A Wireless Pressure Sensor Integrated with a Biodegradable Polymer Stent for Biomedical Applications.

This paper describes the fabrication and characterization of a wireless pressure sensor for smart stent applications. The micromachined pressure sensor has an area of 3.13 × 3.16 mm² and is fabricated with a photosensitive SU-8 polymer. The wireless pressure sensor comprises a resonant circuit and can be used without the use of an internal power source. The capacitance variations caused by changes in the intravascular pressure shift the resonance frequency of the sensor. This change can be detected using an external antenna, thus enabling the measurement of the pressure changes inside a tube with a simple external circuit. The wireless pressure sensor is capable of measuring pressure from 0 mmHg to 230 mmHg, with a sensitivity of 0.043 MHz/mmHg. The biocompatibility of the pressure sensor was evaluated using cardiac cells isolated from neonatal rat ventricular myocytes. After inserting a metal stent integrated with the pressure sensor into a cardiovascular vessel of an animal, medical systems such as X-ray were employed to consistently monitor the condition of the blood vessel. No abnormality was found in the animal blood vessel for approximately one month. Furthermore, a biodegradable polymer (polycaprolactone) stent was fabricated with a 3D printer. The polymer stent exhibits better sensitivity degradation of the pressure sensor compared to the metal stent.

Clinical utility of procalcitonin in severe odontogenic maxillofacial infection.

BACKGROUND: Most of the maxillofacial infections are bacterial infections, and there is a possibility that systemic infections occur by maxillofacial infections. The aim of this study was to investigate the diagnostic value of procalcitonin in patients with odontogenic bacterial infections of the maxillofacial region. METHODS: We enrolled sixty patients, who were admitted with odontogenic maxillofacial infection from September 2018 to March 2020. White blood cell counts, C-reactive protein, and procalcitonin concentrations were evaluated. Sixty patients were classified into two groups, sepsis and non-sepsis groups, based on systemic inflammatory response syndrome. A Student t test was performed to statistically analyze the difference in inflammatory markers between sepsis and non-sepsis groups. RESULTS: The mean procalcitonin values on admission were 7.24 ng/mL (range, 0.09-37.15 ng/mL) and 0.40 ng/mL (range, 0.02-4.94 ng/mL) in the sepsis group and non-sepsis group, respectively. The procalcitonin values between the two groups showed a significant difference (P < 0.05). The area under the curve of procalcitonin was 0.927 (P < 0.001), and the cutoff value of procalcitonin that maximizes the area under the curve was calculated to be 0.87 ng/mL. CONCLUSIONS: According to our study, routine laboratory tests have insufficient accuracy in diagnosing sepsis syndrome. Therefore, it is strongly recommended to perform the procalcitonin test in patients with maxillofacial infection in addition to the conventional laboratory tests to diagnose the systemic inflammatory condition of the patients.