Biomedical Devices

Current Projects:

Intraocular Drug Delivery:

Both manually- and electrically-operated micro-pumps are being developed to deliver nL volumes of drug to directly targeted locations within the eye.  These devices are capable of being refilled and used repeatedly with only a single implantation surgery.  This approach represents a new paradigm in ocular drug delivery that is made possible with biomedical microsystems technology.

Our microfabricated drug delivery devices are being applied to the treatment of glaucoma.  Glaucoma is a chronic disease characterized by progressive optic nerve damage and vision loss.  There is no cure for glaucoma; management of the disease focuses on lowering intraocular pressure which has been effective in reducing the progression of the disease.  We are investigating a novel method for targeted intraocular delivery of glaucoma medication at therapeutic levels with a microelectromechanical systems (MEMS)-fabricated microfluidic device.  Directed delivery to intraocular tissues reduces the diffusion distance of the drug, increases the efficacy of each dose, reduces the size of the dose, and reduces the amount of unintended systemic absorption of unused drug and the associated side effects.  Furthermore, this platform enables precise temporal and spatial control of ocular drug delivery not possible with conventional methods.

(funding sources: Bausch & Lomb, NSF BMES ERC, NIH)

Catheter-Based Shear Stress Sensors:

Intravascular shear stress sensors are being developed to measure in real time shear stress to investigate its role in the formation of arterial plaques.  These tiny sensors fabricated from Parylene C enable measurement of small-scale hemodynamics beyond what is possible in current imaging techniques.

(funding source: NIH)

Electrothermal Valves for Implantable Drug Delivery Systems:

Disposable valves that operate on electrothermal principles enable rapid delivery of radiotracers for neuroimaging of brain blood flow in freely-moving untethered small animals.  Key requirements are that these normally-closed valves must be light weight and require low power for wireless operation.

(funding source: NIH)

Past Projects:

Glaucoma Pressure Sensing and Drainage:

A novel microsystems approach is explored to address two aspects of glaucoma therapy: monitoring of intraocular pressure and drainage of aqueous humor.  Implantable mechanical (un-powered) and electrical pressure sensors are being developed for continuous monitoring of intraocular pressure.  Also, drainage shunts with pressure-activated valves to maintain normal IOP levels are being developed.

(funding sources: Bausch & Lomb, NSF ERC)