Federal award (PURCHASE ORDER, fiscal year 2022)
Recipient: PHYSICAL SCIENCES INC.
Awarding agency: National Aeronautics and Space Administration / National Aeronautics and Space Administration
Funding agency: National Aeronautics and Space Administration / National Aeronautics and Space Administration
Period of performance: 2018-09-18 to 2022-09-30
Current total value of award: $100000
Description: EO14042 PHYSICAL SCIENCES INC. (PSI) DEVELOPED IN PHASE II A NOVEL OPHTHALMIC IMAGING PLATFORM FOR THE CHARACTERIZATION AND MONITORING OF POTENTIAL VISUAL IMPAIRMENT OBSERVED IN LONG-DURATION SPACE FLIGHTS. THIS PLATFORM COMBINES NONINVASIVE MEASUREMENT OF RETINA/CHOROID STRUCTURE AND OCULAR BLOOD FLOW WITH OPTICAL COHERENCE TOMOGRAPHY (OCT) AND WIDE-FIELD SEMI-QUANTITATIVE GLOBAL FLOW VISUALIZATION WITH LINE-SCANNING DOPPLER FLOWMETRY (LSDF), WHICH IS A MORE ADVANCED VERSION OF THE TRADITIONAL LASER DOPPLER FLOWMETRY (LDF OR LDV). PSI PROPOSES TO FURTHER IMPROVE THE TECHNOLOGY AND TO ADD FEATURES OF SIGNIFICANT INTEREST TO NASA IN A PHASE II-X PROGRAM. THE PROPOSED SPECIFIC OBJECTIVES OF THE PHASE II-X PROGRAM ARE: 1. DEMONSTRATE QUANTITATIVE BLOOD FLOW MEASUREMENT OVER LARGE AREAS. 2. DEVELOP A METHOD FOR GLOBE FLATTENING EVALUATION. OBJECTIVE 1. DEMONSTRATE QUANTITATIVE BLOOD FLOW MEASUREMENT OVER LARGE AREAS. (FUNDED BY THE SBIR PROGRAM) DESPITE DECADES OF RESEARCH AND THE INTRODUCTION OF SEVERAL ADVANCED SYSTEMS FOR MEASUREMENT OF BLOOD FLOW, RETINAL BLOOD FLOW DOPPLER IMAGING DIAGNOSTICS HAVE NOT YET ACHIEVED THE CLINICAL PROMINENCE THAT RETINAL BIOLOGY WOULD SEEM TO JUSTIFY. IN PARTICULAR FOR LDV, THE MEASUREMENTS ARE GIVEN IN ARBITRARY UNITS (VOLUME AND FLOW) OR HZ (VELOCITY) AND THEIR CONVERSION FACTOR TO THE CORRECT PARAMETERS CLAIMED TO BE MEASURED WERE RATHER ELUSIVE SO FAR. THE MEASUREMENTS SEEM TO DEPEND ON A LOT OF UNCONTROLLED FACTORS, ARE OPERATOR DEPENDENT AMONG OTHER THINGS, AND CANNOT RELIABLY SUPPORT LONGITUDINAL STUDIES ON THE SAME EYE OR COMPARISONS AMONG INDIVIDUALS. EVEN IF OUR LINE-SCANNING VERSION OF LDV IS SIGNIFICANTLY FASTER, COVERS A LARGER AREA, AND ENABLES MEASUREMENT OF LARGER VELOCITIES, IT STILL SUFFERS FROM SOME OF THE DISADVANTAGES OF THE STANDARD LDV AND IN PHASE II WE USED IT MAINLY AS A SEMI-QUANTITATIVE VISUALIZATION METHOD TO MAP RETINAL AND CHOROIDAL VESSELS. FOR PHASE II-X WE PROPOSE TO DEVELOP A METHOD TO ENABLE QUANTITATIVE MEASUREMENT OF THE BLOOD VELOCITY BY DETERMINING THE CALIBRATION FACTOR, THE CONVERSION FROM HZ TO MM/S DIRECTLY IN THE LIVING EYE AND FOR EACH MEASUREMENT SESSION ELIMINATING THE UNCERTAINTIES ASSOCIATED WITH STANDARD LDV. OBJECTIVE 2. DEVELOP A METHOD FOR GLOBE FLATTENING EVALUATION. (FUNDED BY HRP) AS PART OF THE MICRO-GRAVITY INDUCED ADVERSE EFFECTS OBSERVED TO AFFECT THE ASTRONAUTS VISION IN LONG-TERM SPACE FLIGHTS, GLOBE FLATTENING IS A MAJOR MACROSCOPIC GEOMETRICAL MODIFICATION OF THE EYE THAT IS DIRECTLY RELATED TO REFRACTIVE ERRORS AND REDUCES VISUAL ACUITY. GLOBE FLATTENING HAS BEEN MEASURED SO FAR ONLY WITH MRI WHICH HAS LOW RESOLUTION COMPARED TO OPTICAL IMAGING, IS VERY EXPENSIVE, AND IS DIFFICULT TO PERFORM DURING SPACE TRAVEL. LARGE AREA OCT SCANS CAN DETERMINE THE SHAPE OF THE BACK OF THE EYE WITH BETTER RESOLUTION THAN THE CURRENT TECHNIQUES HOWEVER THE CORRECT RECONSTRUCTION OF THE EYE SHAPE DEPENDS ON THE SCANNING GEOMETRY AND ASSUMES THAT THE PIVOTING POINT OF THE SCANNING BEAN IS PROPERLY PLACED NEAR THE EYE PUPIL. PSI PROPOSES TO ADD A REFERENCE MEASUREMENT RELATED TO THE ANTERIOR PART OF THE EYE THAT CAN BE MADE CONSISTENTLY AND RELIABLY TO IMPROVE ACCURACY OF EYE SHAPE MEASUREMENT FOR INVESTIGATING GLOBE FLATTENING.