Pulmonary Delivery of Therapeutic and Diagnostic Gases.

Dr. Charles is an Associate Professor of Radiology, a chemist and an expert in MR imaging and spectroscopy with over 40 years of experience in nuclear magnetic resonance. He serves as the Scientific Director of the Duke Center for Advanced Magnetic Resonance Development.  He has had extensive experience in conducting longitudinal clinical trials with MRI and MRS used as imaging biomarkers. He is also director of the Duke Image Analysis Laboratory which is active in conducting clinical trials in CNS disorders (schizophrenia, MCI, AD), cancer, osteoarthritis and lung disease using imaging based biomarkers. His lab has developed approaches for imaging lung function (ventilation and V/Q) in humans with 19F MRI.

1. Mechanical Ventilation and respiratory failure. Current projects involve studying patient-ventilator interactions during modes of support that require patient activity. The focus is on ventilatory muscle function during these assisted modes. Other projects include evaluating respiratory system mechanics in acute respiratory failure and the role of ECMO in the adult. Duke is also one of several institutions in the NIH ARDS Network, a consortium designed to perform multi-center trials.
   
   2) Diffusing capacity of the lung for carbon monoxide. Current projects involve using a rapidly responding gas analyzer to measure lung diffusing capacity in discrete regions of the lung. These analyses are being extended into mechanically ventilated patients.
   
   3) COPD. Current projects involve studying the physiology of cardio-respiratory conditioning in patients with obstructive lung disease and the role of pulmonary rehabilitation in improving COPD outcomes. Duke is also a member of two NIH sponsored multicenter programs: the COPDgene project correlating genetic profiles with physiologic/clinical phenotypes; and the NIH LOTT project evaluating the role of oxygen therapy in exercise and sleep hypoxemia.
   
   4) Aerosol delivery systems. The current project is the development of a prototype aerosol generating catheter that can be directly inserted into the airways. Studies are being conducted in both ex vivo animal lungs and in mechanically ventilated patients.

Research interests include the study of cardiorespiratory function in humans during challenging clinical settings including the perioperative period, and exposure to environmental conditions such as diving and high altitude. Studies have included gas exchange during diving, the pathophysiology of high altitude and immersion pulmonary edema, the effect of anesthesia and postoperative analgesia on pulmonary function and monitoring of tissue oxygenation. Ongoing human studies include the effect of respiratory muscle training on chemosensitivity and blood gases during stressful breathing: underwater exercise.