Background
Introduction
Currently, Pulse Therapeutics, Inc. is developing a Magnetically-Enhanced Diffusion (MED) Therapy for ischemic stroke to be used in the Emergency Department. Their therapy aids in clot dissolution in stroke patients by applying an external magnetic field to the top of the head, and utilizing magnetite particles co-infused with a thrombolytic, particularly tissue plasminogen activator (tPA). The magnetic field directs the magnetite particles to the area of the bloodstream occluded by the clot, and the rotational motion of the particles entrains tPA and significantly decreases delivery time of the thrombolytic. The continued mixing motion of the magnetite particles mechanically aids clot-dissolution as well. Experimentally, the therapy has generally taken about 15-20 minutes to run to completion, fully dissolving a target clot; however, the therapy will clinically run for 90 minutes in order to ensure complete recanalization of the vessel and avoid re-occlusion of downstream blood vessels.
According to the World Health Organization, in 2008, stroke was the second largest cause of death worldwide, contributing to 6.15 million deaths that year and 10.8% of deaths overall. In addition, time is crucial with respect to the onset of stroke, as more brain tissue is lost the longer it takes to restore blood flow. There is currently a standard device intervention involving intra-arterial administration of tPA as well as surgical intervention, but both take hours of preparation and procedural time and suffer high death rates from intracranial hemorrhage and pose a high risk of brain vessel perforation, respectively. With Pulse’s MED Therapy, vessels open faster and more consistently with a lower dose of tPA than without magnetite particles, and magnetite is proven to be safe and biocompatible. Thus, MED Therapy successfully integrated into Emergency Departments could prove extremely valuable in improving stroke outcomes by more quickly and effectively treating ischemic stroke than current solutions.
According to the World Health Organization, in 2008, stroke was the second largest cause of death worldwide, contributing to 6.15 million deaths that year and 10.8% of deaths overall. In addition, time is crucial with respect to the onset of stroke, as more brain tissue is lost the longer it takes to restore blood flow. There is currently a standard device intervention involving intra-arterial administration of tPA as well as surgical intervention, but both take hours of preparation and procedural time and suffer high death rates from intracranial hemorrhage and pose a high risk of brain vessel perforation, respectively. With Pulse’s MED Therapy, vessels open faster and more consistently with a lower dose of tPA than without magnetite particles, and magnetite is proven to be safe and biocompatible. Thus, MED Therapy successfully integrated into Emergency Departments could prove extremely valuable in improving stroke outcomes by more quickly and effectively treating ischemic stroke than current solutions.
Customer Needs
The therapy process presently operates without any form of real-time imaging. During clinical trials, CT angiography was performed before therapy, two hours after therapy, and again 24 hours after therapy to verify successful clot dissolution. Real-time visualization of clot dissolution would allow the physician to monitor and ensure lysis of the clot without further cumbersome tests, to track the possibility of re-occlusion, and to begin preparation for another kind of clot intervention should the therapy happen to be ineffective. Moreover, the imaging system must be unaffected by weak magnetic fields and must be designed for use in the ER, so it must be portable, small, and non-invasive with a startup time of less than 30 seconds. Finally, the imaging system must be mechanically compatible with the therapy’s current set-up, in which the patient lies supine with his or her head laying unrestricted upon a headrest. Thus, the imaging modality must run for at least the full 90 minutes of therapy, as well as allow movement of the patient’s head in case of sudden seizures during therapy.