Development of a synchronous motion-tracking and video capture tool for flexible ureteroscopy.

INTRODUCTION: Hand/instrument motion-tracking in surgical simulation provides valuable data to improve psychomotor skills and can serve as a formative evaluation tool. Motion analysis has been well-studied in laparoscopic surgery; however, there are essentially no studies looking at motion-tracking for flexible ureteroscopy (fURS ), a common surgical procedure requiring hand dexterity and 3D spatial awareness. We aimed to design a synchronized motion-tracking and video capture system for fURS capable of collecting objective metrics for use in surgical skills training. METHODS: Motion tracking of the ureteroscope was performed using a motion-tracking platform, inertial measurement units (IMUs), and an optical sensor. Position (x, y, z) and orientation (roll, pitch, yaw) of the ureteroscope handle, lever deflection, and translation of the scope insertion point were collected. Video capture of the operator's hands was collected with a Raspberry Pi camera. All peripherals were controlled on a Raspberry Pi 4 and synchronized to its system clock. RESULTS: Our system demonstrated good accuracy in detecting translation of the ureteroscope in the x- and y-axes, and yaw, pitch and roll of the ureteroscope at discrete orientations of 0, ±30, ±60, and ±90 degrees. Unique to fURS, deflection of the lever was captured by the difference in IMU static accelerations with good accuracy. The optical sensor detected translation of the ureteroscope at the insertion point with good precision and an average error of 5.51%. CONCLUSIONS: We successfully developed a motion-tracking and video-capture system capable of collecting motion-analysis parameters unique to fURS . Future studies will focus on establishing the construct validity of this tool.

An Autonomous Continuous Bladder Irrigation System.

Introduction and Objective: Continuous bladder irrigation (CBI) is used in a variety of clinical settings, including post-transurethral surgery and the emergency department. Currently, CBI administration relies on nurses to diligently monitor and switch irrigation bags, as well as titrate the inflow rate based on effluent color. Inappropriate administration can result in discomfort to patients, clot urinary retention, repeat injury to the pathologic or surgical site, extended hospital stays, and even operative management. Our objective was to create an autonomous CBI system that decreases the incidence of disrupted irrigation flow and monitors the outflow to alert clinicians of critical events. Methods: 3D printing and off-the-shelf microcontrollers were used to design a device to fit the needs identified by stakeholders at our institution. An in vitro model of the bladder was created to test our design. The mechanical, electrical, and software subsystems were adjusted accordingly to meet our design requirements. Results: Our in vitro CBI model was able to simulate routine CBI administration with sudden bleeding. Bovine blood was used to simulate the bleeding events. A device was created that met identified stakeholder needs. Accurate detection of critical bleeding events, catheter blockage, and empty irrigation bags were achieved. The device responds to bleeding appropriately by increasing the irrigation rate. When the catheter is blocked, it stops the irrigation and alerts the nurse. Our system accurately titrated the irrigation rate to match a set outflow blood level parameter, conserving irrigation and minimizing nursing workload. Continuous monitoring of CBI effluent was recorded. Conclusions: We anticipate our device will decrease the cognitive load on nurses in busy clinical settings and improve workflow. Moreover, the detection of critical events will likely decrease patient morbidity. Continuous monitoring of the CBI outflow may prove to be a new clinical decision-making tool for ongoing hematuria. Clinical trial is pending.

Relation between surgeon age and postoperative outcomes: a population-based cohort study.

BACKGROUND: Aging may detrimentally affect cognitive and motor function. However, age is also associated with experience, and how these factors interplay and affect outcomes following surgery is unclear. We sought to evaluate the effect of surgeon age on postoperative outcomes in patients undergoing common surgical procedures. METHODS: We performed a retrospective cohort study of patients undergoing 1 of 25 common surgical procedures in Ontario, Canada, from 2007 to 2015. We evaluated the association between surgeon age and a composite outcome of death, readmission and complications. We used generalized estimating equations for analysis, accounting for relevant patient-, procedure-, surgeon- and hospital-level factors. RESULTS: We found 1 159 676 eligible patients who were treated by 3314 surgeons and ranged in age from 27 to 81 years. Modelled as a continuous variable, a 10-year increase in surgeon age was associated with a 5% relative decreased odds of the composite outcome (adjusted odds ratio [OR] 0.95, 95% confidence interval [CI] 0.92 to 0.98, p = 0.002). Considered dichotomously, patients receiving treatment from surgeons who were older than 65 years of age had a 7% lower odds of adverse outcomes (adjusted OR 0.93, 95% CI 0.88-0.97, p = 0.03; crude absolute difference = 3.1%). INTERPRETATION: We found that increasing surgeon age was associated with decreasing rates of postoperative death, readmission and complications in a nearly linear fashion after accounting for patient-, procedure-, surgeon- and hospital-level factors. Further evaluation of the mechanisms underlying these findings may help to improve patient safety and outcomes, and inform policy about maintenance of certification and retirement age for surgeons.

Refinement in the analysis of motion within low-cost laparoscopic simulators of differing size: Implications on assessing technical skills.

BACKGROUND: Simulation is becoming more important in the teaching and assessment of technical skills. The purpose of this study was to refine the use of motion analysis parameters (MAPs) to assess performance of a defined task in low-cost pediatric laparoscopic simulators of differing size. METHODS: 105 participants performed a defined intracorporeal suturing task in large and small pediatric laparoscopic simulators. Outcomes included MAPs - path length, extreme velocity events, and extreme acceleration events in all available degrees of freedom for novices, intermediates, and experts. ANOVA p <0.05 was judged significant. RESULTS: In the smaller simulator, all MAPs discriminated between expertise groups in all degrees of freedom. In the larger simulator, all but one MAP discriminated between expertise groups. Experts demonstrated the greatest variability in performance between the larger and smaller simulators. CONCLUSION: Analysis of motion in the performance of a defined intracorporeal suturing task allowed discrimination between novices, intermediates, and experts in large and small low-cost pediatric laparoscopic simulators. Further refinement in MAPs will determine their role in surgical education. LEVEL OF EVIDENCE: Not applicable.

Inversion group (IG) fitting: A new T1 mapping method for modified look-locker inversion recovery (MOLLI) that allows arbitrary inversion groupings and rest periods (including no rest period).

PURPOSE: The Modified Look-Locker Inversion Recovery (MOLLI) technique is used for T1 mapping in the heart. However, a drawback of this technique is that it requires lengthy rest periods in between inversion groupings to allow for complete magnetization recovery. In this work, a new MOLLI fitting algorithm (inversion group [IG] fitting) is presented that allows for arbitrary combinations of inversion groupings and rest periods (including no rest period). THEORY AND METHODS: Conventional MOLLI algorithms use a three parameter fitting model. In IG fitting, the number of parameters is two plus the number of inversion groupings. This increased number of parameters permits any inversion grouping/rest period combination. Validation was performed through simulation, phantom, and in vivo experiments. RESULTS: IG fitting provided T1 values with less than 1% discrepancy across a range of inversion grouping/rest period combinations. By comparison, conventional three parameter fits exhibited up to 30% discrepancy for some combinations. The one drawback with IG fitting was a loss of precision-approximately 30% worse than the three parameter fits. CONCLUSION: IG fitting permits arbitrary inversion grouping/rest period combinations (including no rest period). The cost of the algorithm is a loss of precision relative to conventional three parameter fits. Magn Reson Med 75:2332-2340, 2016. © 2015 Wiley Periodicals, Inc.

Attentional biases to body shape images in adolescents with anorexia nervosa: an exploratory eye-tracking study.

Body image distortion (BID) plays an important role in the etiology and maintenance of anorexia nervosa (AN). Previous studies of BID in AN showed small biases in visual scanning behavior (VSB) towards images of body shapes. The aim of this study is to investigate biases in VSB when body shape images compete with images with a different theme (social interactions) for subjects׳ attention. When images of thin body shapes (TBS) were presented alongside images of social interactions, AN patients (n=13) spent significantly more time looking at TBSs rather than at social interactions, but controls (n=20) did not. When images of fat body shapes (FBS) were presented alongside images of social interactions, AN patients spent significantly more time looking at FBSs rather than at social interactions, but controls did not. When images of TBSs, FBSs and social interactions were presented alongside each other, AN patients demonstrated a hierarchy in their attention allocation, choosing to spend the most viewing time on TBS images, followed by FBS images and then images with social interactions. Under the three experimental conditions, AN patients demonstrated large biases in their visual scanning behavior (VSB). Biases in VSB may provide physiologically objective measures that characterize patients with AN.