Driving ability after right-sided inguinal hernia surgery.

PURPOSE: To investigate driving ability (brake reaction time, BRT) after right-sided hernia repair. It was assumed that postoperatively BRT would be impaired as compared to the preoperative reference and healthy controls. METHODS: BRT was prospectively collected from 30 patients undergoing hernia repair [Lichtenstein or total extraperitoneal endoscopic procedure (TEP)]. BRT was measured with a driving simulator preoperatively and on postoperative days 2 and 14. After receiving a visual stimulus, the patients had to apply the brake pedal with 160 N. The average of ten runs was used as the patient's BRT value. RESULTS: Thirty patients completed all measurements. In the Lichtenstein group, BRT was significantly impaired as compared to the patient's preoperative values (p = 0.021). Two weeks after surgery BRT had returned to the preoperative level (p = 0.859). BRT in the Lichtenstein group was also significantly impaired 2 days postoperatively as compared to the BRT of 60 healthy controls (p = 0.001). In the TEP group, no impaired BRT was detected. CONCLUSIONS: Based on our finding of significantly impaired BRT in patients following right-sided Lichtenstein hernia repair, it seems wise to recommend that such patients refrain from driving for 2 weeks after surgery. No such impairment was found in patients following TEP surgery. Consequently, it is deemed safe for them to resume driving 2 days after the procedure.

Dynamic vibrotactile signals for forward collision avoidance warning systems.

OBJECTIVE: Four experiments were conducted in order to assess the effectiveness of dynamic vibrotactile collision-warning signals in potentially enhancing safe driving. BACKGROUND: Auditory neuroscience research has demonstrated that auditory signals that move toward a person are more salient than those that move away. If this looming effect were found to extend to the tactile modality, then it could be utilized in the context of in-car warning signal design. METHOD: The effectiveness of various vibrotactile warning signals was assessed using a simulated car-following task. The vibrotactile warning signals consisted of dynamic toward-/away-from-torso cues (Experiment 1), dynamic versus static vibrotactile cues (Experiment 2), looming-intensity- and constant-intensity-toward-torso cues (Experiment 3), and static cues presented on the hands or on the waist, having either a low or high vibration intensity (Experiment 4). RESULTS: Braking reaction times (BRTs) were significantly faster for toward-torso as compared to away-from-torso cues (Experiments 1 and 2) and static cues (Experiment 2). This difference could not have been attributed to differential responses to signals delivered to different body parts (i.e., the waist vs. hands; Experiment 4). Embedding a looming-intensity signal into the toward-torso signal did not result in any additional BRT benefits (Experiment 3). CONCLUSION: Dynamic vibrotactile cues that feel as though they are approaching the torso can be used to communicate information concerning external events, resulting in a significantly faster reaction time to potential collisions. APPLICATION: Dynamic vibrotactile warning signals that move toward the body offer great potential for the design of future in-car collision-warning system.