Know Thermal Relaxation Time (TRT) in Skin Laser Aesthetics — Transcript

Full transcript

1. 0:00Hello friends today we are going to
2. 0:02study trt that is thermal relaxation
3. 0:06time I am principal Dr Ashok
4. 0:09gakar from Ashoka thoughts
5. 0:14Academy so what is thermal relaxation
6. 0:17time thermal relaxation time describes
7. 0:20when hot object is cooling suppose we
8. 0:23are hitting milk and it is
9. 0:27boiling when we stop hitting
10. 0:30the milk starts
11. 0:32cooling this is called thermal
12. 0:35relaxation initially suppose it's
13. 0:37temperature is 100°
14. 0:41C after was of heating the temperature
15. 0:45Falls very rapidly it oys Newton cooling
16. 0:51law it is shown in this
17. 0:56graph in short thermal relaxation means
18. 1:03cooling thermal relaxation time means
19. 1:06time taken by hot object to
20. 1:10cool for reference 50% temperature is
21. 1:14considered what is it mean let's
22. 1:18see a thermal relaxation time is the
23. 1:20time taken by the H tissues to cool down
24. 1:24to the half of the
25. 1:26temperature for example if tissue starts
26. 1:29hitting with initial temperature 25°
27. 1:33C room
28. 1:36temperature and heated it to 85°
29. 1:40C the temperature rise is 60°
30. 1:45C then its thermal relaxation time is
31. 1:49how much time it will take to fall to
32. 1:51the temperature
33. 1:5355°
34. 1:56Centigrade how that 55° Centigrade comes
35. 2:0085 - 25 that is 60° half of the 60 is
36. 2:0530° and 30 + 25 that is
37. 2:1055° what is significance of thermal
38. 2:13relaxation
39. 2:16time let's see for understanding
40. 2:19significance of thermal relaxation time
41. 2:21let's see the graph the half of the
42. 2:24graph on y AIS there is energy and on
43. 2:28x-axis there is time in
44. 2:30milliseconds initially the energy is
45. 2:33zero at this point energy is rising it
46. 2:36goes to up to this point then the
47. 2:40constant energy is delivered again it
48. 2:42drops like
49. 2:44this up to zero then it's zero again it
50. 2:49will rise this thing is called this on
51. 2:51time is called as pulse width okay so
52. 2:55here we're hitting the tissue and here
53. 3:00when we are putting it energy off
54. 3:02naturally that the the tissue will gets
55. 3:05cool again we are hitting the tissue up
56. 3:09to here and again it is going to be cool
57. 3:12so this time is actually known as
58. 3:15thermal relaxation
59. 3:18time okay so let's see what is happening
60. 3:20to the temperature of
61. 3:22tissue when we give energy naturally the
62. 3:26tissue gets heated its temperature is
63. 3:28rising Rising and when we
64. 3:31stop heating at that time
65. 3:35this temperature gets
66. 3:38down okay so I have taken two types of
67. 3:42tissue one is surrounded tissue and one
68. 3:45is targeted
69. 3:46tissue so here we are providing the
70. 3:49wavelength which is absorption maximum
71. 3:53absorption of that chromophor that
72. 3:55wavelength is for targeted tissue it is
73. 3:58shown in the red color and this
74. 4:00temperature in blue color is for the
75. 4:04tissues which are surrounded to the
76. 4:06targeted tissues so let's think about
77. 4:09the surrounded tissue first it is shown
78. 4:12in this blue color no energy is there it
79. 4:15is at room
80. 4:16temperature okay and when we are giving
81. 4:19energy to the
82. 4:20tissue naturally its temperature is
83. 4:24rising up to this point and we stop
84. 4:27energy here it it is cool cooling now
85. 4:31and after some time it comes to the room
86. 4:35temperature again we are hitting it it
87. 4:37is going up and coming to the room
88. 4:40temperature so we are giving enough trt
89. 4:45here to the surrounded tissue so that it
90. 4:48will get cooled down but what is
91. 4:50happening to the targeted
92. 4:53tissues since we're giving the
93. 4:55wavelength to the targeted tissue
94. 4:59by seeing the absorption
95. 5:02spectra the wavelength which the
96. 5:04targeted
97. 5:06tissue absorbs more that wavelength we
98. 5:09are giving that's why as compared to
99. 5:11surrounded tissue its temperature will
100. 5:14rise more there is more rise in
101. 5:17temperature as compared to surrounded
102. 5:19tissue okay it is going up to this
103. 5:22point again when we are putting up the
104. 5:25energy it is cooling down but it it is
105. 5:28not coming to the room temperature again
106. 5:31we are giving the energy the temperature
107. 5:33is rising it is going to up to this
108. 5:35point and again it is going uh it is
109. 5:39coming up but not to the room room
110. 5:41temperature eventually this temperature
111. 5:43is increasing increasing and the
112. 5:46targeted tissue get destroyed
113. 5:49eventually eventually the targeted
114. 5:51tissue get destroyed okay so here by
115. 5:57adjusting
116. 5:58trt we are preventing the surrounding
117. 6:02tissue while we are just targeting the
118. 6:04targeted tissue and that particular
119. 6:06tissue will get destroy this is
120. 6:08importance
121. 6:09of thermal relaxation time so friend
122. 6:13this is all about trt that is thermal
123. 6:16relaxation time and this trt is
124. 6:19beautifully used in selective photo
125. 6:23thermolysis thank you
126. 6:31[Music]