Biomedical subjects

Randy S Haluck

Publications and source records attributed to Randy S Haluck.

8 recordsLinked to original sources

PubMed2005

Design considerations for computer-based surgical simulators.

Computers will allow the creation of novel training environments in ways that can only be imagined at the present time. The design of computer-based simulators for training of surgical procedures is a highly complex and ever-more sophisticated process. A thorough understanding of human learning principles as well as the capabilities and limitations of simulation training is required. Only development teams with expertise in medicine and surgery, computer science, hardware engineering, and simulation training will be able to create the useful surgical simulators of tomorrow.

Journal Article↗

PubMed2005

Smart tutor: a pilot study of a novel adaptive simulation environment.

Computer-based learning environments create the possibility of dynamic adaptation to address learner capabilities and user performance. Software algorithms, code-named Smart Tutor, for motor skill learning were developed and applied to an abstract environment for laparoscopic surgery (RapidFire). Smart Tutor dynamically adjusts the environment to minimize frustration and optimize learning conditions for all learners. This study compared the first generation RapidFire / Smart Tutor (RF / ST) to the Minimal Invasive Surgery Trainer Virtual Reality (MIST VR) system for laparoscopic performance improvement and level of frustration. Two groups of novice laparoscopic learners were assessed by pre- and post- training paper cutting exercise and subjective surveys. Users of both systems showed improvement of laparoscopic skills as measured by the paper cutting exercises. No differences were shown between groups for level of improvement. However, a significant difference was seen in the subjective ratings on the post-training survey with less frustration for the RF / ST training group. Important information was acquired for refinements of the Smart Tutor algorithms.

Clinical Competence↗

PubMed2003

Analysis of cost outliers after gastric bypass surgery: what can we learn?

BACKGROUND: A clinical pathway for gastric bypass surgery (GBS) implemented at our institution in 1999 resulted in reduced costs and decreased variability in patient care. However, a reanalysis of GBS hospital costs identified a 16% incidence of "cost outliers". We hypothesized that analysis of clinical variables would identify factors associated with increased hospital costs following GBS. METHODS: Medical records and financial data for 91 GBS patients from November 2000 to July 2001 were reviewed. Patients with costs >1 SD above the total hospital cost mean comprised the cost outlier (CO) group, while the remaining patients were considered the normal cost (NC) group. Potential etiologies for COs included patient demographics, the number and severity of medical co-morbidities, surgical factors, and major postoperative complications. RESULTS: There were 15 patients in the CO group, and 76 patients in the NC group. Patient demographics were similar in both groups. Diabetes mellitus and severe medical co-morbidities, especially sleep apnea and degenerative joint disease were more common in the CO group (60% vs 9.2%, P < 0.05 vs NC). The incidence of major complications (33% vs 8%) was significantly increased in the CO group (P < 0.05 vs NC). CONCLUSIONS: Despite utilization of a clinical pathway for GBS, 16% of patients were "cost outliers". Factors associated with increased hospital costs after GBS included severe medical co-morbidities (especially diabetes mellitus and sleep apnea) and the occurrence of major postoperative complications. Prospective identification of "high risk" GBS patients may allow hospitals with bariatric surgery programs to modify perioperative care and eliminate potential cost outliers.

Adult↗

PubMed2003

Early results after laparoscopic gastric bypass: EEA vs GIA stapled gastrojejunal anastomosis.

BACKGROUND: Various surgical techniques have been successfully applied to isolated Roux-en-Y gastric bypass (RYGBP). Many surgeons rely on stapling devices for the gastrojejunal (GJ) anastomosis. Early follow-up results were compared for two laparoscopic techniques for GJ anastomosis: circular end-to-end (EEA) and linear cutting (GIA) staplers. METHODS: Medical charts were retrospectively reviewed of all patients who had undergone stapled GJ anastomosis for isolated RYGBP over a 2-year period. The jejunal limb used for GJ anastomosis was fashioned at 1 cm / unit body mass index (BMI). Patients were grouped by GJ anastomotic technique, EEA or GIA, and the results compared. RESULTS: 61 patients underwent RYGBP (EEA=32; GIA=29), with no differences in preoperative BMI or co-morbidities. Mean (+/-SD) operative time was shorter for the GIA group (EEA=180+/-56.1 minutes; GIA=145.3+/-27.9 minutes, P=0.003). There were 2 early re-operations in the GIA group for anastomotic leaks. Postoperative complications were not statistically different; however, there was an increased incidence of wound infections in the EEA group vs the GIA group (21.9% vs 6.9%, P=0.08). Follow-up at 6-8 months revealed an average percent excess weight loss of 46.7%+/-12.2% for EEA and 51.4%+/-10.7% for GIA (P=0.25). Length of stay, total hospital costs and operating-room costs were similar (P=0.34, 0.53 and 0.96 respectively). CONCLUSION: Operative time was significantly shorter in the GIA group. Complications, length of stay, weight loss and costs were similar between the groups. Selection of anastomotic technique may be based on surgeon preference, operative time, and potential for serious complications.

Adult↗

PubMed2002

Heuristic haptic texture for surgical simulations.

Generation of credible force feedback renderings adds the sense of touch crucial for the development of a realistic virtual surgical environment. However, a number of difficulties must be overcome before this can be achieved. One of the problems is the paucity of data on the in-vivo tissue compliance properties needed to generate acceptable output forces. Without this "haptic texture," the sense of touch component remains relatively primitive and unrealistic. Current research in the quantitative analysis of biomechanics of living tissue, including collection of in-vivo tissue compliance data using specialized sensors, has made tremendous progress. However, integration of all facets of biomechanical data in order to transfer them into haptic texture remains a very difficult problem. For this reason, we are attempting to create a library of heuristic haptic textures of anatomical structures. The library of heuristic haptic textures will capture the expert's sense of feel for selected anatomical structures and will be used to convey the sense of touch for surgical training simulations. Once the techniques for converting biomechanical data into haptic texture become more robust, this library can be used as a benchmark to verify theoretical computational models used for generating output forces in haptic devices.

Biomechanical Phenomena↗

PubMed2002

Reliability and validity of Endotower, a virtual reality trainer for angled endoscope navigation.

We hypothesized that a simulator designed to train surgical novices angled laparoscopic navigation would show an improvement in subjects' performance, a high test re-test reliability and high internal validity as measured by standardized coefficient alpha. It was also predicted that simulator performance would be strongly related to objectively assess perceptual and visuospatial ability. EndoTower has good face validity in that it mimics precisely the performance of an angled laparoscope and previous studies suggest construct validity. In this study, EndoTower is shown to be a trainer intended for laparoscopic skill than can test for inherent perceptual and visuospatial ability.

Computer Simulation↗

PubMedDate not supplied

Laparoscopic management of traumatic hemorrhagic cholecystitis.

BACKGROUND AND OBJECTIVES: Blunt trauma to the gallbladder is a rare entity, particularly when no other organ is injured. In isolated blunt traumatic injury to the gallbladder, treatment options vary depending on the specific injury. The types of blunt trauma injuries to the gallbladder and their appropriate management are discussed. In addition, a case successfully managed with minimally invasive techniques is presented. METHODS: A passenger admitted after a high-speed front-end motor vehicle crash was safely managed with laparoscopic surgery for a rare case of isolated gallbladder trauma. The preoperative and operative management are discussed as well as the application of minimally invasive surgery for this rare process. RESULTS: Laparoscopic cholecystectomy was performed successfully. The patient did well postoperatively with no complications. No other injuries were identified at the time of laparoscopy. CONCLUSION: Minimally invasive techniques may be safely applied to blunt trauma of the gallbladder in certain circumstances.

Abdominal Injuries↗

PubMedDate not supplied

Laparoscopic multifunctional instruments: design and testing of initial prototypes.

BACKGROUND: Advances in minimally invasive surgical techniques will require new types of instrument end-effectors for smaller, longer, and flexible instruments. These include a new class of multifunctional instruments capable of performing more than 1 task with a single set of working jaws. Furthermore, it is desired that multifunctional instruments be designed to provide improved dexterity compared with that in currently commercially available instruments. METHODS: Three prototypes of multifunctional laparoscopic surgical instruments are described: (1) a mechanical scissors-grasper, (2) a mechanical scissors-grasperarticulator, and (3) a compliant mechanism scissors-grasper. Methods of baseline analysis, design methods and considerations, and subjective evaluations of interim prototypes are presented. RESULTS: The 3 prototypes demonstrate promising early results. However, based on subjective evaluation, these prototypes do not perform individual functions as well as basic disposable single-function laparoscopic instruments do. CONCLUSIONS: The concept of multifunctionality and increased end-effector dexterity is achievable as demonstrated by the prototypes presented. Further work is required to refine, simplify, and improve the multifunctional instruments to a point where they may be useful as surgical tools.

Equipment Design↗