Hydrocephalus is a neurological disorder characterized by an abnormal accumulation of cerebrospinal fluid in the ventricles of the brain. This debilitating disease has no known cure and is typically treated using a chronically implanted shunt system, which is critical in maintaining normalcy in hydrocephalus patients. Unfortunately, these important medical devices are plagued with a high rate of failure of up to 40% within the first two years post- implantation and up to 98% within 10 years. Although hydrocephalus may be acquired in life, approximately one in every 1000 newborns is diagnosed with congenital hydrocephalus. The annual cost of hospital care for treating pediatric hydrocephalus patients is estimated to exceed $2 billion in the United States. A large portion of shunt failures can be attributed to occlusions at the ventricular catheter due to inflammatory reaction, blood clots, or choroid plexus tissue ingrowth. Although there have been attempts to use in situ clearing methods using laser, ultrasound, or electrocautery to remove catheter obstructions, these surgical interventions did not attain wide acceptance due to their invasiveness. For patients with hydrocephalus, a self-clearing ventricular catheter that retards biofouling occlusion could lead to a reduction in costly shunt replacement surgeries and therefore an overall reduction in morbidity/mortality. To address catheter obstruction non-invasively in situ, we have developed thin-film-based magnetic microactuators and integrated them into implantable catheters in an effort to create self-clearing smart catheters. Compare to other transducers, microfabricated magnetostatic actuators are ideal for combatting biofouling due to their simplicity and strong actuation force. Since magnetic microactuators are powered by an externally applied magnetic field, the biofouling-removal can be done non-invasively without additional surgical procedures. Previously, we have demonstrated capability to remove cellular occlusions in both a static and a dynamic fluid environment using magnetic microactuators, however, no in vivo evaluation has been done to measure the functional capability of our self-clearing catheters in the body. In this proposal, we seek to fill this gap by using an intraventricular hemorrhage-induced animal model. By comparing the occlusion process of ventricular catheters with and without integrated magnetic microactuators, we will be able to determine biofouling-removal capability of our self-clearing catheters in the body. The results from proposed studies will significantly improve our knowledge on the capability of our self-clearing catheters in combatting biofouling on implantable devices, which may be beneficial for other applications beyond hydrocephalus.
The standard treatment for hydrocephalus, which affects 1 in 1000 newborns, requires chronic implantation of a shunt system designed to divert excess cerebrospinal fluid from the brain to other parts of the body. Unfortunately, these shunt systems have a very high rate of failure ? up to 40% ? within 2 years post-implantation partly due to mechanical blockage of ventricular catheter inlet pores. Our goal is to improve hydrocephalus patient outcome by developing a self-clearing ventricular catheter, which features microfabricated magnetic actuators, that can greatly reduce the probability of shunt obstruction-related device failures.
|Hyunsu Park; John, Simon; Hyowon Lee (2016) Low-cost rapid prototyping of liquid crystal polymer based magnetic microactuators for glaucoma drainage devices. Conf Proc IEEE Eng Med Biol Soc 2016:4212-4215|
|Qi Yang; Tran Nguyen; Chunan Liu et al. (2016) Polyimide-based magnetic microactuators for biofouling removal. Conf Proc IEEE Eng Med Biol Soc 2016:5757-5760|