Development of a Slider Type Mechanical Ventilator System Using Ambu Bag for Emergency Breathing Assistance

In this paper, a slider type mechanical ventilator system using Ambu bag for emergency breathing assistance device was proposed and evaluated. A new type coronavirus infection occurred in early December 2019, and the infection has spread worldwide. When it became severe, respiratory failure often occurs, and there is concern about a shortage of ventilators. Meanwhile, MIT has released a blueprint for a mechanical type ventilator using an Ambu bag. In this study, we started the development based on the MIT ventilator. In our method, we proposed to reduce the load on the motor compared to the MIT type by using a horizontally moving slider to push in the pads. Using a test lung connected to Ambu bag device, we confirmed the mechanical stability between the MIT type and our proposed device. Next, we confirmed the three pads device manufacturing methods for device failure characteristics when driven for a long time (max two weeks). At last, we introduced the simple proportional type controller, and confirmed the pressure stability. The proposed a slider type mechanical Ambu bag ventilator system could realize that the Ambu bag did not move for at least one week and showed stable driving characteristics. Comparing the three types of pads manufacturing methods, the highest-performance pads used duralumin for the columns, and surface of the pad used ABS resin. Simple P controller real time pressure control experiment shows that it was necessary to device a pressure control method after carefully considering the characteristics of the check valve that responds to non-linear pressure inside the Ambu bag. © 2022 IEEE.

Novel Drone Design Using an Optimization Software with 3D Model, Simulation, and Fabrication in Drone Systems Research

This paper presents the design of a small size Unmanned Aerial Vehicle (UAV) using the 3DEXPERIENCE software. The process of designing the frame parts involves many methods to ensure the parts can meet the requirements while conforming to safety and industry standards. The design steps start with the selection of materials that can be used for the drone, which are polylactic acid (PLA), acrylonitrile styrene acrylate (ASA), and acrylonitrile butadiene styrene (ABS). The drone frame consists of four main parts, which are the center top cover (50 g), the side top cover (10 g), the middle cover (30 g), and the drone’s arm (80 g). A simulation was carried out to determine the stress, displacement, and weight of the drone’s parts. Additionally, a trade-off study was conducted to finalize the shapes of the parts and the various inputs based on their priorities. The outcome of this new design can be represented in design concepts, which involve the use of the snap hook function to assemble two body parts together, namely the middle cover and the center top cover, without the need of an additional fastener.

Experimental investigations into abrasive flow machining (AFM) of 3D printed ABS and PLA parts

PurposeThe surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM).Design/methodology/approachA hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa).FindingsThe developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts.Practical implicationsThe FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study.Research limitations/implicationsThe present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques.Originality/valueAn abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.