What is UV (Ultraviolet) Light?
• UV Light is very short wave light!
– UVA 320-400 nm (Nano Meter)
– UVB 290-320 nm
– UVB Narrow Band (313 nm)
– UVC 200-290 nm
1
Sources of UV Light
• The Sun
– Shorter wavelengths are blocked by the Earth’s atmosphere.
– UVC is virtually all blocked by the Ozone in our atmosphere.
– UVA and UVB are not totally blocked.
• Low Pressure Mercury Vapor Lamps
–
–
–
–
–
Produce UV and White light.
Used in some tanning lamps,
Stadium Lighting
UV Phototherapy
Industrial Applications
• Specialized Fluorescent Lamps
– Virtually all UVA and UVB lamps used in Phototherapy today are
Specialized Fluorescent Tubes.`
2
Erythemal Response
Our Skin's Sensitivity
100
90
Relative Percent (%)
80
70
60
50
This red line represents our
skin’s erythemal response
(sun burning response) to
Ultraviolet light.
40
30
20
10
0
280 285 290 295 300 305 310 315 320 325 330 335 340
Wavelength (nm)
3
UVB Broadband (Conventional UVB)
100
90
Relative Percent (%)
80
70
The blue line is the typical
Conventional UVB (Broad Band)
broadband UVB spectra.
Notice that a lot of the BB
UVB spectrum overlaps our
erythemal response curve
and hence causes significant
undesired burning.
60
50
40
30
20
10
0
280 285 290 295 300 305 310 315 320 325 330 335 340
Wavelength (nm)
4
UVB Narrow Band
UVB Narrow Band
100
90
The green line is UVB
Narrow Band. Note that very
little of it’s output overlaps
with our erythemal response
curve and therefore we
experience very little burning.
Relative Percent (%)
80
70
60
50
40
30
20
10
0
280 285 290 295 300 305 310 315 320 325 330 335 340
Wavelength (nm)
5
UVB Narrow Band (the green line)
UVB Narrow Band
100
90
Relative Percent (%)
80
70
60
50
40
30
20
10
0
280 285 290 295 300 305 310 315 320 325 330 335 340
Wavelength (nm)
6
Action Spectrum for Psoriasis
‫זה השקף המשמעותי ביותר‬
‫מראה כי ע"י שימוש ב‪ ,NB UVB -‬האזור הירוק אנו נמצאים עדיין‬
‫בקצה התחום היעיל לטיפול ב‪( P -‬הגרף הסגול)‬
‫וכמעט לגמרי מחוץ לתחום ה ‪ERYTHEMA‬‬
‫ולכן אין סכנת כוויות ועדיין יש יעילות טיפולית‪.‬‬