In this study, a non-invasive pressure monitoring system that is portable and convenient was designed for detecting compartment syndrome. The system combines a wireless module and smartphone, which aids in the achievement of mHealth objectives, specifically, the continuous monitoring of the compartment pressure in patients. A compartment syndrome detecting method using a wireless sensor system and finite element analysis is developed and verified with an in vitro lower-leg model by rapid prototyping. The sensor system is designed to measure a five point pressure variation from the outside of the lower leg and transmit the data to a smartphone via Bluetooth. The analysis model based on the finite element method is employed to calculate the change of pressure and volume inside the four compartments of the lower leg. The in vitro experimental results show that the non-invasive detecting method can monitor the compartment pressure and provide a warning for the occurrence of compartment syndrome if the compartment pressure is higher than 30 mmHg. Furthermore, the theoretical simulation of the real lower leg shows similar trends to those of the in vitro experiments and can promptly detect the occurrence of compartment syndrome. Measured pressure values exceeding 6.3, 2.7, and 2.8 kPa for the three sensors contacting the outside centers of the superficial posterior, anterior, and lateral compartments, respectively, can indicate that each compartment contains a pressure higher than 30 mmHg. These results can provide a warning for the risk of compartment syndrome of each compartment. In addition, the measured values from the three sensors contacting the superficial posterior compartment at the outside center, close to the tibia, and close to the lateral compartment exceeding 1.8, 0.7, and 0.7 kPa, respectively, can indicate the risk of deep posterior compartment syndrome.

Porous scaffolds fabricated from biodegradable polymers have been widely used and play a vital role in tissue engineering and in situ tissue reconstruction. This study presents a novel fabrication technique involving injection molding and conventional particulate leaching (IM/PL) to obtain the L‐shaped nasal scaffold for rhinoplasty. The results indicate that the porous nasal scaffold made by the IM/PL method shows the acceptable biocompatibility and degradation. The nasal scaffold may degrade well after surgery and the cartilage tissue may grow well in it. This IM/PL technique may replace the traditional artificial silicone filler and reduce the surgery cost. POLYM. ENG. SCI. 2013. © 2012 Society of Plastics Engineers

Polylactide (PLA) is a thermoplastic polymer derived from renewable resources. In this study, we measured the material properties and forming conditions of PLA under the thermal imprint process. The properties of PLA were investigated under various imprint temperatures and imprint times. The results show that increasing the imprint temperature and imprint time results in a progressive rise in Young's modulus and a decrease in elongation at break. Furthermore, if the imprint time exceeds 10 min, crystallinity at imprint temperatures 90 and 110 °C increases visibly. Measurements of rheology properties was performed and the results show viscoelastic behaviors which are combination of irreversible viscous flow and reversible elastic deformation at the temperature of 110–180 °C. The forming conditions of PLA micro structures under thermal imprint technology were studied based on the Taguchi method. The experimental results show that the transfer rate was enhanced to 96.3%. This study therefore contributes to research on the fabrication of biomedical devices using biodegradable polymers produced by the thermal imprint process.

This study presents the concept for a circular imprint process for polylactide (PLA) stent fabrication that can reduce processing time and costs compared to traditional processes. The properties of PLA were measured for the theoretical simulation of the PLA stent firstly. Two proposed simulation models were built to predict the filling rate of the PLA material in the circular imprint process by the finite volume method (FVM) and to comprehend the compressibility of the PLA stent using the finite element method (FEM). A specially designed circular mold and imprint system are employed to imprint the stent structure. Experimental results show a similar trend to the theoretical results for the circular imprint process under varying conditions. Moreover, a filling rate of up to 98.3% can be achieved, and the PLA stent, which had good material properties and compressibility, was fabricated successfully using the circular imprint system.

A biliary stent cutting system based on nanosecond fiber laser was designed in this study. In order to achieve the stent cutting, the main modules and the critical technologies were analyzed. Then with the cutting system, the kerf width size was studied for different cutting parameters including laser power, repetition rate, cutting speed and assisting gas pressure. Finally, a high quality of fabricated nitinol biliary stent was achieved.