To evaluate the performance of automatic stimulation mode of a new rechargeable implantable vagus nerve stimulation system for drug-refractory epilepsy

The study is a prospective, single-group, open-lable trial designed to collect data on patients implanted with a Model G114R VNS system (Beijing PINS Medical) from baseline through an EMU (epilepsy monitoring unit) stay of up to 5 days, and 3-mouth follow-up. The seizure burden and quality of life were evaluated. Adverse events were recorded during the trial.

Inclusion Criteria:

• Age: ≥3 years old; gender is not limited;
• Patients with clinically diagnosed drug-resistant epilepsy, suitable for vagus nerve stimulation therapy;
• At least 6 seizures per month;
• Patients with a history of increased heart rate (tachycardia) associated with seizure onset based on clinical data obtained from medical history, admission/hospital charts, or prior neurophysiologic evaluations;
• When the patient is lying on the left side and in an upright position, from the proposed electrode position on the neck to the proposed pulse generator on the chest, the peak-peak R-wave of the ECG should be higher than 0.40mV;
• Patients who are willing to undergo EMU phase assessment and activate the automatic mode function during this period;
• Patients must be in good general health and ambulatory;
• Children and guardians must be willing and able to give informed consent;
• Patients and their families have good compliance and can cooperate with the completion of postoperative follow-up requirements.

Exclusion Criteria:

• Patients have had a bilateral or left cervical vagotomy;
• One or both sides of the vagus nerve have lesions or damage;
• Patients have a history of VNS Therapy;
• Patients with a history of status epilepticus within 1 year prior to enrollment;
• Patients with a history of mental illness or pseudoepileptic seizures or epilepsy caused by intracranial space-occupying lesions;
• Patients currently use, or are expected to use, short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy;
• Patients expected to require full body magnetic resonance imaging;
• VNS therapeutic system implants will bring unacceptable surgical or medical risks to patients (according to the judgment of the investigator);
• Patients with surgical contraindications identified by surgeons and anesthesiologists such as tumors, insulin-dependent diabetes mellitus or poor general condition;
• A record of clinically significant seizure-related bradycardia (heart rate below 50 bpm);
• Patients prescribed drugs specifically for a cardiac or autonomic disorder that in the investigator's opinion would affect heart rate response unless the patient has ictal tachycardia while taking said drugs. These include, but are not limited to, beta adrenergic antagonists ("beta blockers");
• Patients with known clinically significant arrhythmias, and patients with clinically significant arrhythmias identified by 24-hour ambulatory ECG recordings obtained at the screening visit;
• Adult patients with severe mental illness, severe cognitive impairment, history of severe depression, or suicidal tendencies, which, in the judgment of the investigator, would pose an unacceptable risk to the patient or prevent the patient from successfully completing the study;
• Abusing alcohol or use narcotic drugs;
• Women who are pregnant. Women of childbearing age must take a pregnancy test;
• Patients currently enrolled in another investigational study;
• Those deemed unsuitable by the researcher.