Flow-Dop - GAMPT mbH
Contents
1. With the switch 9 the transmitted ultrasonic frequency can be selected The frequency selection switch has 3 settings 1 2 and 4 MHz gt To obtain a Doppler signal the frequency of the used ultrasonic probe must correspond with the frequency selection switch setting 2 2 Flow Dop GAMPT 50100 Rear Panel ial O M E Figure 2 rear panel with connectors left parallel port right USB port Attach the power cable to the power socket on the left side of the rear panel The fuse is located in the power socket gt Notice Please follow the voltage and power specifications on the device Connect the data cable to the parallel port or USB port of the device on the right side of the rear panel and the parallel interface or USB interface of the computer Use a DB25M M cable 25 pole male male or an USB device cable Components 2 3 Ultrasonic Probe standard GAMPT 10131 10132 10134 The standard probes are suitable for wide range employment Because of the higher frequency the axial and lateral resolution power is evidently better for 2 and 4 MHz probes compared to the 1 MHz probes On the other hand the damping of 2 MHz compared to the 4 MHz sound in most materials is not yet too large so that investigations in middle depth can be obtained easily With the different probes it is possible to show the dependence of the Doppler shift on the transmitter frequency Technical specification Frequency 1 2 42. MHz Size l 70mm d 27mm cable Im Sound adaptation to water acrylic Special plug connector with probe identification for connection to GAMPT Scan or universal plug connector BNC gt To obtain a Doppler signal the frequency of the used ultrasonic probe must correspond with the frequency selection switch setting I MHz GAMPT 10131 blue 2 MHz GAMPT 10132 red 4 MHz GAMPT 10134 green 2 4 Ultrasonic Probe for the Arm Dummy GAMPT 50135 The ultrasonic Doppler probe with a frequency of 2 MHz is especially designed for measurements with the arm dummy The pencil form and the small probe area result in a good handling and an adequate local resolution The delay line with a determined angle of 30 is responsible for a constant Doppler angle and a significant Doppler frequency shift So a quantitative analysis to determine the flow velocity is possible Technical specification Frequency 2 MHz Size I 200mm d 15mm cable Im Special plug connector for connection to FlowDop Delay line angle 30 sound velocity 2700m s gt To obtain a Doppler signal the selection switch setting must be 2 MHz Software The software is complemented and updated constantly For the newest update please contact the com pany GAMPT mbH at info gampt de In the following documentation the software FlowView in the version number 1 3 is described Other versions can show some deviations 3 1 Introduction The software FlowView is a measur
3. the current values during the measurement In the bottom lines current parameters and results are shown Before starting a measurement some parameters are needed Selecting parameter will open a window to feed in these values see chapter Parameter The button begins a measurement The button export jpg is enabled during and after a measurement It can be used to save the actual shown win dows as jpg images After pressing the button a dialog will ask for the filename With the program will end The text beside the button shows the current status of data transfer When the text 1s red the simulation mode is active otherwise the text is green With a mouse click on this text only available when no measurement is running or the menu item preference data transfer the data transfer can be changed Software 3 3 Data Transfer By selection of the menu item preference data transfer in the main window the data transfer window will open data transfer data transfer data transfer refresh refresh refresh data connectio data connecta data connecta um USB wm USB USB parallel port numbe parallel port numbe USB 2 Adapter not found LPT 1 LPT 1 wT switched to simulation C LPT LPT4 USB adapter into no info i LPT 2 parallel port mode EFF C non EPP LFT 1000 port open no connection to device 13 unable to connect ta LPT check cable device off hot configured or enabled no halff
4. EDUCATION Pulse Doppler Flow Dop GAMPT 50100 User Manual Gesellschaft fur Angewandte Medizinische Physik und Technik mbH GAMPT mbH Hallesche StraBe 99F Fon 49 0 3461 278 691 0 06217 Merseburg Fax 49 0 3461 278 691 101 Germany email info gampt de powanie ULTRASONIC SOLUTIONS Revision 1 1 March 2007 with software version 1 2 Revision 1 2 February 2008 with software version 1 3 Revision 2 0 February 2009 with software version 1 3 with selectable frequencies 1 2 4 MHz All rights are reserved by the GAMPT mbH No part of this manual may be copied reproduced translated or transmitted in any form without permission of the GAMPT mbH The GAMPT mbH does not assume responsibility for damages as a result of false use as well as repair and changes which are carried out from third not authorized by the GAMPT mbH Technical and software changes reserved Errors and omissions excepted Copyright GAMPT mbH Hallesche Stra e 99F 06217 Merseburg Germany Phone 49 0 3461 278 691 0 Fax 49 0 3461 278 691 101 info gampt de e www gampt de 1 Introduction 4 2 Components 5 2 1 Flow Dop GAMPT 50100 Front Panel 5 2 2 Flow Dop GAMPT 50100 Rear Panel 6 2 3 Ultrasonic Probe standard GAMPT 10131 10132 10134 7 2 4 Ultrasonic Probe for the Arm Dummy GAMPT 50135 y ar Software 8 3 1 Introduction 8 3 2 Main Window 8 3 3 Data Transfer 9 3 4 Parameter 10 3 5 Start a Measurement 11 3 6 Additional Window
5. In the Doppler spectrum we estimate two values f max and f mean f max is the highest occurring frequency in the spectrum over the noise level This frequency represents the fastest particle in the flow green line f mean represents the centre of the occurring frequencies blue line The estimated results are shown in the bottom result lines The program measures up to 12 values per second for f mean and f max All these values will be shown in the additional windows see below In the bottom result lines we work with average values Outgoing from f mean the speed and flow values are calculated The stan dard deviation gives the statistical error for the average and 1s valid for f mean and all derived measures gt When there is a pulsatile flow the statistical error will strongly increase depending on the frequency change during the averaging interval The ratio f max f mean can be helpful to describe the flow Laminar flow profiles have another ratio than turbulent flows The signal intensity is a measure of the energy in the back scattered signal When the signal intensity is less than the lower limit further frequency calculation is stopped see chapter Parameter The shown value will be red gt Keep in mind that the intensity value is calculated from the signal values shown in the left diagram and these depend on the adjusting of the gain The resistance index RI should help to describe the resistance in a pulsatile circulation f
6. adapted With help of the incident angle and the given sound velocities the Doppler angle can be calculated Together with the Doppler equation we can calculate the speed from the estimated frequency Knowing the speed we can calculate the flow For this we need the cross section of the tube To calculate it out of the diameter of the tube or pipe we assume a circular cross section The signal intensity is a measure of the energy in the back scattered signal It is calculated as the mean of squares of the signal values A small integral value shows that there are less or small scatterer in the sample volume To avoid error measures there is a lower limit for the intensity When the measured intensity is less than this limit the program assumes there are no moving scattering particles and stops further calculation Maybe you have to adapt the lower limit value for special measurements like profile measurements with small sample volume When changing the used incident angle or tube the user has to tell it the program Otherwise the calculated values for speed and flow are wrong You can change the parameters during a measurement 10 Software 3 5 Start a Measurement A measurement will be started with the button Then the following picture will be shown The but ton changes to stop with it the measurement can be finished With the button on the right side the measurement can be interrupted break will change to continue It is no
7. e not connected the program switches to simulation ol mode You get a message window In this case you have to restart the pro gram or check again the connection in the data transfer window i LPT 2 i non EPP OF data connection checked Software 3 4 Parameter To calculate speed and flow from the frequency value we need parameter 4 x sound velocities 1480 4 delay line acrylic mis 2700 4 a angle 5 lt gt quid medium m s incident angle preselection angle ar Par C 60 Doppler angle Inner diameter tube pipe 6 35 4 _ a diameter mm preselection diamete A C aa C 7 mm C 10m et 16 mm cross section mr 31 87 4 r signal intensity signal intensity lower limit 1000 es 50 a Close some parameters These are the Doppler angle and the cross section ofthe used tube or pipe The Doppler angle depends in first line on the incident angle of the sound beam In reason of the law of refraction the incident angle is not the Doppler angle To calculate the Doppler angle we need the sound velocities of the involved materials The first material is the acrylic Doppler prism Cacrytic 2700m s The other one is the used liquid here water Cwate 1480m s The Doppler prism allows three incident angles you can change it with the preselection When other materials or delay lines are used the parameters have to be
8. end diastolic minimum value In the diagram we can estimate equivalent frequency values for vs and vp see brown horizontal line The resis tance index can be calculated i H H i y in Keep in mind that the resistance index makes At sec only sense in a pulsatile circuit BSE ests es alle When there is a pulsatile flow the pulse fre quency can be estimated For this we calculate the spectrum of the 10 sec section When there is a stable pulsatile flow we get a peak with the searched pulse frequency When there is no pulsatile flow a pulse calcula tion and the appearance of this window make no sense u 1 2 3 4 5 B frequency Hz 12 Technical Details 4 Technical Details 4 1 Power Supply Power supply Europe 230V 50Hz USA 115V 60Hz Fuse Europe T250mA 250V USA T500mA 250V 4 2 Measurement Range Resolution Gain 10dB 20dB 30dB 40dB Transmitter power Low 2us Burst High 4us Burst Sample volume Small 2us receiver gate Large Full receiver gate ca 32us 4 3 Display optical display of Doppler signal amplitude Acoustical Doppler signal 4 4 Software FlowView with driver for communication via parallel interface for Win9x Me WinNT 2000 XP optional via USB adapter 4 5 Cleaning Do not clean sensors with sharp detergents do not dip into water Clean the control unit only with a damp cloth 13
9. f switched to simulation switched to simulation The FlowDop can be connected via parallel port LPT 1 4 or using the USB adapter Please select at first the type of data connection Pressing the button will try to establish a connection When there is a problem with it you get a red message in the bottom window part The program will switch to simulation mode and stay there until a correct connection can be realized In the message you get a hint of the probable reason for the prob lem When you selected the LPT mode you have the choice between the EPP or non EPP mode The EPP mode has a better performance faster data transfer but not all PC especially notebooks can support this mode Then you have to select the non EPP mode Before using the USB connection the adapter driver has to be installed For this insert the delivered CD connect the USB adapter to an USB port and follow the instructions When the connection was checked and no problems occur you get the information as green text in the bottom line By pressing the pro gram goes back to the main window and you can start a measurement The information text in the main window is now green and shows you the se refresh lected transfer type LPT or USB SEES The program stores the selected transfer type and checks t each time you LPT C USB start the program and before a measurement In case of a problem i e the parallel port numbe device is off or cabl
10. ge 32us With the turning knob 4 the volume of the Doppler signal audio output with the built in speaker can be ad justed gt The audio signal serves only for orientation and control purposes during the measurement because its am plitude depends on the frequency and might falsify the Doppler frequency The measuring probes are connected at the socket 5 The same socket will be used in the GAMPT A Scan echoscope Therefore the standard probes 1 2 or 4 MHz of the echoscope experiments can also be used for the Doppler experiments The light bar 6 shows the amplitude of the current Doppler signal gt The display serves only for a rough orientation Exact results can only be obtained by the software The multiple switch 7 has 32 positions to vary the time position of the receiver gate This switch has only a function with the SAMPLE VOL switch in position SMALL The minimum time position of the gate is 4 us That is equivalent to a distance between probe and measurement volume of 6mm in water or a depth of 10mm in acryl The position can be varied in steps of 0 5us up to a maximum distance of 19 5us or 30mm in Components water or 50mm in acryl So one can measure the frequency velocity distribution in a tube by varying the posi tion of the sample volume inside the tube Use the smallest possible sample volume with the POWER switch in position LOW and the SAMPLE VOL switch in position SMALL
11. ing program for the Flow Doppler Before starting the program connect the Flow Doppler device to the PC via the parallel port LPT optional you can use the USB adapter The program has a simulation mode When there is no connection to the device or the device s switched off the program will go automatically into this simulation mode To leave the simulation mode you have to establish a data connec tion see also chapter Data Transfer 3 2 Main Window After starting the program the ma n window appears FlowYiew AE x File preference about al aunnnnnennnennnennnnennneee n data transfer i nar parameter 7 time course 0s section pulse Petra Simulation iti signal amplitude m Doppler amplitude spectrum mY 500 100 t a 0 20 40 60 80 8000 6000 4000 2000 0 2000 4000 6000 sono Time ms Frequency Hz o gt tube diameter mm 352 speed cm s incident angle 60 0 flow l min f max Hz f mean Hz signal intensity 1000 s measured values f max f mean Resistance Rl 2 25 st dev calculated values 2 The main window will always be aligned to the top of the screen The window can be resized by moving the bottom window border This can be helpful when additional windows are shown The menu line and the button panel at the top serve to start the measurements select different parameters or show additional windows The two diagrams show
12. or more detailed infor mation see also 3 5 10 sec section 11 Software 3 6 Additional Windows Depending on the windows selection in the upper main window additional windows in the bottom part of the screen can appear time course grayscale color level width E 4 00 4 a inverted The first of them is the time course window Here we see the Doppler spectrum grey or colour scaled The frequencies are shown in y direction the amplitude of the frequencies in the spectrum are colour scaled The x axis represents a time LE section The diagram shows always the last sec 3000 onds of a measurement in the picture beside this 2000 are 10 sec The length of the time section can be roen changed by using the arrows below 1000 The colour values can be changed in the upper 2000 area Thereby the slider works similar to the pees level width window technique well known from 0 2 4 6 8 ia f different medical applications like computer At sec tomography The special values f max and f mean are distinguished in own colour values 10 sec section f sustole 2747 Hz f diastole 653 Hz frequency Hz 4000 In the 10 sec section we see always the last 10 sec of a measurement The values for f max and f mean are shown separately Here we can also explain the resistance index RI It s defined as Pourcelot RI v SO x D Vs t with vs as highest speed during systole and vp as
13. ream These frequencies and the velocities and flow values calculated of these data are displayed on the screen as values or as time curves respectively Additionally the energy content of the signal is displayed Further evaluation functions are the representation of the spectrum with colour coded intensities over the time range or the examination of the pulsa tility of the flow By varying the sample volumes information from different layers of the stream can be obtained In that way the velocity and concentration profiles can be built Components 2 1 Flow Dop GAMPT 50100 Front Panel ULTRASONIC UNIT SAMPLE VOLUME AUDIO POWER Ka 30 100 f7 I 1 VOLUME gaMPT ULTRASONIC SOLUTIONS FREQUENCY MHz TT lo 055 SIGNAL 9 6 7 8 Figure 1 Front panel with control and display components Use the power button 8 to switch on the device The switch lights up green when the device is on With the switch 1 the gain of the received Doppler signal can be adjusted There are four gain steps 10dB 20dB 30dB and 40dB with a maximum difference of 30dB or 31 times magnification The two switches of the area SAMPLE VOLUME are designed for the adjustment of the measurement region The POWER switch 2 varies the transmitter burst length between 2us LOW and 4us HIGH With the switch SAMPLE VOL 3 the receiver gate can be switched between 2us SMALL and LARGE full ran
14. s 12 4 Technical Details 13 4 1 Power Supply 13 4 2 Measurement Range Resolution 13 4 3 Display 13 4 4 Software 13 4 5 Cleaning 13 Introduction 1 Introduction The pulse Doppler device generates pulses of transmission with a selectable frequency of 1 2 or 4 MHz which are sent as ultrasonic waves by a connected transducer If these waves are scattered or reflected at moved parti cles or bubbles they suffer a frequency shift Doppler effect The device registers and evaluates these scattered waves An audio signal is created The audible volume is a measure of the amplitude of the reflected signal the frequency is a measure of the speed of the scattered particles Simultaneously the amplitude is indicated as a deflection of a LED bar Moreover the device can pass on the measured data to a PC in order to perform records and evaluations in detail Sensitivity and volume can be adjusted at the device by means of control knobs By means of the supplied software FlowView the data measured by the device can be evaluated on a PC laptop The connection of the device is realized via a parallel port interface LPT or an USB interface Dur ing the measurement the software shows the current Doppler signal The evaluation uses a transformation into the frequency space by means of a Fourier transformation In this way the most frequently occurring or the high est occurring frequencies are determined which are a measure of the speed in the st
15. t possible to exit the program during a measurement FlowYiew BE x windows l i i data transfer stop parameter T time course 10s section pulse export ipg LPT Epit signal amplitude m Doppler amplitude spectrum mW 2500 100 0 20 40 60 80 8000 6000 4000 2000 0 2000 4000 6000 8000 Time ms Frequency Hz ao gt tube diameter mm incident angle f max Hz f mean Hz signal intensity 1000 s measured values 9 52 60 0 591 Sa speed cm s flow l min st dev f max f mean Resistance Rl 2 02 In the left diagram we see the current signal values changing over the time The scale of this diagram is fixed to 0 5V per division To adapt the amplitude in the diagram you have to use the amplifier knob GAIN at the front panel of the device In the right diagram we see the Doppler spectrum of the signal The vertical black line describes the zero value there are also positive and negative frequency values possible Generally the sign describes the flow direction in the tube A negative frequency value means the flow goes to the opposite direction or the ultrasonic probe has turned around This meaning of negative values is also valid for the derived measures like speed and flow The arrows beside and below serve to scale the diagram It is possible to zoom in or zoom out with it The double one makes an auto scale which means that the diagram is self scaling to maximum values
Download Pdf Manuals
Related Search