comparing---with--- 比较的东西不对等啊？

Potential EAdi‑derived indices 

Patient‑ventilator breath contribution index 

The inspiratory tidal volume (VT,insp) during NAVA reflects the volume resulting from the patient’s effort plus the proportional ventilator assist. An ‘effort-sharing’ index can be derived by comparing assisted to unassisted breaths. This patient-ventilator breath contribution (PVBC) index is defined as the ratio of VT,insp/ΔEAdi of an unassisted breath (i.e., NVE, as described above) to that of a breath with ventilator assistance (Fig. 5a) [73, 75]: 

PVBC = (VT,insp/ΔEAdi)no-assist/(VT,insp/ΔEAdi)assist

PVBC values can range between 0 (VT,insp fully provided by the ventilator) and 1 (VT,insp completely generated by the patient) and have been validated against measurements of transpulmonary pressure [73, 75]. Reliability of PVBC improves when comparing unassisted and assisted breaths with similar respiratory drive (i.e., EAdi amplitude and slope) [76]. PVBC interpretation is complex. For instance, high PVBC values can be found in patients with low respiratory drive that are ready to be weaned (patient effort is low but sufficient to perform the majority of the work), but also in patients with excessive respiratory drive (the patient is under-assisted). Interpretation must take into account absolute ventilator assist and patient effort.

潜在的EADI衍生指数

患者-呼吸机呼吸贡献指数

NAVA期间的吸气潮气量（VT，Insp）反映了患者努力加上比例呼吸机辅助产生的潮气量。通过比较辅助呼吸和非辅助呼吸，可以得出“努力分担”指数。患者-呼吸机呼吸贡献（PVBC）指数定义为无辅助呼吸（即如上所述的NVE）的VT，insp/ΔEAdi与呼吸机辅助呼吸的VT，insp/ΔEAdi比率。

PVBC =（VT，Insp/ΔEAdi）无辅助呼吸/（VT，insp/ΔEAdi）辅助呼吸

    PVBC值的范围在0（VT，Insp完全由呼吸机提供）到1（VT，Insp完全由患者产生）之间，并且已经由跨肺动脉压的测量进行了验证。当比较无辅助呼吸和辅助呼吸具有相似呼吸动力（即EADI振幅和斜率）时，PVBC的可靠性提高。PVBC解释很复杂。例如，可以在准备脱机的低呼吸驱动力患者（患者努力程度较低，但足以完成大部分工作）中发现高PVBC值，但也可以在呼吸驱动过度的患者中发现高PVBC值（患者辅助不足）。解释必须考虑到绝对的呼吸机辅助和病人的努力。

 comparing unassisted and assisted breaths with similar respiratory drive (i.e., EAdi amplitude and slope) 

comparing---with---  比较的东西不对等啊？谢谢