Closed-loop wearable naloxone injector system

Overdoses from non-medical use of opioids can lead to hypoxemic/hypercarbic respiratory failure, cardiac arrest, and death when left untreated. Opioid toxicity is readily reversed with naloxone, a competitive antagonist that can restore respiration. However, there remains a critical need for technologies to administer naloxone in the event of unwitnessed overdose events. We report a closed-loop wearable injector system that measures respiration and apneic motion associated with an opioid overdose event using a pair of on-body accelerometers, and administers naloxone subcutaneously upon detection of an apnea. Our proof-of-concept system has been evaluated in two environments: (i) an approved supervised injection facility (SIF) where people self-inject opioids under medical supervision and (ii) a hospital environment where we simulate opioid-induced apneas in healthy participants. In the SIF (n = 25), our system identified breathing rate and post-injection respiratory depression accurately when compared to a respiratory belt. In the hospital, our algorithm identified simulated apneic events and successfully injected participants with 1.2 mg of naloxone. Naloxone delivery was verified by intravenous blood draw post-injection for all participants. A closed-loop naloxone injector system has the potential to complement existing evidence-based harm reduction strategies and, in the absence of bystanders, help make opioid toxicity events functionally witnessed and in turn more likely to be successfully resuscitated.

Optimization of a Marine Medium-Speed Engine With Multi-Injector System by 1D Predictive Simulation

The thermal efficiency and emission of large bore marine medium-speed diesel engine are required to be improved under the stringent legislations. A multi-injector system has been proposed in order to improve the thermal efficiency and NOx emission instantaneously. However, application of the multi-injector system increased the complexity of parameter optimization and control. To develop proper control strategy of the novel multi-injector system, a 1D engine model of the original engine configurations was developed initially, including a predictive combustion model in commercial 1D simulation program (GT-Power). After calibrated by test results and literature data under various engine loads, the engine model was modified from a central single injector engine to a multi-injector engine. On the basis of a conventional direct-injection diesel engine, another two injectors were added to the cylinder as side injectors in the model. And the fundamental combustion characteristics and engine performance of the marine medium-speed diesel engine with multi-injector are investigated under various injection quantity ratio between the central injector and side injectors. The effects of injection timing and split injection are also studied by simulation. The result indicated that the effective thermal efficiency and NOx emission of the medium speed marine diesel engine are optimized instantaneously by changing the injection strategies of the central and side injectors. Finally, the preferred injection strategy is proposed by the 1D model.

Experimental Study on Delivery Performance of an Automated Preloaded Intraocular Lens Injector System for Corneal and Sclerocorneal Incisions

Purpose. To evaluate delivery performance of an automated preloaded intraocular lens (IOL) injector systems (AutonoMe) in the porcine eyes. Methods. In the freshly excised porcine eyes, lens removal and IOL implantation were performed. There were 4 groups (10 eyes per group) with different incision site and size: 2.2-mm and 2.4-mm corneal incisions and 2.2-mm and 2.4-mm sclerocorneal incisions. Delivery performance and wound enlargement of AutonoMe were analyzed and compared with those of iTec and iSert from a previous study. Results. There were a few minor troubles associated with AutonoMe, such as overriding plunger within cartridge and trapped trailing haptic during IOL insertion, but the incidence was low. Other interactions were not observed, such as IOL adherence to plunger, sudden ejection of IOL, intrawound lens manipulation, IOL behavior, and gross damage to IOL. AutonoMe caused significantly less wound enlargement for both corneal and sclerocorneal incisions than other injector devices. Wound enlargement by using AutonoMe was significantly smaller with 2.4-mm corneal incision than with 2.2-mm corneal incision, but the final incision size was still smaller with 2.2-mm corneal incision. For sclerocorneal incisions, the amount of wound stretch was not different between 2.2 and 2.4 mm incisions. Conclusion. The wound enlargement caused by the automated preloaded insertion system, AutonoMe, was smaller than that of other preloaded injectors for both corneal and sclerocorneal incisions. There were a few minor technical events during IOL insertion, but the overall incidence was low.

Optimization of Marine Medium Speed Diesel Engine Performance based on Multi-Injector System

Multi-injector system is potential to improve thermal efficiency and NOx emission of diesel engine at the same time. In order to optimize the combustion and emission of Marine medium speed diesel engine, the engine combustion with a multi-injector system is simulated and analyzed by CFD software Converge. In this research, two injectors are installed at the side of the cylinder head while the central injector is maintained. Various injection directions of side injectors and injection strategies of multi-injector system are simulated to optimize the fuel spray and combustion. The analysis results show that the spray angle of the side injector plays a key role for effective thermal efficiency improvement, since complex spray jet-jet interaction and spray impingement may deteriorate the combustion if the arrangement of spray angle was not set properly. Once the fuel injection direction has been optimized, the fuel ratio of the three injectors is optimized and improved the effective thermal efficiency with lower NOx emission. The results show that the two side injectors could increase the fuel injection rate into the cylinder, leading to high brake power and consequently increased the thermal efficiency by 1.26% and decreased the NOx emission by 16% for the best optimization.

Optimization of Operating Parameters for Stable and High Operating Performance of a GDI Fuel Injector System

In this study, a novel injector driving circuit was developed to achieve the regulation of fuel injection quantity and to work with the engine control system in a vehicle. The main purpose of the proposed injector driving circuit is to control the quantity and timing of fuel injection within the gasoline direct injection (GDI) fuel injector system. In this paper, a mathematical state model of a high-pressure (H.P.) fuel injector system is derived and the improved Taguchi method is proposed to define the optimal operating parameter settings of a fuel injector system. The experiments on fuel injection quantity were performed to achieve the requirements of the injector driving circuit. The fuel quantity sprayed from a fuel injector system under these control parameters was analyzed by leading the design of experiments. The S/N and β slopes were analyzed to determine their optimal control settings. The H.P. injector driving circuit developed was designed to drive the fuel injector and spray the injected quantity of fuel into the flask following the optimized control factors. The experimental results demonstrate that the H.P. fuel injecting system exhibits better and more stable operating performance, to assure the accurate injection quantity for the GDI injector, and it was also realized with low cost metal oxide semiconductor field effect transistor (MOSFET) switches.