Director of the Electroconvulsive Therapy (ECT) Service and Director of the Parent. Reliability was also greater for continuation ECT as compared with the index course. ECT was delivered using the Thymatron DGx ECT device, bifrontal and bitemporal at one and a half times seizure threshold, right unilateral at six times seizure. The System-IV lets you choose this same DGx program, or the more efficient “ Low. Petrides et al (2001) used a Thymatron DGx ECT device to treat 253 patients with unipolar major depression with bilateral ECT at 50% above.