Surgeon Upper Extremity Kinematics During Error and Error-Free Retropubic Trocar Passage.

Introduction And Hypothesis: Surgeon kinematics play a significant role in the prevention of patient injury. We hypothesized that elbow extension and ulnar wrist deviation are associated with bladder injury during simulated midurethral sling (MUS) procedures.

Methods: We used motion capture technology to measure surgeons' flexion/extension, abduction/adduction, and internal/external rotation angular time series for shoulder, elbow, and wrist joints.

Cognitive models for mentally visualizing a sharp instrument in a blind procedure.

Purpose: Our objective was to understand the cognitive strategies used by surgeons to mentally visualize navigation of a surgical instrument through blind space.

Methods: We conducted semi-structured interviews with 15 expert and novice surgeons following simulated retropubic trocar passage on 3D-printed models of pelvises segmented from preop MRIs. Midurethral sling surgery involves blind passage of a trocar among the urethra, bladder, iliac vessels, and bowel while relying primarily on haptic feedback from the suprapubic bone (SPB) for guidance.

Surgeon estimation of retropubic trocar position in blind 3D space.

Introduction And Hypothesis: Retropubic midurethral sling surgery involves the blind passage of trocars near vital organs. We quantified the proximity of surgeons' mental representation of trocar position relative to actual position using a pelvis simulation platform. We hypothesized that novice surgeons, compared with experts, would estimate the trocar's location to be further from the actual location.

Retropubic trocar modified with a load cell to verify contact with pubic bone.

Background: Vital injuries during midurethral sling surgery are avoided by maintaining constant trocar contact with bone, and yet this is challenging for a teaching surgeon to monitor during this blind procedure. We modified a retropubic trocar with a load cell to distinguish on-bone and off-bone movement and tested it on a midurethral sling surgery 3-dimensional surgery simulator.

Methods: Two experts and 3 novice surgeons performed retropubic trocar passage on the physical pelvic floor model using the modified trocar.

Neural control of postural sway: Relationship to strength measures in young and elderly adults.

Age-related changes in postural sway are well-established, and studied from a control perspective using an inverted pendulum model. The purpose of the present work was to expand previous research in this area by investigating relationships between sway-related control parameters and musculoskeletal measures of muscle function and health. Eleven female older adults and eight female young adults completed blood draw, grip, leg extension, and balance tests.

A multimodal assessment of balance in elderly and young adults.

Falling is a significant health issue among elderly adults. Given the multifactorial nature of falls, effective balance and fall risk assessment must take into account factors from multiple sources. Here we investigate the relationship between fall risk and a diverse set of biochemical and biomechanical variables including: skeletal muscle-specific troponin T (sTnT), maximal strength measures derived from isometric grip and leg extension tasks, and postural sway captured from a force platform during a quiet stance task.

Machine learning methods for credibility assessment of interviewees based on posturographic data.

This paper discusses the advantages of using posturographic signals from force plates for non-invasive credibility assessment. The contributions of our work are two fold: first, the proposed method is highly efficient and non invasive. Second, feasibility for creating an autonomous credibility assessment system using machine-learning algorithms is studied.

Deception effects on standing center of pressure.

Accurate deception detection is a desirable goal with many applications including credibility assessment, security screening, counter-terrorism, and homeland security. However, many deception detection methodologies involve intrusive sensors or other limitations that preclude their use in a covert manner. Posturography may overcome these limitations by using minimally invasive force platform technology.

Classification of body movements based on posturographic data.

The human body, standing on two feet, produces a continuous sway pattern. Intended movements, sensory cues, emotional states, and illnesses can all lead to subtle changes in sway appearing as alterations in ground reaction forces and the body's center of pressure (COP). The purpose of this study is to demonstrate that carefully selected COP parameters and classification methods can differentiate among specific body movements while standing, providing new prospects in camera-free motion identification.

The influence of core musculature engagement on hip and knee kinematics in women during a single leg squat.

Purpose/background: Excessive frontal plane motion and valgus torques have been linked to knee injuries, particularly in women. Studies have investigated the role of lower extremity musculature, yet few have studied the activation of trunk or "core" musculature on hip and knee kinematics. Therefore, this study evaluated the influence of intentional core engagement on hip and knee kinematics during a single leg squat.

Effects of age and localized muscle fatigue on ankle plantar flexor torque development.

Background And Purpose: Older adults often experience age-related declines in strength, which contribute to fall risk. Such age-related levels of fall risk may be compounded by further declines in strength caused by acute muscle fatigue. Both age- and fatigue-related strength reductions likely impact the ability to quickly develop joint torques needed to arrest falls.

Age-related differences in kinetic measures of landing phase lateral stability during a balance-restoring forward step.

Lateral stability during stepping is critical to successful balance recovery, and has been previously studied from a kinematics perspective. However, relatively little is known about the kinetic aspects of lateral stability. The purpose of this paper is to investigate age-related changes in laterally directed landing phase ground and joint reactions during a balance-restoring step response.

Automated agar plate streaker: a linear plater on Society for Biomolecular Sciences standard plates.

Several protocols for bacterial isolation and techniques for aerobic plate counting rely on the use of a spiral plater to deposit concentration gradients of microbial suspensions onto a circular agar plate to isolate colony growth. The advantage of applying a gradient of concentrations across the agar surface is that the original microbiological sample can be applied at a single concentration rather than as multiple serial dilutions. The spiral plater gradually dilutes the sample across a compact area and therefore saves time preparing dilutions and multiple agar plates.

Effects of step length on stepping responses used to arrest a forward fall.

This study investigated effects of step length on the stepping response used to arrest an impending forward fall. Twelve healthy young (mean age 22, S.D.

The use of correlation integrals in the study of localized muscle fatigue of elbow flexors during maximal efforts.

Innovative applications of non-linear time series analysis have recently been used to investigate physiological phenomena. In this study, we investigated the feasibility of using the correlation integral to monitor the localized muscle fatigue process in the biceps brachii during sustained maximal efforts. The subjects performed isometric maximum contractions until failure in elbow flexion (90 degrees from neutral).