Inclusion Criteria:

• Patient is male or female.
• Patient is 65 years of age or older.
• Patient has a physical status between ASA I and III. (Appendix C).
• Patient scheduled for general anesthesia for non-cardiac surgery expected to last at least one hour.
• Patient able to communicate in English.
• Patient has signed an approved informed consent.

Exclusion Criteria:

• Patient's age is less than 65 years
• Anesthetic duration of less than one hour expected
• Treatment of beta blockers contra-indicated
• Not a candidate for general anesthesia
• Patient requires regional anesthesia with general anesthesia.
• ASA physical status of IV or V. (Appendix C)
• Patient has known drug or alcohol abuse.
• Patient has scalp or skull abnormalities such as psoriasis, eczema, angioma, scar tissue, burr holes, cranial implants (such as plates, shunts, etc.).
• Patient has experienced a head injury with loss of consciousness within the last year.
• Patient has known neurological and psychiatric disorder that interferes with the patient's level of consciousness.
• Known concurrent chronic usage of psychoactive or anticonvulsive drugs within the last 90 days, or any use in the last 7 days (i.e. tricyclic antidepressants, MAO inhibitors, lithium, SSRIs, neuroleptics, anxiolytics or antipsychotics).
• Patient has any medical condition which, in the judgment of the investigator, renders them inappropriate for participation in this study, such as Guillen Bare syndrome
• Known hypersensitivity to the intended anesthetic agents including significant post-operative nausea or vomiting.
• Uncontrolled hypertension (unresponsive to medication):

Systolic BP > 180 mmHg or Diastolic BP > 105 mmHg

• Pre-Op baseline heart rate < 45 beats per minute
• Weight 50% greater than ideal body weight
• Already monitored for EP or EEG, i.e., Spinal cord cases
• Actual anesthetic duration < 1 hour (assessed after emergence).