National Instrument TTL-DAQ DEMO1
Contents
1. SOFTWARE DEMO VI FOR USER APPLICATIONS physiological signals The provided demo VI may also be adapted by the user to acquire process and display signals for other physiological sensors Programming Walkthrough of TTL DAQ DEMO VI Going to the back panel note the VI is structured into 3 distinct parts an initialize sequence a main loop and a terminate sequence The program begins by initializing the DAQ hardware according to various pre defined settings and the physical channels defined by the user Here certain program variables and arrays are also initialized g B TTL NI cDAQ Demo Mode O g Main Tab Control Raw and Filtered Data Arra Display Array Indexes Polar EKG Heart Rate CH1 Display array Sound file path ecg current peak E e P i m boxing bell wav 1 CH2 Display array und task ID CH3 Filtered CH3 Display array G Tab Control 1 CH4 Display array In the main loop a nested sequence structure executes a series of tasks inside a while loop We start with acquiring the raw data from the DAQ fPlayback Moder f f DAQ CH2 p fttask out gt f pepe DAQ CH3 Then we scale the raw data according to the user selected sensor type The sub VI TTL Sensor Type vi is available in the project folder and provides the mapping required to turn raw DAQ acquired voltages into meaningful sensor units for all Thought Technology sensors Context Help El POOODOODOODOODOOODOOOOOOOOODO2. most heavily processed signal Filtering options can be defined by the user while running the VI Custom filtering Vis provide up to three cascaded Butterworth filters to be applied to the data array and the result is sent to another custom VI that performs an RMS averaging on the data array CHI Filter Setup Filter 1 Magnitude Plat Filter 2 RMS CH1 RMS Averaging 5 Peak Indicator The filtered data array is also sent to a custom FFT averager that processes and then displays the result CH1 Process FFT FFT averaging parameters Finally the data array is placed in the display array where a sliding window plots a segment of data to the front panel CH1 Display Data EMG Signal Waveform ELE gt A CH1 Display Index gt CH1 Display array EMG Signal Waveform ibe Signal i a Select data to displa Put NewSample in the Display arra For the remaining channels some processing is typically required to extract meaningful parameters For CH2 s Polar heart rate signal nested sequence frame 3 we compute the time interval between peak pulses based on the number of samples and sampling rate The computed instantaneous HR value is averaged with the results of the 10 previous values and then displayed On CH3 the temperature sensor nested sequence frame 4 the raw signal is scaled a low pass filter at 3HZ is applied and the resulting signal is then displayed As for the respiration sensor on CH 4 ne
3. ODOOOOOODOOOODOOOOODODOOOOOOoOoOnDnonoonoOonnDoooononooooo 4 1 10 2 vpPRGBOOoOoon ono oneAoAoAnA oy TTL Sensor Type vi InputDataArray OutputDataArray Offset z 5 Unit Gain Sensor Type Panel Name TTL Sensor Type Mounu TR TTT TRE TSE TR TRY TR OeTR TR TAIT TE Ta TST TEC TRE TRC TR TA TACT ae Tae nu gununu 0 6 gt pepe RTT TT TTT ee Scaling DAQ Acquired Data Read scaled data files VI Description Select appropriate Sensor Type to scale InputDataArray and obtain OutputDataArray with the corresponding sensor Unit type If Generic Sensor is selected the Gain and Offset inputs OSE CTE ISO DEO TODE TOTO ROOST ORT TOTOTTITIM SRE ICS BE FSC GE BOSS BEEOSOBETOSOSTESSOSOETR will scale the InputDataArray as desired By default Gain is 1 and Offset is 0 Acquisition Mode Scale DAQ Data S71 lt fDAQ CH1 gt e181 CH1 Sensor Type sish abet nye gt ACHI Raw ADAQ CH2 gt A Playback Mode gt CH2 Sensor Type DIN ANPE j kl TL leis TPE j ADAQ CHL gt ADAQ CH2 ADAQ CH3 CH3 Sensor Type Labet ADAQ CH4 gt 2 nnn nnannnnnnnnnnnunnnnnannnnnunnnnunnnnannnnnunnunnunnnnnunnnnunnnnnunnunnnnnnnnnnnunnn ununun nnunnnunnnnnnuNnNunNnEnnNNEnNnnNEmMmNU stop DoOOUUUUUDUD ODDO DDO In the nested sequence frames 2 5 each frame is strictly devoted to the processing and display of the 4 signal types As an example we can look at CH1 EMG Of the 4 signal types this is the
4. P 4 JG ence ivision NougNtE fecnnology Lita TTL DAQ DEMO National instruments USEnAPPICIUOMINOtE Measure More Sense Better TTL DAQ DEMO Application Note for National Instrument User Pnr Thought Technology Ltd 8205 Montreal Toronto Blvd Suite 223 Montreal West Quebec Canada H4X 1N1 Tel 800 361 3651 514 489 8251 Fax 514 489 8255 E mail mai thoughttechnology com Webpage www thoughttechnology com sciencedivision index html Thought Technology s Science Division provides researchers and biomedical engineering students a reliable and accurate way to measure important bio signals using our physiological sensors along with National Instruments data acquisition DAQ system and LabVIEW software Visit our website for more information regarding technical notes for sensors and solutions as well as application notes for other third party devices For a quick summary of this application note please consult the following videos e TTL DAQ DEMO VI Interfacing Thought Technology Sensors with National Instruments NI cDAQ 9172 and LabVIEW Hardware Setup Tutorial http Awww youtube com watch v WvlivFKWlel e TTL DAQ DEMO VI Interfacing Thought Technology Sensors with National Instruments NI cDAQ 9172 and LabVIEW Software Demo Tutorial http Awww youtube com watch v VgnoxnXmL60 This application note will provide the intended user s with step by step inst
5. aking the wired connections from the TT Sensor Isolator to the DAQ input For screw terminal and spring terminal connector inputs we recommend the DB15 to pigtail break out cable SA9409PGT As an alternative the users may also prepare two 3 5mm stereo to pigtail break out cables See User Manual Sensor Isolator SE9405AM for details For BNC connector inputs we recommend the DB15 to BNC break out cable SA9409BNC Making Interface Connections For demonstration purposes we used the NI 9215 module screw terminal option with NI CDAQ 9172 CompactDAQ chassis This DAQ setup provides 4 differential analog inputs at 16 bit resolution with an adjustable input range of up to 10V select software to use 5V Many other NI DAQ systems are available and are equally compatible See the previous section Choosing Your NI DAQ Device for selection guidelines The following steps detail the physical connections for setting up the 4 predefined physiological sensors with the TT Sensor Isolator SE9405AM and connecting them to a typical NI DAQ system 1 Connect each of the 4 physiological sensors to the TT Sensor Isolator using the provided sensor cables in the following order Input CH1 MyoScan EMG Sensor Input CH2 EKG Receiver for Polar Heart Rate Input CH3 TT Infra pIR Temperature Sensor Input CH4 Respiration Sensor a m Note Align the white dot on the cable with the notch on the connector 2 As
6. com white paper 3344 en 4 Connect the provided power adapter to the TT Sensor Isolator to supply the output side of the unit Ensure the 9V battery inside the unit is functional supplies power to the sensor side by turning the TT Sensor Isolator ON A bright blue light should turn ON SETUP OF TTL DAQ DEMO VI IA YS ACQUIRING AND PROCESSING PHYSIOLOGICAL SIGNALS 1 Download the TTL DAQ DEMO project from www thoughttechnology com sciencedivision media TTL_ DAQ DEMO zi 2 Unzip the folder Find and open TTL DAQ DEMO lvproj 3 Connect each physiological sensor to a participant subject s body following the methods described for each sensor in their respective Technical Notes series 4 Open TTL DAQ DEMO vi and click on the Setup tab Under NI Acquisition Hardware select the appropriate DAQ device and input choices for Physical CH1 to CH4 These choices should also correspond to the sensors connected to CH1 through 4 MyoScan Generic Sensor TT Infra piR deg C Generic Sensor Polar EKG Recetv TT infra pR sensor senerc any sent 5 Run the demo VI A pop up window will appear Ensure Playback Mode is unselected and then click Start If Playback Mode is selected no hardware setup Is required and the demo VI will display pre recorded physiological signals 6 Examine each signal tab as live physiological signals are acquired and processed from a participant subject A Generic Sensor ADAPTING
7. ct Additional accessories NuPrep 10 30 conductive gel 10 20 4T UniGel electrodes 13425 with extender cable T8720M or Triode electrode T3402M EKG Receiver for Polar SA9330 The EKG Receiver detects the heart rate of a user from the Polar transmitter belt T31 T31c and WearLink not provided that the user wears around the chest Note that Polar transmitter belt T31 T31c or WearLink is not provided by Thought Technology and must be purchased separately pIR Sensor T2600 The pIR sensor is a passive infrared temperature sensor for measuring radiated temperature in the infrared range It is used to measure the changes in forehead temperature when attached to the pIR HEadGear Respiration Sensor SA9311M The respiration signal is a relative measure of abdomen expansion The Respiration Sensor is a sensitive girth sensor using an easy fitting high durability latex rubber band fixed with self adhering belt It detects chest or abdominal expansion contraction and shows the respiration waveform and amplitude It can be worn over clothing e Minimum system environment Core 2 Duo 1GB RAM Windows 7 Vista XP SP3 e Requires LabVIEW version 11 0 1 or later to explore or modify project files If you wish to only run the executable of the demonstration provided visit www ni com to download and install Lab VIEW Run Time Engine 2011 LVRTE201 1f3std exe e Requires DAQ mx driver to be installed if ac
8. cy and RMS Averaging window size to generate QutputRMSArray Signal multiplier allows output data to be scaled and is by default 1 Reset flushes the contents of internal buffer This VI is reentrant and maintains the state of each instance This VI is for demo purposes only FFlaverager vi FFT averaging parameters Reset InputDataArray Signal Multiplier Sampling Frequency Hz FFT Frequency Resolution Hz dB On F Window Type SpectrumWindow Progress Bar FFT Butter Size FFT Samples Available Panel Name TTL FFT Averager VI Description Computes magnitude FFT on InputDataArray Requires FFT averaging parameters Sampling Frequency and FFT Frequency Resolution to generate OutputSpectrumWindow Signal multiplier allows output data to be scaled and is by default 1 dB On specifies whether the results are expressed in decibels the default is FALSE Reset flushes the contents of internal buffer This VI is reentrant and maintains the state of each instance This VI is for demo purposes only SANO0O001 00 Application Note for National Instrument User
9. mentioned the NI DAQ module we are using has a screw terminal connector Therefore choosing the DB15 to pigtail break out cable SA9409PGT we will make the wired connections from the TT Sensor Isolator to the screw terminal on the DAQ inputs Connect the DB15 cable to the TT Sensor Isolator On the pig tail end connect CH1 signal to Al0 and ground to Al0 Keeping in mind it is preferable to make each connection in a logical sequence connect the remaining 3 channels 3 The output side of the TT Sensor Isolator is considered a floating source and is supplied by the provided power adaptor The voltage on the output side SIG lines will span 2 8 2V relative to the GND lines All output side GND lines are tied together Many NI DAQ systems except ones with internal biasing circuits require the user to place external resistors for biasing each analog input This is required in the setup to ensure proper measurement of the desired signal and reduce unwanted noise pick up The following diagram shows the electrical configuration of the external resistors Physically these resistors can be placed directly across the inputs on the DAQ connector block If Al GND is not available use the COM input External resistors are needed in either DAQ input configurations differential or single ended non referenced TT Sensor Isolator NI DAQ SYSTEM adenice source see Field Wiring and Noise Considerations for Analog Signals http www ni
10. quiring live signals from NI DAQ hardware Playback mode option is available to simulate acquisition of physiological signals without use of sensor or NI DAQ hardware INTERFACING THOUGHT TECHNOLOGY SENSORS WITH NATIONAL INSTRUMENTS DATA ACQUISITION SYSTEM Choosing Your NI DAQ Device National Instruments provides a wide selection of PC based DAQ devices and modular systems The following recommendation serves as our general guideline for ensuring the specified performance for all Thought Technology sensors Recommended Specifications for DAQ Hardware e Recommended resolution of 0 15mV 16 bit ADC over 10V span or better e Minimum input range 5V bipolar via SE9405AM TT Sensor Isolator For applications involving EEG or EMG signals the recommended specifications are required For other applications the user may choose a lower resolution DAQ device This is acceptable depending on the user s required resolution if Known the nature of the acquired signal and the type of signal processing to be done Examples of sensor signals that may be compatible with a lower resolution 14 bit DAQs are Polar EKG HR BVP respiration and goniometer bend sensor InclinoTrac and force sensor Selecting an Interface Cable Most NI DAQ devices are available in one of the following I O connector option screw terminal spring terminal or BNC Based on your I O connector option you will need to choose the appropriate interfacing cable for m
11. ructions on how to e quickly and safely interface Thought Technology sensors to a National Instruments DAQ system e set up the provided software demo VI to acquire and process live physiological signals such as EMG heart rate temperature and respiration e adapt the provided software demo VI for your applications The following Thought Technology products will be used in this demonstration We strongly encourage you to review each product s technical note for detailed specifications and user guidelines Additional accessories e g power adaptor cables skin prep conductive gel electrodes Polar transmitter belt will also be needed to properly carry out this demonstration TT Sensor Isolator SE9405AM The Sensor Isolator is an interface device which A EX provides electrical isolation 4 5kV providing two pee gt e means of protection It allows Thought Technology sensors to be safely interfaced with analog inputs of line powered systems such as computers with DAC cards Additional accessories SE9408 power adaptor SAI409BNC SA9409PGT or two user supplied 3 5mm stereo male to male cables and 9V battery MyoScan EMG Sensor T9503M EM oScan Pan Ltd The MyoScan sensor is a differential amplifier for surface electromyography SEMG Surface EMG is a non invasive measure of underlying muscle activity by detecting and amplifying tiny electrical impulses generated by muscle fibers when they contra
12. sted sequence frame 5 no processing was developed The raw signal is simply scaled according to the mapping selected by the user and provided by the TTL Sensor Type VI The scaled signal is then displayed Should the user wish to replace the attached respiration sensor for a different sensor the proper scaled signal can easily be selected and the resulting waveform will continue to be displayed In the nested sequence frame 6 the display data from each of the previous sequence frames is synchronously updated to the 4 display graphs in the BioSensor DEMO tab Update BioSensor Demo Tab EMG Signal Waveform 2 EMG Signal Waveform gt Hibesi EKG Signal Waveform 2 REKG Signal Waveform Hei TT pIR Waveform 2 bet Respiration Waveform 2 o Finally in the terminate section we close the DAQ resource and any other resources that were previously opened A Playback Moder 3 Release sound device gL ftSound task ID KA Reusable Vis From This DEMO The TTL DAQ DEMO vi has demonstrated how to easily acquire scale and display Thought Technology physiological signals in LabVIEW using non specific NI DAQ systems The challenge that remains for the user will be to develop their own application specific processing algorithms for each of the different physiological signal required in their setup There are 5 subVls available from the demo project folder They may serve as a helpful starting point for users interested in developing
13. their own applications and may be reused or modified OutputDataArray Unit Panel Name TTL Sensor Type VI Description Select appropriate Sensor Type to scale InputDataArray and obtain OQutputDataArray with the corresponding sensor Unit type If Generic Sensor is selected the Gain and Offset inputs will scale the InputDataArray as desired By default Gain is 1 and Offset is 0 CreateFilter vi Filter 1 input ig Magnitude vs freq Filter 2 input Phase vs freq Filter 3 input TR Filter Cluster 1 Sampling Frequency Hz A IR Filter Cluster 2 Plot Filter Fanere OR Filter Cluster 3 Fanel Name TTL Create Filter VI Description Computes coefficients for three cascaded butterworth filters based on the selected filter settings and sampling frequency Plot Filter generates a magnitude and phase plot for display This VI is for demo purposes only FilterData vi InputDataArray IR Filter Custer 1 IIR Filter Cluster 2 IR Filter Cluster 3 FilteredDataArray Panel Name TTL Filter Data VI Description Applies cascaded filters to InputDataArray All inputs are required This VI is for demo purposes only OutputRMSArray RMS Samples Available AC estimate Vrms DC estimate W Signal Multiplier Sampling Frequency Hz RMS Averaging s Panel Name TTL RMS Averager VI Description Computes a sliding window rms on InputDataArray Requires Sampling Frequen
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