@article{gurumurthy_kleinstreuer_2022, title={Analysis of improved oral drug delivery with different helical stream inhalation modes}, volume={141}, ISSN={["1879-0534"]}, DOI={10.1016/j.compbiomed.2021.105132}, abstractNote={A challenging aspect of pulmonary drug delivery devices, e.g., metered dose inhalers (MDIs), is to deliver therapeutic drugs to prescribed target locations at the required dosage level. In this study, validated computer simulations of micron-drug inhalation with angled or radially positioned helical fluid-particle streams are simulated and analyzed. For a suitable swirl number significant improvements in drug delivery, especially to deeper lung regions, have been achieved. Specifically, considering realistic polydisperse particle distributions at the mouth inlet for a subject-specific upper lung airway geometry, a 10-degree angled helical stream increased the local efficacy by up to 26% in comparison to a conventional helical stream, causing an overall dosage of about 60% to the deep lung. Considering lobe-specific drug targeting scenarios, while using an off-center, i.e., radially well positioned, helical-flow mouthpiece, the local particle-deposition efficacy increased from 9% to 24% in the left lobe and from 25% to 38% in the right lobe in comparison to conventional drug-aerosol stream released from the central position. The efficacy of helical streams for pulmonary drug delivery applications has been established.}, journal={COMPUTERS IN BIOLOGY AND MEDICINE}, author={Gurumurthy, Adithya and Kleinstreuer, Clement}, year={2022}, month={Feb} }
 @article{gurumurthy_kleinstreuer_2021, title={Helical fluid-particle flow dynamics for controlling micron-particle deposition in a representative human upper lung-airway model}, volume={151}, ISSN={["1879-1964"]}, DOI={10.1016/j.jaerosci.2020.105656}, abstractNote={The transport and deposition of inhaled micron particles is largely determined by their inlet conditions, breathing rate, and the individual airway geometry. In this study, helical air-particle flow is introduced, which significantly affects the particle dynamics with applications to targeted drug delivery. Specifically, helical flow, which reduces axial momentum, can be controlled by varying the swirl number and hence the characteristics of the fluid-particle stream. In case of drug-aerosol delivery, the waste of inhaled drugs in the human upper respiratory tract due to inertial impaction can be mitigated by implementing a controlled helical flow with a modified inhaler. For example, 2 μm-particle deposition was reduced in the oral cavity for a helical fluid-particle stream with 10 l/min inhalation by 39.7% when the swirl number was increased from 0 to 0.6. Considering a 30 l/min inhalation flow rate, the deposition fraction of 2 μm-particles in the oral cavity was reduced by 73.5% as the swirl number increased from 0 to 2. A new non-dimensional parameter called the swirl number threshold (Sth), is also discussed, which is useful in assessing the impact of helical streams in drug-aerosol delivery. All computer experiments were performed with an enhanced version of the open-source computational fluid dynamics toolbox OpenFOAM.}, journal={JOURNAL OF AEROSOL SCIENCE}, author={Gurumurthy, Adithya and Kleinstreuer, Clement}, year={2021}, month={Jan} }
 @article{gurumurthy_kleinstreuer_2021, title={Improving Pulmonary Nanotherapeutics Using Helical Aerosol Streams: An In Silico Study}, volume={143}, ISSN={["1528-8951"]}, DOI={10.1115/1.4051217}, abstractNote={Abstract}, number={11}, journal={JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME}, author={Gurumurthy, Adithya and Kleinstreuer, Clement}, year={2021}, month={Nov} }