Here is the design of a clinical trial:

Official Title: Efficacy and Mechanism of Acupuncture on Patients With Chronic Sciatica Using fMRI: A Randomized, Patient-Assessor Blind, Sham-Controlled Clinical Trial

Included conditions:
- Chronic Sciatica

Study Armgroups:
- {'label': 'Real acupuncture', 'type': 'EXPERIMENTAL', 'description': 'manual acupuncture + electroacupuncuture on acupoints, twice a week, for 4 weeks', 'interventionNames': ['Device: Real acupuncture']}
- {'label': 'Sham acupuncture', 'type': 'SHAM_COMPARATOR', 'description': 'sham acupuncture (no skin penetration) + placebo electroacupuncture without electrical stimulation on acupoints, twice a week, for 4 weeks', 'interventionNames': ['Device: Sham acupuncture']}

Interventions:
- {'type': 'DEVICE', 'name': 'Real acupuncture', 'description': 'manual acupuncture(0.25mm diameter x 40mm length, stainless steel, Dongbangacupuncture Inc., Korea) (unilateral GB30) + electroacupuncture(0.25mm diameter x 40mm length, stainless steel, Dongbangacupuncture Inc., Korea) (unilateral EX-B2 (L4 \\& L5), BL25, BL23, BL40, GB34), twice a week, for 4 weeks, common approaches for the treatment of chronic sciatica used by doctors of Korean medicine in Korea today', 'armGroupLabels': ['Real acupuncture']}
- {'type': 'DEVICE', 'name': 'Sham acupuncture', 'description': 'sham acupuncture without skin penetration(0.25mm diameter x 40mm length, stainless steel, Acuprime, UK) (unilateral GB30) + placebo electroacupuncture (0.25mm diameter x 40mm length, stainless steel, Dongbangacupuncture Inc., Korea) without electrical stimulation (unilateral EX-B2, BL25, BL23, BL40, GB34), twice a week, for 4 weeks', 'armGroupLabels': ['Sham acupuncture']}

Primary Outcomes:
- {'measure': 'Visual analogue scale for bothersomeness', 'description': 'change in visual analoge scale for bothersomeness \\[range: 0(better)-100(worse) mm\\]', 'timeFrame': 'baseline, 1-1, 1-2, 2-1, 2-2, 3-1, 3-2, 4-1, 4-2, 5, and 8 weeks'}

Please estimate the sample size based on the assumption: 
Using a two-sample t test model with a two-tailed test, 80% test power, 5% significance level, and a 20% dropout rate.
Sample size
        Referring to a previous study [52], an appropriately powered full-scale sample size was estimated using the mean difference of VAS for bothersomeness due to sciatica between groups in the primary endpoint. The researchers expect the mean difference will be 12.4âmm with a standard deviation (SD) of 16.2âmm between the two groups, which is not moderately clinically meaningful but represents a minimally important difference [53].
        Considering the mean comparison method of the two-sample t test model with a two-tailed test, 80% test power, and a 5% significance level, the total number of individuals required per group is 27. For equal allocation of the two groups, the total sample size required when considering a dropout rate of 20% is 68 subjects with 34 subjects in each group.
        Considering the nature of fMRI studies that use approximately 90,000 voxels to estimate the BOLD signal indirectly and for which conventional power calculations are meaningless, we determined 20 subjects in each group for fMRI scanning according to the trend of related neuroimaging studies [54â58]. Most studies decided that 20 participants is an adequate sample size regarding the high cost of fMRI examinations.