Cost-effective 3D-printed rotatable reflectors for two-dimensional beam steering.

In this paper, we have developed a 2D optical scanning module comprising cascaded 3D-printed one-axis rotating mirrors with large areas (30×30m m 2 for the X-direction scan and 60×25m m 2 for the Y-direction scan). Each mirror device contains a square or rectangular silicon substrate coated with aluminum, serving as the mirror. A 3D-printed structure, including the mirror frame (with four embedded mini permanent magnets on the backside), torsion springs, and base, is combined with the mirror; two electromagnets are situated under the mirror as the actuation mechanism. We apply DC voltage to the electromagnets to create magnetic force. The electromagnets can interact with the permanent magnets to make the mirror rotate. The X scan of the 2D scanning module can achieve a static optical scan angle of ∼11.8deg at the -X corners, and the corresponding Y-scan angle is ∼4.5deg, both with 12 VDC. Moreover, we have observed a fan-shaped distortion, a phenomenon not thoroughly studied previously for combining two single-axis scan mirrors. Therefore, we also perform a simulation to establish and demonstrate a correlation between the simulation prediction and experimental results. The 2D scanning module can be a low-cost alternative to the expensive conventional galvanometer scanners, and it can be used to upgrade a rangefinder to a simplified LiDAR.

Assessing Continuous Epidural Infusion and Programmed Intermittent Epidural Bolus for Their Effectiveness in Providing Labor Analgesia: A Mono-Centric Retrospective Comparative Study.

Background and Objectives: Local anesthetics administered via epidural catheters have evolved from intermittent top-ups to simultaneous administration of continuous epidural infusion (CEI) and patient-controlled epidural analgesia (PCEA) using the same device. The latest programmed intermittent epidural bolus (PIEB) model is believed to create a wider and more even distribution of analgesia inside the epidural space. The switch from CEI + PCEA to PIEB + PCEA in our department began in 2018; however, we received conflicting feedback regarding workload from the quality assurance team. This study aimed to investigate the benefits and drawbacks of this conversion, including the differences in acute pain service (APS) staff workload, maternal satisfaction, side effects, and complications before and after the changeover. Materials and Methods: Items from the APS records included total delivery time, average local anesthetic dosage, and the formerly mentioned items. The incidence of side effects, the association between the duration of delivery and total dosage, and hourly medication usage in the time subgroups of the CEI and PIEB groups were compared. The staff workload incurred from rescue bolus injection, catheter adjustment, and dosage adjustment was also analyzed. Results: The final analysis included 214 and 272 cases of CEI + PCEA and PIEB + PCEA for labor analgesia, respectively. The total amount of medication and average hourly dosage were significantly lower in the PIEB + PCEA group. The incidences of dosage change, manual bolus, extra visits per patient, and lidocaine use for rescue bolus were greater in the PIEB + PCEA group, indicating an increased staff workload. However, the two groups did not differ in CS rates, labor time, maternal satisfaction, and side effects. Conclusions: This study revealed that while PIEB + PCEA maintained the advantage of decreasing total drug doses, it inadvertently increased the staff burden. Increased workload might be a consideration in clinical settings when choosing between different methods of PCEA.

No association of postoperative opioid usage with long-term surgery outcomes in patients with liver cancer: a population-based retrospective cohort study.

ABSTRACT: Hepatocellular carcinoma (HCC) is a fatal cancer worldwide, and surgical resection remains the standard treatment. Postoperative opioid prescription has been believed to affect cancer recurrence through complex biological pathways. We conducted a retrospective cohort study using the Longitudinal Health Insurance Database of Taiwan to evaluate the relationship between postoperative opioid use and long-term surgical outcomes of patients with HCC. This study had a retrospective cohort design. In total, 812 patients older than 20 years who underwent hepatectomy because of HCC were included. The exposure group comprised patients who used opioids during hospitalization postoperatively. The comparison group included those who never used opioids during hospitalization postoperatively. A Cox proportional hazards model was used to evaluate the overall survival or recurrence-free survival rate between the opioid group and the nonopioid group. A total of 530 patients received opioids postoperatively and 282 patients did not. The hazard ratios of overall survival and recurrence-free survival were 1.10 (95% confidence interval [CI], 0.85-1.41) and 1.15 (95% CI, 0.91-1.46), respectively. Total postoperative opioids were converted into oral morphine milligram equivalents and then divided into 3 equal subgroups: low dose, <40 mg; medium dose, 40 to 144 mg; and high dose, ≥145 mg. The hazard ratios of overall survival were 0.88 (95% CI, 0.63-1.24) for the low-dose group, 1.27 (95% CI, 0.92-1.74) for the medium-dose group, and 1.14 (95% CI, 0.83-1.58) for the high-dose group. Postoperative opioids do not affect overall and recurrence-free survival in patients undergoing hepatectomy or liver transplantation because of HCC. Cancer recurrence should not be a clinical concern regarding postoperative opioid prescription.

Observation of hemodynamic parameters using a non-invasive cardiac output monitor system to identify predictive indicators for post-spinal anesthesia hypotension in parturients undergoing cesarean section.

The administration of high-level spinal anesthesia for cesarean section may lead to significant hemodynamic changes. Bioreactance-based non-invasive cardiac output monitoring (NICOM™) provides an accurate monitoring system for parturients under spinal anesthesia. The present study hypothesized that baseline hemodynamic parameters obtained via the NICOM™ system could serve as predictive indicators for post-spinal anesthesia hypotension. Therefore, 80 full-term parturients with singleton pregnancies who underwent scheduled cesarean section were enrolled and allocated to either a supine position group or a 15˚ left tilt group. All parturients received standard pre-hydration with 750 ml of 0.9% saline. Baseline cardiac output index (CI), total peripheral resistance index (TPRI) and stroke volume (SV) were recorded using the NICOM™ system. Subsequently, spinal anesthesia with 2.4 ml of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl and 0.2 mg of morphine was administered. Receiver operating characteristic (ROC) curves and multivariate logistic regression were used to analyze the data. A total of 40 parturients (51.9%) developed hypotension. The areas under the ROC curves were 0.666, 0.594 and 0.622 for the CI, TPRI and SV, respectively. The optimal cut-off value of the CI in predicting hypotension was 3.68 l/min/m2 (ROC, sensitivity=85.0%, specificity=48.6%). Furthermore, CI was considered as an independent factor for post-spinal anesthesia hypotension. In conclusion, the baseline CI obtained via the bioreactance-based NICOM™ system may serve as a predictor of post-spinal anesthesia hypotension in parturients regardless of patient position.

An alternative method to achieve one-lung ventilation by surgical pneumothorax in difficult lung isolation patient: a case report.

It is challenging to establish one-lung ventilation in difficult airway patients. Surgical pneumothorax under spontaneous breathing to obtain well-collapsed lung is a feasible method for thoracic surgery. A 76-year-old man with right empyema was scheduled for decortication. The patient had limited mouth opening due to facial cellulitis extending from the left cheek to neck. Generally, lung isolation is achieved by double-lumen endotracheal tube or bronchial blocker. Double-lumen tube insertion is difficult for patients with limited mouth opening and right-side placement of bronchial blocker usually causes insufficient deflation. We introduce an alternative lung isolation technique by surgical pneumothorax under spontaneous breathing simply with an endotracheal tube placement. This technique has never been applied into the management of difficult one-lung ventilation. By this method, we provide an ideal surgical condition with safer, less time-consuming, and less skill-demanding anesthesia. It would be an alternative choice for management of one-lung ventilation in the difficult lung isolation patient.