McCool F D, Paek D
Pulmonary Division, Memorial Hospital of Rhode Island, Pawtucket 02860.
Res Rep Health Eff Inst. 1993 May(59):1-17; discussion 57-69.
Both the level of ventilation and breathing pattern (breathing frequency, inspiratory time, and tidal volume) have an important influence on particle deposition and gas uptake in the lungs. Accordingly, a description of these measures is needed to assess better the dose of particulate deposit and gas uptake in the lungs during varied activities. The long-term objectives of this study were to develop a means of measuring minute ventilation in the field by using body surface displacements, and to evaluate the utility of heart rate as an index of minute ventilation. By using respiratory inductance plethysmographic belts and magnetometers placed on the rib cage and abdomen, ventilation and breathing pattern can be noninvasively measured in mobile individuals. Our specific aims were (1) to validate measurements of ventilation using body surface displacement; (2) to describe breathing patterns in subjects performing a variety of daily activities in the laboratory; (3) to analyze relationships between minute ventilation and heart rate; and (4) to measure ventilation in the field with one technique utilizing body surface displacements and another based upon heart rate. We found that values of tidal volume, inspiratory time, and breathing frequency derived from body surface displacement measurements correlated well with those determined spirometrically during a variety of activities. The coefficient of determination for tidal volume was 0.97 +/- 0.2 for cycling, 0.93 +/- 0.07 for arm cranking, 0.91 +/- 0.05 for pulling, and 0.84 +/- 0.12 for lifting. Our experiments showed that the breathing pattern was altered by the use of a mouthpiece and varied according to the type of activity. The use of a mouthpiece increased tidal volume by 34%, decreased the breathing frequency by 10%, and increased minute ventilation by 16%. There was more variability of these parameters during lifting and pulling activities than during cycling. The ventilation-heart rate relationship varied from subject to subject and was altered by the use of a mouthpiece. We found that ventilation measured in the field from body surface displacement correlated well with ventilation measured using the pneumotachograph (R2 = 0.89). However, measurements of ventilation derived from heart rate were not as accurate as those derived from body surface displacements. We concluded that minute ventilation can be measured accurately using body surface displacements in the laboratory and in the field. Heart rate can also be utilized, but factors affecting the minute ventilation-heart rate relationship, such as the use of a mouthpiece and range of heart rate, must be addressed to obtain more accurate estimates of minute ventilation.
通气水平和呼吸模式（呼吸频率、吸气时间和潮气量）对肺部颗粒沉积和气体摄取都有重要影响。因此，需要对这些指标进行描述，以便更好地评估不同活动期间肺部颗粒沉积和气体摄取的剂量。本研究的长期目标是开发一种利用体表位移在现场测量分钟通气量的方法，并评估心率作为分钟通气量指标的实用性。通过使用放置在胸廓和腹部的呼吸感应体积描记带和磁力计，可以对活动中的个体进行无创通气和呼吸模式测量。我们的具体目标是：（1）验证使用体表位移进行的通气测量；（2）描述在实验室中进行各种日常活动的受试者的呼吸模式；（3）分析分钟通气量与心率之间的关系；（4）使用一种利用体表位移的技术和另一种基于心率的技术在现场测量通气量。我们发现，通过体表位移测量得出的潮气量、吸气时间和呼吸频率值与在各种活动中通过肺活量测定法确定的值具有良好的相关性。潮气量的决定系数在骑自行车时为0.97±0.2，手摇曲柄时为0.93±0.07，拉拽时为0.91±0.05，举起重物时为0.84±0.12。我们的实验表明，使用咬嘴会改变呼吸模式，且呼吸模式会因活动类型而异。使用咬嘴会使潮气量增加34%，呼吸频率降低10%，分钟通气量增加16%。与骑自行车相比，举起重物和拉拽活动期间这些参数的变异性更大。通气量与心率的关系因受试者而异，并且会因使用咬嘴而改变。我们发现，通过体表位移在现场测量的通气量与使用呼吸流速仪测量的通气量具有良好的相关性（R2 = 0.89）。然而，由心率得出的通气量测量不如由体表位移得出的测量准确。我们得出结论，在实验室和现场使用体表位移可以准确测量分钟通气量。心率也可以利用，但必须考虑影响分钟通气量与心率关系的因素，如使用咬嘴和心率范围，以获得更准确的分钟通气量估计值。
