Design of a 1V CMOS operational amplifier for programmable resolution A/D converter

International audienceThis paper describes a programmable resolution A/D converter architecture. Circuit techniques used include a differential operational amplifier which is simulated in 0.35µm CMOS Technology. The proposed amplifier uses self biased complementary folded cascode (SB-CFC) which exploits the characteristics of the wide swing cascode current mirror as output stage. This analog portion of the design of ADC operates at a 1V supply. The open-loop gain and the gainbandwidth product are higher than 90 dB and 10MHz, respectively

Central processing of rectal pain in patients with irritable bowel syndrome: an fMRI study.

International audienceOBJECTIVES: In healthy subjects, the neural correlates of visceral pain bear much similarity with the correlates of somatic pain. In patients with irritable bowel syndrome, the central nervous system is believed to play a strong modulatory or etiological role in the pathophysiology of the disease. We hypothesize that this role must be reflected in aberrations of central functional responses to noxious visceral stimulation in these patients. To verify this hypothesis, we have induced transient rectal pain in patients and assessed the functional responses of the brain by means of functional magnetic resonance imaging. METHODS: Twelve right-handed patients (11 female) were examined. Functional imaging (1.5 T) was performed following a block paradigm, alternating epochs with and without noxious stimulation of the rectum. Rectal pain was induced by inflating a latex balloon. Whole-brain coverage was achieved by means of echo-planar magnetic resonance acquisition. RESULTS: A strong variability of the individual responses to rectal pain was found in patients with irritable bowel syndrome. Significant activations were found in only two patients, and group analysis did not reveal significant activations. In contrast, all patients exhibited significant deactivations. Group analysis revealed significant deactivations within the right insula, the right amygdala, and the right striatum. CONCLUSIONS: This study reveals aberrant functional responses to noxious rectal stimulation in patients with irritable bowel syndrome. Those results add grounds to the hypothesis that the central nervous system plays a significant role in the pathophysiology of this syndrome