Observation and mechanism of transcutaneous auricular vagus nerve stimulation in the treatment of limb motor dysfunction after ischemic stroke

INTERVENTION: The taVNS group:Transcutaneous aural vagus nerve stimulation +Basic treatment+rehabilitation treatment;The sham taVNS group:taVNS stimulates the vagus‐rich region of the left auricular tail + Basic treatment+rehabilitation treatment;Routine rehabilitation group:Basic treatment+rehabilitation treatment; CONDITION: cerebral arterial thrombosis PRIMARY OUTCOME: WOLF Motor Function Assessment Scale;Fugl‐Meyer scale; SECONDARY OUTCOME: Function Independent Measure, FIM;The SF‐36 scale; INCLUSION CRITERIA: 1. 35 <= 75 years old; 2. Stroke (infarction) occurred for the first time, in the recovery period (course of the disease from 2 months to 6 months), basically stable, unconscious disorder, no obvious language disorder; 3. The diagnosis conforms to the key points of cerebrovascular disease diagnosis adopted by the fourth National Academic Conference on Cerebrovascular Disease in 1995; 4. Unilateral subcortical cerebral infarction (basal ganglia, thalamus, internal capsule, etc.) confirmed by head CT or MRI; 5. Brunnstrom grade of the affected hand 0‐3; 6. There is no metal implant or pacemaker in the body; 7. No previous history of epilepsy or clear cognition does not affect communication and assessment; 8. Informed consent signed by the patient himself or by his immediate family member.