title: A passive MEMS drug delivery pump for treatment of ocular diseases.
abstract: An implantable manually-actuated drug delivery device, consisting of a refillable drug reservoir, flexible cannula, check valve, and suture tabs, was investigated as a new approach for delivering pharmaceuticals to treat chronic ocular diseases. Devices are fabricated by molding and bonding three structured layers of polydimethylsiloxane. A 30 gauge non-coring needle was used to refill the reservoir; this size maximized the number of repeated refills while minimizing damage to the reservoir. The check valve cracking pressure was 76 +/- 8.5 mmHg (mean +/- SE, n = 4); the valve sustained > 2000 mmHg of reverse pressure without leakage. Constant delivery at 1.57 +/- 0.2 microL/sec and 0.61 +/- 0.2 microL/sec (mean +/- SE, n = 4) under 500 mmHg and 250 mmHg of applied pressure, respectively, was obtained in benchtop experiments. The valve closing time constant was 10.2 s for 500 mmHg and 14.2 s for 250 mmHg. Assembled devices were successfully demonstrated in benchtop, ex vivo, and in vivo experiments.
authors.affiliation: Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, 1042 Downey Way, DRB-140, Los Angeles, CA 90089-1111, USA.
authors.forename: Ronalee
authors.initials: R
authors.lastname: Lo
authors.forename: Po-Ying
authors.initials: PY
authors.lastname: Li
authors.forename: Saloomeh
authors.initials: S
authors.lastname: Saati
authors.forename: Rajat N
authors.initials: RN
authors.lastname: Agrawal
authors.forename: Mark S
authors.initials: MS
authors.lastname: Humayun
authors.forename: Ellis
authors.initials: E
authors.lastname: Meng
mesh_terms: D000818:Animals; D016503:Drug Delivery Systems / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D005128:Eye Diseases / Q000601:surgery / Q000628:therapy*; D008297:Male; D055595:Mechanical Phenomena; D055616:Microtechnology / Q000295:instrumentation*; D009339:Needles; D019736:Prostheses and Implants; D011817:Rabbits; D013552:Swine