Quantifying Viscoelastic Properties of Nylon-6,6 Actuators

Orthostatic Hypotension (OH) is a prevalent condition affecting 52.1% of stroke patients, characterized by a drop in atrial blood pressure upon standing. This is due to the pooling of blood in the abdomen and leg, and OH results in debilitating symptoms of nausea, lightheadedness, and dizziness. Current management techniques are limited and not very effective, so I propose an active, compression abdominal band that contracts when needed. This device should have a minimal design, so nylon-6,6 actuators, powerful artificial muscles created from fishing line and conductive thread, were chosen as the compressive element. Given that previous research focused on strength and force-excursion characteristics of these actuators, this study focuses on determining their viability for this application by conducting stress-relaxation and creep tests on single actuators (sample sizes of 10) and on a forty actuator band. Stress-relaxation results indicate that actuators will be able to maintain tension levels required effective compression 18 times as long as necessary. Creep testing is inconclusive due to oscillations found in the data as a result of low processing power of the Instron machine used to conduct tests. Despite the fact that more tests need to be conducted to resolve various limitations of this study,I conclude that I can move forward to create a prototype of the abdominal band.Biomedical Engineerin

Total intravenous anesthesia compared to traditional general anesthesia in shoulder arthroscopy with interscalene block in the beach chair position

Background: Shoulder arthroscopy is commonly performed in the beach chair position, which has been linked to cerebral oxygen desaturation. Previous studies comparing general anesthesia (GA) to total intravenous anesthesia (TIVA) using propofol indicate that TIVA can preserve cerebral perfusion and autoregulation, as well as shorten recovery time and reduce the incidence of postoperative nausea and vomiting. However, few studies have evaluated the use of TIVA in shoulder arthroscopy. Thus, this study seeks to determine if TIVA is superior to traditional GA methods in terms of improving operating room efficiency, shortening recovery time, and reducing adverse events while theoretically preserving cerebral autoregulation in patients undergoing shoulder arthroscopy in the beach chair position. Methods: This is a retrospective study of patients undergoing shoulder arthroscopy in the beach chair position, comparing 2 anesthetic techniques. One hundred fifty patients were included (75 TIVA and 75 GA). Unpaired t-tests were used to determine statistical significance. Outcome measures included operating room times, recovery times, and adverse events. Results: Compared to GA, TIVA significantly improved phase 1 recovery time (53.2 ± 32.9 min compared to 65.8 ± 41.3 min; P = .037) and total recovery time (120.3 ± 31.0 min compared to 131.5 ± 36.8 min; P = .048). TIVA also decreased time from case finish to out-of-room (6.5 ± 3.5 min compared to 8.4 ± 6.3 min; P = .021). However, the in-room to case start time was slightly longer for the TIVA group (31.8 ± 7.22 min compared to 29.2 ± 4.92 min; P = .012). Although not statistically significant, there were fewer readmissions in the TIVA group compared to the GA group (P = .08), and TIVA had lower rates of postoperative nausea and vomiting (P = .22) and higher intraoperative mean arterial pressures (87.1 ± 11.4 mmHg in the TIVA group compared to 85.0 ± 9.3 mmHg in the GA group; P = .22). Conclusion: TIVA may be a safe and efficient alternative to GA in shoulder arthroscopy in the beach chair position. Larger scale studies are needed to evaluate the risk of adverse events related to impaired cerebral autoregulation in the beach chair position

Plastic multilayered closure versus orthopedic surgeon closure after spinal instrumentation in pediatric neuromuscular scoliosis

Objective To compare wound complication rates between orthopedic closure (OC) and plastic multilayered closure (PMC) in patients undergoing primary posterior spinal fusion for neuromuscular scoliosis (NMS). We hypothesize that multilayered closure will be associated with better postoperative outcomes.Methods We collected data on pediatric patients diagnosed with NMS who underwent first time spinal instrumentation between 1 January 2018 and 31 May 2021. Patient demographics, length of surgery, spinal levels fused and operative variables, wound complication rate, treatments, and need for wound washout were reviewed in depth and recorded.Results In total, 86 patients were reviewed: 46 with OC and 40 with PMC. There was a significant increase in operating room (OR) time with PMC compared with OC (6.7±1.2 vs 7.3±1.3, p=0.016). There was no difference in complication rate, mean postoperative day of complication or unplanned return to the OR for OC and PMC, respectively. There was a slightly significant increase in the number of patients going home with a drain in the PMC cohort compared with the OC cohort (2.1% vs 15%, p=0.046).Conclusions PMC demonstrated longer OR times than OC and did not demonstrate a statistically significant reduction in wound complications or unplanned returns to the OR. However, other studies have demonstrated statistical and clinical significance with these variables. Surgical programs should review internal patient volumes and outcomes for spinal fusion in NMS patients and consider if PMC after spinal fusions in pediatric patients with NMS or other scoliosis subtypes is an appropriate option in their institution to minimize postoperative wound complications