Clinical evidence based review and recommendations of aerosol generating medical procedures in otolaryngology - head and neck surgery during the COVID-19 pandemic.

BACKGROUND: Aerosol generating medical procedures (AGMPs) present risks to health care workers (HCW) due to airborne transmission of pathogens. During the COVID-19 pandemic, it is essential for HCWs to recognize which procedures are potentially aerosolizing so that appropriate infection prevention precautions can be taken. The aim of this literature review was to identify potential AGMPs in Otolaryngology - Head and Neck Surgery and provide evidence-based recommendations. METHODS: A literature search was performed on Medline, Embase and Cochrane Review databases up to April 3, 2020. All titles and abstracts of retrieved studies were evaluated and all studies mentioning potential AGMPs were included for formal review. Full text of included studies were assessed by two reviewers and the quality of the studies was evaluated. Ten categories of potential AGMPs were developed and recommendations were provided for each category. RESULTS: Direct evidence indicates that CO2 laser ablation, the use of high-speed rotating devices, electrocautery and endotracheal suctioning are AGMPs. Indirect evidence indicates that tracheostomy should be considered as potential AGMPs. Nasal endoscopy and nasal packing/epistaxis management can result in droplet transmission, but it is unknown if these procedures also carry the risk of airborne transmission. CONCLUSIONS: During the COVID-19 pandemic, special care should be taken when CO2 lasers, electrocautery and high-speed rotating devices are used in potentially infected tissue. Tracheal procedures like tracheostomy and endotracheal suctioning can also result in airborne transmission via small virus containing aerosols.

Dynamical analysis and development of a biologically inspired SMA caterpillar robot.

With the goal of robustly designing and fabricating a soft robot based on a caterpillar featuring shape memory alloy (SMA) actuators, analytical and numerical models for a soft robot were created based on the forward crawling motion of the Manduca sexta caterpillar. The analytical model features a rod theory and the mechanics of undulation were analyzed using a motion pattern based on the 'Witch of Agnesi' curve. Complementing these models, experiments on a SMA actuator sample were performed in order to determine its flexural rigidity and curvature as a function of the actuation voltage. A series of these actuators can be modeled as a system of rigid bodies connected by torsional springs. As these bodies are actuated according to the motion pattern based on the individual caterpillar segments, ground contact forces are calculated and analyzed to determine the requirements of successful forward locomotion. The energetics of the analytical and numerical models are then compared and discussed.

The roles of impact and inertia in the failure of a shoelace knot.

The accidental untying of a shoelace while walking often occurs without warning. In this paper, we discuss the series of events that lead to a shoelace knot becoming untied. First, the repeated impact of the shoe on the floor during walking serves to loosen the knot. Then, the whipping motions of the free ends of the laces caused by the leg swing produce slipping of the laces. This leads to eventual runaway untangling of the knot. As demonstrated using slow-motion video footage and a series of experiments, the failure of the knot happens in a matter of seconds, often without warning, and is catastrophic. The controlled experiments showed that increasing inertial effects of the swinging laces leads to increased rate of knot untying, that the directions of the impact and swing influence the rate of failure, and that the knot structure has a profound influence on a knot's tendency to untie under cyclic impact loading.

Objective and subjective scar aesthetics in minimal access vs conventional access parathyroidectomy and thyroidectomy surgical procedures: a paired cohort study.

OBJECTIVE: To determine if performing parathyroidectomy surgery through minimal access (MA) incisions has any notable aesthetic or quality-of-life impact on patients compared with conventional access (CON) techniques. DESIGN: Paired cohort with (1) a prospective MA incision and scar cohort and (2) a sex- and age-matched (within 3 years) retrospective CON incision and scar cohort. SETTING: Tertiary care center. PATIENTS: Fifteen patients enrolled in prospective study protocol over a 2-year period; 11 patients met inclusion criteria. A sex- and age-matched retrospective cohort of patients was selected from a patient population undergoing surgical treatment of thyroid neoplastic diseases using a CON approach. Inclusion criteria were use of MA incision for parathyroidectomy and return for long-term follow-up scar assessment. INTERVENTIONS: Minimal access parathyroidectomy surgery vs CON thyroidectomy surgical procedures, postoperative follow-up assessment of scar aesthetics by patient and naive viewers, and digital photography and analysis of the surgical incision site. All patients were followed for at least 8 months after surgery. MAIN OUTCOME MEASURES: The Patient and Observer Scar Assessment Scale (POSAS), Vancouver Scar Scale, and photographic scar analysis by naive viewers. RESULTS: There was no significant difference in scar assessment scale scores between the MA and CON cohorts and no clinically significant difference in overall patient satisfaction with scars between cohorts (POSAS: Patient Scar Assessment Scale, P = .14, and Observer Scar Assessment Scale, P = .79; Vancouver Scar Scale, P = .76). There was increased visibility of scars in the CON cohort to naive viewers. CONCLUSIONS: Although they were more readily visible to naive viewers, CON (larger) cervical scars created in parathyroidectomy or thyroidectomy surgery do not translate into decreased patient satisfaction with their scar result. This may indicate a limited quality-of-life benefit in using MA approaches in transcervical surgical procedures.