Quiz - 24 - Diving Knowledge Workbook - Diving Physiology

[Pedro Burrito]

From the Diving Physiology Section of the PADI Diving Knowledge Workbook Version 2.02 © PADI 2009:

Objective 2.8 - Define the term "silent bubbles" as it relates to decompression sickness.

Question 2

What is the device used to detect silent bubbles?

a. x-ray

b. MRI

c. CT scan

d. Doppler Ultrasound Flowmeter​

I will post a daily question from my exams to help newer divers and to encourage more experienced divers to interact gracefully and helpfully with the newer divers.

Reminder - this is a post in the Basic Forum and it is a green zone. Please be nice and on topic.

Thank you for your patience while we try to give people something to discuss other than Covid-19 and/or Politics. I will post the answer covered by the spoiler tag later today.

 

[Blueringocto_73]

Doppler ultrasound flow meter detects residual nitrogen in the blood stream. This occurs as a result of diving on air.

 

[Couv]

@Blueringocto_73 It's a bit early for a spoiler.

 

[Blueringocto_73]

OK I didn't realize

 

[TMHeimer]

@Blueringocto_73 It's a bit early for a spoiler.

Agree. But let's face it, 3 of the answers are things most of us (oldsters at least) have had in a hospital.
This is a clear question. Maybe even too clear. Maybe that's why they try to make some a bit less clear.....to make you think....

Side note- This may be one of those bits of info. that is neat to know, but which ALMOST no divers (pro or not) would have any practical use for.

 

[scubadada]

Doppler ultrasound flow meter detects residual nitrogen in the blood stream. This occurs as a result of diving on air.

Doppler ultrasound detects bubbles in the bloodstream after breathing air, nitrox, trimix. Sorry, this was not a spoiler, just wrong

 

[Ukmc]

Doppler ultrasound detects bubbles in the bloodstream after breathing air, nitrox, trimix. Sorry, this was not a spoiler, just wrong

Precisely. Ultrasound detects bubbles. Doppler detects flow.
Now, we have done spoiled it for everyone...

 

[Couv]

Now, we have done spoiled it for everyone...

...so I guess my, "None of the above" answer is not correct.

 

[Blueringocto_73]

OK that rings true after researching more

Doppler ultrasound detects bubbles in the bloodstream after breathing air, nitrox, trimix. Sorry, this was not a spoiler, just wrong

 

[Diving Dubai]

Since the answer has been given away.

As an FYI - actually more of useless trival...

A layman will have no idea of the differences between X-Ray, Gamma-Ray and Neutron, Radiography equipment, generally referring them all as X-Ray machines, where the correct term would be radiographic equipment

N-Ray could easily see these silent bubbles, sin unlike X- and Gamma which are attenuated by material desisity N- Rays aren't. N-Rays are attenuated by materials of little density. O-rings in a thick metal component for instance are easily imaged for instance

Gas bubbles in a casting even the meniscus within the delivery tube of an aerosol can, all easily imaged - where as other methods like ultrasound may not have the ability nor resolution to image these defects within the material substrate. I was doing this 20 years ago

Practically speaking it would be easy to image silent bubbles in a person with N-ray - The fact that it might kill them is a secondary issue and perhaps minor complication

I told you it was useless and something you didn't need to know