Biocompatibility Testing of a Compact, Lightweight Pulmonary Assist System Pump
Abstract
The goal of this project is to develop a pulmonary assist system (PAS) to support Veterans with long-term, incurable lung disease for a period of months to years. Over 12 million patients in the U.S. suffer from these lung diseases. The function of these patients’ lungs declines gradually over time, but they also experience recurring, temporary periods with a severe loss in lung function that are typically brought on by a lung infection or breathing in harmful materials. Veterans are 1.5 to 3 times more likely than the general population to develop these long-term lung diseases, making them the fourth most prevalent disease in the Veterans Administration (VA) patient population and requiring $5.2 billion of annual VA spending. The only treatment capable of restoring a relatively normal lifestyle for these patients is lung transplantation, but less than 2,800 donor organs are available in the U.S. each year. Our goal, therefore, is to develop a PAS that supports these patients for years at home. This system uses a small pump to pump blood from a patient’s body through a small artificial lung and back to the patient. Patients suffering a temporary, life-threatening worsening of their lung disease would have a PAS attached within the hospital. This will allow them to recover from their loss in lung function and rehabilitate more effectively. Patients suffering from significant, debilitating lung disease would be maintained on the PAS and transitioned to home-based care with assistance from a visiting nurse. Every 2-3 months, the patient would return to the hospital to have just the artificial lung portion of the PAS replaced. The PAS system would allow the patient to return to a relatively normal life and increase the patient’s lifespan. Due to its compact size, it could also be used to transport Soldiers with short-term respiratory failure, known as acute respiratory distress syndrome (ARDS). The primary topic area of this proposal is thus “Respiratory Health.” It addresses the Areas of Encouragement “research on the causes, treatment, and prevention of obstructive pulmonary diseases” and “strategies to stabilize and support the safe transport of patients with ARDS in order to optimize therapeutic interventions, particularly in operational scenarios requiring prolonged or extended care and/or longer transport times prior to definitive care.” During our original funding, we utilized computer modeling to adjust blood flow patterns through the artificial lung to reduce blood clot formation and enhance device longevity and long-term function. We then verified that a single artificial lung module provides the oxygen and carbon dioxide transfer necessary to support a patient with lung disease. We also proved that the entire system, including pump and batteries, weighs 2.3 kg. Lastly, we performed several long-term studies in sheep to determine the ideal circuit components to use with the PAS artificial lung. We then performed respiratory support for 7 and 14 days in sheep using a modified ReliantHeart HA5 pump. At the end of these experiments, the sheep were healthy and able to walk briskly around the room on the system. Our goal was to then progress to 60-day studies using a new pump from the ReliantHeart team, the Cardiodyme CDX, that was designed specifically for this application. Unfortunately, both experiments had to be halted prior to attaching the artificial lung due to clot formation in the system. These results indicate that studies are necessary to evaluate short-term pump performance within the PAS prior to evaluating the PAS for 60 days. Thus, we propose to compare the performance of the modified ReliantHeart HA5 and the Cardiodyme CDX to that of a traditional, much larger, commercial pump, the Maquet Rotaflow. We hypothesize that (1) the Rotaflow and HA5 will generate similar, low levels of blood damage, clot formation, and activation of the immune system, but that there may be clot formation where the HA5 con
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Dec 05, 2021
- Source ID
- W81XWH2110591
Entities
People
- Keith Cook
Organizations
- Carnegie Mellon University
- United States Army