Intensive Care Unit (ICU) is a data intensive environment, requiring continuous monitoring of patient's physiology and response to treatment. In assisted ventilation, where patient effort that triggers the ventilator and there is need for patient-ventilator coupling, attention is required in cases where patient's effort that doesn't trigger the ventilator at all. When synchronization between the patient's attempt to breath and the assisted ventilation event is lost, an ineffective effort (IE) event takes place. A series of relevant bioparameters continuously monitored, are meant to guide the medical professionals in appropriately adapting the operation and treatment, in order to minimize IEs. The purpose of this work is to investigate the causal relations between physiological or ventilation parameters and IE events. A multiscale approach is proposed, based on wavelet similarity and localized phase relationship. The proposed method indicates the existence of distinct frequency zones correlated with the IE experienced by the patient.