Pressure spike near the end of inspiration can occur if there is inspiratory muscle relaxation or active exhalation (delayed cycling).
The rounded contour of the inspiratory flow-time scalar in pressure support mode (normal shape is descending ramp/triangular) occurs when the patient is generating strong Pmus which may be an indication of insufficient pressure support.
Note: the expiratory flow-time scalar showing air-trapping
How to differentiate the pressure overshoot due to inspiratory muscle relaxation and active exhalation?....leave your comments!
Read this article for further information on pressure overshoot