"user manual"
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1. be used as substitutes 13 SM Red Dot conductive banana we ekctically neutral skin Zl surface banana lt n connector yt conductive ip electrode disk connector Figure 10 The Reference Electrode The banana connector is mated with the Input Module while the alligator or tip is used to connect to conductive adhesive electrodes Connecting the EMG Electrodes The Myomonitor EMG System is supplied with DE 2 3 Surface EMG electrodes These plug into the receptacles labeled Ch 1 8 on the Input Modules The connectors have a key so that they can only be inserted with a specific orientation The order of the electrodes can be interchanged with no consequences to the per formance of the EMG System The electrode cables are five feet in length so that they can be placed on any part of a user s body when the Input Modules are mounted at waist level CAUTION Never use any EMG electrode other than the DE 2 3 Surface EMG Electrode as an input to the Myomonitor EMG System Connecting anything other than Delsys specified electrode sensor as an input to the Myomonitor EMG System constitutes an invalidation of the Delsys Warranty and may result in personal injury and or permanent damage to the system or the electrodes Orienting the EMG electrodes on the Skin The DE 2 3 Surface EMG Electrode is fitted with two silver bar contacts for detecting the EMG signal at the skin surface It is2. crucial that the orientation of these bars be perpendicular to the muscle fibers for maximum signal detection The top of the 14 Myomonitor IIl EMG System User Manual electrode is stamped with an arrow to aid in the determination of this orientation The arrow should be placed parallel to the mus cle fibers underneath the electrode as demonstrated in Figure 11 It is important that the electrode and the skin are clean and free of oil and other resides before placement of the electrodes It is advised to remove excessive hair from the EMG site The elec trodes are easily attached to the skin with the Delsys Electrode Interface orientation underlying muscle arrow Ass direction of muscle fibers jjy Figure 11 Electrode orientation with respect to the muscle fibers It is important that the orientation of the arrow on the electrode be parallel to the underlying muscle fibers Using the Delsys Electrode Interface The Delsys Interfaces are made from medical grade adhesive specifically designed for dermatological applications Usage of the interface promotes a high quality electrical connection between the electrode bars and the skin minimizing motion arti facts and the ill effect of line interference To ensure a strong bond with the skin it is advised to shave excessive hairs and wipe the skin area with isopropyl alcohol to remove oils and surface residues Allow the skin to dry completely before apply ing the interfac
3. 50 Hz It is extremely difficult to completely remove the presence of line interference in noisy environments In most cases the optimum scenario is to keep line interference to unobservably low amplitudes when compared to the EMG signal amplitude Motion Artifact A transient disturbance in the detected EMG signal caused by the movement of the electrode with respect to the skin surface Motion artifacts are undesirable and can be minimized by attaching the electrode to the skin with aggressive adhesive by providing sufficient cable slack and by avoiding jarring motions and disturbances Other types of transient disturbances include stimulus artifacts caused by the applied voltage to a skin area for the purposes of eliciting a biological response or electrostatic artifacts caused by static discharges detected in the vicinity of the electrode Reference Potential An arbitrary voltage potential on the surface of the body used in establishing differential potential recordings All voltages measured by the surface electrodes and propagated throughout the Bagnoli EMG System have significance only when measured with respect to a well defined Reference Potential Note that the reference potential is not the same as and is completely isolated from the Ground Potential Sampling Frequency This is an important parameter characterizing A D systems It is defined by the number of digital samples taken of an analog signal per second According to t
4. AM za E 2 Using the Virtual Keyboard type a unique protocol name in the Name field and tap OK 27 Protocol File myprotocol oK x Channels Sample Rate js zl set on off Reps v emgce eo gt 12 03 am DA 3 Select the number of Channels to record and the Sample Rate 4 Tap Add to add a new protocol set The Add Protocol Item dialog box will open as shown below Add protocol item ane 2 ZER ZIR 5 Enter the set parameters Type a unique protocol Set name Type the duration for each repetition in the On field Type the duration for each rest period in the Off field 28 Myomonitor IIl EMG System User Manual Type the number of repetitions in the Repeat field Tap OK when done this will revert to the protocol dialog Repeat steps 4 7 to add additional protocol sets Edit a protocol set by selecting it and tapping Edit Delete a protocol set by selecting it and tapping Del Move a set in the protocol order by selecting it and tapping Up or Down To exit the protocol setup and specify where the acquired data files should be stored tap OK This opens the Data Directory dialog Select a directory The data from the proto col recording will be saved in the specified directory Each repetition will be saved as a separate file with its protocol set name and repetition number A copy of the protocol will also be saved in the d
5. Pin Signal Nn A U NY Stop In GND Stop Out Start Out 5V Start In The Main Unit has an internal Li Ion battery and an internal bat tery charger To maintain the charge of the battery the Main Unit should be connected to external power when not in use CAUTION Never use any battery other than the one supplied with the system Connecting anything other than the specified battery constitutes an invalidation of the Delsys Warranty and may result in personal injury and or permanent damage to the system Replacing the Battery To replace the battery 1 Press the On Off button to turn off the device It is important that the device is in suspend mode while replacing the battery to preserve what is stored in memory Place the Unit upside down taking care not to scratch the display Remove the Phillips screws cross slot and remove the bat tery panel see Figure 13 Remove the old battery and replace with the new battery Note this should be done as quickly as possible to preserve the memory The orientation of the battery does not matter as long as the battery s contacts mate with the Main Unit s con tacts 18 Myomonitor IIl EMG System User Manual Figure 13 Open the battery compartment at the back of the Myomonitor to replace the battery 19 20 Myomonitor IIl EMG System User Manual Myomonitor lll Software Introduction The Myomonitor III comes in two configurations wir
6. Port Do not change Control Panel Tapping Control Panel brings up Windows control panel 34 Myomonitor IIl EMG System User Manual Troubleshooting EMG Recordings Problem Excessive Presence of Line Interference power ine o itt gt EMG signal muscle ste e va 5 e differential Power line interference from surrounding sources is always an issue to contend with when recording body potentials on the sur face of the skin This interference is due to the presence of a 60 Hz or 50 Hz displacement current flowing on the skin surface due to the capacitance between the body and ground and between the body and surrounding power sources refer to Figure 14 People are exposed to this surface current on a con tinual basis as it is present anytime a body is near an AC power source This current cannot be sensed or felt and poses no risk to the body it is flowing on The surface potentials resulting from this displacement current on the skin can be orders of magnitude larger than the EMG potentials being detected by the electrodes If the EMG system is working correctly however the detected amplitude of these interfering potentials are negligible when compared to the detected EMG potentials Recall that the output of the EMG electrode is a subtraction of the potentials detected at the electrode contacts The interfering potentials are large signals and change very little as they propagate across the space of
7. potentials These action potentials can come from muscle fiber located directly below the electrode detection surface as well as muscle fibers located adjacent to and farther away from the 45 electrode detection surface When the electrode detects EMG signals not only from a muscle directly beneath it but also from surrounding muscles which may not necessary be of interest then crosstalk from adjacent muscles is said to be present Note that single differential electrodes have limited capacities for minimizing EMG signal crosstalk Double differential electrodes significantly reduce this type of crosstalk as EMG signals originating from distance sources are cancelled while those with more immediate sources remain D Subminiature D Sub Connectors Multiple contact assemblies commonly used for connecting multi conductor cable between equipment These connectors are in the shape of a D and come with standard 0 100 inter contact spacing as well as high density versions with 0 050 inter contact spacing Floating Signal This term refers to the indeterminate voltage state of a terminal when it remains unconnected If the signal terminal is not connected to any established potential for example the Reference Potential then it is said to be floating A floating signal at the input of recording devices is typically characterized by a wandering baseline voltage and may contain an inconsistent presence of line interferen
8. save all data in the folder My Computer Storage Card The location has persistent memory which retains the data in the event of power loss See Transferring Acquired EMG Data for Analysis on page 30 for information on how to download the data from the device Exit Closes the EMGworks Datalogger software 24 Myomonitor IIl EMG System User Manual View Menu Provides options for workspace viewing during data acquisition Chart Plot Properties Allows the user to select the background colors for the display Voltage Allows the user to select the desired voltage range for the display 5 2 5 1 0 5 0 2 or 0 1 Volts Note that this range is only for display purposes All data is saved with a 5 Volts range Nn Time Base Allows the user to select the desired time scale for the display 5s 2s 1s 5 00ms 250ms Note that this scale is only for display purposes Protocol Toggle menu that when enabled displays a protocol status window during data acquisition Data Menu Provides control for data acquisition Start Initiates the data acquisition This function can be accessed directly from the play P recording control at the top of the session Stop Pauses all data acquisition including protocols This function can be accessed directly from the stop W recording control at the top of the session Data acquisition can be resumed by selecting Data gt Start or pressing
9. the Main Amplifier Unit Insert the cable into the receptacle on the Input Module and make sure that the latching mechanism secures the connection For the 8 channel version make the connection to bank A on the Main Unit For the 16 channels version see Figure 9 connect one Input Module to bank A channel 1 8 and the other Input Module to bank B channel 9 16 12 Myomonitor IIl EMG System User Manual Ewe Figure 9 Connecting the Main Unit and Input Modules via the Input Cable Connecting the Reference Electrodes REF Connect the Reference Electrode cable to the Input Module using the banana jack Attached the Reference Electrode to the skin considering the points below e A high quality electrical connection between the Reference Electrode and the skin is as important for obtaining reliable EMG signals as a high quality EMG Electrode skin connec tion Be sure to clean the skin prior to affixing the reference e Only one reference connection is required when collecting EMG signals The site should be an electrically inactive area on the skin surface e Delsys EMG Systems are supplied with two examples of dis posable reference electrodes shown in Figure 10 The small tab electrodes are an economical solution while the large conductive disc electrodes provide a better connection Both types are lined with a conductive medical grade adhesive Conductive electrodes other than the examples supplied can
10. trodes 5 Ensure high quality electrical contacts In extreme cases it may be necessary to wet the electrode bars or use conductive 39 gel to enhance the stability of the electrode skin electrical connection See the Troubleshooting section on Excessive Presence of Line Interference for methods to ensure a high quality electrode skin contact 40 Myomonitor IIl EMG System User Manual Specifications Myomonitor Ill Main Unit System General Typical Operating Range 35 m closed office 270m open space unlimited Datalogger Data Capacity host PC dependent Wireless 512 MB standard Datalogger Medical Device Conformity IEC 601 Classification Class 1 93 42 EEC Type BF Dimension 165 x 91 x 61 mm 6 6 x 3 6 x 2 5 Mass 900g 2 Ibs Enclosure Material ABS Temperature Range 0 40 C Electrical Signal Resolution 16 bits Signal Input Range 5 V Sampling Rate 1024 Hz channel minimum Number of Channels 8 or 16 Screen Size 240 x 320 pixels Battery Requirements 7 2V 4 2Ah Li Ion Battery Duration per charge 6 hours wireless 8 hours datalogger 41 DE 2 3 EMG electrodes General Number of Contacts 2 Contact Dimension 10x 1mm Contact Material 99 9 Ag Case Dimension 41x20x5 mm Cable Length 1 5 m Connector LEMO 4 pin male Case Material Polycarbonate pl
11. types of soaps can be used to facilitate ion transfer across the skin to the EMG electrode contacts 48 Myomonitor IIl EMG System User Manual
12. Bin E untitled emg 416 bytes EMGworks Data Doc 9 1 2003 2 21 45 AM El Control Panel 23bytes Shortcut 8 31 2003 7 00 02 The saved files can then be copied or moved from the Myomonitor III to the host computer Once the data files are transferred to the PC they can be analyzed using EMGworks Analysis software 31 EMGworks Wireless Software This section describes how to use the Myomonitor III as a wire less real time EMG data acquisition system The EMGworks Wireless client application on the Myomonitor interfaces directly to EMGworks Acquisition on the host PC enabling the Myomonitor III device to exchange information with the host computer Before proceeding make sure that a wireless connection between the Myomonitor III and the host computer has been setup and established Refer to the Release Notes for wireless network installation instructions Starting the EMGworks Wireless application To start the wireless application double tap the EMGworks Wireless icon on the desktop g 7 a z My Internet Computer Explorer m Lere ZES PC Connection v 2 12 14 am A Double tapping the icon opens the EMGworks Wireless main screen 32 Myomonitor III EMG System User Manual Attempting to connect to 172 169 0 1 v EMGwor 3 gt 12 15 AM wie EMGworks Wireless will instantly attempt to connect to the default host computer on the Myomonitor network If EMGworks Acqu
13. Myomonitor lll EMG system User Manual December 2004 Edition PM M04A Copyright 2004 by Delsys Incorporated Specifications and procedures outlined in this manual are subject to change without notice Delsys Logo EMGworks and Myomonitor are Registered Trademarks of Delsys Incorporated 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 Warnings and Precautions Disclaimer Delsys products are not designed to be used in conjunction with any devices not approved by Delsys Inc Please contact Delsys for further information 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 Do not use Delsys products in the presence of any liquid or during conditions where the device or the user s may become exposed to liquids The presence of liquids may compromise the safety features of the device Delsys EMG amplifiers are extremely sensitive to electrical disturbances Avoid static discharges and electromagnetic f
14. arted with the Myomonitor System 12 Charging the Battery l ll llllllii kak ekk 12 Connecting the Input Modules EE 12 Connecting the Reference Electrodes j ULEEEEjjjj jU 13 Connecting the EMG Electrodes 14 Orienting the EMG electrodes on the Skin 14 Using the Delsys Electrode Interface 15 Starting the Myomonitor Main Unit 16 Myomonitor Hardware FeatUresS llidi k 17 Connecting to a PC compUter Eiui Ee 17 Power and Reset 2 cceseccceceeeeeeeeeeedeseeeeeeeedeeneeeeddensneeees 17 Trigger Connettore a 17 n md 18 Replacing the Battery ui eee 18 Myomonitor lll SOf Ware ELL EEE kek 21 IntrOdUCHION s nan heise ees 21 Using the stylus and the virtual keyboard 21 EMGworks Datalogger Software Ei Eek 23 Starting the Myomonitor Datalogger Software 23 EMGworks Datalogger Program Layout 23 File Men s socrii eniai n aA 24 VIEW MEDU aies ar ERE E L RRE 25 Data Men ansiar k n da AA sra ed 25 Recording EMG Data Eiiu kk ek K k kek 26 Using Data Acquisition ProOtOColS E uiEEEEE 27 Creating a New Protocoll cccecceeeseeeeeeeeettteeeeerees 27 Opening an Existing Protocol E E uEE E 29 Recor
15. astic Electrical Gain 1000 1 Bandwidth 205 Hz to 450 50 Hz 12 dB oct Overall Channel Noise lt 1 2uV RMS RTI CMRR gt 80 dB Input Module General Number of Sensor Input 8 Sensor Input Connector LEMO 4 pin female Case Dimension 81 x 46 x 23 mm 3 2 x 1 8 x 0 9 Mass 85 g 3 oz Input Module Cable General Connector Honda 14 pin male Length 2 5 ft 42 Myomonitor III EMG System User Manual Reference Electrode Cable General Connector Banana plug to Alligator Clip or Tip plug Conductor Single Length 1 67m 5 ft 43 44 Myomonitor IIl EMG System User Manual Glossary of Commonly Used Terms A D System Analog to Digital System These devices are commonly used in conjunction with computers for translating continuous i e analog voltage signals into binary i e digital data Once in digital format the data can be viewed manipu lated and stored on digital media devices such as disk drives and CD ROMs Aliasing A condition arising when digitally sampling a signal at a frequency less than twice the highest frequency content of the signal Aliasing inhibits the faithful reconstruction of a digitally sampled signal It can be avoided by ensuring that the Nyquist Criterion is not violated which forces the representation of any frequency component in the signal with at
16. ce Output signals of the Bagnoli EMG System will float if either the EMG Electrode or the Reference Electrode is not properly connected Ground Potential This the electric potential sometimes referred to as Earth and is connected to the metal chassis of many electrical instruments It can act as a current sink for any line potentials which may come in contact with the chassis of instruments Note that the Ground Potential is different than the Reference Potential The BNC outputs and the output connector on the rear panel of the Bagnoli EMG System are typically connected to the Ground Potential when recording instruments are used The Reference Potential used in the differential EMG recordings is separated from the Ground Potential via channel independent isolation transformers LED Light Emitting Diode This is a semiconductor device which illuminates when current is allowed to flow through it The Bagnoli EMG system contains LEDs which appropriately illuminate when either a line error or a hi error is detected in any one of the channels Line Interference The contamination of electrical signals by the superposition of cyclic noise induced by surrounding AC power lines and sources In North America line interference has 46 Myomonitor IIl EMG System User Manual a fundamental frequency of 60 Hz while in most European and other international countries the line interference has a fundamental frequency of
17. de contacts not firmly pressed against the skin will result in line interference The use of the Delsys Electrode Interfaces is recommended for this purpose Refer to the section on Poor Electrode Skin Adhesion if this is a problem 36 Myomonitor IIl EMG System User Manual Clean the skin Ensure that the skin under all the electrodes is clean and free from hair The area should be wiped with isopropyl alcohol swabs before the electrodes are applied If necessary hair can be removed with a safety razor or with commercially available hair removing lotions such as Neet or Nair Allow the electrode to settle When first applied to the skin the electrode may display high levels of noise and interfer ence Allow the electrode to settle for a few minutes giving time for the ionic currents between the electrode and the skin to become established Wetting the electrode bars with water will expedite this process Use surfactants On particularly dry skin it may be neces sary to wet the EMG electrode contacts with water or to line them with electrode gel so as to promote the necessary ionic flow For this purpose it is recommended to use medical grade conductive gel similar to those used for EKG and TENS applications A very small amount should be applied to the electrode bars prior to attaching them to the skin Cot ton swabs can be used to spread a very thin layer on the silver bars Take care not to smudge the g
18. ding EMG Data with a Protocol 29 Transferring Acquired EMG Data for Analysis 30 EMGworks Wireless Software EEEu kk 32 Starting the EMGworks Wireless application 32 Setting up Myomonitor II manually 34 Troubleshooting EMG Recordings ccecesseeeeeeteeeeeeenaees 35 Problem Excessive Presence of Line Interference 35 Problem Poor Electrode Skin Adhesion 38 Problem Excessive Presence of Motion Artifact 39 SPECIICATIONS eierne lana aee Kaza ka San raxan E Ara thet dk k Sen deface dees 41 Myomonitor II Main Unit System n 41 DE 2 3 EMG electrodes emiiri lalik xewka a kika ley k ake lak ke k 42 Input ModUl isi k n la A a Rukiye deal l y Kesek k la k r y 42 Input Module Cable Eu keke 42 Reference Electrode Cable LEu E 43 Glossary of Commonly Used Terms E EEUUEUEUUU UEUUjU 45 6 Myomonitor IIl EMG System User Manual Myomonitor lll Portable EMG System General Description The Myomonitor System is a portable electromyographic EMG data acquisition system The device comes in two con figurations Myomonitor Wireless which transmits data to a host com puter nearby for storage and real time viewing Myomonitor Datalogger which acquires and stores data in onboard memory It can disp
19. e adhesion is achieved Check the shelf life of the interfaces or the tape The Del sys Electrode Interfaces have a shelf life of 24 months If the interfaces are not used within this period the medical grade skin adhesive may begin to dry and deteriorate The date of manufacturing can be found on the front of the package Ensure that the time limit has not expired Keep in mind that other adhesives such as surgical tape have similar time limi tations on their shelf life Use elastic bandages If difficulty in attaching the electrodes persists after addressing the above points then one remaining 38 Myomonitor IIl EMG System User Manual alternative is to wrap the electrodes to the body with elastic bandages Commercially available athletic wraps and ban dages are suitable for this purpose if obviously the record ing sites allow their use Note that this method of electrode attachment is highly discouraged and should only be used as a last resort Problem Excessive Presence of Motion Artifact Motion Artifact is characterized by large amplitude low fre quency spikes which may saturate the sensitive EMG amplifiers This type of electrical interference is usually associated with jar ring motions excessive stretching of the skin under the electrode sites and other forms of mechanical vibrations which cause movement of the electrode with respect to the skin It is caused by a temporary fluctuation in the DC skin poten
20. e cable Up to eight electrodes can be connected to an Input Module The EMG signals detected by the electrodes are communicated to the Main Unit via the Input Cable The Input Modules have a clip on one side which simpli fies fastening to the waist belt or lumbar pack Figure 3 The Input Module The Input Cable connects the Input Modules with the Main Unit supplying power to the active EMG electrodes and transmitting EMG data back to the Main Unit Figure 4 The Input Cable Reference Electrode Cable Two types of reference electrode cables are provided with the system in order to support several reference electrode options see Figure 5 Both cables are single conductor wires with a banana connector on one end and either an alligator clip or a tip plug on the other end The banana plug is hosted by a receptacle located in the Input Module Although two cables are provided only one reference connection shoud be used when collecting EMG l rt a p Figure 5 a The Alligator Reference Electrode Cable b The Tip Reference Electrode Cable Power Supply The power supply is fitted with a universal IEC 320 input plug so as to accept power cables from all countries The power sup ply accepts input voltages ranging from 100 240V 50 or 60 Hz Delsys strives to supply the correct power cable for each destination however it may at times be necessary to separately purchase power cords suitable for t
21. econds of each rest period with audible ticks The recording controls described in Data Menu on page 25 can be used to control data acquisition for each repetition of the protocol The repetitions will automatically be saved as they are completed It is also possible to save the current repetition when recording is paused by selecting File gt Save As Acquisition will be automatically stopped when the end of the protocol is reached Transferring Acquired EMG Data for Analysis Follow the instructions under Connecting to a PC computer on page 17 to prepare the Myomonitor for file transfer The Myomonitor automatically connects when the cable is inserted and Microsoft ActiveSync is installed The Myomonitor III is accessible directly from Windows Explorer Open a new Windows Explorer window and tap 30 Myomonitor IIl EMG System User Manual Mobile Device in the left hand pane to browse the Myomonitor fs Mobile Device SEE File Edit Yiew Favorites Tools Help Av Q sxx Q E pe Search J Fokers E Address J Mobile Device FI Folders x Name Sze Typ A beskop A IC Application Data File Folder E My Documents My Documents File Folder S My Computer network File Folder Eb 3 Floppy A profiles File Folder E Local Disk C Program Files File Folder amp G Control Panel Recycled File Folder a p Temp File Folder r sa My Network Places windows File Folder Recycle
22. el on the skin when the electrodes are placed Any connection between the electrode bars through the conductive gel will short circuit the input of the EMG electrodes and result in erroneous readings Ionic soap is also an excellent surfactant of this purpose As with the gels it should be used in extremely small quantities Check the Reference Electrode It is crucial to have a well established reference electrode contact It may be necessary to use large reference electrodes to ensure a high quality con nection Various samples of reference electrodes are pro vided with the system Test them to determine which is best for your application Uncoil cables Any cable carrying EMG signals electrode cables input module cables A D cables should be uncoiled and allowed to drape freely Cables that are arranged in coils act like antennae promoting the induction of line interfer ence Note that it is extremely difficult to eliminate all presence of line interference In most situations a residual amount will always be present due to the finite electrode CMRR and the imperfect electrical connections between the skin and the electrode contacts However with proper use of the EMG System this 37 residual amount should be insignificant and in most cases not detectable when compared to the amplitude of the EMG signal Problem Poor Electrode Skin Adhesion For best results it is recommended to use the Delsys Interfaces to attach t
23. electrode capable of subtracting signals perfectly would have an infinite CMRR The second condition is within the user s control and is attributable to most instances of excessive line interference It is crucial that the reference electrode and all the silver bars of the EMG electrodes make a high quality electrical connection with the surface of the skin Failure to establish a high quality connection will drastically increase the probability of observing line interference The following checklist should help in eliminating potential problem areas 1 Turn off surrounding power sources While it is gener ally not feasible to completely cut all the power in the ambi ent experimental area all electronic equipment not in use should be turned off The more AC power sources in the experimental area there are the higher the probability of line interference Pay careful attention to high current devices which radiate strong magnetic and electric fields such as motors transformers lights and equipment power supplies If a portable computer is being used it is advisable to discon nect the power supply as these tend to be quite noisy and run the machine from battery power for the data acquisition portion of the experiment 2 Check electrode skin contact Ensure that all the electrodes are aggressively attached to the skin The electrodes should not be easily dislodged when pulled by the connecting cables Any portions of the electro
24. eless transmission and onboard datalogging EMGworks Wireless Software on page 32 describes the details for the wireless oper ation and EMGworks Datalogger Software on page 23 describes details regarding the datalogger operation Consult the Release Notes that came with the system for additional information Using the stylus and the virtual keyboard The virtual keyboard can be usd any time it is required to enter information To show the virtual keyboard tap the pen icon in the task bar at the bottom right of the screen Computer ka Recycle Bin PC Connection EMGworks py Keyboard Wireless Hide Input Panel Tap Keyboard in the pop up menu 21 Text can now be entered by tapping the different characters individually To hide the virtual keyboard tap the Keyboard icon in the taskbar and tap Hide Input Panel 22 Myomonitor III EMG System User Manual EMGworks Datalogger Software The EMGworks Datalogger software is used to control the data acquisition process Two versions are available one for 8 chan nels and one for 16 channels of EMG data The data is stored on board and can later be downloaded to a host computer for analy sis The EMGworks Datalogger software is also equipped with signal acquisition protocols that can be defined by the user Pro tocols permit the automatic acquisition of multiple data sets without user intervention Before proceed
25. es Figure 12 illustrates the correct application of the Interface 15 NF D a 4 N electrode site Figure 12 Application of the Delsys Electrode Interface 1 Peel the top clear liner to expose the first layer of adhesive 2 Mount the interface on the electrode taking care to align the electrode contacts through the interface slots 3 Peel the white liner located on the bottom side of the interface to expose the second layer of adhesive 4 Attach the electrode to the desired muscle site on the skin surface Discard after using 4 EEE Cy Starting the Myomonitor Main Unit Start the Myomonitor by pressing the ON OFF button on the bottom panel of the Main Unit The first time you use the device you will have to start the applicable program from the desktop of the system by double clicking with the stylus The next time the device is used it will automatically launch the program last used For details regarding software operation see the Software section below 16 Myomonitor IIl EMG System User Manual Myomonitor Hardware Features Connecting to a PC computer Uy KE Consult the Release Notes that came with the system for Microsoft ActiveSync installation instructions prior to attempting to connect the Myomonitor to the PC To connect the Myomonitor to a PC computer first connect the Docking Module to the Main Unit Using the USB cable provided with the sys
26. he DE series EMG electrodes to the skin Alterna tively surgical tape may be used If the electrodes persistently fail to adhere to the skin the following points should be addressed 1 Clean and dry the skin lt is imperative that the skin be thor oughly cleaned before applying any type of adhesive Allow the skin to completely dry after cleaning Adhesive will not stick to wet or oily skin Be sure to remove all hairs under the observation sites This can be easily done with a safety razor or with commercially available hair removing lotions and waxes Remove dry skin cells The human body is constantly gener ating skin tissue New skin cells originate on the inner layer of the skin and grow outward towards the surface progress ing through several distinct layers and levels of activity By the time the cells reach the skin surface they become inac tive on a cellular level and are generally considered to be dead The body is constantly shedding this outermost cell layer as it is replaced by the new cells from underneath Since these inactive cells are easily dislodged from the skin adhesives tend not to function properly when placed in con tact with them To avoid this problem it is useful to remove the outermost layer of skin cells This can be easily done by lining the skin with strips of surgical tape When the tape is removed most of these dry cells will be dislodged This pro cess can be repeated until satisfactory electrod
27. he Nyquist criterion it is crucial that the sampling frequency expressed in Hertz be at least twice the highest frequency component of the signal being sampled in order to correctly capture all the information in the signal and to avoid aliasing The Bagnoli EMG Systems has a maximum bandwidth of 15 Hz to 500 Hz It is thus imperative that the sampling frequency be at least 1000 Hz Signal Clipping The non linear distortion of a signal due to excessive channel amplification for the given input signal Signal clipping on the Bagnoli EMG System is indicated by the HI LED warning light and can be observed when the output signals appear to be truncated at 5 Volts This phenomenon is almost always caused by amplifier saturation present either in the EMG System or the AD System The only solution is to 47 reduce the channel gain so that the output signals are within the 5 Volt specification Signal to Noise Ratio This is a mathematical technique used to express the energy of the EMG signal compared to the energy of the noise present The SNR is defined as Vemg Vnoise expressed as a unitless number or 20 log Vemg Vnoise expressed in dB Obviously the higher the SNR the better the quality of the recorded EMG signal Surfactant This class of substances are also called surface active agents or wetting agents and are used to reduce the surface tension of some types of cleaning solutions Their presence in certain
28. he local receptacles in use 10 Myomonitor IIl EMG System User Manual Figure 6 The universal input power supply 100 240 VAC 50 60 Hz Docking Module The docking module provides connections to the power supply and to the PC through the Universal Serial Bus USB It con nects to the top of the Main Unit For safety the docking module design prevents the EMG electrodes from being connected to the subject when the Main Unit is connected to external power or USB Figure 7 The Docking module 11 Getting Started with the Myomonitor System Please be sure to read the Release Notes that came with the sys tem before continuing with the instructions below These contain important additional information regarding the configuration and operation of the system Charging the Battery w Before using the system the battery should be fully charged Connect the Docking Module to the Main Unit Connect the External Power Supply to the electrical outlet and to the Docking Module see Figure 8 Figure 8 The Main Unit connected to the Docking Module and the Power supply for charging purposes The charging of the internal Li Ion Battery starts immediately and completes within 6 hours Delsys recommends that the device is left plugged into external power when not in use so as to keep the battery fully charged at all times Connecting the Input Modules D The Input Cable connects the Input Module with
29. ields 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 of the relevant room complies with the appropriate requirements and the equipment is used in accordance with the instructions for use 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 Myomonitor IIl EMG System User Manual consequential damages resulting from any defect failure or mal function 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 dis claimer DELSYS INC makes no diagnosis or prescription by virtue of anything about this product Limited Warranty The Myomonitor III Portable 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 specified power sup ply or input vol
30. ing in the document make sure that Microsoft AcitveSync has been properly installed Refer to the Release Notes for ActiveSync installation instructions Starting the Myomonitor Datalogger Software Double tap the EMGworks Datalogger icon on the Myomonitor desktop display to start the software Internet Computer Explorer o g Recycle Bin PC Connection EMGweorks Wireless EMGworks Datalogger Program Layout When the EMGworks Datalogger software is opened a new data acquisition session will automatically open as shown below 23 x gt Jo 1 x 5 0 Boob Re ee abt 5 0 ae i ae Time 0 100 sec div od emgce 2 6 19 pm AS File Menu Provides options for data acquisition and protocol management New Opens a new data acquisition session If data was recorded in the previous session the user will be prompted to save the data The new session will inherit the properties of the previous session by default Open Protocol File Allows the user to open an existing EMG protocol file epf or to create a new protocol See Using Data Acquisition Protocols on page 27 Close Protocol File Closes an open protocol Save Save As Saves the data in the data acquisition session When using a data collection protocol only the data for the current repetition can be saved In addition recording should be paused before attempting to save the data Note It is important to
31. irectory Opening an Existing Protocol 1 A 9 1 fF WO N Select File gt Open Protocol File The Open Protocol dialog box will open Find and select an existing EMG protocol file epf Tap OK The Protocol File dialog box will open If desired edit the protocol using the instructions from Cre ating a New Protocol on page 27 When the protocol is complete tap OK The Data Directory dialog box will open Select a location and type a unique folder Name The data from the protocol recording will be saved in this specified folder Each repetition will be saved as a separate file with its protocol set name and repetition number A copy of the protocol will also be saved in the directory 10 Tap OK Recording EMG Data with a Protocol Once a data acquisition protocol has been created or opened it is possible to begin collecting data Press the play P recording control at the top of the workspace or select Data gt Start to initiate data acquisition 29 If Yiew gt Protocol is checked the protocol status window will be displayed in the lower right hand corner of the screen and the current protocol set will be highlighted in blue as shown below x IGAKS ars emgce 2 1 12 AM E In addition the Myomonitor III will provide audible cues to indicate the protocol status It will produce a tone at the end of the recording for each repetition It will also count down the last five s
32. isition is running on the host computer and the network has been setup using the default parameters the Myomonitor III should instantly connect Please refer to the Release Notes if a connection can not be established EMGworks Wireless Fz El Myomonitor IIT Delsys Inc Version 1 0 0 1 Status Connected to 172 169 0 1 on port 49153 Settings 2 EMGwor 2 12 15 am A S The Myomonitor III is now ready and connected to EMGworks Acquisition The data acquisition is controlled by EMGworks 33 Acquisition on the host computer Refer to the EMGworks manual for details Setting up Myomonitor lll manually The Myomonitor III is configured to connect to the server appli cation at IP address 179 16 0 1 To meet specific end user net working requirements there may be reasons for changing the network settings Under those circumstances the address of the host computer must be set manually Chaging the Myomonitor settings manually is not a standard procedure and is not recommended To access Myomonitor s manual settings tap Unlock once to enable the Settings button and then tap Settings This opens Myomonitor s network setup dialog Target IP Address j 2 16 0 1 Command Port as153 Data Port as154 Control Pane 2 gt 0 12 03 aw AB e Target IP Address Specifices the IP address of the host computer e Command Port Do not change e Data
33. jr lt Duration sec Sample Rate sc 1 2 3 4 5 6 7 8 9 0 le u w e r tly lu Les Denes From the dropdown list select number of Channels to record the Sample Rate and type the desired Duration in seconds for the recording Tap OK to continue Initiate Data Acquisition Press the play P recording control at the top of the screen or select Data gt Start to initiate data acquisition Acquisition will automatically stop when the end of the specified dura tion is reached The other recording controls described in the Data Menu section on the previous page can also be used to control data acquisition 26 Myomonitor IIl EMG System User Manual 3 Save the EMG Data EMG data must be saved after it is recorded Select Fi e gt Save As choose the file location and type in the desired file name to save the data from the data acquisition work space Using Data Acquisition Protocols EMG data can be recorded with the Myomonitor III using struc tured data collection protocols These protocols consist of a number of protocol sets each consisting of a number of repeti tions with the same duration and the same rest time Creating a New Protocol 1 Select File gt Open Protocol File The Open Protocol dialog box will open Ope Application Data Program File My Documents Temp Network Windows profiles 2 emgce a 0 gt 12 02
34. lay a specified channel in real time Each configuration is available in 8 or 16 channels The Myomonitor EMG System is designed to make the acquisition of EMG signals hassle free and reliable The active electrodes are specifically designed to optimally detect EMG signals at the skin surface while rejecting common noise signals such as motion and cable artifacts yielding an excellent signal to noise ratio In addition the Myomonitor EMG System s portable design allows experiments to be conducted that would be impossible with conventional systems The Myomonitor III Portable EMG System is comprised of the following items 1 Myomonitor Main Unit 1 9V Power Supply 1 512 MB Memory Datalogger 1 USB cable 2m 1 WLAN Transmitter Wireless 1 Lumbar Pack 1 WLAN Receiver Wireless 1 Carrying Case 8 16 DE 2 3 EMG Electrodes 1 Reference Cable alligator 1 2 Belt mounted Input Module 1 Reference Cable tip 1 2 Input Module Cable 1 Package of Small Reference Electrodes 1 Docking Module 1 Package of Large Reference Electrodes 1 7 2V 4300 mAh Li Ion Battery 1 Package of Skin Interfaces Myomonitor System Components Main Unit The Main Unit powers the EMG electrodes and digitizes the EMG signal In Datalogging mode the EMG data are stored on internal flash memory 512 MB standard which will keep data secure even in the case of power loss In Wireless mode the EMG data are sent over the wireless l
35. least two samples BNC Bayonet locking coupling is a standard connector configuration providing quick connect and disconnect coaxial connections between instruments The conducting cable is completely surrounded by a flexible shield and insulated with specially designed dielectric materials BNC cables are commonly designed with a 50 ohm impedance Channel Crosstalk In the context of this manual this term is used to describe the electrical interference present in a particular channel as a result of the electrical signals present in other channels This situation may arise in physically adjacent channels and becomes more noticeable as the signal amplitude increases This problem may be resolved by lowering the channel gains Channels on A D cards with unconnected floating inputs will typically experience channel crosstalk or phantom electrical signals caused by signals in other channels This problem can be resolved by terminating all unused A D channels to the A D ground potential A D saturation may also cause channel crosstalk talk due to long recovery times of the internal A D amplifiers In this case it is necessary to ensure that the amplitude of the signals input to the A D card is never in excess of the A D card s rated specifications EMG Signal Crosstalk This term is specific to the EMG signals being recorded at the electrode site The EMG signal detected at the skin surface is a composition of hundreds of action
36. ocal area network WLAN to the host computer for storage and real time display The Main Unit is shown in Figure 1 The front of the Main Unit contains the touch screen where the application program is executed The top of the Main Unit has the connectors for the Input Modules and to the Docking Module For subject safety the design prevents the Input Module and the Docking Module to be connected at the same time The bottom panel of the Main Unit has the controls for Power on off and the reset button It also has the Trigger Connector the speaker and the status LEDs Figure 1 Tne Myomonitor Main Unit DE 2 3 Differential Surface Electrodes The differential electrode subtracts EMG potentials detected at two distinct locations on the surface of the skin directly above an active muscle The EMG potentials are always measured with Myomonitor IIl EMG System User Manual respect to the electric potential of a neutral site located away from the EMG muscle source The electrodes are designed using a parallel bar contact geometry for ensuring signal stability repeatability between recordings and optimal frequency content representation These versatile electrodes are well suited for most EMG applications ideal for both large and small muscles Figure 2 DE 2 3 Single Differential Surface EMG Electrode Input Modules Input Cable The Input Modules see Figure 3 host the EMG electrodes and the Reference Electrod
37. tage ranges specified by DELSYS INC or use with any other input devices other than DELSYS INC elec trodes constitute an invalidation of this limited warranty This warranty is not transferable All devices to be returned require a return authorization number issued by DELSYS INC All authorized returned merchandise must be shipped prepaid to DELSYS INC If authorization for the return of a device is given please insure the product in transit for any loss or damages that may occur Technical Support Visit our web site at http www delsys com Tel 617 236 0599 Fax 617 236 0549 A lr C A Myomonitor IIl EMG System User Manual IMPORTANT INFORMATION kek k k 2 Intended Usan orientan aa mak T Serkan eee kad ka d z 2 Warnings and PrecaUti OnS iiiiEE EEE kk k 2 DISCIAIN GD e Se DD es cat E E sl AEE AA 2 Limited Warranty cisi irnia a 3 Technical Support uEE kk kk kk kk kk kk kK KAYA 3 Myomonitor III Portable EMG System 7 General Description L kk 7 Myomonitor System Components cceeeeeeceeeeeeeeetteeeeeeenaaes 8 Main Witt aeea DD Aa be tiee i eave DD 8 DE 2 3 Differential Surface Electrodes 8 Input MOdUIeS S riaa aaan dEi 9 Input Cable i iret Gala aa daa aea 9 Reference Electrode Cable EEE 10 Power SUDD V ceii nina diene ked raa eee 10 Docking Mod le s lt sun cik ken aha a A MP 11 Getting St
38. tem connect the Docking module to a free USB port on the host computer Power and Reset To activate the Myomonitor press the On Off button This will bring the device from the Suspended state to the active state Press the On Off button again to suspend the device Power to the memory is still maintained in the suspended state so that user settings are preserved To reset the device push the reset button on the bottom panel of the Main Unit using the stylus This will reset the device clearing the memory on the device To bring the device back to the factory state you should perform a cold reset From the active mode press the On Off button With the On Off button depressed push the reset button with the stylus A succesful cold reset is indicated by the initiation of the touch screen calibration Follow the instructions on the screen to complete the calibration Trigger Connector The trigger connector on the bottom panel of the Main Unit allows the user to input and output triggering signals to manage and synchronize data collection The four trigger signals are Start In Initiates data collection on a 5V rising edge Stop In Ends data collection on a 5V rising edge Start Out Outputs a 5V rising edge once data collection is initiated Stop Out Outputs a 5V rising edge once data collection is stopped 17 Battery The pinout diagram of the trigger connector is shown in the table below
39. the electrode contacts The EMG potentials on the contrary change drastically as they propagate between the electrode bars Ideally the result is a differential EMG signal with a complete subtraction of the line interference refer to Figure 14 b electrode output voltage source vo fH feta i yi v N displacemeni line interference j current Figure 14 a The source of line interference in recorded EMG j signals Displacement current flows along the surface of the bos ll capacitive skin due to capacitive coupling between local AC voltage T F sources and ground The subtraction of power line induced _ coupling to 8 P ground voltages with a differential electrode 35 Line interference becomes overwhelmingly apparent if either of the following conditions arises a the electrode does not subtract signals in an ideal fashion b the quality of one or more electrode skin contacts becomes compromised The interference will appear as a high amplitude cyclic signal with a frequency of 60 Hz for North American AC sources or 50 Hz for European Australian and other international AC sources The first condition is intrinsic to the construction of the electrode preamplifier The parameter used to gauge the electrode s ability to subtract signals ideally is called the common mode rejection ratio CMRR and is measured in decibels Most surface bio potential applications require a minimum CMRR of 80 dB An
40. the play P recording control Rewind Erases all data in the session In the case of an active protocol only the current repetition will be erased This function can be accessed directly from the rewind 44 recording control at the top of the session workspace Data acquisition can be resumed by selecting Data gt Start or pressing the play P recording control Properties Opens the EMG Properties dialog box This allows the user to specify the number of channels of EMG data to acquire and the duration of acquisition in seconds Note that properties can only be changed before recording is initiated External Trigger Synchronizes start of data acquisition with an external input After selecting External Trigger press play 25 gt or select Data gt Start to begin data collection The program will wait for the rising edge of a 5 volt signal on the trigger input to begin data acquisition Reset Re initializes the Data Acquisition hardware Recording EMG Data There are three simple steps for recording EMG data 1 Change the Recording Properties There are two properties that must be set for an EMG data recording These properties can only be set before the recording is initiated If they are not set the properties that were specified for the previous recording will be used by default Select Data gt Properties to display the EMG Prop erties dialog box as shown below EMG Properties Channels i
41. tial While the Delsys EMG systems and electrodes are specifically designed to be insensitive to fluctuations in DC skin potentials complete immunity to motion artifact is impossible The following points should be addressed when excessive motion artifact is present 1 Strong electrode skin adhesion Ensure that the electrodes are robustly attached to the skin It is crucial that there not be any electrode movement with respect to the skin at the recording site Delsys Electrode Interfaces are specifically designed for this purpose See the Troubleshooting section on Poor Electrode Skin Adhesion if this is problem 2 Provide sufficient cable slack lt is important that the elec trode never be tugged by its cable Some movements throughout an experiment may result in electrode cable ten sion Take care to provide the necessary relief from cable tension so that the electrode is not disturbed in any way 3 Minimize jarring motions Some types of activities such as jogging may cause vibration of the tissue located at the recording site If possible keep these activities to a mini mum or modify them so as to reduce tissue vibration 4 Keep clothes clear If electrodes are being used underneath loose clothing ensure that body movements do not cause the clothes to disturb the electrodes or the skin in their vicinity Note also that many fabrics can build high electrostatic charges which may pose operational problems for the elec
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