Biomedical subjects

E D Oberg

Publications and source records attributed to E D Oberg.

6 recordsLinked to original sources

PubMed1997

The development of a hybrid analog/digital retinal surgical laser system.

In the last few years the progress made in producing an integrated automated retinal surgical laser system has grown tremendously. Two different techniques have been developed in parallel: an analog and a digital system. Both the analog and digital systems are capable of tracking the retina while precisely placing lesions in desired locations. However, each system has its unique advantages and disadvantages to an automated surgical system. Current work has been conducted to integrate these two techniques to take full advantage of their unique capabilities. The goal of this research is to successfully integrate the systems to provide a better retinal surgical treatment for those individuals affected by diabetes, retinal tears, and other eye disorders.

Computers, Hybrid↗

PubMed1997

Integration of analog and digital retinal tracking and coagulation subsystems.

Laser photocoagulation is used by ophthalmologists to treat retinal disorders such as diabetic retinopathy and retinal breaks and tears. Currently, the procedure is performed manually and suffers from several drawbacks: it often requires many clinical visits, it is very tedious for both patient and physician, the laser pointing accuracy and safety margin are limited by a combination of the physician's manual dexterity and the patient's ability to hold their eye still, and there is a wide variability in retinal tissue absorption parameters. This paper describes progress in developing a computer-assisted robotic laser system that will rapidly and safely place multiple therapeutic lesions at desired locations on the retina in a few seconds.

Analog-Digital Conversion↗

PubMed1997

Development of an integrated automated retinal surgical laser system.

Diabetes is a serious disease that affects millions of people world wide. One of the many complications that may result from this disease is an eye disorder called diabetic retinopathy. This side effect is characterized by the leaching of fluid, mainly blood, into the retinal tissue ultimately killing the rods and cones in the area. Scientists have discovered that by occulating and destroying some of the capillaries near the infected area, further damage may be limited and further vision loss prevented. This procedure is performed on the retina by using a Continuous Wave argon laser to place a pattern of lesions that kill the rods, cones, and underlying capillaries. The "Computer Aided Laser Optics System for Ophthalmic Surgery" or CALOSOS is a system that fully integrates the placement of therapeutic retinal lesions through computer control. To date, two different sub-systems have been used to achieve the desired accuracy needed including lesion placement and depth; an all-digital system and a hybrid analog/digital system. The current tracking system that precisely controls the laser uses a wide-angle lens camera to view the whole retina. The difficulty lies in the fact that the only way to control the depth of the lesion is to measure the central reflectance. The goal of this research is to establish that there is a linear relationship between the reflectance of the lesion and the depth of the lesion when this wide-angle lens is used.

Diabetic Retinopathy↗

PubMed1997

Digital integrated retinal surgical laser system.

The year is 2001--ophthalmic retinal surgery is now fully computer assisted. Patients arriving for scheduled treatments of diabetic retinopathy, retinal tears, or macular degeneration have their retina digitally mapped by a technician. From the retinal map, the ophthalmologist plots therapeutic lesion sites with a light pen on the computer screen that will automatically be placed by a computer controlled argon laser. The treatment only requires 100 ms per lesion placement thus reducing office calls to approximately 45 minutes freeing the ophthalmologist for other pressing cases. This paper reports on the development of a clinically significant prototype system that will help bring this scenario to fruition.

Animals↗

PubMed1997

Hybrid retinal photocoagulation system using analog tracking.

We describe initial in vivo experimental results of a new hybrid digital and analog design for retinal tracking and laser beam control. An overview of the design is given. The results show in vivo tracking rates which exceed the equivalent of 38 degrees per second in the eye, with automated lesion pattern creation. Robotically-assisted laser surgery to treat conditions such as diabetic retinopathy and retinal breaks may soon be realized under clinical conditions with requisite safety using standard video hardware and inexpensive optical components based on this design.

Analog-Digital Conversion↗

PubMed1996

Development of an integrated automated retinal surgical laser system.

Researchers at the University of Texas and the USAF Academy have worked toward the development of a retinal robotic laser system. The overall goal of this ongoing project is to precisely place and control the depth of laser lesions for the treatment of various retinal diseases such as diabetic retinopathy and retinal tears. Separate low speed prototype subsystems have been developed to control lesion depth using lesion reflectance feedback parameters and lesion placement using retinal vessels as tracking landmarks. Both subsystems have been successfully demonstrated in vivo on pigmented rabbits using an argon continuous wave laser. Preliminary testing on rhesus primate subjects have been accomplished with the CW argon laser and also the ultrashort pulse laser. Recent efforts have concentrated on combining the two subsystems into a single prototype capable of simultaneously controlling both lesion depth and placement. We have designated this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. Several interesting areas of study have developed in integrating the two subsystems: 1) "doughnut" shaped lesions that occur under certain combinations of laser power, spot size, and irradiation time complicating measurements of central lesion reflectance, 2) the optimal retinal field of view (FOV) to achieve both tracking and lesion parameter control, and 3) development of a hybrid analog/digital tracker using confocal reflectometry to achieve retinal tracking speeds of up to 100 dgs. This presentation will discuss these design issues of this clinically significant prototype system. Details of the hybrid prototype system are provided in "Hybrid Eye Tracking for Computer-Aided Retinal Surgery" at this conference. The paper will close with remaining technical hurdles to clear prior to testing the full-up clinical prototype system.

Animals↗