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Biomedical subjects

A Kjellin

Publications and source records attributed to A Kjellin.

13 recordsLinked to original sources
PubMed2006

High-level visual-spatial ability for novices correlates with performance in a visual-spatial complex surgical simulator task.

BACKGROUND: This study addresses how high-level visual-spatial ability of surgical novices is related to performance of two simulator tasks with (KSA) and without (MIST) anatomic graphics and haptic feedback, differing in visual-spatial complexity. METHODS: Visual-spatial test scores assessed by Mental Rotation Test (MRT) and BasIQ and performance scores for Instrument Navigation (IN) in Key Surgical Activities (Procedicus KSA) and Manipulate and Diathermy (MD) in Minimally Invasive Surgical Trainer (Procedicus MIST) were correlated for 54 Swedish surgical novices. RESULTS: Significant Pearson's r correlations were obtained between visual-spatial scores measured by MRT-C and total score from the last trial for IN (r = 0.278, p < 0.05). Visual-spatial scores (measured by BasIQ) also correlated with total score from the first trial (r = 0.443, p < 0.05) and from the last trial (r = 0.489, p < 0.05). CONCLUSION: High-level visual-spatial ability is important for surgical novices to possess in the early training phase of a visual-spatial complex task in KSA.

Adult↗
PubMed2006

Early exposure to haptic feedback enhances performance in surgical simulator training: a prospective randomized crossover study in surgical residents.

BACKGROUND: In the literature of skill acquisition and transfer of skills, it often is assumed that the rate of skill acquisition depends on what has been learned in a similar context (i.e., surgical simulators providing haptic feedback). This study aimed to analyze whether the addition of haptic feedback early in the training phase for image-guided surgical simulation improves performance. METHODS: A randomized crossover study design was used, in which 38 surgical residents were randomized to begin a 2-h simulator training session with either haptic or nonhaptic training followed by crossover after 1 h. The graphic context was a virtual upper abdomen. The residents performed two diathermy tasks. Two validated tests were used to control for differences in visual-spatial ability: the BasIQ general cognitive ability test and Mental Rotation Test A (MRT-A). RESULTS: After 2 h of training, the group that had started with haptic feedback performed the two diathermy tasks significantly better (p < 0.05, unpaired t-test). Only the group that had started with haptic training significantly improved during the last 1-h session (p < 0.01, paired t-test). CONCLUSION: The findings indicate that haptic feedback could be important in the early training phase of skill acquisition in image-guided surgical simulator training.

Abdomen↗
PubMed2006

Objective assessment of visuospatial and psychomotor ability and flow of residents and senior endoscopists in simulated gastroscopy.

BACKGROUND: Advanced medical simulators have predominantly been used to shorten the learning curve of endoscopy for medical students and young residents. Rarely have the effects of visuospatial ability and attitudes of intermediately experienced and experienced specialists been studied with regard to simulator training. The aim of this study was to assess the effects of visuospatial ability and attitude on performance in simulator training. METHODS: Eighteen surgical residents were included in the study. Prior to the simulated gastroscopy task, they performed a visuospatial test (the card rotation test). After the simulated gastroscopy task, they completed a questionnaire regarding flow experiences. Their results were compared with those of 11 expert endoscopists who performed the same tests. RESULTS: Total gastroscopy time was significantly shorter for the expert endoscopists compared to residents (2 min 11 sec, p = 0.003). There was also a trend of more mucosa inspected (p = 0.088) and higher efficiency of screening (p = 0.069) by the experts. The residents made fewer errors in the card rotation test than the expert endoscopists (2.5 +/- 0.8 vs 5.5 +/- 1.2, respectively; p = 0.034), and their visuospatial card rotation test results correlated better with their performance in the simulated gastroscopy. CONCLUSIONS: A virtual gastroscopy task presents more of an emotional as well as a psychomotoric challenge to intermediately experienced endoscopists than to senior experts. Our study demonstrates that these differences can be objectively assessed by the use of visuospatial ability tests, flowsheets, and an endoscopic simulator.

Adult↗
PubMed2003

Training in tasks with different visual-spatial components does not improve virtual arthroscopy performance.

BACKGROUND: We earlier showed that training in the Procedicus KSA Simulator improves the performance of tasks done later in the same simulator. However, it is still unclear how performance in a specific visual-spatial simulator context may change after training in other simulators with different visual-spatial components. In particular, the aim of this study was to test whether performance in the Procedicus Virtual Arthroscopy (VA) Knee Simulator would remain unchanged after a training session in three other simulators with different visual-spatial components. METHODS: Twenty-eight medical students participated in a quasi-transfer study. They were randomly allocated to an experimental group ( n = 14) and a control group ( n = 14). RESULTS: Performance in the Procedicus VA Knee Simulator did not improve after training in other simulators with different visual-spatial components ( t-test p = NS). No significant correlation was found between the Procedicus VA Knee and the Minimally Invasive Surgical Trainer (MIST) simulators. CONCLUSION: One hour of training in different visual-spatial contexts was not enough to improve the performance in virtual arthroscopy tasks. It cannot be excluded, however, that experienced trainees could improve their performance, because perceived similarity between different situations is influenced by many psychological factors, such as the knowledge or expertise of the person performing the transfer task.

Adult↗
PubMed2003

Heller's esophagomyotomy with or without a 360 degrees floppy Nissen fundoplication for achalasia. Long-term results from a prospective randomized study.

Heller's esophagomyotomy relieves dysphagia but does not restore esophageal peristalsis. The myotomy may induce reflux and the addition of a 360 degrees fundoplication may be hazardous with regard to the remaining aperistaltic esophagus. The aim of this prospectively randomized clinical trial was to compare the outcome for patients with uncomplicated achalasia who underwent an anterior Heller's esophagomyotomy (H group) with or without an additional floppy Nissen fundoplication (H + N group). Between 1984 and 1995, 20 patients were prospectively randomized to one or other of the performed operations, 10 patients per group. Esophagitis including Barrett's esophagus (n = 2) was seen under medical treatment, in 6 of 9 in the H group but none in the H + N group. No patient in the H + N group required postoperative continuous acid-reducing drugs. Twenty-four-hour esophageal pH-studies in median 3.4 years after surgery showed pathological reflux expressed as a percentage of time below pH 4 of 13.1% in the H group compared to 0.15% (P < 0.001) in H + N group. One patient with recurrent dysphagia in the H + N group later had an esophagectomy. The remaining patients reported significant improvement of dysphagia without symptoms of reflux at 8.0 years follow-up. Heller's esophagomyotomy eliminates dysphagia, but can induce advanced reflux that requires medical treatment. The addition of a 360 degrees fundoplication eliminates reflux without adding dysphagia in the majority of patients and can be recommended for most patients with uncomplicated achalasia.

Adult↗
PubMed2002

Validation and learning in the Procedicus KSA virtual reality surgical simulator.

BACKGROUND: Advanced simulator training within medicine is a rapidly growing field. Virtual reality simulators are being introduced as cost-saving educational tools, which also lead to increased patient safety. METHODS: Fifteen medical students were included in the study. For 10 medical students performance was monitored, before and after 1 h of training, in two endoscopic simulators (the Procedicus KSA with haptic feedback and anatomical graphics and the established MIST simulator without this haptic feedback and graphics). Five medical students performed 50 tests in the Procedicus KSA in order to analyze learning curves. One of these five medical students performed multiple training sessions during 2 weeks and performed more than 300 tests. RESULTS: There was a significant improvement after 1 h of training regarding time, movement economy, and total score. The results in the two simulators were highly correlated. CONCLUSION: Our results show that the use of surgical simulators as a pedagogical tool in medical student training is encouraging. It shows rapid learning curves and our suggestion is to introduce endoscopic simulator training in undergraduate medical education during the course in surgery when motivation is high and before the development of "negative stereotypes" and incorrect practices.

Computer Simulation↗
PubMed2001

[Simulator training in medicine and health care. A new pedagogic model for good patient safety].

Advanced simulation within medicine and health care is a rapidly growing field. Simulator based training can be applied in minimal invasive surgery, in endoscopic procedures as well as in anaesthesia and critical care management. At Huddinge University Hospital a center for advanced simulation of both endoscopic surgery and anaesthesia/critical care management is currently being set up. The objective is to focus on improved medical and health care training and thus improving patient safety by reducing medical errors.

Anesthesiology↗
PubMed2000

Omeprazole and CYP2C19 polymorphism: effects of long-term treatment on gastrin, pepsinogen I, and chromogranin A in patients with acid related disorders.

BACKGROUND: The polymorphic enzyme CYP2C19 is of importance for the metabolism and effects of omeprazole during short-term treatment. AIM: To investigate the relationship between CYP2C19 genotype and the effects of long-term omeprazole treatment. MATERIAL AND METHODS: A total of 180 patients with acid related disorders were genotyped for wild type and mutated CYP2C19 alleles by allele-specific PCR amplification. Gastrin and chromogranin A were assessed by radioimmunoassays, and pepsinogen I and H. pylori serology were assessed by ELISA methods. RESULTS: In 108 of the patients, who received a single dose of 20 mg omeprazole, there was no difference in gastrin and chromogranin A concentrations between the three CYP2C19 genotypes. In 72 patients on long-term treatment (> 1 year) with 20 mg omeprazole daily, serum gastrin as well as plasma chromogranin A concentrations (mean +/- s.e.) were both about threefold higher in the wild type/mutated (52.1 +/- 7.6 pM and 7.3 +/- 1.3 nM (n=19), respectively) compared to wild type/wild type (14. 7 +/- 0.9 pM and 2.5 +/- 0.1 nM (n=52), respectively; both comparisons P=0.0001). In a single mutated/mutated patient on long-term treatment, both gastrin and chromogranin A were high (88 pM and 13.7 nM, respectively). Serum pepsinogen I concentration was significantly lower in wild type/mutated (n=19) patients on long-term treatment, compared with the corresponding wild type/wild type (n=49) group (147 +/- 19 microg/L vs. 193 +/- 12 microg/L, P=0. 04). CONCLUSION: Patients with one (and probably also with two) mutated CYP2C19 allele(s) on long-term treatment with omeprazole had significantly affected serum gastrin and pepsinogen I and plasma chromogranin A concentrations compared with patients with two normal alleles. This indicates that changes in gastric mucosal morphology during omeprazole treatment might be dependent upon the degree of the individual's capacity to metabolize omeprazole.

Anti-Ulcer Agents↗
PubMed2000

Gastric stasis in neuronal nitric oxide synthase-deficient knockout mice.

BACKGROUND & AIMS: Nitric oxide (NO) is a major inhibitory neurotransmitter in the gut. This study aimed to identify the effect of chronic deprivation of NO derived from neuronal (nNOS) or endothelial (eNOS) nitric oxide synthase on gastric emptying. METHODS: nNOS-deficient (knockout) mice were compared with wild-type mice for gastric size, fluoroscopic appearance after gavage of contrast, and histology of the pyloric sphincter. Wild-type mice treated with the NOS inhibitor N(omega)-nitro L-arginine (L-NA) and eNOS-deficient mice were also compared with wild-type and nNOS-deficient mice for liquid and solid gastric emptying. RESULTS: nNOS-deficient mice showed gastric dilation. Fluoroscopy showed delayed gastric emptying of radiologic contrast. There was no marked localized hypertrophy or luminal narrowing at the pyloric sphincter by histology of relaxed wild-type, nNOS-deficient, and eNOS-deficient tissues. Gastric emptying of both solids (28% +/- 27%) and liquids (22% +/- 18%) was significantly delayed in nNOS-deficient mice compared with control wild-type mice (82% +/- 22% for solids; 48% +/- 17% for liquids). eNOS-deficient mice showed no significant difference from wild-type mice (74% +/- 28% for solids; 47% +/- 23% for liquids). Wild-type mice treated acutely with L-NA showed delay in emptying of solids (43% +/- 31%) but not liquids (39% +/- 15%). CONCLUSIONS: Chronic depletion of NO from nNOS, but not eNOS, results in delayed gastric emptying of solids and liquids.

Animals↗
PubMed1996

Gastroesophageal reflux in obese patients is not reduced by weight reduction.

BACKGROUND: The present study tested the hypothesis that weight reduction improves the subjective and objective manifestations of gastroesophageal reflux. METHODS: Twenty obese patients with gastroesophageal reflux as shown by 24-h pH measurement and with symptoms requiring daily medication were studied. The patients were randomized into a group (A) treated with very low-caloric diet (VLCD) and a control group (B). Objective measurements were repeated after 6 months. Group B was then treated with VLCD and reexamined. RESULTS: Patients in group A lost 10.8 +/- 1.4 kg whereas group B gained 0.6 +/- 0.7 kg (P < 0.001). There was no reduction in reflux according to pH measurement. Furthermore, there were no significant changes in reflux symptoms. After VLCD treatment, group B lost 9.7 +/- 1.6 kg, but reflux indicators remained unchanged. All patients except one in group B remained dependent on daily anti-reflux medication. CONCLUSION: Weight reduction does not improve the subjective or objective manifestations of reflux.

Body Mass Index↗