Characterization of Sleep Using Bispectral Analysis
Abstract
This study investigated the relationship between a Bispectral Index (BIS), as measured by Aspect Medical Systems' A-1000 EEG monitor, and clinical sleep staging based on the Rechtschaffen and Kales (RK) scoring procedure, Eleven subjects - with no known sleep, respiratory, or cardiovascular disease - were tested using full polysomnography and respiratory monitoring with simultaneous recording of BIS, in an accredited sleep laboratory, in Ft, Worth, Texas. An ordinal scale was assigned to RK-based sleep stages: Wake = 1, REM = 2, Stage 1 = 3, Stage 2 = 4, Stage 3 = 5 and Stage 4 = 6. By performing linear regression between average BIS values and assigned scales, it was found that average BIS values were highly correlated with non-rapid eye movement (NREM) sleep stages and wakefulness, both within (average R2 +/- one standard deviation 0.9376 +/- 0.0264) and across subjects (R2=0.896), However, there was a considerable amount of inter-subject variability about the average BIS value for each sleep stage. The mean BIS values for each sleep stage across all subjects were: Wake: 87.057 +/- 12.967 (97.7 - 17.4); REM: 78.081 +/- 10.690 (95.2 - 27.5); Stage 1: 79.452 +/- 13.337 (97.7 - 25.5); Stage 2: 66.771 +/- 15.493 (97.6-24.4); Stage 3: 41.277 +/- 9.280 (87.6 - 16.9); and Stage 4: 33.832 +/- 8.021(72.3 - 13.1), Across all subjects, only the mean BIS values for REM and Stage 1 were not significantly (P < 0.05) different from each other, These results indicate that BIS alone may not be adequate for automated sleep staging.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 25, 2001
- Accession Number
- ADA412067
Entities
People
- Cameron Mcpherson
- Dzu Dao
- Edgar Lucas
- John Burk
- Khosrow Behbehani
Organizations
- University of Texas Southwestern Medical Center