Social integration of robots into groups of cockroaches to control self-organized choices.

Collective behavior based on self-organization has been shown in group-living animals from insects to vertebrates. These findings have stimulated engineers to investigate approaches for the coordination of autonomous multirobot systems based on self-organization. In this experimental study, we show collective decision-making by mixed groups of cockroaches and socially integrated autonomous robots, leading to shared shelter selection. Individuals, natural or artificial, are perceived as equivalent, and the collective decision emerges from nonlinear feedbacks based on local interactions. Even when in the minority, robots can modulate the collective decision-making process and produce a global pattern not observed in their absence. These results demonstrate the possibility of using intelligent autonomous devices to study and control self-organized behavioral patterns in group-living animals.

Examination of voiding in seated women using a remote-controlled ultrasound probe.

BACKGROUND: A remote-controlled steering arm was developed that allows the ultrasound probe to be held on the perineum under ultrasound image guidance with the woman seated on a commercially available bedside commode. TECHNIQUE: The arm's servomechanism monitors contact pressure between the scanning head and the perineum, keeping constant gentle pressure on the perineum so that the transducer follows perineal movement. EXPERIENCE: Twenty patients with urinary incontinence and ten normal volunteers were examined during two voiding episodes, one without perineal ultrasound and one with ultrasound. Ultrasound images and intrarectal pressure measurements were displayed simultaneously on a video monitor. Bladder and urethral visibility and behavior were analyzed during bladder emptying. Of the 30 women, 28 were able to void, with and without the ultrasound probe applied. Two women were not able to urinate under observation either with or without sonography. The bladder base, bladder neck, and upper two-thirds of the urethra were visible throughout voiding in the 28 women able to void. Bladder neck opening could be observed in all of the 28 women. Bladder neck descent during initiation of voiding occurred in 17 women, whereas 11 voided without bladder neck descent. CONCLUSION: The use of this device facilitates ultrasound evaluation of micturition in the physiologic sitting position and allows bladder neck behavior to be seen during bladder emptying.