Myomonitor® Analog Output
Software User’s Guide
April 2008 Edition
MAN-010-1-0
Copyright © 2008 by Delsys Incorporated
Specifications and procedures outlined in
this document are subject to change
without notice.
Delsys Logo, EMGworks, and Myomonitor
are Registered Trademarks of Delsys
Incorporated.
Table of Contents
Important Information ........................................................ 3
Intended Use ................................................................................ 3
Contraindications .......................................................................... 3
Technical Service and Support ..................................................... 3
Warnings and Precautions ............................................................ 3
Device Information ........................................................................ 5
Disclaimer ..................................................................................... 5
Limited Warranty ........................................................................... 6
Introduction......................................................................... 7
Quickstart ............................................................................ 8
Product Activation............................................................ 11
Software Operation........................................................... 12
Operation .................................................................................... 12
Configuration .............................................................................. 13
Communications Quality ................................................. 14
Menus ................................................................................ 16
File .............................................................................................. 16
View ............................................................................................ 16
Tools ........................................................................................... 17
Help ............................................................................................ 17
Settings Dialog.................................................................. 18
General Tab ................................................................................ 18
Advanced Tab ............................................................................. 18
Network Tab ............................................................................... 19
Restore Factory Settings ............................................................ 20
Save as Default Settings ............................................................ 20
Diagnostic Windows......................................................... 21
Status Window ............................................................................ 21
Performance Plot ........................................................................ 23
Troubleshooting ............................................................... 24
Underflows .................................................................................. 24
Reduced Quality Indications ....................................................... 25
Networking Connectivity Problems ............................................. 25
Important Information
Intended Use
The Myomonitor® EMG Systems are designed for research,
investigational and scholarship purposes only. Delsys® products
are not intended for measurement purposes or for use in the
treatment and diagnosis of humans.
Rx ONLY
Contraindications
DO NOT USE on Patients with implanted electronic devices of
any kind, including cardiac pace-makers or similar assistive
devices, electronic infusion pumps, and implanted stimulators.
DO NOT USE on irritated skin or open wounds.
DO NOT USE on Patients with allergies to Silver.
Technical Service and Support
For information and assistance visit our web site at:
www.delsys.com
Contact us at:
E-mail: support@delsys.com
tel: (617) 236 0599
Warnings and Precautions
Consult all accompanying documents for precautionary statements and
other important information.
Consult accompanying user’s guide for detailed instructions.
3
Keep the device dry. The presence of liquids may compromise the safety
features of the device.
Handle with care.
Sensitive electronic device. Avoid static discharges. Do not operate or
store near strong electrostatic, electromagnetic, magnetic or radioactive
fields. Interference from external sources may decrease the signal-tonoise ratio or result in corrupted data.
This device may cause electrical disturbances in sensitive equipment
within its operating environment.
Connect only to Delsys-approved devices.
Connecting a patient to high-frequency surgical equipment while using
Delsys EMG systems may result in burns at the site of the EMG sensor
contacts.
Immediately discontinue device use if skin irritation or discomfort
occurs.
Immediately discontinue device use if a change in the device’s performance is noted. Contact Delsys technical support for assistance.
Delsys Inc. guarantees the safety, reliability, and performance of the
equipment only if assembly, modifications and repairs are carried out by
authorized technicians; the electrical installation complies with the
appropriate requirements; and the equipment is used in accordance with
the instructions for use.
Device contains a Li-Ion battery. Do not damage or mishandle.
Recharge only with the approved power supply originally included with
the system.
Myomonitor EMG systems should be stored and operated between 5
and 65 degrees Celsius due to the presence of an internal Li-Ion
rechargeable battery. Storing or operating the device, and consequently
the battery, outside of this temperature range may compromise the integrity and the safety features of the Li-Ion cell pack.
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Myomonitor® Analog Output Software User’s Guide
Device Information
Complies with Requirements put forth by the Medical Device Directive
93/42/EEC. Class I device, Annex VII.
Type BF device (IEC 60601-1).
Isolated device, (Class II, IEC 60601-1)
Do not dispose this product with house waste. Contact Delsys Inc. for
instructions on responsibly disposing this device. This product should
not be mixed with other commercial wastes.
Date of Manufacturing (appears on device)
Serial Number (appears on device)
EC
REP
EMERGO EUROPE
Molenstraat 15
2513 BH, The Hague
The Netherlands
Authorized Representative
DELSYS INC.
650 Beacon St.
Boston MA 02215
USA
Manufacturer
Disclaimer
DELSYS INC. makes no warranties, express or implied, as to
the quality and performance of this product including but not
limited to, any implied warranty of applicability for other than
research uses by qualified individuals. DELSYS INC. shall not
be liable to any person for any medical expenses or any direct or
consequential damages resulting from any defect, failure or malfunction, whether a claim for such damages is based upon theory
of warranty, contract, tort or otherwise. No representative, agent,
or licensed practitioner is authorized to waive this disclaimer.
DELSYS INC. makes no diagnosis or prescription by virtue of
anything about this product.
5
Limited Warranty
The Myomonitor® EMG Systems are warranted against failure
of materials and workmanship for a period of 1 year from the
date of delivery, provided that the product is given proper care
and has not been subject to abuse during this period. This warranty is in lieu of all other warranties expressed or implied.
Operation of this device outside specifications determined by
DELSYS INC. or use with any other input devices other than
DELSYS INC. sensors constitute an invalidation of this limited
warranty. This warranty is not transferable.
We thank you for supporting our products and we hope that they
will fulfill your research needs. Your feedback is always
appreciated. Please do not hesitate to contact us with any
questions, comments, or concerns you may have.
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Myomonitor® Analog Output Software User’s Guide
Introduction
1
Myomonitor Main Unit
6
D-Link Drivers
2
Myomonitor Analog
Output Software
7
Analog Output Software
3
Wireless Transmission
8
NI drivers for Waveform
Generator
4
Host Computer
with PCI slot
9
PCI Waveform Generator
5
D-Link USB Receiver
10
Analog Filter Unit
The Myomonitor is capable of generating analog output signals
for direct connection to external data acquisition systems. In this
operation mode, data are acquired by the Myomonitor Main Unit
and its associated sensors (1,2) and transmitted over a wireless
network (3) to a host PC (4) outfitted with a wireless receiver
(5,6). Analog Output Software (7) sends the received data to the
Waveform Generator (9), also installed on the PC. The reconstituted analog signals are filtered (10) and then connected to the
desired acquisition System.
7
Quickstart
Prior to proceeding, please ensure that the Myomonitor
Analog Output System and software has been properly
installed as outlined in the Myomonitor System Installation
Guide provided with your device.
Ensure that the following steps were performed during the System Installation procedure:
Verify that the Myomonitor Analog Output
software is installed on the host PC. Both a start
menu item and desktop shortcut are provided after
installation.
Verify that the National Instruments PCI-6723
Waveform Generator and its drivers are installed
and functioning on the PC.
Verify that the Filter Module is properly connected, powered and turned “ON”.
Ensure that you Secondary Data Acquisition System is connected to the Filter Module and is proper
sampling data.
Ensure that the Myomonitor is able to connect
through the wireless D-Link adapter. If you have
previously used your Myomonitor with
EMGworks then this should already be operational.
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Myomonitor® Analog Output Software User’s Guide
1.
Run the Myomonitor Analog Output program on the PC and
activate the software using the CD key provided. The program can be started from the Windows START menu or by
double-clicking the icon on the PC desktop.
2.
Run the Myomonitor Analog Output program on the Myomonitor. This program is initiated by double-tapping the
Myomonitor Analog Output icon on the Myomonitor Desktop.
3.
Once the Connected LED lights on the program's control
panel click the Start button to start outputting the data being
acquired by the Myomonitor.
9
10
4.
Click the Stop button to end data output.
5.
You can restart at any time as long as the Myomonitor is connected as indicated by the green Connected LED.
Myomonitor® Analog Output Software User’s Guide
Product Activation
The first time you run Myomonitor Analog Output the following
dialog will appear:
If you are evaluating the product and do not have a product key
you can continue in demo mode and run the application for an
unlimited number of times for 30 days. After the 30 day trial
period you must activate the product for continued use.
To activate the program, please enter the product activation code
provided with the product's installation CD or provided by
Delsys sales. Click activate to register your activation. You do
not have to be online to do this. Activation is local to your
machine. Please adhere to the Delsys end user license agreement
EULA.
11
Software Operation
Operation
When the program opens the control panel should look like this:
Once the Myomonitor is connected via the wireless
communications link and the program running on the
Myomonitor has established a software connection with the host
computer software, the Connection LED will turn green as
shown here.
The Connected LED indicates that the Analog Output
application on the Myomonitor has successfully established a
connection to application on the PC. There are two levels of
connectivity; a network connection, which is the connection
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Myomonitor® Analog Output Software User’s Guide
between the PC and the Myomonitor device and the application
connection, which is the communication connection between the
two software applications. The application connection cannot be
established without a valid network connection. The Connected
LED turns green when a valid connection between the
applications has been established. Data flow can not be started
until the Connected LED has turned green.
After a successful start the panel should look like this:
The Running LED has turned green and the Running Time is
displayed. The Communication Quality bar should be green with
a value at or slightly below 100%. See the section on
Communication Quality for an explanation of the quality bar and
its significance.
Configuration
Configuration should not be necessary except under unusual
circumstances such as poor wireless communication or conflicts
with network ports.
13
Communications Quality
Wireless communications using 802.11 (WiFi) is very reliable
when used over short distances. Factors that can affect the
reliability of this communication include:
• Physical obstructions between the Myomonitor and the host
computer, including human bodies.
• Interference from other sources using the same frequencies
(2.4GHz) as the wireless communication such as wireless
cameras etc.
• General wireless activity in your building and local environment.
• Movement of the test subject.
As these factors come into play the quality of wireless
communication may drop. The Myomonitor Analog Output
System dynamically manages itself to optimize performance as a
function of the wireless connection quality. A low quality
connection will force a trade-off between signal integrity and
system latency. If longer input to output delays can be tolerated,
better quality can be obtained over less optimal wireless links.
It is suggested that unless input to output delay is a critical factor
that you set the delay value between 100 and 500 ms. These
setting result in near 100% signal integrity.
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Myomonitor® Analog Output Software User’s Guide
A well-performing system displays a quality bar at or near 100%
as shown here:
The bar turns orange if the quality drops below 95%. In the
examples below, 88% of the EMG data is reproduced without
error from input to output. The quality bar will turn red once it
drops below 85%
Quality Calculation
The quality value is a time average of the percentage of correct
packets that are output. When there is a wireless delay, dummy
packets are inserted into the output stream to keep the output in
synch with the input. When the actual packet arrives late it is
discarded out of necessity since the dummy packet has replaced
it.
The percentage of valid packets that are output is calculated each
second. These values are averaged over a 10 second window so
that the quality metric represents a usable average and does not
express the instantaneous calculations.
15
Menus
The menu bar contains the following items and drop-downs.
File
Exit
Exists the program unconditionally.
View
Status Window
Opens the status window.
Performance Plot
Opens the performance plot window.
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Myomonitor® Analog Output Software User’s Guide
Tools
Settings
Opens the settings dialog.
Help
Contents
Opens the online help.
About
Opens in information dialog with the program version etc.
17
Settings Dialog
The settings dialog has three tabs.
General Tab
The general tab allows you to change the input to output delay.
Increasing the delay can overcome problems due to poor
wireless communications as discussed under Troubleshooting
and the Performance Plot. The values allowed are dependent on
the data transmission interval set under the advanced setting tab.
The default Delay is 50ms. In a high density environment e.g.
several walls between the subject and the PC the Quality can be
improved by increasing the Delay.
Advanced Tab
The advanced tab allows you to set the data transmission
interval. Data samples are sent as a packet at discreet intervals.
The default transmission interval is 10 ms. Increasing the
interval may allow operation on slower systems if you
experience underflows.
The underflow threshold determines when a dummy packet is
inserted into the output stream. Normally the threshold is one
interval of data. Increasing this value may also help to eliminate
underflows. If you do increase this value you should also
increase the delay as discussed above. If the delay is not
increased an excessive number of dummy packets may be
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Myomonitor® Analog Output Software User’s Guide
inserted. It is advisable to increase both the interval and
underflow threshold together for underperforming systems.
Network Tab
The network tab allows changing the TCP/IP ports the program
operates on. This is rarely required unless there is a port conflict
with other software you are running. Please contact you network
administrator for advice on port selections. Note - you must also
reconfigure the Myomonitor to correspond to these values. See
the Myomonitor documentation for instructions.
You must restart the analog output application for these changes
to take effect.
19
Restore Factory Settings
Clicking the Restore Factory Default button will reset all
settings on the three tabs to the factory values. However, they
will not be saved permanently unless Save as Default Settings is
also clicked.
Save as Default Settings
Clicking the OK button will save the settings for the current run
only, the settings are not saved as default when you restart the
program. If you wish to save these settings for the next time you
run the program click the Save as Defaults Settings button.
Settings are saved in the Windows registry.
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Myomonitor® Analog Output Software User’s Guide
Diagnostic Windows
There are two diagnostic windows that can be displayed to assist
in troubleshooting. These windows should not be left open while
engaged in actual data collection since they impact the system
performance.
Status Window
The Status Window dialog is divided into two regions. The top
lists information that does not change while running. The bottom
region is dynamically updated as the program runs.
Version
The version of the Analog Output software running on the
Myomonitor
Channels
The number of channels in use.
Actual input and output sampling rates
The desired sample rate is fixed at 4,000 Hz. The actual input
and output sample rates are shown. It is the slight difference that
results in the long term skew correction. An actual sample rate
of 4,000 Hz. is not possible because of constraints at the
hardware level due to clock dividers.
21
Samples per interval,
Samples per channel,
Delay in samples
Samples are sent at periodic intervals. The default is 10 ms.
These values show the number of samples per interval, per
channel during an interval, and the input to output delay in
samples rather than time.
Samples in output buffer
The number of samples currently in the output buffer of the NI
analog output card's software buffer.
Total samples generated and acquired
These values show the exact number of samples generated and
acquired from the time the program was placed in the running
state.
Delay
Average delay
The instantaneous and average delays between the data being
acquired and the data being output.
Total inserted packets
Total dropped packets
These values indicate the number of dummy packets that have
been inserted in the output stream to compensate for
communication delays and the number of data packets that have
been dropped in order to keep the proper time synchronization
between input and output. Packets can be inserted and dropped
as a result of long term clock skew as well as from
communication related factors.
Quality
The current communications quality value
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Myomonitor® Analog Output Software User’s Guide
Performance Plot
The performance plot is used to monitor wireless network
performance.
The vertical axis indicates the time delay between input and
output. The horizontal axis is in units of 0.1 Seconds.
The yellow plot is the instantaneous delay and the green plot is
the average delay over time. This value is used in determining
the Skew Correction. If the instantaneous delay falls below a
threshold value then dummy data is inserted in the output
stream.
23
Troubleshooting
Underflows
Myomonitor Analog Output requires a fast and dedicated
system. You may encounter the following error message:
This error can result from running on a system that is not fast
enough to support data transfer with the default delay setting of
50 ms. or you are running other applications that require CPU
time.
• Make sure you are not running other applications. Close all
other running applications.
• Disable all timed applications such as e-mail, virus scanner
update services such as "Live Update" used with Norton
products, Windows Update, and any tasks that run periodically. The best solution is to run a dedicated system with no
added software.
• If these steps do not solve the problem you can increase the
delay value using the Settings dialog. It may also be necessary to increase the data transmission interval and/or the
underflow threshold. Experiment to determine what settings
work best.
• If none of the above steps eliminate the Buffer Underflow
error then upgrading to a faster system with more memory is
necessary.
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Myomonitor® Analog Output Software User’s Guide
Reduced Quality Indications
If the quality bar consistently shows a lower quality value than
you desire the following solutions might help.
• Increase the delay
• Reduce the distance between the Myomonitor and the host
computer.
• Turn off all sources of wireless communication including
wireless access points (WAP), wireless cameras, other computers with wireless adapters.
• Make sure there is a clear line of sight to the Myomonitor. In
other words do not have walls or other barriers between the
Myomonitor and the host computer.
Networking Connectivity Problems
There are many factors that can prevent the wireless adapter
from communication with the Myomonitor. These are items to
check:
• Is the wireless adapter and associated software installed correctly?
• Are the settings such as the WEP security code set up correctly?
• Is the IP address correct?
• Are there port conflicts with the software?
• If the Windows Firewall blocking the required ports? Temporarily turn off the Windows Firewall to confirm this.
If you have access to an IT person with networking experience,
he or she might be able to assist in your network configuration.
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Myomonitor® Analog Output Software User’s Guide