Dataset Information

A comparison of free-hand vs laser-guided long-axis ultrasound techniques in novice users.

ABSTRACT: OBJECTIVE: The increasing use of point-of-care ultrasonography for targeted procedures justifies a device that helps both novices in training and experts perform the long-axis needle approach. The initial success of traditional needle guidance devices in reducing the time of target procedures is not universal and they can be cumbersome. We aim to investigate whether the less bulky and previously untested laser guide can succeed in reducing procedure time in novice ultrasonographers. METHODS: 82 medical students with no ultrasound experience volunteered. Random allocation determined whether, during a targeted procedure in a turkey breast and olive phantom, participants were assisted by the laser guide or not. The time taken to pierce the target was recorded at 1-cm depth. RESULTS: The mean procedure time in the laser-assisted (LA) group was 25.1 s (14.0 s; 18.0-25.0 s). The mean procedure time in the free-hand group was 45.5 s (23.0 s; 7.0-55.0 s). The procedure time in the LA group was significantly reduced (p<0.01). CONCLUSION: The laser guide significantly improved procedure times. It is felt that the cheaper, smaller, easy to integrate, sterile and more user-friendly laser guidance unit may be a better alternative to the needle guide in improving procedure times for the novice ultrasonographer or to assist the expert, during training for, or performance of, ultrasound-guided targeted procedures. ADVANCES IN KNOWLEDGE: Following from the prototype paper, this is the first study to investigate the effectiveness of attaching a laser-guidance device to an ultrasound probe. The device succeeded in reducing the procedure times of targeted procedures.

SUBMITTER: Collins GB

PROVIDER: S-EPMC3755392 | biostudies-other | 2013 Sep

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:Fractured neck of femur generally requires operative fixation and is a common cause of admission to hospital. The combination of femoral nerve block and spinal anesthesia is a common anesthetic technique used to facilitate the surgical procedure. The optimal disposition of local anesthetic (LA) relative the femoral nerve (FN) has not been defined. Our hypothesis was: that the deposition of LA relative to the FN influences the quality of analgesia for positioning of the patient for performance of spinal anesthesia. The primary outcome was verbal rating (VRS) pain scores 0-10 assessed immediately after positioning the patient to perform spinal anesthesia.With Institutional ethical approval and having obtained written informed consent from each, 52 patients were studied. The study was registered with ClinicalTrials.gov (NCT01527812). Patients were randomly allocated to undergo to one of three groups namely: intention to deposit lidocaine 2% (15 ml) i. above (Group A), ii. below (Group B), iii. circumferential (Group C) to the FN. A blinded observer assessed i. the sensory nerve block (cold) in the areas of the terminal branches of the FN and ii. VRS pain scores on passive movement from block completion at 5 minutes intervals for 30 minutes. Immediately after positioning the patient for spinal anesthesia, VRS pain scores were recorded.Pain VRS scores during positioning were similar in the three groups [Above group/Below group/Circumferential group: 2(0-9)/0(0-10)/3(0-10), median(range), p:0.32]. The block was deemed to have failed in 20%, 47% and 12% in the Above group, Below group and Circumferential group respectively. The median number of needle passes was greater in the Circumferential group compared with the Above group (p:0.009). Patient satisfaction was greatest in the Circumferential group [mean satisfaction scores were 83.5(19.8)/88.1(20.5)/93.8(12.3), [mean(SD), p=0.04] in the Above, Below and Circumferential groups respectively.We conclude that there is no clinical advantage to attempting to deposit LA circumferential to the femoral nerve (relative to depositing LA either above or below the nerve), during femoral nerve block in this setting.

Project description:Hand-eye calibration is an important step in controlling a vision-guided robot in applications like part assembly, bin picking and inspection operations etc. Many methods for estimating hand-eye transformations have been proposed in literature with varying degrees of complexity and accuracy. However, the success of a vision-guided application is highly impacted by the accuracy the hand-eye calibration of the vision system with the robot. The level of this accuracy depends on several factors such as rotation and translation noise, rotation and translation motion range that must be considered during calibration. Previous studies and benchmarking of the proposed algorithms have largely been focused on the combined effect of rotation and translation noise. This study provides insight on the impact of rotation and translation noise acting in isolation on the hand-eye calibration accuracy. This deviates from the most common method of assessing hand-eye calibration accuracy based on pose noise (combined rotation and translation noise). We also evaluated the impact of the robot motion range used during the hand-eye calibration operation which is rarely considered. We provide quantitative evaluation of our study using six commonly used algorithms from an implementation perspective. We comparatively analyse the performance of these algorithms through simulation case studies and experimental validation using the Universal Robot's UR5e physical robots. Our results show that these different algorithms perform differently when the noise conditions vary rather than following a general trend. For example, the simultaneous methods are more resistant to rotation noise, whereas the separate methods are better at dealing with translation noise. Additionally, while increasing the robot rotation motion span during calibration enhances the accuracy of the separate methods, it has a negative effect on the simultaneous methods. Conversely, increasing the translation motion range improves the accuracy of simultaneous methods but degrades the accuracy of the separate methods. These findings suggest that those conditions should be considered when benchmarking algorithms or performing a calibration process for enhanced accuracy.

Project description:BACKGROUND:Historically, the anterolateral interscalene block--deposition of local anesthetic adjacent to the brachial plexus roots/trunks--has been used for surgical procedures involving the shoulder. The resulting block frequently failed to provide surgical anesthesia of the hand and forearm, even though the brachial plexus at this level included all of the axons of the upper-extremity terminal nerves. However, it remains unknown whether deposition of local anesthetic adjacent to the seventh cervical root or inferior trunk results in anesthesia of the hand and forearm. METHODS:Using ultrasound guidance and a needle-in-plane posterior approach, a Tuohy needle was positioned with the tip located between the deepest and next-deepest visualized brachial plexus root/trunk, followed by injection of mepivacaine (1.5%). Grip strength and the tolerance to cutaneous electrical current in 5 terminal nerve distributions were measured at baseline and then every 5 minutes following injection for a total of 30 minutes. The primary end point was the proportion of cases in which the interscalene nerve block resulted in a decrease in grip strength of at least 90% and hand and forearm anesthesia (tolerance to >50 mA of current in all 5 terminal nerve distributions) within 30 minutes. The primary hypothesis was that a single-injection interscalene brachial plexus block produces a similar rate of anesthesia of the hand and forearm to the published success rate of 95% for other brachial plexus block approaches. RESULTS:Of 55 subjects with blocks placed per protocol, all had a successful block of the shoulder as defined by inability to abduct at the shoulder joint. Thirty-three subjects had measurements at 30 minutes following local anesthetic deposition, and only 5 (15%) of these subjects had a surgical block of the hand and forearm (P < 0.0001; 95% confidence interval, 6%-33%). We therefore reject the hypothesis that the interscalene block as performed in this study provides equivalent anesthesia to the hand and forearm compared with other brachial plexus block techniques. Block failures of the hand and forearm were due to inadequate cutaneous anesthesia of the ulnar (n = 27; 82%), median (n = 26; 78%), or radial (n = 22; 67%) distributions; the medial forearm (n = 25; 76%); and/or the lateral forearm (n = 14; 42%). Failure to achieve at least a 90% reduction in grip strength occurred in 16 subjects (48%). CONCLUSIONS:This study did not find evidence to support the hypothesis that local anesthetic injected adjacent to the deepest brachial plexus roots/trunks reliably results in surgical anesthesia of the hand and forearm.

Project description:ObjectiveTo demonstrate how bladder ultrasound can be useful in completing morcellation during difficult Holmium Laser Enucleation of the Prostate (HoLEP). As HoLEP has emerged as a standard of care for the treatment of benign prostatic hyperplasia, multiple studies have reported the potentially catastrophic complication of bladder injury during morcellation. This video aims to assist any urologist performing HoLEP by providing step-by-step instruction for using ultrasound to complete morcellation safely.MethodsEnucleation is performed using a 26-French continuous flow scope, off-set laser bridge with a laser stabilization catheter, and a 550 µm holmium laser fiber. Once the median and lateral lobes have been enucleated, the outer sheath is removed and the nephroscope is inserted to facilitate morcellation. Under dual inflow irrigation, the Piranha morcellator (Richard Wolf, Knittlingen, Germany) is introduced and set to the manufacturer's recommended settings of 1500 rpm. A 3.5-MHz convex abdominal ultrasound transducer (Hitachi Prosound Alpha 7; Hitachi Aloka Medical America, Wallingford, CT) under B-mode is used to visualize the bladder, predominantly in the sagittal orientation. Morcellation proceeds under simultaneous ultrasound and direct cystoscopic guidance.ResultsThe distended bladder is visualized concurrently with the ultrasound and via the nephroscope as the Piranha engages the adenoma and begins morcellation. Once the adenoma is engaged, the operator then drops their hands to place the morcellator in the center of the bladder. Ultrasound provides real-time feedback as to the location of the morcellator in relation to the adenoma and bladder.ConclusionThis video highlights the use of intraoperative bladder ultrasound as a visual aid to assist during the morcellation portion of HoLEP. This proof of concept demonstrates that ultrasound can be an additional tool to utilize during difficult cases when cystoscopic visualization during morcellation is limited.

Dataset Information

A comparison of free-hand vs laser-guided long-axis ultrasound techniques in novice users.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets