bmdo technologies for biomedical applications - MDA Technology

SPIRE’S ION-BEAMAPPLICATIONSBMDO HISTORYWith the help of BMDO SBIR contracts, Spire Corporation (Bedford, MA)developed an ion-beam texturization method that can create intricate surfaceson a variety of materials. For BMDO’s Advanced Optical Baffles program,Spire used its patented SPI-TEXT method to create random patternson optical sensors that aid in rejecting stray light. These sensors were usedin BMDO’s moon-orbiting spacecraft,Clementine, as part of the light collectionBacterial endocarditis issystem for star tracking. The same texturizationmethod plays an integral role inan infrequent complicationSpire’s biomaterial product line.• SPI-TEXT creates random patternson surfaces that can be useful for manybiomaterials.of valve replacementsurgery, but once acquiredit can be fatal to nearly60 percent of patients. Itcan also be acquired byrheumatic heart patientsafter simple surgery ordental procedures. In bothcases it can usually beHOW IT WORKSSpire developed an advanced surface modificationtechnology based on ion-beamimplantation and ion-beam-assisted depositiontechniques. To produce optically darksurfaces, metals are bombarded with ions tocreate micrometer-scale textures, increasingsurface area and providing light-trappingpores. For biomaterials that are either polymericor metallic, this etching can alter surfacesfor all manner of applications—forexample, providing better anchoring forbacteria in petri dishes or, conversely, bycoating and smoothing a catheter surface toprevent bacterial adherence.72MEDICAL SIGNIFICANCEprevented with antibiotics.While medical procedures certainly savelives and alleviate suffering, many of thephysical invasions associated with modernpractices automatically introduce new problems. Any device that is insertedinto the body carries with it a threat of infection. Bacteria are often particularlyattracted to polymers in portions of hip and knee implants, as wellas indwelling catheters and heart valve sewing cuffs. They easily take upresidence on these devices in a resistant covering called a biofilm. Evenbacteria that are normally eradicable by antibiotics can avoid harm by colonizingimplants in this manner. In addition, rough surfaces on medicaldevices can promote the formation of clots that can travel to the lung,heart, and brain, with devastating consequences.One of Spire’s latest efforts has been in impregnating replacement heartvalve sewing cuffs with silver metal through an ion-beam process calledSPI-ARGENT. This coating of elemental metal helps prevent bacterialChapter 3 - Intervention TechnologiesSection A - ImplantsBMDO Technologies for Biomedical Applications