Datex monitor help

[Gerald77]

Hello,

I'm a physician without any computer training. I know what labview is but i have absolutley no idea how to work with it.

lately i have been trying to aquire data from our operating room datex AS3 monitor.

I have followed the instructions given by the department of anesthesia in the chinese university of hong kong and their monitor software:

http://www.cuhk.edu.hk/med/ans/softwares.htm

I bought a DB9 double sided female cable and a USB adapter and tried two options:

1) a USB adapter to a labtop (driver was installed correctly)

2) serial connection to a desktop computer

In both cases the software worked, the monitor worked, but there was no connection between the two.

my questions:

1) do i have to set some option on the monitor itself?

2) is there importance to the serial card inside the desktop computer? is there importance to the brand of the USB adapter? do I have the right cable?

3) is there some other simple way for me to extract the data?

4) Does anyone has a theory why things arent working?

I thank anyone in advance for help.

[Coq_Rouge]

Since you are measuring on people in an operating room. I will strongly suggest you contact you technical department. And get your setup approved by them. Before you do any more. Your technical department will also for sure be able to help you with the setup.

The problem is that the monitor is approved as a medical device. But your PC/laptop is classified as consumer electronics. And by connecting the two devices you may end up with a system that do not comply to the medical safety regulations. If something go wrong you will be responsible for the damage. But if your technical department has approved your setup. It will be a problem for your hospital. And not you as a single person. Big difference as you may understand.

I have done what you want to do several times. It is indeed doable. But as I said let your technical department evaluate your setup. And decide what safety measures that is needed.

[LuI]

Gerald,

at first I have to support CoqRouge's statement. ANYTHING connected to a patient can be considered a medical device and as such falls under apropriate regulations.

Back to your problem: Serial communications is quite reliable once established, but can be a bit tricky to get running. A simple cable to connect two 'devices' is not good enough. There are some things to check and consider:

1. Serial connection settings: You need to know what settings the Datex monitor is actually requiring (e.g. set to). There are 'baud rate', 'data width', 'parity' and 'number of stop bits'. Your SW needs to be set to exactly the same settings as the monitor is set. See also at http://en.wikipedia.org/wiki/Serial_port for more explanations on serial port connections.

2. Cabling: There are at least two different 'types' of serial devices, that need different cabling. There are 'straight' and 'crossed' cables, depending on what kind of flow control is used for data transfer between the devices. And this is not necessarily related to the type of the cable connectors (e.g. DB9 female etc.). You have to check what kind of cabling is requested by your monitor.

3. SW: A tailored SW is a good thing as long as it does what is expected. But you do not get any clue why a missing connections is not working. You may try the windows program 'hyperternminal' or any other terminal program to see if this can get anything from the monitor. If the terminal program detects absolutely nothing than you probaly have a defective or the wrong cable or adapter or whatever. It might be easier to try different port settings to detect the right settings for a stable connection with your monitor.

Just my 0.02 €!

HTH!

Greetings from Germany!

--

Uwe

[Gerald77]

Thank you CoqRouge,

I have cleared everything with my technical department at the hospital and got the necessary approval. Unfortunely they were unable to help me with the technical side and that's how I got here

[Gerald77]

Thank you too Lul,

I will try the 'hyperternminal' SW and see what I get.

[Coq_Rouge]

You will not see much with Hyper-Term since the Datex monitor use a partly binary protocol. And data is sent by request from the PC. In order to get anything from the monitor you must have the correct cable. AND the software on the PC must use the correct port. The cable you are using shall have configuration as shown in the picture. It is by any means not enough the cable fits. It must also have the correct internal wiring. Serial cables come in all sorts of variations. Again the technical department should be able to help you.

[andycnmc]

hello Gerald77

I just wanted to put in my two cents worth on the connection of medical equipment to humans.

I would like to recommend that you consider having your computer and display plugged into an appropriately sized isolation transformer.  If you have a biomedical engineering group, they should be able to obtain one for you.

Also some manufacturers of medical equipment have cable specifications for interface cables (like serial cables and cables that plug into the ECG output connectors on some monitors).  You would want to check with the vendor to see if there are any stipulations.

one example of this is something I am working on-- a Philips Intelliview MP70 physiologic monitor.  I will be connecting to the serial port on the side to access the data that is sent out there.  the vendor specified that the cable needs to be essentially a CAT5 type cable.

sorry my experiences with serial port data is minimal.  I will be attempting MP70(philips) and AVITA XL vendtilator(Draggar) serial data extraction myself.

I hope the group can help you through that.

andy

[Feiner]

The Datex monitor is a little bit of a pain. I managed to find someone who

had already solved the problem.

You will need a Null modem cable.

Settings are:

Baud rate: 19200

8 data bits

Even Parity

1 stop bit

Flow control: RTS/CTS

Data is read asynchronously. The frames can be difficult to take apart.

You will also have to send a code to the Datex to get it to start sending

data.

---

John Feiner

From: Gerald77 <web.community@ni.com>

Reply-To: <ni-1644198906-15ly-2-hpw@decibel.ni.com>

Date: Wed, 06 Apr 2011 05:41:39 -0500

To: John Feiner <feinerj@anesthesia.ucsf.edu>

Subject: - Re: Datex monitor help

Community <http://decibel.ni.com/content/index.jspa>

Re: Datex monitor help

created by Gerald77 <http://decibel.ni.com/content/people/Gerald77> in

Biomedical User Group - View the full discussion

<http://decibel.ni.com/content/message/22964#22964>

Thank you CoqRouge,I have cleared everything with my technical department

at the hospital and got the necessary approval. Unfortunely they were unable

to help me with the technical side and that's how I got here

Reply to this message by replying to this email -or- go to the message on

Community <http://decibel.ni.com/content/message/22964#22964> Start a new

discussion in Biomedical User Group by email

<mailto:message-groups-biomedicalusergroup@decibel.ni.com> or at

Community

<http://decibel.ni.com/content/choose-container!input.jspa?contentType=1&con

tainerType=700&container=1113

[jimjoe]

use a standard null modem cable connected to the (serial) COM port of computer and AS3 monitor. You can use this open source C# .NET software http://sourceforge.net/projects/vscapture/ to capture data every 5 seconds. It requires Visual Studio 2010 to compile and for now its a console application, a GUI is planned in future. One caveat, startup the software and press enter button to the desired COM port in the app as soon as you connect the cable to AS3 monitor, else the monitor may freeze, especially with USB to serial cables like BAFO. It is otherwise quite stable on testing.