Re: Selecting embedded Linux for a new medical device project (LONG)

"DavidK" <PleaseReplyTo@xxxxxxxxxxxxxx> wrote in
news:rZXMi.122$LD2.46@xxxxxxxxxxxxxxxxxxxxxxxxxx:

Hi,

I've just begun working on a new project for a medical device, and I'm
in the early stages of deciding which RTOS we'll use.

To summarize the device, it's a medical device that will have a
graphical user interface (and possibly a touchscreen), a control knob
to set the power level, a footswitch, an RF power generator, and an
'applicator' that's connected to the system by a long cable.

The doctor will use the device by setting the desired power level
using the knob (the knob position is read by the software), and when
the footswitch is pressed, the device will deliver the appropriate
level of RF energy to the patient via an applicator. During the
'treatment', the device will display the setpoint power level, the
measured power level, the time in seconds since the treatment was
started, and the temperature of the patient's tissue that's being
'treated'. The device will emit a beep tone every three seconds
during 'treatment' to indicate that RF energy is being applied. When
the doctor deems the 'treatment' is complete, he will release the
footswitch, and the RF power will be turned off. Data aquisition
(temperature and measured power level) will be performed every 10ms or
so.

Of course the final device, including its software, will be run
through rigorous testing and clinical trials as required by the US
FDA. But it would be nice to select an operating system that has been
used successfully in safety-critical (such as medical) applications,
so that I won't be the first one going down that road with the OS we
select.

At this stage, we have not decided which CPU will be used, but I
suspect it will be a single-board computer (such as a PC/104 form
factor) with an Intel x86 or compatible processor.

I am considering using embedded / RT Linux for this project, to help
keep costs down by avoiding operating system per-copy royalty charges.
How should I go about selecting a particular distro or Linux? I was
reading about uCLinux, but it doesn't seem to have been ported to
Intel x86 CPUs yet.

Any links or tips in selecting a particular version of Linux is
appreciated!

David K

Hi David,

Interesting project. Your company costs will be dominated by the
approvals and testing time. Everything else will disappear, in relation
to those.

You don't give much information. The only timing info you gave was 3
seconds for a beep and 10 ms for a input check. If those are your only
constraints I would consider a 8051 or a PIC with no operating system.

Why do we use an operating system at all and a RTOS in particular? To
allocate resources; sometimes control response time, cpu availability
etc. The big plus with an OS is I/O. Display drivers, control input
drivers, higher level things like tcp/ip or usb really need a decent OS.

If all you are doing is reading a pot for the foot control and doing
other similar, slow timing a much smaller no-os cpu is indicated. It
will make your testing much easier.

Regards, Steve


.

Relevant Pages

  • Selecting embedded Linux for a new medical device project (LONG)
    ... it's a medical device that will have a graphical ... The doctor will use the device by setting the desired power level using the ... During the 'treatment', the device will display ... I am considering using embedded / RT Linux for this project, ...
    (comp.os.linux.embedded)
  • Re: Selecting embedded Linux for a new medical device project (LONG)
    ... the early stages of deciding which RTOS we'll use. ... it's a medical device that will have a graphical ... The doctor will use the device by setting the desired power level using the ... I am considering using embedded / RT Linux for this project, ...
    (comp.os.linux.embedded)