quantification of the ultraviolet radiation (uvr) field in the human eye in vivo using novel instrumentation and the potential benefits of uvr blocking hydrogel contact lens - solar street light design

by:Litel Technology     2019-08-01
quantification of the ultraviolet radiation (uvr) field in the human eye in vivo using novel instrumentation and the potential benefits of uvr blocking hydrogel contact lens  -  solar street light design
BACKGROUND/OBJECTIVE: Some degenerative ophthalmopathy mainly occurs in the nasal margin, which is related to solar ultraviolet radiation. (UVR)induced damage.
Relative contribution of ocular flow in vivo(a)
Ultraviolet radiation from the skin of the nose to the edge of the nose, and(b)
The focus of UVR on the temporal cornea to the nasal margin was studied.
Methods A new type of photodiode sensor array was used to measure the ultraviolet radiation field of human eyes.
In addition, a new spectrometer device-
UP is used to measure the radiation spectrum of corneal refraction.
The effect of ultraviolet shielding hydrogel contact lenses on filtering incident ultraviolet rays was evaluated in vivo.
Results Qualitative and quantitative data showed that the number of Staphylococcus nasalis increased.
Photodiode readings showed a net increase in ultraviolet radiation from the temporal side to the nasal side.
The transmission curves show that most of the ultraviolet radiation is absorbed by the eye tissue or transmitted through the eye tissue.
Ultraviolet shielding soft contact lenses can filter this radiation.
Conclusion In vivo, it is found that the ultraviolet radiation flux in the nasal side of the eye increases due to the skin reflex in the nose.
Any ultraviolet receptor passing through the cornea is either absorbed by the conjunctiva or transmitted to the sclera through the conjunctiva.
Ultraviolet shielded hydrogel contact lenses can eliminate these ultraviolet sources.
Materials and Methods: Reflection theory was tested in vivo, and a series of ultraviolet radiation sensors were established to sample the incident light field on or near the exposed eye surface.
According to refractive theory, a sensor based on optical fiber spectrophotometer is placed on the nasal conjunctival rim to detect any light passing through the cornea and determine its spectrum.
These two unique experimental devices-
Now we introduce UPS.
The main components of the reflective sensor array are five Texas Instrument TSL250 photodiodes.
The spectral response curves of these photodetectors extend to 300 nm in the UVR region of the spectrum, covering all the UVA regions and part of the UVB regions.
The angle between the field of view and the normal direction is about 60 degrees, so photons with a wide range of incident angles can be detected.
High sensitivity and integral amplifiers provide high signal output, allowing detection of low levels of ultraviolet radiation.
Each sensor assembly is 5 square millimetres, so five of them are installed side by side, covering an area of about 25 millimetres, which covers the average horizontal diameter of exposed eye tissue.
These five sensors are mounted on a plastic case, usually placed on the eye to protect it during eyelid surgery. Sensors 1 and 2 are located on the temporal side of the pupil, sensor 3 is directly above the pupil, and sensors 4 and 5 are located on the nasal side, as shown in Figure 1.
Download the diagram in the new tab, open and download PowerPoint Figure 1 UVR photodiode sensor array, mounted above the left eye, sensor 1 at the temporal side, sensor 5 at the nasal side.
The analog voltage output of the sensor is digitized by LabVIEW program and stored in a laptop computer. All five sensors are read in milliseconds, which greatly reduces the change of sensor signal caused by the movement of the subject.
By recording the signals of each sensor in a uniform light field (without the presence of the subject), and dividing these values into their respective signals when the subject is in position, the relative readings of the sensor are calculated.
To provide a stable test environment, a light box is illuminated by stable diffuse visible ultraviolet light. -
A near infrared tungsten light source was constructed.
Because the inner wall of the box is white, the test object is in a relatively uniform diffuse light field, which is similar to the diffuse solar light field.
A low-pass filter is used in front of the light source to limit the light to the spectral region of interest.
Main Components of Refraction Sensor Group of Refraction Sensors-
Look up as shown in Figure 2.
The improved slit lamp was used to install two fibromas on the cornea.
Input optical fiber images emit light from ultraviolet rays-visible-
Near infrared tungsten light source was irradiated on the cornea at an angle of about 30 degrees behind the coronal plane.
The output fibers detect light emitted from the cornea or reflected from the sclera according to the relative position of the eyes.
The detected light is fed into the marine optical system S2000 optical fiber spectrometer, where it is scattered over the detector array, where the signal is read and digitized by a laptop computer.
The transmission spectrum is calculated by using the spectrum of the light source as a reference. When no subjects are present, the spectrum is recorded.
Each spectrum can be recorded in about 20 milliseconds, greatly reducing any unnecessary signal changes caused by the movement of the test object.
Download FigureOpen in the new tab to download PowerPoint Figure 2 Refractive Index Sensor Group Diagram-up.
Light from the fibroma temporarily illuminates the cornea and refracts onto the sensing fiber.
To prevent ultraviolet rays from focusing through the eyes, two different types of ultraviolet blocking contact lenses were used. the Acuvue 2 (
Etafican, 58% water content, Vistaken)
Accurate ultraviolet radiation(
Vasurfilcon, 74% water content, Wesley Jessen).
The power of the near-plane lens is chosen to reduce the refractive effect of the lens.
Result Reflective sensor array was used to test the repeatability of the device on the white polystyrene human model head. -up.
Read the sensor readings in the optical box, headless, headless, calculate the relative changes in intensity.
Fig. 3A shows the relative variation of the strength of five sensors on the simulated head, averaging in several separate experiments.
When the head exists, all sensors show an increase higher than the ambient light signal.
Compared with the other four sensors, the signal in the fifth sensor using the dummy head (located at the nose side) increased significantly, indicating an increase in light scattered and reflected from the facial structure on the nose side.
Similar measurements were made on 12 subjects. Ten of the 12 subjects had stronger nasal sensors than lateral sensors.
Each subject was measured five times and the error bar was calculated according to the standard deviation of the average value of each sensor's five samples. (p
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