Here is the design of a clinical trial:

Official Title: Effectiveness of a Projection-based Augmented Reality Exposure System in Treating Cockroach Phobia. A Randomized Controlled Trial

Included conditions:
- Specific Phobia

Study Armgroups:
- {'label': 'Projection-based augmented reality exposure therapy', 'type': 'EXPERIMENTAL', 'description': 'Intervention group that receives the projection-based augmented reality to carry out the exposure therapy for cockroach phobia.', 'interventionNames': ['Behavioral: Projection-based augmented reality exposure therapy (P-ARET).']}
- {'label': 'In vivo exposure', 'type': 'EXPERIMENTAL', 'description': 'Intervention group that receives traditional in vivo exposure therapy for cockroach phobia.', 'interventionNames': ['Behavioral: In vivo exposure therapy']}
- {'label': 'WL Control', 'type': 'NO_INTERVENTION', 'description': 'Waiting list control group.'}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'Projection-based augmented reality exposure therapy (P-ARET).', 'description': 'The intervention will be based on exposure therapy to cockroaches using P-ARET. The treatment will follow the guidelines of the "one-session treatment" (OST). Main components: Psychoeducation, Exposure to the feared object (cockroach), modeling (the therapist will interact with the phobic stimulus first and if possible, the patient will follow the same steps), cognitive challenge, and reinforcement and relapse prevention.', 'armGroupLabels': ['Projection-based augmented reality exposure therapy']}
- {'type': 'BEHAVIORAL', 'name': 'In vivo exposure therapy', 'description': 'The intervention will be based on traditional in vivo exposure therapy to real cockroaches. The treatment will follow the guidelines of the "one-session treatment" (OST). Main components: Psychoeducation, Exposure to the feared object (cockroach), modeling (the therapist will interact with the phobic stimulus first and if possible, the patient will follow the same steps), cognitive challenge, and reinforcement and relapse prevention.', 'armGroupLabels': ['In vivo exposure']}

Primary Outcomes:
- {'measure': "Change in Behavioral Avoidance Test (BAT; adapted from Öst, Salkovskis, & Hellström's, 1991)", 'description': 'Patients will be confronted to a real cockroach and they will be encouraged to get closer and interact with the stimulus as much as they can. The anxiety level (0-10), distance and level of interaction with the animal will be registered and evaluated on a scale ranging from 0 (the participant does not enter the room) to 12 (the participant interacts with the cockroach).', 'timeFrame': 'Baseline (At the beginning of the intervention) and immediately after the intervention, also at follow-up assessment periods (1, 6 and 12 months).'}

Please estimate the sample size based on the assumption: 
power of 0.80, alpha of 0.05, and an additional 20% for expected follow-up attrition
Sample size calculation
        Power calculations were performed using Epidat V.4.2 statistical software to estimate the sample size necessary to detect a large standardised mean difference between groups (Cohenâs d=0.80) with a power of 0.80 and an alpha of 0.05, based on previous studies using AR systems.15 21 These calculations were conducted based on the primary outcome: the Behavioral Avoidance Test (BAT), specifically on the âperformanceâ variable of this test, which is explained below. The minimum sample size for each group was identified as 26 (78 in total), but at least an additional 20% will be recruited to take into account expected follow-up attrition; thus, a minimum total sample of 96 participants (32 per group) is estimated.15 34