited settings is reasonable, acceptable and cost-effective, it should be widely propagated. None declared.

IMR: High-Performance Low-Cost Multi-Ring NoCs

A ring topology is a common solution of network-on-chip (NoC) in industry, but is frequently criticized to have poor scalability. In this paper, we present a novel type of multi-ring NoC called isolated multi-ring (IMR), which can even support chip multi-processors (CMPs) with 1,024 cores. In IMR, any pair of cores are connected via at least one isolated ring, so that each packet can reach the destination without transferring from one ring to another. Therefore, IMR no longer needs expensive routers as mesh, which not only enhances the network performance but also reduces hardware overheads. We utilize simulated evolution to design optimized IMR topologies. We compare these IMR topologies against nine representative NoCs (e.g., traditional mesh, multi mesh, low-cost mesh, Express-virtual-channels mesh (EVC), torus ring, and hierarchical ring). We observe from experiments that IMR significantly outperforms its competitors in both saturation throughput and latency across all scenarios considered. For example, in a 16 $\times$ 16 CMP, IMR improves the saturation throughput of a state-of-the-art mesh (EVC) by 265.29 percent on average, and reduces the average packet latency on SPLASH-2 application traces by 71.58 percent, while consuming 5.08 percent less area and 9.76 percent less power. In a 32 $\times$ 32 CMP, IMR averagely improves the saturation throughput of EVC by 191.58 percent, and averagely reduces the packet latency on SPLASH-2 application traces by 23.09 percent, while consuming 2.86 percent less area and 10.81 percent less power.

A Randomized Trial of Low-Cost Mesh in Groin Hernia Repair

BackgroundThe most effective method for repair of a groin hernia involves the use of a synthetic mesh, but this type of mesh is unaffordable for many patients in low- and middle-income countries. Sterilized mosquito meshes have been used as a lower-cost alternative but have not been rigorously studied.MethodsWe performed a double-blind, randomized, controlled trial comparing low-cost mesh with commercial mesh (both lightweight) for the repair of a groin hernia in adult men in eastern Uganda who had primary, unilateral, reducible groin hernias. Surgery was performed by four qualified surgeons. The primary outcomes were hernia recurrence at 1 year and postoperative complications.ResultsA total of 302 patients were included in the study. The follow-up rate was 97.3% after 2 weeks and 95.6% after 1 year. Hernia recurred in 1 patient (0.7%) assigned to the low-cost mesh and in no patients assigned to the commercial mesh (absolute risk difference, 0.7 percentage points; 95% confidence interval [CI], −1.2 to 2.6; P=1.0). Postoperative complications occurred in 44 patients (30.8%) assigned to the low-cost mesh and in 44 patients (29.7%) assigned to the commercial mesh (absolute risk difference, 1.0 percentage point; 95% CI, −9.5 to 11.6; P=1.0).ConclusionsRates of hernia recurrence and postoperative complications did not differ significantly between men undergoing hernia repair with low-cost mesh and those undergoing hernia repair with commercial mesh. (Funded by the Swedish Research Council and others; Current Controlled Trials number, ISRCTN20596933.)

Low-cost mosquito mesh effective for hernia repair

Low-cost mosquito mesh effective for hernia repair

Enhancement of Characteristics of a Touch Sensor by Controlling the Multi-Layer Architecture of a Low-Cost Metal Mesh Pattern.

In this study, the characteristics of a metal mesh touch sensor were enhanced by optimizing the multi-layer architecture of the metal mesh pattern. Low-cost metal such as an aluminum (Al) layer was mainly applied to the architectures for practical applications in touch screen panel (TSP) industries. As well, molybdenum (Mo) was added to the architectures in order to minimize the drawbacks of Al. Three types of Mo/Al, Al/Mo and Mo/Al/Mo layers were fabricated by DC sputtering. The thickness of the Al and Mo layer was optimized at 150 and 30 nm, respectively. Low sheet resistance below 0.27 Ω/square was achieved with good adhesion on a glass substrate. Especially, in the case of architectures in which the Al layer was covered with an Mo layer, thermal stability and corrosion resistance was enhanced. The change in resistance of the Mo/Al/Mo architecture was less than 0.056 even after heat-treatment at 260 °C. By using the optimized layer architecture, the mesh pattern with a 4 μm line width showed good optical transmittance (86.7%) and reflectivity (13.1%) at 550 nm, respectively. Also, a touch sensor fabricated by using the Mo/Al/Mo mesh pattern operated well indicating that the mesh pattern is feasible in a TSP application.

An Experimental Vehicular Wireless System and Link Performance Analysis

Reliable wireless communication is a key component for intelligent transportation systems (ITS). This paper develops a wireless module for ITS using an AR7100 series embedding platform. The module consists of a low-cost multi-interface wireless mesh and control unit to provide high quality of services for different applications. It acts as a node in a vehicular wireless network with a pure software extension without costly hardware modifications. The developed system was tested in the urban area of the Wuhan city, China. It is observed that the fast fading effect plays a significant role in the performance of vehicular communications. To characterize these effects, a physical-level model of the radio link between two moving vehicles is proposed. This model takes the impacts of Rician K-factor, vehicle speed ratio, and Doppler spectrum into consideration. Compared with the existing physical models, the proposed physical-level model is shown to be more accurate in describing the packet-level characteristics of vehicle communications. Furthermore, the analysis of the proposed physical-level model indicates the necessity of cross-layer design of vehicular wireless networks.

Low-cost mesh for inguinal hernia repair in resource-limited settings

Hernia repair is one of the most frequently performed surgical procedures worldwide, yet more than half of hernias may be untreated in African countries that lack adequate and affordable surgical care. Although this disease burden can be effectively reduced by surgical repair, public health efforts to promote repair have been sparse because of the presumed high cost of surgery. To review the epidemiology and treatment of hernias in African countries and to assess the efficacy and safety of using low-cost mesh for repair in resource-limited settings. An extensive literature search was performed using PubMed and the Cochrane Library to locate pertinent background information and studies that used low-cost alternatives to commercial mesh. Most hernia repairs in Africa are performed as high-risk emergency procedures. When treatment is provided, fewer than 5% are repaired using implanted mesh because of its high cost, despite the demonstrated improvement in clinical outcomes with tension-free repair. A total of four studies using low-cost mesh were reviewed. Three of the studies compared postoperative outcomes for repairs using sterile mosquito nets with those using commercial surgical mesh. The fourth study randomized patients to receive either an indigenous bilayer device or the Prolene Hernia System. No significant differences in recurrence or in incidence of wound complications between repairs using low-cost and commercial mesh were observed. The price of low-cost mesh was generally less than 1/1,000 the price of commercial mesh. There were no significant differences in outcomes between repairs using low-cost and commercial mesh. While the size of the study populations and the limited time for follow-up preclude conclusive measures of effectiveness, recurrence, and long-term complications, these studies demonstrate that providing an improved standard of surgical care need not be prohibitively expensive.

Commentary on: low-cost mesh for inguinal hernia repair in resource-limited settings

Governments and donor organisations have consistently given priority to sanitation, immunisation, children’s health, women’s health and human immunodeWciency virus (HIV) treatment when funding healthcare in resource-limited countries. This has caused a serious impact on surgical health in rural areas where poverty is endemic and more than 80% of the household income is spent on food. In this setting, healthcare is a luxury. Ozgediz et al. concluded that there is tacit global acceptance for allowing patients to live with chronic surgical disabilities such as hernia, or to die from a lack of access to care [1]. Worldwide, 2–3 billion people do not have basic surgical care. Their nearest rural hospital will have minimal infrastructure, lacks staV and has an acute shortage of electrical supply, running water, oxygen and fuel [2–4]. The average rural hospital only performs Wve operations per week, twothirds do not perform hernia repairs and most operations are emergent [5, 6]. Such a catastrophic picture requires imaginative solutions that apply cheaper, alternative and innovative technologies, such as the low-cost (mosquito net) mesh for inguinal hernia repair reviewed by Yang et al. Undoubtedly, this “frugal innovation” will be challenged by the global healthcare industrial complex. Frugal innovation involves the search for tools and techniques that spare resources, yet maintain or improve outcomes [7]. The hernia healthcare industrial complex has developed over 200 diVerent types of mesh which can be applied to repair hernias of the abdominal wall hernia, with costs ranging from about $40 to $6,000. Powerful marketing strategies which spend $2 for every $1 spent on research and development, and which result in an average spend of $5 on the product, encourage the use of the latest design, which is invariably more expensive than its predecessor. These new hernia devices are rarely put to the test of comparative or randomised trials before marketing. Frugal innovators believe that there is no need to adopt every new piece of equipment, material or device. With this approach applied at multiple levels in India, small for-proWt hospitals can oVer operations at one-Wfth of the price demanded at larger private hospitals. The application of mosquito net mesh to inguinal hernia surgery is another example of inexpensive technology which could meet an overwhelming need in healthcare systems with limited resources [8]. Farmer has recently described the use of mosquito net mesh as a fabulously clever, inexpensive and context-appropriate way to treat inguinal hernia [9]. Even though India is a fast-developing country with world-class facilities, including robotic surgery being performed in many metropolitan cities, the fact remains that around 70% of the Indian population resides in rural areas and 40% of Indians live below the poverty line. Even today, 400 million people in India do not have access even to primary surgical care. Therefore, aVordable surgery, including surgery for hernia using cheaper mesh, is the need of the day. During the last 15 years, mosquito net mesh has been used in India for the repair of hernias [10]. The mesh is 3,700–4,000 times cheaper than commercial meshes and is A. N. Kingsnorth (&) Peninsula College of Medicine and Dentistry, Department of Surgery, Derriford Hospital, Plymouth PL6 8DH, UK e-mail: andrew.kingsnorth@phnt.swest.nhs.uk

Supporting carrier grade services over wireless mesh networks: The approach of the European FP-7 STREP CARMEN [Very Large Projects

CARMEN is a three-year Specific Targeted Research Project (STREP) funded by the European Commission within the 7th Framework Program. The CARMEN access network will complement existing access technologies by exploiting low cost mesh networking techniques, thus minimizing deployment and maintenance costs. The CARMEN architecture introduces an abstraction layer that hides the specifics of the underlying access technology providing an abstract interface on top of which higher layers can be easily developed. This allows for the integration of current and future heterogeneous wireless technologies to provide scalable and efficient mobile ubiquitous Internet access, able to adapt to different environments and user requirements. Following these goals, CARMEN aims to define, study and implement link and technology abstractions, mobility support, and quality of service. The architecture also includes advanced monitoring features that allow for dynamic self-configuration, thereby reducing the installation and operational costs.

Re: Pubovaginal sling with a low-cost polypropylene mesh

OBJECTIVE: The aim of this study was to present the results of pubovaginal sling with a low-cost polypropylene mesh in the treatment of stress urinary incontinence MATERIALS AND METHODS: 118 women diagnosed with stress urinary incontinence (SUI) due to urethral hypermobility or intrinsic sphincteric deficiency, treated with pubovaginal sling (PVS) with a low-cost polypropylene mesh confectioned by the surgeon, were analyzed. All patients had a basic evaluation that included a medical history, physical examination, stress tests and urodynamic investigation RESULTS: The average follow up was of 42 months. Urethral hypermobility was observed in 67% of the cases. The process was carried out on an outpatient basis on 67 patients. Intra-operative complications included 4 vesical injuries, treated with catheterization for 3 days. There were 13 early complications, of which 8 were urinary retentions treated with vesical drainage for 1 to 3 weeks and 3 vaginal extrusions of the mesh treated with covering of the sections with mucous membrane. There was a need for 6 urethrolysis in patients who presented irritative and postoperative obstructive symptoms; 81.3% of the patients were considered cured, while 9.3% had significant improvement. Three initially unsuccessful cases required sling reconfiguration. All cases were eventually cured CONCLUSION: The construction of a pubovaginal sling using a low-cost polypropylene mesh is a safe and effective technique for the relief of SUI. It should be considered an alternative, especially for patients in public health systems with low financial resources.

Microfibrous Mesh Coated with Titanium Dioxide: A Self-Sterilizing, Self-Cleaning Filter

The utility of metal microfibrous mesh coated with titanium dioxide as a self-sterilizing, self-cleaning filter for air is explored. The low-cost mesh is produced via a roll-to-roll process similar to paper manufacturing. The titanium dioxide is applied by spraying an aqueous suspension of the photocatalyst on the surface of the mesh using an airbrush. Photocatalytic activity comparable to a powder layer is achieved at one quarter of the mass loading. The coating enhanced the separation of Escherichia coli (E. coli) from aqueous suspension, but also led to an increase in pressure drop in an air stream flowing through the mesh. The self-cleaning property of the coated mesh is established by recovery of pressure drop performance lost due to biofilm buildup. This is accomplished via a photocatalytic regeneration process involving exposing the mesh to ultraviolet light in air. Oxidation is confirmed by monitoring CO2 evolution during the regeneration. Scanning electron photomicrographs also provide visual evidence of successful regeneration via photocatalysis.

Deployment analysis of large space antenna using flexible multibody dynamics simulation

Flexible multibody dynamics is applied to the deployment analysis of a large space antenna composed of a reflective mesh, a cable network and a deployable truss structure. It is clarified that the tension of some of the cables increase when the reflector is stowed. The largest deployment force is observed slightly before the completion of the deployment. A proper allocation of both translational and rotational springs can provide an efficient deployment force. A deployment experiment on a 4.8 m aperture reflector model verifies the computational results. It is concluded that a flexible multibody dynamics simulation is an indispensable design tool for reducing the weight and ensuring the secure deployment of low-cost mesh reflectors.