Effects of a chair for ophthalmic microsurgery on pressure distribution and pelvic tilt in surgeons.

BACKGROUND: Ophthalmic surgeons experience high levels of physical strain in the neck, lower back, and buttocks. While ergonomic interventions may help to solve these problems, only a few studies have reported chair designs for ophthalmic microsurgery. OBJECTIVE: To design a chair that reduces the physical strain on surgeons and examine its effectiveness in improving posture and reducing seat pressure. METHODS: A prototype chair with a three-dimensional seat surface and a sliding adjustment mechanism for the backrest was designed to fit the surgeon's body. A conventional chair (A) and the prototype chair (B) were compared during microsurgeries performed by five surgeons. Seat pressure was measured using a pressure-sensing device, and the pelvic tilt angle was measured using a gyroscope sensor. RESULTS: A paired t-test indicated significant differences between the chairs: average seat pressure was 70.4±12.7 mmHg for A and 40.5±3.8 mmHg for B (p = 0.008); the maximum seat pressure was 242.2±19.7 mmHg for A and 170.5±38.5 mmHg for B (p = 0.024); contact area was 906.1±114.5 cm2 for A and 1,255.9±60.1 cm2 for B (p < 0.001); and relative value of the pelvic tilt angle was -13.7°±3.7° for A and -7.1°±4.9° for B (p = 0.032). CONCLUSIONS: The prototype chair was associated with lower seat pressure and maintenance of a more neutral posture than the conventional chair, indicating that it may help to reduce physical strain in ophthalmic surgeons.

Difference in Pain and Discomfort of Comparable Wrist Movements Induced by Magnetic or Electrical Stimulation for Peripheral Nerves in the Dorsal Forearm.

PURPOSE: Both repetitive peripheral magnetic stimulation (rPMS) and transcutaneous electrical current stimulation (TES) could elicit the limb movements; it is still unclear how subjective sensation is changed according to the amount of limb movements. We investigated the pain and discomfort induced by newly developed rPMS and TES of peripheral nerves in the dorsal forearm. METHODS: The subjects were 12 healthy adults. The stimulus site was the right dorsal forearm; thus, when stimulated, wrist dorsiflexion was induced. The rPMS was delivered by the new stimulator, Pathleader at 10 stimulus intensity levels, and TES intensity was in 1-mA increments. The duration of each stimulation was 2 s. The analysis parameters were subjective pain and discomfort, measured by a numerical rating scale. The rating scale at corresponding levels of integrated range of movement (iROM) induced by rPMS or TES was compared. The subjective values were analyzed by two-way repeated measures ANOVA with the stimulus conditions (rPMS, TES) and the seven levels of iROM (20-140 ºs). RESULTS: In the rPMS experiments, stimuli were administered to all subjects at all stimulus intensities. In the TES experiments, none of the subjects dropped out between 1 and 16 mA, but there were dropouts at each of the intensities as follows: 1 subject at 17 mA, 20 mA, 22 mA, 23 mA, 27 mA, 29 mA and 2 subjects at 21 mA, 24 mA, 26 mA. The main effects of the stimulus conditions and iROM were significant for pain and discomfort. Post hoc analysis demonstrated that pain and discomfort in rPMS were significantly lower compared to TES when the iROM was above 60 ºs and 80 ºs, respectively. CONCLUSION: New rPMS stimulator, Pathleader, caused less pain and discomfort than TES, but this was only evident when comparatively large joint movements occurred.

Angular acceleration and angular jerk of elbow extension-flexion movement as parameters for discriminating a sequential transform of spontaneous movements in early infants.

Objective: We assessed the root mean square (RMS) of angular acceleration and the RMS of an angular jerk as expressions of the transformation of spontaneous movements in early infancy. Methods: During 36-56 weeks post-menstrual age (PMA), 15 premature infants (6 male, 9 female; 36 weeks PMA>) were measured every 4 weeks. A three-dimensional motion analyzer (Fastrak system; Polhemus Inc.) was used to measure spontaneous movements of the upper right limb in the supine infants. Upper limb position data were used to calculate the RMS of angular acceleration and the RMS of angular jerk at the elbow. The calculated data were classified into three terms: 36th and 40th week PMA (termⅠ), the 44th and 48th week PMA (termⅡ), and the 52nd and 56th week PMA (termⅢ). The typical value was the mean value for each term. Results: The RMS of angular acceleration in termⅡ was significantly less than that of termⅠ (p<0.05). The RMS values of angular jerk in termⅡ and termⅢ were significantly less than that of termⅠ (p<0.05). Conclusion: The RMS of angular acceleration and the RMS of the angular jerk are useful for expressing changes in the strength of spontaneous movements of elbow extension-flexion movements.

A case of mixed ductal-endocrine carcinoma of the pancreas.

A 66-year-old male patient underwent a stomach-preserving pancreatoduodenectomy procedure because of a tumor located around the lower bile duct under the diagnosis of carcinoma of the lower bile duct. The tumor (3.5 × 2.5 cm) was found at the head of the pancreas and had invaded the papillae of Vater at the duodenum. Histology findings indicated both ductal adenocarcinoma and endocrine tumor. The ductal adenocarcinoma component expressed carcinoembryonic antigen, cytokeratin (CK)-19, CK-20, carbohydrate 19-9, and amylase, whereas the endocrine component, which occupied about one-third of the tumor, expressed glucagon, neuron-specific enolase, and chromogranin A. The Ki-67 labeling indices of the two components were 49.7% and 5.3%, respectively. Herein, we present this case of mixed ductal-endocrine carcinoma of the pancreas. Our findings indicate that its aggressive mass may be ascribable to the adenocarcinoma component with a high proliferative potential.