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FD patients with gastric reddish streaks have abnormal fasting and postprandial gastric myoelectrical activity. Perceived severity of stressful life events and interpersonal sensitivity are associated with disturbance of gastric myoelectrical activity.

We designed a new three-channel electrogastrographic (EGG) system, which was easily operated on the Windows 95 platform and could automatically provide slow wave parameters. The purpose of the present study was to test its reliability and accuracy in clinical recording. The system included a signal acquisition device assembled on a printed circuit board. Recorded myoelectrical signals were filtered, amplified, digitized, and transmitted via this device into a notebook personal computer (PC). Based on the short-term Fourier transform the software could transfer the time domain of the signal into the frequency domain. Real-time displayed slow wave parameters, including dominant frequency/power, percent of normal frequency (2-4 cpm), instability coefficient in frequency/power, and power ratio, were automatically renewed every 64s. Twenty healthy subjects (M/F, 12/8; age, 23-51 years) were enrolled to measure both fast and postprandial myoelectrical activities for each 30-min recording. Our results indicated that meal ingestion significantly increased dominant frequency (3.15+/-0.20 vs 3.23+/-0.23 cpm; P < 0.05) and power (26.1+/-3.8 vs 28.4+/-3.9 dB; P < 0.05). The power ratio of the meal effect was 2.02+/-2.07. Other parameters, including instability coefficient and percent of normal frequency, remained similar despite food ingestion. This newly designed EGG system is acceptable for clinically measuring gastric myoelectrical activity; the real-time display of many EGG parameters is an advantage with this new system.

Abstract-Functional electrical stimulation (FES) has been applied to restore or maintain the muscle activity of paralyzed patients who suffer from spinal cord injuries and related neural impairments for several decades. In this paper, a direct-synthesized arbitrary waveform stimulator for multichannel FES applications is described. A novel element-envelope method is proposed for flexible waveform generation and implemented by a digital signal processor based system. We also designed an output circuit that can provide bi-phasic, voltage-controlled, constant-current outputs while keeping high-voltage compliance and wide signal bandwidth. High time-resolution and arbitrary stimulating waveforms can thus be synthesized, and more flexible closed-loop feedback controllers can be achieved. The proposed stimulator can be considered as a full-featured electrical stimulator for various FES applications with its flexibility in pattern generation and feedback processing capabilities.