John M. Graham

Jejunal Atresia Associated with Cafergot® Ingestion During Pregnancy

Fetal vascular accidents have been suggested as one cause for jejunal atresia due to in utero interruption of the superior mesenteric arterial supply to the intestines. Experimental studies support this hypothesis, and ergotamine has been shown to be a teratogen in experimental animals as a consequence of its vasoconstrictive action. We report the occurrence of intrauterine growth retar dation and jejunal atresia in an offspring of a woman who also experienced four spontaneous abortions. During each of six pregnancies, the mother had taken as many as eight Cafergot® tablets daily. We raise the hypothesis that Cafergot (1 mg ergotamine tartrate and 100 mg caffeine) might represent a vascular dis ruptive teratogenic agent during pregnancy. This hypothesis is supported by the clinical association of nonduodenal intestinal atresia with other defects that have a disruptive vascular etiology.

Preaxial polydactyly of the foot associated with early amnion rupture: Evidence for mechanical teratogenesis?

THE SPECTRUM of resultant defects for early amnion rupture has been expanded to include defects other than those caused by amniotic band disruption per se. These include craniofacial defects, limb reduction defects, cutaneous syndactyly, body wall deficiency, a short umbilical cord, scoliosis, and growth deficiency. 1-~ The nature of these additional defects is thought to relate to early intrauterine compression of the embryo resulting from at least a temporary loss of amniotic fluid. Support for this hypothesis derives from experimental studies in rats, in which the same duster of anomalies is induced by early amnion puncture at a time equivalent to four to six weeks in the human. 6 The purpose of this communication is to report yet another potential consequence of early amnion rupture, namely, a rare form of preaxial polydactyly of the foot, observed in two unrelated patients who had evidence of early amnion rupture.

RetroShape: Leveraging Rear-Surface Shape Displays for 2.5D Interaction on Smartwatches

The small screen size of a smartwatch limits user experience when watching or interacting with media. We propose a supplementary tactile feedback system to enhance the user experience with a method unique to the smartwatch form factor. Our system has a deformable surface on the back of the watch face, allowing the visual scene on screen to extend into 2.5D physical space. This allows the user to watch and feel virtual objects, such as experiencing a ball bouncing against the wrist. We devised two controlled experiments to analyze the influence of tactile display resolution on the illusion of virtual object presence. Our first study revealed that on average, a taxel can render virtual objects between 70% and 138% of its own size without shattering the illusion. From the second study, we found visual and haptic feedback can be separated by 4.5mm to 16.2mm for the tested taxels. Based on the results, we developed a prototype (called RetroShape) with 4×4 10mm taxels using micro servo motors, and demonstrated its unique capability through a set of tactile-enhanced games and videos. A preliminary user evaluation showed that participants welcome RetroShape as a useful addition to existing smartwatch output.