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Help on small and fast RF-transreciever

Rusty

Nov 30, 2012
16
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Nov 30, 2012
Messages
16
Hey guys! I need some help here.

I'm currently writing my bachelor project now, and need some help to find a small and fast RF-transreciever.

About my project:
My group and me are going to design and construct a wireless hand-grip controller that is going to be in a fMRI-machine (medicine). The system will probably consist a on-chip computer and amplifiers that are going to handle data from different sensors (heart monitoring, sweat-sensors, guro ++)

We need a way to transfer this data wireless to a Windows-PC. USB would be nice. Specifications says that the company wish to do it with RF. Timerespons is important and the size have to be small.

Any suggestions?

We found something from Texas Instruments, but haven't done so much research yet.
The fMRI have huge and powerful magnetic fields, thats why we cant have any inductors in it.

Any suggestions would be helpfull. In return, I will try to update you guys about the project.
 

oyvdahl

Oct 11, 2012
15
Joined
Oct 11, 2012
Messages
15
Hey guys! I need some help here.

I'm currently writing my bachelor project now, and need some help to find a small and fast RF-transreciever.

About my project:
My group and me are going to design and construct a wireless hand-grip controller that is going to be in a fMRI-machine (medicine). The system will probably consist a on-chip computer and amplifiers that are going to handle data from different sensors (heart monitoring, sweat-sensors, guro ++)

We need a way to transfer this data wireless to a Windows-PC. USB would be nice. Specifications says that the company wish to do it with RF. Timerespons is important and the size have to be small.

Any suggestions?

We found something from Texas Instruments, but haven't done so much research yet.
The fMRI have huge and powerful magnetic fields, thats why we cant have any inductors in it.

Any suggestions would be helpfull. In return, I will try to update you guys about the project.



Wifi maybe?
To make it simple you can use an Arduino with a WiFi shield.

Or would that be too big?
 

Rusty

Nov 30, 2012
16
Joined
Nov 30, 2012
Messages
16
Hi, and thanks for the reply.

Arduino will be too big for our use. The space is very limited because its going to be hand held and the battery takes lots of space. We will need space for sensors, RF, one-chip computer, amplifiers and filters too.

We have contact with Nordic Semiconductor now and they recommended a HID that seems very interesting. I will update more specific later. Its going to be based on nRF24LE1.

Again, thank you for reply :)
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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Jan 21, 2010
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25,510
Yeah, those Nordic chipsets are pretty amazing.

I have a few boards with their tiny 2.4GHz radios on them, but I wonder if they contain too much metal to safely put inside an MRI machine?

I didn't suggest them on that basis...

Just how much metal can you safely put inside them?
 

Rusty

Nov 30, 2012
16
Joined
Nov 30, 2012
Messages
16
Hi Steve, and thank you for your reply.
I didnt know about the metal content on Nordics chips. But we will give it a try. A little metal is not a problem. Main problem is the vibrations from the battery. I will report here how its going.

Do you have any suggestions for a humidity-sensor that can be used to determine sweat on humans skin? Can we use regular capasitive humidity sensors for that use?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Not so much metal in the chip, but they require a crystal, and they're generally in a metal case. But they're also small, so it may not be an issue. I guess I'm reacting against the "rules" that say everything metal must be kept well away from the machine...

I would think that measuring skin conductivity would be a better measurement. Maybe through a salty pad (to swamp out differences in salt content of sweat between individuals).
 

Rusty

Nov 30, 2012
16
Joined
Nov 30, 2012
Messages
16
A little update here:
We descided to go with TexasInstruments instead of NordicSemiconductor
The series ez430-rf2500 with MPS430F2274.
We will use this to handle data from sensors, battery-measurements and different button-responses, then transmit data with RF.
2.4GHz, ultralow power and cheap. Hope it will do the job.
http://www.ti.com/tool/ez430-rf2500t

Also ordered a sensor for sweating measurement based on electrodes to measure different potensials in the skin. And as pulse sensors we have ordered a lot of different IR-LED og photodiode-based sensors to test. Hope to get started with testing next week.
 
Last edited:

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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25,510
Thanks for the update.
 
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