| generally | 8 | degree |
| for introduction into the subarachnoid space | 5 | purpose |
| during surgical procedures | 4 | temporal |
| invention → relate to → cannula | 10 |
| invention → comprise → cannula | 4 |
| invention → provide → cannula | 3 |
| negative | neutral | positive |
| 0.044 | 0.881 | 0.075 |
| Raw frequency | 17 |
| Normalized frequency | 0.228 |
| Modifier score | 0.500 |
| Perplexity | 154.823 |