Infrared sensors help please

[ezzo]

Hi, I need help by someone who is very knowledgeable with infrared sensors / detectors etc. I have bought a sleep mask that can detect when a person is in REM sleep (dreaming) The sleep mask has a small circuit board inside with an infrared detector that detects eye movementthroughout the night.

When the infrared detector picks up a lot of eyeball movement it then knows the person is dreaming and will flash 2 bright LED lights at the closed eyes allowing the dreamer to know when they are dreaming. The device is acurate and does what it says 'on the tin' Anyway, my issues are as follows. I am concerned that all night i have a electronic sensor constantly monitoring my eye for movement.

The reason this is a concern is that it could damage the eye / long term problems etc. Im no expert but having infrared detector / device 1mm from the eye all night could be dangerous?

This is a passage from their website ........... "The REM-Dreamer uses infrared sensors to detect when you are in REM (dreaming) sleep. At that point the REM-Dreamer gives you sound and light cues (beeps and flashing lights) to remind you that you are dreaming. Thus, external world stimuli are transferred to the world of your dreams, and it becomes easy to achieve lucidity"

Please take a look at their website to get full details on this device, thanks you

RemDreamer description - http://remdreamer.com/index.php
Rem dreamer photos - http://remdreamer.com/rem-dreamer_pro.php Thank you Terry

 

[ChosunOne]

I've been working with passive infrared (PIR) motion sensors for decades. The only thing you need to understand is that they're passive. They don't emit any form of radiation whatsoever. The PIR sensors detect the infrared (heat) being emitted by whatever they're watching.

So no, there is zero effect the PIR sensors can have on your lids and eyes.

 

[ezzo]

Thanks for replying ChosenOne. How can you tell if the sensors in the remdreamer are passive or not? thanks

 

[ChosunOne]

Well, there are two choices in IR sensing: They're Passive InfraRed sensors, or Active InfraRed sensor assemblies. The sensor assemblies of Passives or Actives are different. Active IR assemblies don't detect "motion" per se, they detect loss of the active beam (such as something blocking the path between emitter and receiver--or misalignment of emitter, or loss of emission from emitter)--Active IR is more complicated to set up, and requires more maintenance; but is good for long-distance narrow applications. Passive IR detection is suited for shorter distances, typically less than 40 ft but there isn't any lower limit.

A PIR motion sensor is more complex: Instead of just sensing that there is IR emission, it sees a mosaic pattern of IR emission. Some parts of your eyelid are slightly warmer than others. The sensors detect very small differences. When your eyelid is moved by your eyeball moving, it shifts the mosaic heat pattern being watched by the sensor.

Unless you've had IR beam emitters implanted into your eyeballs, your device uses PIR--Passive.

 

[BobK]

Well, it could be bouncing IR light off the eyelids and detecting changes with detectors.

But let's talk about the power that it might use. Compare it, for instance to the power of sunlight. It would be millions of times smaller. So, unless avoid going outside when the sun is out, I don't think you would need to worry about it damaging your eyes.

Bob

 

[ChosunOne]

Well, it could be bouncing IR light off the eyelids and detecting changes with detectors.

(SNIPPED)

Bob

That might be theoretically possible, but highly unlikely. Eyelids (or any human skin) aren't particularly IR-reflective. IR is heat, and skin tends to absorb heat rather than reflect it.

Aside from that, eyes and lids already emit more than enough IR/heat to be detected in patterns and analyzed and we've had sensors and algorithms for that for decades, in PIR motion detectors.

 

[ezzo]

Hi and thank you everyone for your input. I contacted the manufacturer in Poland. Below is the question I asked and the reply I got back

Q: HI, is the infrared detector a passive or active ir? I appreciate your precious answer but I am concerned that having a device with infrared pulsing / aiming at the eye all night could cause damage over time due to infrared lights from the sensor or emmitor. I know you say its 100% safe but can you explain why it is safe please. I need to remove my anxiety about using an electronic device next to my eyes before i buy one, thankyou

A: It is active. Infrared which we use is very close to red light. Red light is safe and infrared is even more safe than red light becouse eye doesn’t see infrared. Pupil doesn’t react with infrared. So that’s why it is 100% safe. We have been selling REM-Dreamer for 12 years and we didn’t have even one customer who said that it did damage to his eye.

If you look at the device in the link below you can see that the ir detectors are tiny, the red led lights that flash are not an issue as they are not too bright and only flash for 1/4 of a second every 1 second for 2 seconds max so throughout the night the red led flash for about4 seconds total

Its the whole infrared that worrys me (maybe unnecessarily) im no expert. Another poster gave this response when posed with the same question

I agree with part of what the manufacturer told you: it is active. That small LED that I circled in the photo above is almost certainly an IR LED. The human eye does not react to IR, but that does not mean IR is safe. IR has a higher heat component than visible light. So, logic would indicate that IR is potentially more dangerous than visible light for the following reason. If the human eye doesn't see and doesn't react to IR light and if IR light has significant heat, then the human eye (retina) could be burned without the eye reacting by blinking or contracting the pupil. However, they probably wouldn't stay in business long if the product was damaging people's eyes. Personally, I wouldn't use it, but that's just my cynical nature. I wash my hands after I shake hands whenever possible.

So does this device seem safe? It definatley does what its supposed to do, thats for sure, its an excellent device for inducing lucid dreams, i just dont want to use it if its unsafe :-/

I then further questioned the manufacturer and got THIS reply!

This information is not correct. Infrared which we use doesn’t produce heat. There are three types of infrared and only third type-far infrared produces heat.
We use infrared very close to red light and it doesn’t produce heat.
Also power of IR LED is around 0,015 Watt so this level of power is too low to do damage. In comparison power of microwave ovens is around 2000W.
So please compare 0,015W to 2000W.
And also infrared in microwave ovens is far infrared, the one which produces heat.
So we still are sure that our device is 100% safe.

Thank you for you time and comments
Terry