Study recruitment was put on hold for interim data analysis and during this time period the PI requested to pre-maturely terminate the study

To determine the efficacy of using the Jan Medical NNW system as a diagnostic aid in detection of moderate and severe vasospasm for detection of vasospasm in patients with subarachnoid hemorrhage.

This study is a prospective, comparative, non-randomized study in subjects with subarachnoid hemorrhage who are undergoing surveillance for vasospasm. The study will be conducted in one center.

The primary objective of Phase I of this non-significant risk study is proof of principle. During this phase the goal is to build a library of Jan Medical NNW system recordings from patients with moderate and severe vasospasms. A signature for detecting vasospasms will be developed using the signals from a vasospasm epoch to a patient's individual baseline recording and confirming the presence of vasospasm by comparison of Jan Medical NNW system data to TCD and, when available Digital Subtraction Angiography (DSA). The number of patients required for Phase I is estimated to be 20 patients with confirmed moderate or severe vasospasm with a minimum of 10 these patients having at least one severe vasospasm recording confirmed by TCD or DSA. Daily recordings are to be taken.

During Phase II the Jan Medical NNW system will independently utilize the signatures identified in Phase I to identify the presence or absence of moderate and severe vasospasm in a blinded recording. This recording will be compared to TCD or DSA, when DSA is available, for analysis of sensitivity and specificity. Up to 50 subjects will be enrolled in Phase II. When possible, multiple recordings will be obtained from each subject to include recordings with and without vasospasm.

Duration of each subject's enrollment in this study is limited to the period of time when Jan Medical NNW system recordings are performed. No additional tests or procedures will be performed during participation in this study and all other data collected (including TCD or DSA) will be based on available evaluations conducted as part of the patient's standard of care. Upon completing the last Jan Medical NNW system recording or when no further data collection is expected, the subject will be exited from the study.

Inclusion Criteria:

1. Male or female subjects 18 years of age or older.
2. Subjects with subarachnoid hemorrhage who are receiving clinical and diagnostic surveillance for vasospasm.
3. Signed informed consent from the patient or the patient's Legally Authorized Representative

Exclusion Criteria:

1. Unstable medical illness such that recordings might interfere with medical care.
2. Presence of head bandages or brain monitors that might physically interfere with the NNW recording device.
3. Current hemicraniectomy.

Subjects with subarachnoid hemorrhage who are undergoing surveillance for vasospasm