(Greek) From the mouth of the river; the fourth letter of the Greek alphabet Dellta, Deltah, Delltah
Abnormal electrical waves observed in the electroencephalogram (see ELECTROENCEPHALOGRAPHY (EEG)). The frequency of the normal alpha waves is 10 per second; that of the delta waves is 7 or fewer per second. They occur in the region of tumours of the brain, and in the brains of patients with EPILEPSY.... delta waves
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