How do ventilators work? - Alex Gendler

2,594,077 views ใƒป 2020-05-21

TED-Ed


ืื ื ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ืœืžื˜ื” ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ.

ืชืจื’ื•ื: Ido Dekkers ืขืจื™ื›ื”: Sigal Tifferet
00:06
In the 16th century, Flemish physician Andreas Vesalius
0
6778
4100
ื‘ืžืื” ื”-16, ื”ืจื•ืคื ื”ืคืœืžื™ ืื ื“ืจืืก ื•ื•ืกืœื™ื•ืก
00:10
described how a suffocating animal could be kept alive
1
10878
3750
ืชื™ืืจ ืื™ืš ื—ื™ื” ืฉื ื—ื ืงืช ื™ื›ื•ืœื” ืœื”ื™ืฉืืจ ื‘ื—ื™ื™ื
00:14
by inserting a tube into its trachea and blowing air to inflate its lungs.
2
14628
6741
ืขืœ ื™ื“ื™ ื”ื›ื ืกืช ืฆื™ื ื•ืจ ืœืงื ื” ื”ื ืฉื™ืžื” ื•ื ืฉื™ืคืช ืื•ื™ืจ ื›ื“ื™ ืœื ืคื— ืืช ื”ืจื™ืื•ืช ืฉืœื”.
00:21
In 1555, this procedure didnโ€™t warrant much acclaim.
3
21369
4173
ื‘-1555, ื”ืชื”ืœื™ืš ืœื ื–ื›ื” ืœืชื”ื™ืœื” ื’ื“ื•ืœื”.
00:25
But today, Vesaliusโ€™s treatise is recognized
4
25542
3360
ืื‘ืœ ื”ื™ื•ื, ื”ืžืืžืจ ืฉืœ ื•ื•ืกื™ืœื™ื•ืก ืžื•ื›ืจ
00:28
as the first description of mechanical ventilationโ€”
5
28902
3870
ื›ืชื™ืื•ืจ ื”ืจืืฉื•ืŸ ืฉืœ ื”ื ืฉืžื” ืžืœืื›ื•ืชื™ืช --
00:32
a crucial practice in modern medicine.
6
32772
3400
ืคืขื•ืœื” ื—ื™ื•ื ื™ืช ื‘ืจืคื•ืื” ื”ืžื•ื“ืจื ื™ืช.
00:36
To appreciate the value of ventilation,
7
36172
2970
ื›ื“ื™ ืœื”ืขืจื™ืš ืืช ื—ืฉื™ื‘ื•ืชื” ืฉืœ ื”ื ืฉืžื”,
00:39
we need to understand how the respiratory system works.
8
39142
3870
ืฆืจื™ืš ืœื”ื‘ื™ืŸ ืื™ืš ืžืขืจื›ืช ื”ื ืฉื™ืžื” ืขื•ื‘ื“ืช.
00:43
We breathe by contracting our diaphragms, which expands our chest cavities.
9
43012
5759
ืื ื—ื ื• ื ื•ืฉืžื™ื ืขืœ ื™ื“ื™ ื›ื™ื•ื•ืฅ ื”ืกืจืขืคืช, ืฉืžืจื—ื™ื‘ื” ืืช ื—ืœืœ ื”ื—ื–ื” ืฉืœื ื•.
00:48
This allows air to be drawn in, inflating the alveoliโ€”
10
48771
5317
ื–ื” ืžืืคืฉืจ ืœืื•ื™ืจ ืœื”ื™ืฉืื‘, ืžื” ืฉืžื ืคื— ืืช ื”ื ืื“ื™ื•ืช --
00:54
millions of small sacs inside our lungs.
11
54088
4297
ืžื™ืœื™ื•ื ื™ ืฉืงื™ื•ืช ืงื˜ื ื•ืช ื‘ืชื•ืš ื”ืจื™ืื•ืช ืฉืœื ื•.
00:58
Each of these tiny balloons is surrounded by a mesh of blood-filled capillaries.
12
58385
5873
ื›ืœ ืื—ื“ ืžื”ื‘ืœื•ื ื™ื ื”ื–ืขื™ืจื™ื ื”ืืœื” ืžื•ืงืฃ ื‘ืจืฉืช ืฉืœ ื ื™ืžื™ื ื”ืžืœืื™ื ื“ื.
01:04
This blood absorbs oxygen from the inflated alveoli
13
64258
4817
ื”ื“ื ืกื•ืคื’ ืืช ื”ื—ืžืฆืŸ ืžื”ื ืื“ื™ื•ืช ื”ื ืคื•ื—ื•ืช
01:09
and leaves behind carbon dioxide.
14
69075
3470
ื•ืžืฉืื™ืจ ืื—ืจื™ื• ืคื—ืžืŸ ื“ื• ื—ืžืฆื ื™.
01:12
When the diaphragm is relaxed,
15
72545
1980
ื›ืฉื”ืกืจืขืคืช ืžืฉื•ื—ืจืจืช,
01:14
the CO2 is exhaled alongside a mix of oxygen and other gases.
16
74525
6161
ื”ืคื—ืžืŸ ื”ื“ื•-ื—ืžืฆื ื™ ื ื ืฉืฃ ื™ื—ื“ ืขื ืชืขืจื•ื‘ืช ืฉืœ ื—ืžืฆืŸ ื•ื’ื–ื™ื ืื—ืจื™ื.
01:20
When our respiratory systems are working correctly,
17
80686
3170
ื›ืฉืžืขืจื›ืช ื”ื ืฉื™ืžื” ืฉืœื ื• ืขื•ื‘ื“ืช ื ื›ื•ืŸ,
01:23
this process happens automatically.
18
83856
2710
ื”ืชื”ืœื™ืš ื”ื–ื” ืžืชืจื—ืฉ ืื•ื˜ื•ืžื˜ื™ืช.
01:26
But the respiratory system can be interrupted by a variety of conditions.
19
86566
4780
ืื‘ืœ ืžืขืจื›ืช ื”ื ืฉื™ืžื” ื™ื›ื•ืœื” ืœื”ื™ืคื’ืข ืขืœ ื™ื“ื™ ืžื’ื•ื•ืŸ ืฉืœ ืžืฆื‘ื™ื.
01:31
Sleep apnea stops diaphragm muscles from contracting.
20
91346
4681
ื“ื•ื ื ืฉื™ืžื” ื‘ืฉื™ื ื” ืขื•ืฆืจ ืืช ื›ื™ื•ื•ืฅ ืฉืจื™ืจื™ ื”ืกืจืขืคืช.
01:36
Asthma can lead to inflamed airways which obstruct oxygen.
21
96027
4649
ืืกื˜ืžื” ืขืœื•ืœื” ืœื”ื•ื‘ื™ืœ ืœื“ืœืงืช ื‘ื“ืจื›ื™ ื”ื ืฉื™ืžื” ืฉื—ื•ืกืžืช ืืช ืžืขื‘ืจ ื”ื—ืžืฆืŸ.
01:40
And pneumonia, often triggered by bacterial or viral infections,
22
100676
5113
ื•ื“ืœืงืช ืจื™ืื•ืช, ืฉื”ืจื‘ื” ืคืขืžื™ื ื ื’ืจืžืช ืขืœ ื™ื“ื™ ื”ื“ื‘ืงื” ื—ื™ื™ื“ืงื™ืช ืื• ื•ื™ืจืืœื™ืช,
01:45
attacks the alveoli themselves.
23
105789
2860
ืžืชืงื™ืคื” ืืช ื”ื ืื“ื™ื•ืช ืขืฆืžืŸ.
01:48
Invading pathogens kill lung cells,
24
108649
2980
ืคืชื•ื’ื ื™ื ืคื•ืœืฉื™ื ื”ื•ืจื’ื™ื ืชืื™ ืจื™ืื”,
01:51
triggering an immune response that can cause lethal inflammation
25
111629
4515
ื•ืžืคืขื™ืœื™ื ืชื’ื•ื‘ื•ืช ื—ื™ืกื•ืŸ ืฉื™ื›ื•ืœื•ืช ืœื’ืจื•ื ืœื“ืœืงื•ืช ืงื˜ืœื ื™ื•ืช
01:56
and fluid buildup.
26
116144
1930
ื•ืœื”ืฆื˜ื‘ืจื•ืช ื ื•ื–ืœื™ื.
01:58
All these situations render the lungs unable to function normally.
27
118074
5214
ื›ืœ ื”ืžืฆื‘ื™ื ื”ืืœื” ืคื•ื’ืขื™ื ื‘ืชืคืงื•ื“ ื”ืชืงื™ืŸ ืฉืœ ื”ืจื™ืื•ืช.
02:03
But mechanical ventilators take over the process,
28
123288
3880
ืื‘ืœ ืžื›ื•ื ื•ืช ื”ื ืฉืžื” ืžื›ืื ื™ื•ืช ืžืฉืชืœื˜ื•ืช ืขืœ ื”ืชื”ืœื™ืš,
02:07
getting oxygen into the body when the respiratory system cannot.
29
127168
4787
ื•ืžื‘ื™ืื•ืช ื—ืžืฆืŸ ืœื’ื•ืฃ ื›ืฉืžืขืจื›ืช ื”ื ืฉื™ืžื” ืœื ื™ื›ื•ืœื”.
02:11
These machines can bypass constricted airways,
30
131955
3430
ื”ืžื›ื•ื ื•ืช ื”ืืœื• ื™ื›ื•ืœื•ืช ืœืขืงื•ืฃ ื“ืจื›ื™ ืื•ื™ืจ ืžื•ืฆืจื•ืช,
02:15
and deliver highly oxygenated air to help damaged lungs diffuse more oxygen.
31
135385
6700
ื•ืœืกืคืง ืื•ื™ืจ ืžื—ื•ืžืฆืŸ ื›ื“ื™ ืœืขื–ื•ืจ ืœืจื™ืื•ืช ืคื’ื•ืžื•ืช ืœืกืคื•ื’ ื™ื•ืชืจ ื—ืžืฆืŸ.
02:22
There are two main ways ventilators can workโ€”
32
142085
3200
ื™ืฉ ืฉืชื™ ื“ืจื›ื™ื ืขื™ืงืจื™ื•ืช ื‘ื”ืŸ ืžื›ื•ื ื•ืช ื”ื ืฉืžื” ืขื•ื‘ื“ื•ืช --
02:25
pumping air into the patientโ€™s lungs through positive pressure ventilation,
33
145285
4881
ื”ื–ืจืžืช ืื•ื•ื™ืจ ืœืจื™ืื•ืช ื”ื—ื•ืœื” ื‘ื”ื ืฉืžื” ื‘ืœื—ืฅ ื—ื™ื•ื‘ื™,
02:30
or allowing air to be passively drawn in through negative pressure ventilation.
34
150166
5786
ืื• ืœืืคืฉืจ ืœืื•ื™ืจ ืœื”ื™ื›ื ืก ืคืกื™ื‘ื™ืช ื“ืจืš ื”ื ืฉืžื” ื‘ืœื—ืฅ ืฉืœื™ืœื™.
02:35
In the late 19th century,
35
155952
1850
ื‘ืฉืœื”ื™ ื”ืžืื” ื”-19,
02:37
ventilation techniques largely focused on negative pressure,
36
157802
4000
ื˜ื›ื ื•ืœื•ื’ื™ื•ืช ื”ื”ื ืฉืžื” ื”ืชืžืงื“ื• ื‘ืขื™ืงืจ ื‘ื”ื ืฉืžื” ื‘ืœื—ืฅ ืฉืœื™ืœื™,
02:41
which closely approximates natural breathing
37
161802
2650
ืฉืžื“ืžื” ื”ื™ื˜ื‘ ืืช ื”ื ืฉื™ืžื” ื”ื˜ื‘ืขื™ืช
02:44
and provides an even distribution of air in the lungs.
38
164452
4439
ื•ืžืกืคืงืช ืคื™ื–ื•ืจ ืื—ื™ื“ ืฉืœ ืื•ื™ืจ ืœืจื™ืื•ืช.
02:48
To achieve this, doctors created a tight seal around the patientโ€™s body,
39
168891
5305
ื›ื“ื™ ืœื”ืฉื™ื’ ื–ืืช, ืจื•ืคืื™ื ื™ื•ืฆืจื™ื ืื˜ื™ืžื” ื”ื“ื•ืงื” ืกื‘ื™ื‘ ื”ื’ื•ืฃ ืฉืœ ื”ื—ื•ืœื”,
02:54
either by enclosing them in a wooden box or a specially sealed room.
40
174196
6367
ื‘ื™ืŸ ืื ื‘ื”ื›ืœืชื• ื‘ืงื•ืคืกืช ืขืฅ ืื• ื‘ื—ื“ืจ ืื˜ื•ื ื™ื™ืขื•ื“ื™.
03:00
Air was then pumped out of the chamber,
41
180563
2624
ื”ืื•ื™ืจ ื ืฉืื‘ ืื– ืืœ ืžื—ื•ืฅ ืœื—ื“ืจ,
03:03
decreasing air pressure, and allowing the patientโ€™s chest cavity
42
183187
3840
ืžื” ืฉืžืคื—ื™ืช ืืช ืœื—ืฅ ื”ืื•ื™ืจ ื•ืžืืคืฉืจ ืœื—ื–ื” ืฉืœ ื”ื—ื•ืœื”
03:07
to expand more easily.
43
187027
2580
ืœื”ืชืจื—ื‘ ื™ื•ืชืจ ื‘ืงืœื•ืช.
03:09
In 1928, doctors developed a portable, metal device
44
189607
5095
ื‘-1928, ืจื•ืคืื™ื ืคื™ืชื—ื• ืžื›ื•ื ื” ืžืชื›ืชื™ืช ื ื™ื™ื“ืช
03:14
with pumps powered by an electric motor.
45
194702
3666
ืขื ืžืฉืื‘ื•ืช ืฉืžื•ื ืขื•ืช ืขืœ ื™ื“ื™ ืžื ื•ืข ื—ืฉืžืœื™.
03:18
This machine, known as the iron lung,
46
198368
2990
ื”ืžื›ื•ื ื” ื”ื–ื•, ืฉื™ื“ื•ืขื” ื›ืจื™ืืช ื”ื‘ืจื–ืœ,
03:21
became a fixture in hospitals through the mid-20th century.
47
201358
4788
ื”ืคื›ื” ืœื ืคื•ืฆื” ื‘ื‘ืชื™ ื—ื•ืœื™ื ื‘ืืžืฆืข ื”ืžืื” ื”-20.
03:26
However, even the most compact negative pressure designs
48
206146
4020
ืขื ื–ืืช, ืืคื™ืœื• ื”ืขื™ืฆื•ื‘ ื”ื›ื™ ืงื•ืžืคืงื˜ื™ ืฉืœ ืœื—ืฅ ืฉืœื™ืœื™
03:30
heavily restricted a patientโ€™s movement
49
210166
2380
ื”ื’ื‘ื™ืœ ืžืื•ื“ ืืช ื”ืชื ื•ืขื” ืฉืœ ื”ื—ื•ืœื”
03:32
and obstructed access for caregivers.
50
212546
3790
ื•ื”ืคืจื™ืข ืœื’ื™ืฉื” ืฉืœ ื”ืžื˜ืคืœื™ื.
03:36
This led hospitals in the 1960โ€™s to shift towards positive pressure ventilation.
51
216336
6001
ื–ื” ื”ื•ื‘ื™ืœ ื‘ืชื™ ื—ื•ืœื™ื ื‘ืฉื ื•ืช ื”-60 ืœืขื‘ื•ืจ ืœืžื›ื•ื ื•ืช ื”ื ืฉืžื” ื‘ืœื—ืฅ ื—ื™ื•ื‘ื™.
03:42
For milder cases, this can be done non-invasively.
52
222337
4000
ื‘ืžืงืจื™ื ืงืœื™ื ื™ื•ืชืจ, ื ื™ืชืŸ ืœื”ื ืฉื™ื ื‘ืื•ืคืŸ ืœื ืคื•ืœืฉื ื™.
03:46
Often, a facemask is fitted over the mouth and nose,
53
226337
3390
ื‘ื“"ื›, ืฉืžื™ื ืžืกื›ืช ืคื ื™ื ืขืœ ื”ืคื” ื•ื”ืืฃ,
03:49
and filled with pressurized air which moves into the patientโ€™s airway.
54
229727
5145
ื•ืžืขื‘ื™ืจื™ื ื“ืจื›ื” ืื•ื™ืจ ื“ื—ื•ืก ืฉื ืข ืœืชื•ืš ื“ืจื›ื™ ื”ื ืฉื™ืžื” ืฉืœ ื”ื—ื•ืœื”.
03:54
But more severe circumstances
55
234872
2100
ืื‘ืœ ื‘ืžืฆื‘ื™ื ืงืฉื™ื ื™ื•ืชืจ
03:56
require a device that takes over the entire breathing process.
56
236972
4837
ื ื“ืจืฉ ืžื›ืฉื™ืจ ืฉืžืฉืชืœื˜ ืขืœ ื›ืœ ืชื”ืœื™ืš ื”ื ืฉื™ืžื”.
04:01
A tube is inserted into the patientโ€™s trachea
57
241809
3420
ืฆื™ื ื•ืจ ืžื•ื—ื“ืจ ืœืชื•ืš ืงื ื” ื”ื ืฉื™ืžื” ืฉืœ ื”ื—ื•ืœื”
04:05
to pump air directly into the lungs,
58
245229
2730
ื›ื“ื™ ืœื“ื—ื•ืก ืื•ื™ืจ ื™ืฉื™ืจื•ืช ืœืชื•ืš ื”ืจื™ืื•ืช,
04:07
with a series of valves and branching pipes
59
247959
3090
ืขื ืกื“ืจื” ืฉืœ ืฉืกืชื•ืžื™ื ื•ืฆื™ื ื•ืจื•ืช ืžืกืชืขืคื™ื
04:11
forming a circuit for inhalation and exhalation.
60
251049
4000
ืฉื™ื•ืฆืจื™ื ืžืขื’ืœ ืœืฉืื™ืคื” ื•ื ืฉื™ืคื”.
04:15
In most modern ventilators,
61
255049
1830
ื‘ืจื•ื‘ ื”ืžื ืฉืžื™ื ื”ืžื•ื“ืจื ื™ื™ื,
04:16
an embedded computer system
62
256879
2050
ืžืขืจื›ืช ืžื—ืฉื‘ ืžื•ื˜ืžืขืช
04:18
allows for monitoring the patientโ€™s breathing and adjusting the airflow.
63
258929
4507
ืžืืคืฉืจืช ืœื ื˜ืจ ืืช ื ืฉื™ืžืช ื”ื—ื•ืœื” ื•ืœื”ืชืื™ื ืืช ื–ืจื™ืžืช ื”ืื•ื™ืจ.
04:23
These machines arenโ€™t used as a standard treatment,
64
263436
3784
ื”ืžื›ื•ื ื•ืช ื”ืืœื• ืœื ืžืฉืžืฉื•ืช ืœื˜ื™ืคื•ืœ ืกื˜ื ื“ืจื˜ื™,
04:27
but rather, as a last resort.
65
267220
2580
ืืœื ื›ืžื•ืฆื ืื—ืจื•ืŸ.
04:29
Enduring this influx of pressurized air requires heavy sedation,
66
269800
5245
ื”ื™ื›ื•ืœืช ืœืกื‘ื•ืœ ืœื—ืฅ ืื•ื™ืจ ื›ื–ื” ื“ื•ืจืฉืช ื”ืจื“ืžื” ืขืžื•ืงื”,
04:35
and repeated ventilation can cause long-term lung damage.
67
275045
4217
ื•ื”ื ืฉืžื•ืช ืžืจื•ื‘ื•ืช ื™ื›ื•ืœื•ืช ืœื’ืจื•ื ืœื ื–ืง ืงื‘ื•ืข ืœืจื™ืื•ืช.
04:39
But in extreme situations,
68
279262
2406
ืื‘ืœ ื‘ืžืงืจื™ื ืงื™ืฆื•ื ื™ื™ื,
04:41
ventilators can be the difference between life and death.
69
281668
3603
ืžื›ื•ื ื•ืช ื”ื ืฉืžื” ื™ื›ื•ืœื•ืช ืœื’ืจื•ื ืœื”ื‘ื“ืœ ื‘ื™ืŸ ื—ื™ื™ื ื•ืžื•ื•ืช.
04:45
And events like the COVID-19 pandemic
70
285271
2790
ื•ืืจื•ืขื™ื ื›ืžื• ืžื’ืคืช ื”ืงื•ืจื•ื ื”
04:48
have shown that theyโ€™re even more essential than we thought.
71
288061
3980
ื”ืจืื• ืฉื”ืŸ ืืคื™ืœื• ื™ื•ืชืจ ื—ื™ื•ื ื™ื•ืช ืžืฉื—ืฉื‘ื ื•.
04:52
Because current models are bulky, expensive,
72
292041
3060
ื‘ื’ืœืœ ืฉื”ื“ื’ืžื™ื ื”ื ื•ื›ื—ื™ื™ื ืžื•ืจื›ื‘ื™ื, ื™ืงืจื™ื,
04:55
and require extensive training to operate, most hospitals only have a few in supply.
73
295101
6802
ื•ื“ื•ืจืฉื™ื ืื™ืžื•ืŸ ืžืชืงื“ื ืœื”ืคืขืœื”, ื‘ืจื•ื‘ ื‘ืชื™ ื”ื—ื•ืœื™ื ื™ืฉ ืจืง ืžื›ื•ื ื•ืช ืžืขื˜ื•ืช.
05:01
This may be enough under normal circumstances,
74
301903
3050
ื–ื” ืื•ืœื™ ืžืกืคื™ืง ื‘ืžืฆื‘ื™ื ืจื’ื™ืœื™ื,
05:04
but during emergencies, this limited cache is stretched thin.
75
304953
4244
ืื‘ืœ ื‘ืžืงืจื™ ื—ืจื•ื, ื”ื›ืžื•ืช ื”ืžื•ื’ื‘ืœืช ื ืžืฆืืช ื‘ืฉื™ืžื•ืฉ ื™ืชืจ.
05:09
The world urgently needs more low-cost and portable ventilators,
76
309197
5049
ื”ืขื•ืœื ืฆืจื™ืš ื‘ื“ื—ื™ืคื•ืช ื™ื•ืชืจ ืžื›ื•ื ื•ืช ื”ื ืฉืžื” ื–ื•ืœื•ืช ื ื™ื™ื“ื•ืช,
05:14
as well as a faster means of producing and distributing
77
314246
4040
ื›ืžื• ื’ื ืืžืฆืขื™ื ืžื”ื™ืจื™ื ื™ื•ืชืจ ืœื™ื™ืฆืจ ื•ืœื”ืคื™ืฅ
05:18
this life-saving technology.
78
318286
2246
ืืช ื”ื˜ื›ื ื•ืœื•ื’ื™ื” ืžืฆื™ืœืช ื”ื—ื™ื™ื ื”ื–ื•.
ืขืœ ืืชืจ ื–ื”

ืืชืจ ื–ื” ื™ืฆื™ื’ ื‘ืคื ื™ื›ื ืกืจื˜ื•ื ื™ YouTube ื”ืžื•ืขื™ืœื™ื ืœืœื™ืžื•ื“ ืื ื’ืœื™ืช. ืชื•ื›ืœื• ืœืจืื•ืช ืฉื™ืขื•ืจื™ ืื ื’ืœื™ืช ื”ืžื•ืขื‘ืจื™ื ืขืœ ื™ื“ื™ ืžื•ืจื™ื ืžื”ืฉื•ืจื” ื”ืจืืฉื•ื ื” ืžืจื—ื‘ื™ ื”ืขื•ืœื. ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ื”ืžื•ืฆื’ื•ืช ื‘ื›ืœ ื“ืฃ ื•ื™ื“ืื• ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ ืžืฉื. ื”ื›ืชื•ื‘ื™ื•ืช ื’ื•ืœืœื•ืช ื‘ืกื ื›ืจื•ืŸ ืขื ื”ืคืขืœืช ื”ื•ื•ื™ื“ืื•. ืื ื™ืฉ ืœืš ื”ืขืจื•ืช ืื• ื‘ืงืฉื•ืช, ืื ื ืฆื•ืจ ืื™ืชื ื• ืงืฉืจ ื‘ืืžืฆืขื•ืช ื˜ื•ืคืก ื™ืฆื™ืจืช ืงืฉืจ ื–ื”.

https://forms.gle/WvT1wiN1qDtmnspy7