Dataset Information

Unintentional Movements During the Use of Vitreoretinal Forceps.

ABSTRACT:

Purpose

Intraocular forceps used in vitreoretinal surgery are actuated by squeezing their handles. We studied the relationship between actuation and any accompanying unintentional movements of the instrument tip, and compared different handle designs and gauges.

Methods

Optical sensors were used to measure involuntary movements of forceps tips while monitoring the extent of actuation. Mean root mean square (RMS) and ranges of signals obtained from sensors were computed before and after applying high (7-13 Hz) and low (<5 Hz) frequency filters. Four handle designs, two gauge sizes, and two users were compared to each other.

Results

In the absence of human contact, mean RMS of noise was 6.47 ? and mean range was 21.67 ?. When the forceps were held by the surgeon but kept motionless (no actuation), mean RMS was 58.01 ? and mean range was 156.66 ?. When the forceps were actuated, mean RMS was 214.71 ? and mean range was 566.11 ?. The differences were statistically significant (P < 0.001). The process of actuation by both users was positively correlated with unintentional movements mainly at low frequencies. No statistically significant differences were found between users and between two gauges (23 and 27) at mixed and low frequencies. Pneumatic handles showed less RMS and range values at higher frequencies compared to conventional handle designs. Eliminating human error by fixing pneumatic forceps to the model did not reduce unintentional movements, but eliminated their correlation with actuation.

Conclusions

Actuating forceps was associated directly with increased unintentional low frequency movements at the tip of the forceps when held by hand.

Translational relevance

A novel system of measuring unintentional forceps tip movement during actuation is described which could be used to guide improved design.

SUBMITTER: Dogramaci M

PROVIDER: S-EPMC6314061 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

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Publications

Unintentional Movements During the Use of Vitreoretinal Forceps.

Dogramaci Mahmut M Steel David H DH

Translational vision science & technology 20181101 6

<h4>Purpose</h4>Intraocular forceps used in vitreoretinal surgery are actuated by squeezing their handles. We studied the relationship between actuation and any accompanying unintentional movements of the instrument tip, and compared different handle designs and gauges.<h4>Methods</h4>Optical sensors were used to measure involuntary movements of forceps tips while monitoring the extent of actuation. Mean root mean square (RMS) and ranges of signals obtained from sensors were computed before and ...[more]

PMID: 30619648

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Project description:BackgroundThe objective of this study was to identify and qualify, by means of a three-dimensional kinematic analysis, the postures and movements of obstetricians during a simulated forceps birth, and then to study the association of the obstetricians' experience with the technique adopted.MethodFifty-seven volunteer obstetricians, 20 from the Limoges and 37 from the Poitiers University hospitals, were included in this multi-centric study. They were classified into 3 groups: beginners, intermediates, and experts, beginners having performed fewer than 10 forceps deliveries in real conditions, intermediates between 10 and 100, and experts more than 100. The posture and movements of the obstetricians were recorded between December 2020 and March 2021 using an optoelectronic motion capture system during simulated forceps births. Joint angles qualifying these postures and movements were analysed between the three phases of the foetal traction. These phases were defined by the passage of a virtual point associated with the forceps blade through two anatomical planes: the mid-pelvis and the pelvic outlet. Then, a consolidated ascending hierarchical classification (AHC) was applied to these data in order to objectify the existence of groups of similar behaviours.ResultsThe AHC distinguished four different postures adopted when crossing the first plane and three different traction techniques. 48% of the beginners adopted one of the two raised posture, 22% being raised without trunk flexion and 26% raised with trunk flexion. Conversely, 58% of the experts positioned themselves in a "chevalier servant" posture (going down on one knee) and 25% in a "squatting" posture before initiating traction. The results also show that the joint movement amplitude tends to reduce with the level of expertise.ConclusionForceps delivery was performed in different ways, with the experienced obstetricians favouring postures that enabled observation at the level of the maternal perineum and techniques reducing movement amplitude. The first perspective of this work is to relate these different techniques to the traction force generated. The results of these studies have the potential to contribute to the training of obstetricians in forceps delivery, and to improve the safety of women and newborns.

Project description:ImportanceVitreoretinal surgery can be technically challenging and is limited by physiologic characteristics of the surgeon. Factors that improve accuracy and precision of the vitreoretinal surgeon are invaluable to surgical performance.ObjectivesTo establish weight-adjusted cutoffs for caffeine and β-blocker (propranolol) intake and to determine their interactions in association with the performance of novice vitreoretinal microsurgeons.Design, settings, and participantsThis single-blind cross-sectional study of 15 vitreoretinal surgeons who had less than 2 years of surgical experience was conducted from September 19, 2018, to September 25, 2019, at a dry-laboratory setting. Five simulations were performed daily for 2 days. On day 1, performance was assessed after sequential exposure to placebo, low-dose caffeine (2.5 mg/kg), high-dose caffeine (5.0 mg/kg), and high-dose propranolol (0.6 mg/kg). On day 2, performance was assessed after sequential exposure to placebo, low-dose propranolol (0.2 mg/kg), high-dose propranolol (0.6 mg/kg), and high-dose caffeine (5.0 mg/kg).InterventionsSurgical simulation tasks were repeated 30 minutes after masked ingestion of placebo, caffeine, or propranolol pills during the 2 days.Main outcomes and measuresAn Eyesi surgical simulator was used to assess surgical performance, which included surgical score (range, 0 [worst] to 700 [best]), task completion time, intraocular trajectory, and tremor rate (range, 0 [worst] to 100 [best]). The nonparametric Friedman test followed by Dunn-Bonferroni post hoc test was applied for multiple comparisons.ResultsOf 15 vitreoretinal surgeons, 9 (60%) were male, with a mean (SD) age of 29.6 (1.4) years and mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) of 23.15 (2.9). Compared with low-dose propranolol, low-dose caffeine was associated with a worse total surgical score (557.0 vs 617.0; difference, -53.0; 95% CI, -99.3 to -6.7; P = .009), a lower antitremor maneuver score (55.0 vs 75.0; difference, -12.0; 95% CI, -21.2 to -2.8; P = .009), longer intraocular trajectory (2298.6 vs 2080.7 mm; difference, 179.3 mm; 95% CI, 1.2-357.3 mm; P = .048), and increased task completion time (14.9 minutes vs 12.7 minutes; difference, 2.3 minutes; 95% CI, 0.8-3.8 minutes; P = .048). Postcaffeine treatment with propranolol was associated with performance improvement; however, surgical performance remained inferior compared with low-dose propranolol alone for total surgical score (570.0 vs 617.0; difference, -51.0; 95% CI, -77.6 to -24.4; P = .01), tremor-specific score (50.0 vs 75.0; difference, -16.0; 95% CI, -31.8 to -0.2; P = .03), and intraocular trajectory (2265.9 mm vs 2080.7 mm; difference, 166.8 mm; 95% CI, 64.1-269.6 mm; P = .03).Conclusions and relevanceThe findings suggest that performance of novice vitreoretinal surgeons was worse after receiving low-dose caffeine alone but improved after receiving low-dose propranolol alone. Their performance after receiving propranolol alone was better than after the combination of propranolol and caffeine. These results may be helpful for novice vitreoretinal surgeons to improve microsurgical performance.

Dataset Information

Unintentional Movements During the Use of Vitreoretinal Forceps.

Purpose

Methods

Results

Conclusions

Translational relevance

Publications

Unintentional Movements During the Use of Vitreoretinal Forceps.

Similar Datasets

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