translation.en: To support this theory, Cartwright helped to perfect a medical device for measuring breathing called the spirometer to show the presumed deficiency in black people's lungs.
translation.zh: 为了支持这个理论， 卡特赖特协助完善了 一个称为肺活量计的 用于监测呼吸的医学仪器， 试图展现黑人肺部所谓的“缺陷”。