User Manual - Precision Systems and Instrumentation
Contents
1.2. The fuses should be replaced as required for the power source 110 115V use 10Amp 220 240V use 5Amp The voltage selection is indicated by the arrow on the right pointing to the voltage range Fig A3 Insert the fuse holder back into the switch socket and firmly push in place Voltage range E indicator Screwdrive M FIG A1 FIG A2 FIG A3 Removing fuse Fusechoder Fuse holder holder replaced indicating 100 to 120v Page 24 of 27 User s Manual PSI IH Impactor 2 Position the cabinet on one end where you can get at the bottom panel Remove 4 corner screws which hold the panel Loosen 2 screws near the bottom edge of either the front or rear panel See Fig A4 This will allow the bottom panel to be removed Once off a hole in the chassis will reveal a switch which can be moved with the blade of a small screw driver to select the appropriate input power See Fig A5 k Figure A4 Control cabinet bottom view Figure A5 Bottom panel removed Page 25 of 27 User s Manual PSI IH Impactor Appendix B Sorbothane test sample The test block is intended to give and indication of the relative health of the impactor and is in no way a calibration tool It can be used to provide a reference level for a particular machine The user can store a few hits at various force levels and use the test block from time to time to check the machine condition The test block needs to be stored in a cool dry place out of the light Te
3. but not limited to failure to observe proper electro static discharge precautions b operated in excess of specified electrical or environmental limits or c improperly calibrated by the user or a user appointed third party Note that we do not guarantee product suitability for all applications Warranty policy is subject to change without notice How You Can Get Service Warranty service can be obtained by notifying Precision Systems amp Instrumentation LLC in writing at the following address Precision Systems amp Instrumentation 6829 Brimstone Lane Fairfax Station VA 22039 Phone Fax 703 978 2319 Also service 1s available through the web http www presysin com e mail sales presysin com tech presysin com Page 23 of 27 User s Manual PSI IH Impactor Appendix A Configuring the power source and fuse access Changing between the 2 options for power is made in 2 locations 1 the main power switch and 2 from the bottom of the chassis Both must be accomplished 1 The main power switch contains a fuse holder where the input supply is switched The fuse holder Fig A2 is removed by placing a small flat blade screw driver in the notch at the bottom edge and wedging it out Fig Al It is tight and will take some effort to get it out Do not twist the screw driver Just push it into the notch and pry Once out the fuses can be changed and the fuse holder rotated one half turn and slipped back into the slot
4. then by viewing the location from several different angles realigning the tip It is not necessary and highly recommended that the impacting tip NOT TOUCH the exposed cord prior to the impact injury Once the proper alignment has been successfully obtained the impacting tip should be raised by turning the vertical adjustment knob Figure 10 2 to 4 complete turns to approximately 5 mm above the exposed cord The impacting tip attached to the rack can move a total distance of 8 mm Be careful to ensure that the encoder strip is still located within the position sensor with a portion crossing the midline of the sensor If the encoder strip is not in the position sensor or a portion of it does not begin in the middle of the sensor incorrect displacement values will be reported Page 13 of 27 User s Manual PSI IH Impactor Initiation of the injury Click the Start Experiment button found in the setup frame to initiate the injury sequence Before an impact occurs the instrument will self calibrate This is seen as a little twitch in the impacting arm The confirmation window will also appear If all of the experimental conditions are properly set i e alignment of impacting tip amount of force to be applied to exposed spinal cord and dwell time defined click the Yes button The stepping motor will immediately activate and the rack will move the impacting tip into the exposed spinal cord The impacting tip will then retract to th
5. Excel or any other spreadsheet program Open Experiment Data File exp To open a previously saved experiment click on File gt Open The open works in the same manner as any other Windows program open feature The current version of the software is able to open experiment files generated with any previous software releases Printing Experiment Data To print experiment data directly from the software click on File gt Print This will print the experiment data right side frame To better control the print use File gt Print Setup and to preview the results before printing use File gt Print Preview A Print Preview is recommended before each print to ensure proper alignment on the page Serial Port Settings Currently the default serial port settings are configured to properly work with the control unit Altering serial port settings may cause the IH Impactor to stop responding However should the serial port settings need to be view or changed they can be found by clicking on View gt Serial Port Settings If there is a problem with the IH Impactor customer service may ask for these settings There is also an interface to communicate directly with the Control Unit This will never be used during an experiment This is simply for customer services troubleshooting purposes It can be accessed by clicking View gt Serial Terminal Page 18 of 27 User s Manual PSI IH Impactor Upgrading Firmware From time to time improved versions
6. Figure 2 Assembled Impactor Page 5 of 27 User s Manual PSI IH Impactor When properly assembled the IH Impactor should appear similar to the above picture The removable experimental table has two permanently mounted support arms with flexible ball joints These arms hold the Adson stabilizing forceps The experimental animal will be positioned between these two forceps with the exposed spinal cord directly beneath the impactor tip and force sensor The stepping motor located on the right side of the IH Impactor drives the impactor rack downwards On one end of the impactor rack is the force sensor and impactor tip while on the other end is an encoder strip that activates the position sensor held in place by the position sensor clamp The experimental table on which the animal is placed can be carefully positioned under the impactor tip prior to injury with the aid of two horizontal control wheels The vertical height of the impactor tip can be initially adjusted with the vertical hand wheel One of the most important components of the IH Impactor is the position sensor This sensor is attached to a clamping mechanism that ultimately attaches to a small stand post on the top of the impactor Carefully remove the bubble wrap on the sensor and clamping mechanism One portion of the clamping mechanism will be attached to a stand post as shown in Figure 3 Care must be taken not to damage the encoder strip that is attached to the top portion of th
7. m 1o siz 78 a asa prior to the deepest penetration of the impactor tip labeled as COS et cs aa qese Starting Position in the table at the left The first point on the 3 en ee Sg 1203 Up Stroke side corresponds to the point where the tip begins to sf 2 ee 2 e ee feverse direction The forces are the real force values in 38 o 854 45 32 1885 kilodynes read by the force sensor To find the displacement MEI ETna from the raw values first find the position value which is the su 0 69 47 o 2011 largest from either side of the chart This value is typically on s a F 48 o boza the Up Stroke side On the chart in Figure 14 this value is i ao a 45 a oa 103 Multiply the raw position value by 17 6 um Next pick 6 2 0 2201 the point where you want to know the displacement To gg aml 3 4 sssq determine displacement into the tissue pick the displacement ao oad 48 S838 value corresponding to the first point where the force value is moe wee T 15 S288 greater than 20 kdyn On the chart in Figure 14 this value is s1 ig ites 5 25 2421 84 Multiply this position value by 17 6 um and then subtract 87 48 1242 2 15 2484 it from the previously calculated value This is the calculated oz s zeil 1 2 26 47 tissue displacement This corresponds to the point on the as diz 12352 4 o 26 10 displacement graph where the horizontal red line was drawn Down Stroke Up Stroke The calculated displacement is relative to the deepest p
8. ms FIGURE 12 Displacement vs Time Graph with Key Points Labeled The Displacement vs Time graph is a plot of the displacement of the tip relative to its deepest point in the tissue against the time taken for the tip to drive down impact the tissue and retract The displacement is measured in microns and the time in milliseconds The graph is always zeroed on the displacement axis at the point where the tip was deepest in the tissue Therefore this is also the point where the tip begins to retract The point where the tip starts Oms is shown as the highest displacement This represents the distance traveled between 14ms prior to the deepest displacement and deepest displacement There is travel of the tip prior to the time interval displayed in the graph The approximate 5 mm gap is covered outside the limits of the graph The graph is inverted like this to correspond with the physical motion of the tip as an impact occurs Two red lines are also drawn on the graph The vertical red line represents the time at which the tip impacted tissue The horizontal red line indicates the displacement of the tip into the tissue The graph is discontinuous at the point where the desired force is achieved as the impactor tip cannot be instantaneously stopped The second half or right half of the graph shows the motion of the impactor tip after the desired force is achieved It can be seen that the tip actually moves a bit further into the tissue before the mot
9. of the firmware will be released via the PSI website The firmware is the program that the control unit runs when conducting an experiment This is permanently stored in the control unit and is typically never seen by the user The software has the ability to reprogram the control unit should a new firmware version be released or the existing one need to be reinstalled Before reprogramming the firmware make sure the control unit is turned on and all cables are securely connected To reprogram the firmware first click on File gt Reprogram Firmware An Open File dialog box will appear Find the firmware program file it has a hex file extension The current version of the firmware will be found 1n the directory the PC software was installed into This is typically C Program Files PSI IH Spinal Impactor v5 0 When the firmware file is loaded a confirmation box will pop up to ask you to confirm Click Yes when ready Reprogramming may take up to 15 minutes to finish During this time the power must stay on to the control until and the serial cable from the computer to the control unit must remain plugged in Any disruption will result in an incomplete copy and may leave the control unit unworkable When the firmware has been successfully reprogrammed a message will be shown alerting the user If the firmware upgrade fails test all connections and power and repeat the process again Force Sensitivity Setting The force sensitivity s
10. to be impacting tissue when a force of 20 kdyn is first measured If an impact is ever observed where the force exceeds 20 kdyn before time starts then the actual displacement value will read as zero This can happen if the spinal cord is not secure and moves during impact At 20 kdyn a red vertical line will be drawn to indicate the time at which initial impact occurred The highest point corresponds to the maximum amount of force applied and should be very close to the desired value This peak will become rounded as the tissue impacted becomes softer and sharp as the tissue becomes harder such as bone If no impact occurs the force graph will read zero or very close to it depending on background noise It is important not to jostle the tip too much before an impact so as to minimize the amount of oscillation in the force sensor and reduce background noise Page 16 of 27 User s Manual PSI IH Impactor Raw Data Values Position Fores Time Position Fore Time Also located in the experiment data frame is a chart consisting oO oO 0 00 100 111 13 86 e 3 gt ie 102 1412 ofthe raw data values received from the control unit Figure g 0 i 12 0 104 103 ca 1478 14 These are listed with the down stroke values on the left 14 Spa Ping 172 _ g 4639 and the up stroke values on the right The first point on the 1a STATENS og Garn Arodado l 18Posiiorg 42 SP gsifioy 02 down stroke side corresponds to a point approximately 15ms
11. User s Manual PSI IH Impactor IH SPINAL CORD IMPACTOR by Precision Systems amp Instrumentation USER S MANUAL 6 2012 _ afation Version 3 Copyright 2000 2004 Precision Systems and Instrumentation LLC This program is protected by US and International copyright laws tia e yo ras i N i m Precision Systems and Instrumentation LLC Page 1 of 27 User s Manual PSI IH Impactor Site Requirements for the PSI IH Impactor A suitable environment is important for the proper optimal performance of the IH Impactor Power Considerations The IH Impactor can be configured for 110 115V or 220 240V 50 or 60Hz power supply See instructions for making the change in appendix A It 1s recommended that the instrument be connected to a power surge protected power strip rated at 1200 or greater joules This will protect the sensitive computerized circuitry in the control against damage from harmful power surges and spikes Shock hazard or damage to the IH Impactor may result if the IH Impactor 1s connected to a line voltage higher than specified Never operate the IH Impactor from a power outlet that has no ground connection Never use a power cord other than that supplied with the IH Impactor Never use cables other than those supplied with the IH Impactor to ensure proper functionality Bench space The IH Impactor dimensions and weight allow for maximum flexibility to fit almost any desk or laborato
12. acked similar to the picture shown to the left The impactor itself will be wrapped and packed in foam The accessories are packaged in the accompanying boxes 2 To unpack first remove the accessory boxes and foam padding User s Manual PSI IH Impactor 3 Remove the Impactor from the shipping box and set aside Remove all the packing material and wrapping 4 Finally remove the control unit from its box It will be wrapped in bubble wrap as shown e A OR y e Ta eee 2 Remove the padding for setup Page 4 of 27 User s Manual PSI IH Impactor Setting Up the PSI IH Impactor You should have the following items CHO NAKRWNS Impactor with force position and motor cables 1 each Control unit 1 each AC power cable for control unit 1 each RS232 Din15 computer interface cable serial cable 1 each Experimental table with attached support arms and flexible ball joints 1 each Adson spinal cord stabilizing forceps 2 each User software CD 1 each Impactor tip rat 1 each Impactor tip mouse 1 each 10 Sorbothane test block 1 each 11 User Manual This Document 1 each Set up the PSI IH Impactor and Control unit When fully assembled the IH Impactor should look similar to Figure 2 POSITION SENSOR MOUNT amp SHIELDS iio POSITION SENSOR IMPACTOR L RACK summers STEPPING MOTOR FORCE SENSOR CABLE FORCE SENSOR WITH TIP SPINAL CORD STABLIZING FORCEPS
13. e impactor rack POSITION Make sure that the encoder strip is properly aligned ENCODER SENSOR It is important that the rack and encoder strip have STRIP MOUNT sufficient room to move up and down and do not bind to any part of the impactor There should be some resistance in movement of the rack from the J ROSTON mechanical assembly The encoder strip should be SENSOR positioned such as is shown in Figure 4 It should be a little skewed toward the top Viewed from the Figure 3 Position Sensor Assembly front and top it should be slightly skewed to the right in the sensor slot As viewed in Figure 4 it will appear to align with the top and bottom corners of the 45 chamfer on the position sensor ni e Figure 4 Encoder Strip Properly Positioned Page 6 of 27 User s Manual PSI IH Impactor The control unit Figure 5 is the interface between the IH Impactor and the computer running the IH Impactor software The rear of the control unit has several different connectors It is important that the different components of the impactor be securely connected for proper operation The connectors on the back of the control unit are all different ensuring proper connection of the different cables Check to see that the position sensor interface cable is completely connected to the 5 prong connector on the position sensor Figure 6 Connect the other end of the interface cable to the rear of the control unit at the connector
14. e start position after the desired dwell time immediately if dwell is set to zero Displaying and Interpreting Experiment Data Experiment settings Desired Actual Force K dynes 100 112 Displacement u 405 Velocity mms 10 115 Dwell Time s o o FIGURE 11 Experiment Settings with Actual Values On completion of the injury cycle the data gathered by the control unit will be sent to the software which will update the actual values in the Experiment Settings portion of the setup frame Figure 11 the displacement graph will be drawn Figure 12 the force graph will be drawn Figure 13 and the raw value chart will be filled in Figure 14 In the example shown here the instrument was set to use 100 kdyn of force with the actual force applied being 112 kdyn The impactor tip displaced the cord by 405 um at a velocity of 115 mm sec The impactor tip did not dwell for any appreciable amount of time Page 14 of 27 User s Manual PSI IH Impactor Displacement vs Time Graph eo Displacement vs Time Disp microns 6OU 2o00 2400 2000 2200 2100 z00 1900 1800 Tip Retraction 1700 1600 1500 1400 1300 1200 1100 1000 SOU oug fOU BOO S00 400 300 Point when Tip 200 100 U Slowing Down Desired Force Achieved Tip Tissue Inte face Threshold Begins to Retract if 012345 6 7 o 9 1001121314151617 186 192021 2223 2425 2627 20 29 30 Time
15. e updates When running a force experiment Seon EL the force input field is highlighted and the displacement is made unavailable Figure 8 Clicking on Displacement Experiment Displacement u will highlight the displacement input field and make the force gt input field unavailable The velocity field while active currentl ised kes os no bearing in how the pana is run This can be left me Dwell Time s o0 o the default value The dwell time is adjustable Dwell time is defined by the length of time the impactor tip remains in the Experiment Comments tissue after the application of the force For example if a 50 kdyn force is applied and the displacement is 475 microns a setting of 5 in the dwell time field would instruct the instrument to hold the impactor tip at that displacement for 5 seconds before withdrawing The amount of force applied to the cord eae will NOT remain at 50 kdyns because of spinal cord tissue dynamics The default value for dwell time is zero indicating that the tip will withdrawal immediately after reaching the FIGURE 8 Experiment desired impact force Currently the maximum dwell time is 1 Settings Setup Fields minute Experimenters requiring longer dwell times should contact PSI for a software modification Next to each of the Desired Value entry fields are Actual Value fields These fields report back the actual experimentally acquired values after an impact The Experiment Comments Box is available to
16. earing and two pressure clamps can be removed from the armature housing The ball joint can be cleaned with 70 alcohol and a soft lint free cloth Care should be taken to remove all dirt from the ball joint and to visually inspect the area for any foreign material that may harm the ball joint surface Page 20 of 27 User s Manual PSI IH Impactor To reassemble the flex ball joint first place the pressure clamps into the armature housing It is extremely important that the small beveled portion of the clamps be visible from the top of the armature opening as shown in Figure 16 The pressure bearing can then be seated on top of these clamps The clamps should be separated enough to accommodate the cone shaped portion of the pressure bearing The ball joint is placed on top of the pressure bearing and the retaining ring is used to secure the ball joint in place Finally the spring loaded tightening screw is placed into position If the pressure bearing is seated properly the ball joint can be secured into place by tightening the screw Armature housing If the ball joint does not appear to work properly after reassembly remove the tightening screw retaining ring and pressure bearing and realign the beveled portion of the pressure clamps and reassemble Figure 16 shows the retaining clamps in the proper position as seen through the top of the armature housing with the retaining ring and pressure bearing removed Note that the beveled port
17. en launch the IH Impactor software by double clicking on the icon now located on the computer desktop or choosing it through the start menu Page 9 of 27 User s Manual PSI IH Impactor Running the IH Impactor Software The IH Impactor software is composed of two main frames The left frame is for setting up all the experiment variables storing comments and running the experiment The right frame contains all the post experiment data displayed as a force graph a displacement graph and a chart of the raw values from the control unit H Spinal Cord Impactor v5 0 otg Fie Edit wiew Help D g Ge Experiment Mode Displacement vs Time Position Force Time Position Force Time Force Displacement Experiment Settings Desired Actual Force K dynes 100 Displacement ui Velocity rms Force vs Time Dwell Time s Experiment Comments start Experiment Figure 7 The PSI IH Spinal Cord Impactor software This is the initial screen from which the experiments will be setup and displayed Page 10 of 27 User s Manual PSI IH Impactor The Setup Left Frame Experiment Mode This frame is where the experiment is setup and run from When O Pane running an experiment first choose which impact mode you want to use The default is to run a force experiment At the present time the displacement experiment option is Semen e unavailable in the current software release Check the PSI Desired Actua Website for futur
18. etting 1s a calibration number unique to each impactor stage It s used to calibrate the force sensor for proper force measurement This value should only be changed when prompted to by the software or when the control unit is connected to a new or different impactor stage When new firmware is programmed into the control unit the software will prompt the user for the force sensitivity number Experiments may still be run on the default value though it is not advised as results will be skewed The force sensitivity value for each impactor stage can be found on the force sensor calibration sheet which is included in the documentation provided with the IH Impactor You may also contact PSI with your IH Impactor serial number to obtain the correct force sensitivity value To set the force sensitivity value click on File gt Force Sensitivity Settings The force sensitivity value is entered as the value from the sensor calibration sheet multiplied by 10 e g 543 1 mV N is entered at 5431 and should be in the range of 4000 to 6000 Once set the software will copy the value to the control unit therefore this value only needs to be set once After completion of this process the power to the unit needs to be turned off and back on Page 19 of 27 User s Manual PSI IH Impactor Care and Cleaning of the IH Impactor The IH Impactor should be kept clean Cleaning should be done with a damp lint free cloth Do not use an excessively damp cloth allowing l
19. ion of each retaining clamp faces the top of the armature housing This is important for the proper seating of the pressure bearing during re assembly of the unit Retaining clamps in correct position FIGURE 16 Armature Housing General routine maintenance should include checking the tightness of mechanical parts There are set screws in each knob The force sensor adaptor and strip sensor mount are clamped to the rack with a small set screw tightened into the tooth side of the rack This accepts a 0 050 hex wrench Page 21 of 27 User s Manual PSI IH Impactor Lubrication of the lead screws The lead screw to bushing interface should be lubricated periodically Use any light weight machine oil The figures below illustrate the locations being referred to Place a drop at the interface and work it in by cranking the knob many turns to feed oil over a large section of the screw wie sI A Ay yore T EA a 3 p 4 s E T s s ON nnn an a i Front screw View under cross slide Frontscrew Page 22 of 27 User s Manual PSI IH Impactor Limited Warranty What the Warranty Covers We warrant the IH Impactor to be free from defects in material and workmanship for 90 days after shipment Our obligation is to repair or replace our product if it should prove to be defective within 90 days of shipment This warranty is void if the product is a handled carelessly including
20. iquid to drip onto the stepping motor or the position sensor It is suggested that a light weight plastic cover be used to protect the instrument from dust and dirt when not in use The encoder strip that is used in the position sensor should not be cleaned or dismantled at any time during the cleaning process since any disruption of the fine markings on this plastic strip will interfere with the precision of the stepping motor and positioning of the rack Once a year depending upon the usage a light weight silicon grease should be applied to the worm drives and gears utilized in the stage movement The Adson forceps should be removed from the adjustable armature and cleaned with a mild surgical cleaning solution Care must be taken to avoid bending the delicate tips of the forceps It is recommended that the forceps be removed from the instrument when not in use and placed in a safe location Additional forceps may be purchased from the manufacturer Tightening screw Retaining ring FIGURE 15 Assembled and Disassembled Support Arm The adjustable ball and socket armature may be disassembled after extensive use for cleaning To disassemble the ball joint unscrew the spring loaded tightening screw immediately below the ball joint that is to be cleaned This will release the pressure on the ball joint and allow the retaining ring to be removed With the retaining ring and spring loaded tightening screw removed the pressure b
21. level the spinal column is stabilized with the Adson forceps attached to the flexible ball joints It is important to stabilize the spinal column by clamping the lateral processes of the vertebral bodies immediately rostral and caudal to the laminectomy Do not clamp the dorsal processes with the Adson forceps It is important not to initially tighten the ball joints too tightly in order that the exposed spinal cord can be made level Once the cord has been leveled the ball joints should be tightened Once the experimental animal has been properly positioned the experimental table can be positioned on the IH Impactor Two table guide brackets help stabilize the table It is suggested that the table be held in place with a spring loaded clamp Before securing the clamp move the table forward or backward between the two table guide brackets such that the exposed spinal cord is close to the impacting tip Exact placement of the exposed spinal cord can be obtained by moving the secured table with the hand wheels located on the front or side of the impacting device Figure 10 These hand wheels allow the table to be moved in an X Y position The height of the impacting tip can be manipulated by turning the top hand wheel Proper alignment of the impacting tip is extremely important in obtaining a reproducible impact and damage to the spinal cord It is recommended that the impacting tip be lowered to within a few mm of the exposed cord and
22. make any comments you would like to save along with the experiment In addition to you own comments the software automatically logs the date and time of the experiments here All experiment comments should be made after the impact Prior to each impact the comments box is cleared to run the new experiment Finally the setup frame contains the Start Experiment button When all fields are set and the animal is in position this will begin the experiment After pressing it a verify window will open to ensure you want to proceed with the experiment This is a precaution against accidentally pressing the button Displacement The Experiment Data Right Frame This frame is where all the data collected during an experiment is displayed It consists of the displacement vs time graph the force vs time graph and a chart listing the raw displacement force and time values received from the control unit Discussion and interpretation of each of these three elements can be found in the post experiment section below Conducting an Experiment This section covers a detail run of an impact experiment start to finish Page 11 of 27 User s Manual PSI IH Impactor Selecting the appropriate impactor tip The IH Impactor is supplied with two different impacting tips The larger tip has a diameter of 2 5 mm and is designed for use with larger animals such as rats The smaller tip has a diameter of 1 25 mm and is designed for use with smaller ani
23. mals such as mice Each tip has an end with screw type threads and an end that is tapered and smooth The threaded portion of the tip screws into the bottom of the force sensor as shown in Figure 2 When changing impactor tips it is extremely important to only HAND TIGHTEN each tip onto the force sensor It is unnecessary to use tools for this purpose since it may cause serious damage to the force sensor Tips may be removed between experiments for sterilization purposes Use 70 alcohol on a cue tip to clean the tip after every injury One has to be very careful not to push too hard on the tip since it is part of the force sensor that is very delicate Clean the tip immediately after the animal is injured and the platform once the animal is removed At the end of each injury session remove the tip and sonicate it in soapy water for 5 minutes Alternatively additional tips may be purchased from the manufacturer Depending upon the user s application one of the two different sizes of impactor tip should be threaded into the force sensor FIGURE 9 Impactor Tips Selecting the appropriate experimental settings Once the appropriate tip has been threaded on and the control unit has power launch the IH Impactor software If previous impact information is being displayed click File gt New from the top menu Set up the experiment by entering the desired force and dwell time values in the appropriate input field in the setup frame Suggested force
24. marked Position Sensor Figure 5 Connect the stepping motor interface cable to the IH Impactor control unit The interface cable is already attached to the stepping motor Figure 6 The opposite end of the cable should be attached to the rear of the control unit at the connector marked Motor Control Figure 5 Connect the force sensor interface cable to the IH Impactor control unit Figure 5 at the position marked Force Sensor The interface cable is already attached to the force sensor Connect the serial cable between the PC and IH A Serial to USB adaptor cable may be used with PC s that do not have the 9 pin D connector Com port Follow the instructions in the appendix C COALS NET UOT LOT CENCE ATE BIN JOE LES S IH Impactor Force Postion Sensor Sgnsor z x EN 4 Figure 5 Back of the Control Unit Page 7 of 27 User s Manual PSI IH Impactor POSITION SENSOR POSITION SENSOR INTERFACE CABLE STEPPING MOTOR TT STEPPING MOTOR INTERFACE CABLE FORCE SENSOR INTERFACE CABLE FIGURE 6 Side View of Impactor Assembly with Cables Connected Installing IH Impactor Software Minimum Software Requirements Pentium 100MHz or higher PC with at least 64 MB RAM a hard disk with 12 MB of free disk space CD ROM drive and video set to a resolution of 800x600 at 256 colors The system should be running Windows 98 2000 XP or higher The IH Impactor Software is required to use the impac
25. oint of impact rather than relative to the starting position of the FIGURE 14 Raw Data aE Values Experimental Comments Following completion of the injury cycle the impactor tip can be raised with the vertical adjustment wheel and the experimental table removed from the guide brackets After visual inspection of the injury comments can be recorded in the Experiment Comments box With each experiment run the software will automatically log the date and time in the Experiment Comments box Comments may be as long as necessary The comments box with begin to scroll once the available area has been filled Page 17 of 27 User s Manual PSI IH Impactor Additional Software Features This next section will discuss additional software features These include saving printing and other utilities Saving the Experiment Data To save an experiment data set click on File gt Save or File gt Save As The save works in the Same manner as any other Windows program save feature Saving the experiment will include all the raw data actual values and experiment comments in a file with a exp extension These files are user readable if opened in a standard text editor Saving the Experiment Data as a Comma Delimited File Excel Readable To save an experiment as a comma delimited file click on File gt Save As Comma Delimited File Doing this will save the experiment data as a cvs file This file may then be imported into Quatro Pro
26. or is able to overcome its inertia and move it back out In an experiment where the dwell time is greater than zero the right half of the curve will not be displayed as it is far out of the range of the graph s time scale In both the down stroke and up stroke of the tip non linear aspects of the curve may be present This is seen as the flattening out of the slope of the graph during the impact run Non linear areas such as is shown in Figure 12 are typical and do not adversely affect the impact Page 15 of 27 User s Manual PSI IH Impactor Force vs Time Graph ee Force vs Time Force kK dynes 260 250 210 230 220 210 200 190 180 170 Maximum Force Applied 160 150 lia Tip Tissure Interface 120 Threshold 110 100 A Residual Forces due 7O to Tip Retraction 60 7 s0 Background Noise EAA o 4 32 6 7 6 9 10111213141516 171061920 21 2223 2425 25627 2029 30 Time msj iis y b FIGURE 13 Force vs Time Graph with Key Points Labeled The Force graph plots the force value recorded by the force sensor on the impactor tip against the time of the impact experiment The force is measured in kilodynes and the time in milliseconds The force graph consists of several small bumps and one larger peak The small bumps represent background noise the force sensor picks up as it encounters the small resistance of the tip during its drive down and up The large peak is when the tip impacts the tissue The tip is considered
27. range values Rat values between 100 and 200 kdyn Mouse values between 30 and 70 K kdyn The suggested values result in varying degrees of contusion resulting in a range of morphologic change to the spinal cord The reproducibility of damage will vary depending upon the reproducibility of the way the animal is positioned with the stabilizing forceps and the manner in which the spinal cord is exposed As with any surgical technique this will require practice by the experimenter for consistency and reproducibility Once the settings are entered it is recommended to do an air impact to test the correct setup of the machine In an air impact the displacement graph should be plotted the force graph should be near zero since there was no force of impact in air and the chart should be filled in with raw values Page 12 of 27 User s Manual PSI IH Impactor Positioning the animal VERTICAL ADJUSTMENT KNOBS ee a ft TABLE GUIDE HORIZONTAL ADJUSTMENT KNOBS FIGURE 10 Impactor with Adjustment Wheels Shown The experimental table contains the moveable arms and Adson forceps used to stabilize the spinal column prior to injury The table can be removed from the IH Impactor by sliding it forward away from the vertical column supporting the impacting motorized mechanism This provides easy accessibility to the flex ball joints and support arms and to the Adson forceps After performing a laminectomy at the appropriate
28. ry bench The impacting portion of the instrumentation should not be placed on the control unit during operation It is recommended that the control unit be placed such that it can achieve adequate ventilation during operation Do not block the ventilation slots on the top of the control unit Itis also recommended that if a laptop computer is running the provided software it Should not be placed on the control unit during operation Environment The IH Impactor will work within temperatures and humidity that are specified by the computer the instrument is interfaced with For practical purposes this would be within the range of 65 F to 85 F and humidity 40 to 95 In order to function properly do not place the IH Impactor on a vibrating surface or near vibrating objects Unpacking the PSI IH Impactor Upon receipt or your IH Impactor control unit and cables inspect the shipping containers for any signs of damage If containers or cushioning material are damaged save them until the contents have been checked for completeness and the impactor and control unit have been mechanically and electrically checked If the shipping container or cushion material is damaged notify the carrier as well as IH Save the shipping material for the carrier s inspection Page 2 of 27 User s Manual PSI IH Impactor backup foam ie ks ee a ee pe ae eee a Sa accessary and surgical plate boxes Mi Page 3 of 27 1 Impactor will be p
29. s the progress window that pops up at the lower right will show the com port assigned The message should be manufacturersname USB to Serial Comm Port Com n or something similar n is the number of the assigned comm port which you will need to use when correcting the port settings in Spinal software Step 2 Upon completion of step 1 connect the IH serial cable to the adaptor cable and turn on the IH device Step 3 Open the Spinal software Click on View click on Serial Port Settings select the correct port from the drop down menu click OK Depending on the USB to Serial adaptor brand it is possible that the port assignment may change when the PC is turned off and or restarted Also the Spinal software will not remember when it is shut down and restarted It always defaults to Com1 and will need to be set each time Spinal is launched Find the assiqned com port If you miss the assignment when the PC is installing the driver as described in step 1 you will need to search Ports This requires searching Ports in Device Manager The process varies across Windows operating systems Generally Device Manager can be launched by selecting Contol Panel and finding it in the list or type it into the search box in the start menu Once Device Manager is open look down the list for Ports Click on it to open The description of the USB to Serial adaptor and Com n will be listed There could be other devices listed as well Page 27 of 27
30. st Block in place Procedure Simply place the test block as a target for the impactor tip Just like with an animal adjust the gap between tip and rubber for 4 to 5mm Set up the conditions for the experiment and perform a hit Expect variability between repeated hits You can reasonably expect overshoot of as much as 10 on force Also since the real displacement resolution is 17 6 micrometer the displacement repeatability will be in increments of 17 or 18 micrometer depending on rounding It is a good idea to perform a few hits using the test block upon setting up the machine the first time and save these for reference Then occasionally repeat for comparison Significant and repeatable differences may be cause for concern You can contact technical services at tech presysin com Page 26 of 27 User s Manual PSI IH Impactor Appendix C Setting up the USB to Serial adaptor for use with the H0400 PSI recommends a USB to Serial adaptor that is considered to be industrial hardened All are not the same PSI will supply one which we can stand behind Please contact the sales department Step 1 Follow the instructions from the adaptor supplier to load and install the drivers on your computer This should include first transferring the drivers from the CD to the PC then plugging the adaptor cable into the USB port and allowing the PC to find and install the driver before attaching to the IH cable Watch closely as this process proceed
31. tor This is included on the installation CD ROM and is also available on the PSI website Check the website for updated versions CD ROM Installation Insert the IH Impactor CD ROM and then follow the installation wizard If the installation wizard does not automatically start then from the Start menu choose RUN and type d setup exe where d is the drive letter of your CD ROM drive note the drive letter may be different for your system Open My Computer to check drive letter assignment Once the program installation is complete the shortcut icon will appear on the desk top and a new folder will appear in the start menu PSI IH Spinal Cord Impactor v5 0 Page 8 of 27 User s Manual PSI IH Impactor Turn on the power to the control unit fats Koe Power Power Toggle Indicator Switch A power indicator light on the front of the control unit will glow green indicating that sufficient power has been supplied to the control unit If the power indicator light does not come on turn the unit off and check to be sure the control unit is plugged into an appropriate socket of the power strip Also make sure the other end of the power cord completely engages the AC power connector on the back of the control unit Use the power toggle switch again to supply power to the control unit If the power light still does not glow green call technical support Once the power indicator light on the front of the control unit glows gre
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