MICROPROCESSOR-CONTROLLED MOVEMENT OF LIQUID GASTRIC-CONTENT USING SEQUENTIAL NEURAL ELECTRICAL-STIMULATION

Background-Gastric electrical stimulation has been attempted for sever al years with little success. Aims-To determine whether movement of li quid gastric content could be achieved using microprocessor controlled sequential electrical stimulation. Methods-Eight anaesthetised dogs u nderwent laparotomy and implantation of four sets of bipolar stainless steel wire electrodes. Each set consisted of two to six electrodes (1 0x0.25 mm, 3 cm apart) implanted circumferentially. The stomach was fi lled with water and the process of gastric emptying was monitored. Art ificial contractions were produced using microprocessor controlled pha se locked bipolar four second trains of 50 Hz, 14 V (peak to peak) rec tangular voltage. In four of the dogs four force transducers were impl anted close to each circumferential electrode set. In one gastropareti c patient the effect of direct electrical stimulation was determined a t laparotomy. Results-Using the above stimulating parameters circumfer ential gastric contractions were produced which were artificially prop agated distally by phase locking the stimulating voltage. Averaged sti mulated gastric emptying times were significantly shorter than spontan eus emptying times (t(1/2) 6.7 (3.0) versus 25.3 (12.9) minutes, p<0.0 1). Gastric electrical stimulation of the gastroparetic patient at ope ration produced circumferential contractions. Conclusions-Microprocess or controlled electrical stimulation produced artificial peristalsis a nd notably accelerated the movement of liquid gastric content.