DGH 500 (PACHETTE™) ULTRASONIC
Contents
1. DB 25 DB 25 FEMALE MALE FGND 1 1 RD 2 2 TxD 3 3 NC 4 4 NC 5 5 NC 6 6 DB 9 DB 9 SGND 7 T MALE FEMALE NC 8 8 NC 9 9 1 1 NC NC 10 0 2 2 TxD NC 11 1 3 3 RxD NC 12 2 4 4 PING NC 13 3 5 5 SGND NC 14 4 6 6 PIN4 NC 15 5 7 7 NC NC 16 6 8 8 RTS NC 17 7 9 9 NC NC 18 8 NC 19 9 DTR 20 20 NC 21 21 NC 22 22 NC 23 23 NC 24 24 NC 25 25 DGH 500 SII DPU 414 SII DPU 414 PACHETTE PRINTER CABLE PRINTER Figure XII A Wiring diagram for the SII DPU 414 printer interface cable DB 25 DB 25 FEMALE MALE FGND 1 1 RD 2 2 TxD 3 3 NC 4 4 NC 5 5 NC 6 6 DB 9 DB 9 SGND 7 7 MALE FEMALE NC 8 8 NC 9 9 1 1 cD NC 10 0 2 2 RxD NC 11 1 3 3 TxD NC 12 2 4 4 DTR NC 13 3 5 5 SGND NC 14 4 6 6 DSR NC 15 5 7 7 RTS NC 16 6 8 8 CTS NC 17 7 9 9 RI NC 18 8 NC 19 19 DTR 20 20 NC 21 21 NC 22 22 NC 23 23 NC 24 24 NC 25 25 DGH 500 PC IBM PC PACHETTE INTERFACE CABLE COM PORT Figure XII B Wiring diagram for a typical PC interface cable 38 XIII APPENDIX B DATA TRANSFER FORMAT When the data transfer interface is im2. G4 PQT Clear Switch PQT Performs a Probe Quality Test when pressed and released Used to initiate the main configuration mode when pressed and held Clear Used to clear all measurements from memory and re initiate measurements at position 1 when pressed and released If the printer interface option is installed a print out will also be initiated Used to initiate the velocity configuration mode when pressed and held 2 Switch Used to program options and numerical values presented on the displays 3 Position Display A 2 character LED display used to correlate a given measurement with a specific location on the cornea It is the operator s responsibility to maintain a record of the position number to the actual corneal location This record may be maintained on a chart such as the Cornel Thickness Chart supplied with each Pachette This display is also used to present setup information to the operator when configuring the Pachette Actual Data Display A 4 character LED display used to present corneal thickness measurements to the operator All measurements are given in microns um and are based on a corneal velocity of 1640m s unless the operator changes the velocity This display is also used to present setup information to the operator when configuring the Pachette Power Switch Pressing 1 side of switch turns the Pachette on Pressing 0 side of switch turns the Pachette off Probe
3. The probe should NEVER be autoclaved or subjected to intense heat As a general rule the above cleaning instructions are sufficient to disinfect the probe in ordinary use Do not scratch or chip the conical probe tip which makes contact with the cornea X B Transport and Storage Conditions The Pachette is capable while packed for transport or storage of being exposed for a period not exceeding 15 weeks to environmental conditions not outside the following ranges 1 An ambient temperature range of 40 C to 70 C 2 A relative humidity range of 10 to 100 including condensation 3 An atmospheric pressure range of 500 hPa to 1060 hPa X C Operating Conditions The Pachette should be operated between temperatures of 18 C to 40 C 30 X D Warranty DGH Technology Inc DGH warrants each new DGH 500 and its accompanying accessories hereinafter called Equipment to be free from defects in material and workmanship for twelve 12 months from the date of delivery to the original purchaser This warranty is not applicable to any defect which is the result of an accident misuse mishandling neglect improper installation improper repair or improper modification by persons other than DGH This warranty does not apply if the Equipment has not been operated and maintained in accordance with the operating and maintenance manuals and instructions or bulletins issued in respect thereof by DGH It is further understoo
4. has been designed to allow the operator to modify certain default parameters to tailor the instrument to meet one s needs Once modified these parameters are permanently stored in non volatile memory and are automatically recalled each time the unit is powered up To change a parameter the operator must first enter one of two configuration modes the Main Configuration Mode or the Velocity Configuration Mode The following procedures explain how to enter each mode and change the default parameters The Main Configuration Mode A complete list of all the parameters for the Main Configuration Mode is given in Table 1 The white sections of this table identify the parameters that are accessible on every Pachette The shaded sections of the table identify parameters that are only accessible when optional features have been added to the basic Pachette for a detailed description of all available options refer to section IX Use the following procedure to enter the main configuration mode and modify the parameters that are accessible Press and hold the PQT switch until the message PACH CNFG appears on the display 2 Release the PQT switch The designator P1 and parameter TYPE should now be displayed A designator is a label that helps to identify a configurable parameter 3 To select a new value for the designated parameter press and release the T or 4 cursor switch To scroll through the available parameter values p
5. Calbox button until the LED lights If the LED fails to light or goes out before the test sequence is completed or if POOR APPL is displayed then replace the 9V alkaline battery If no measurements are taken with 22 minutes after the CalBox button is pressed the Calbox will automatically turn off 6 If Auto Mode is enabled the Pachette will automatically begin taking measurements If Auto Mode is not enebled then use the foot pedal to take measurements 7 Observe actual measurement values of 200um thru 1000um in steps of 100m ALK units start at 100m All values are based on a corneal velocity of 1640m s and should be within 5um If any measurements are out of tolerance contact DGH Technology Inc 8 Important Before taking any corneal measurements re connect the probe and exit the Demo mode by pressing CLEAR and then press PQT 16 IX OPTIONAL FEATURES FOR THE PACHETTE The Pachette has been designed as an economical and easy to use instrument A basic unit contains a variety of features that the operator will find useful when obtaining pachymetry measurements To further enhance the functionality of the Pachette DGH Technology Inc also offers five additional options that can be installed when the unit is purchased Any combination of options may be selected to tailor the unit to fit one s particular requirements The options that are currently available for the Pachette are 1 Automatic Meas
6. Interface Front panel connector which mates to the connector on the Probe cable Biased Data Display A 4 character LED display used to present biased corneal measurements to the operator All biased measurements are given in microns um and are based on a corneal velocity of 1640m s unless the operator changes the velocity The bias can be either a percentage 1 199 of the actual measurement or a fixed offset 1 199um This display is also used to present setup information to the operator when configuring the Pachette Back Panel O O A o O ore o9 olo O O Pachette Manufactured by Model DGH 500 DGH TECHNOLOGY Inc SN 3048 SUITE B EXTON PA 19341 USA 610 594 9100 FOR PROFESSIONAL USE ONLY REPLACE INPUT FUSES 100 340V DANGER EXPLOSION HAZARD DO NOT USE IN PRESENCE OF FLAMMABLE T AN 250V rogoz ANESTHETICS GASES OR OXYGEN RICH ATMOSPHERE MARKED 0 3A DGH 19996 DGH 500BPLCE 0459 Figure II B DGH 500 Back Panel Layout 1 Fuse Holder Location of AC input fuse s If a fuse needs replacing always replace the fuse as marked 2 Model amp Serial Numbers Location of model and serial numbers used to identify the unit 3 Foot Pedal Interface Phone jack that accepts the phone plug attached to the end of the foot pedal cable 4 CE Certification Marks These marks
7. are used to identify CE certified units CE certification is optional Calibration Standard To check Pachymeter calibration an electronic CalBox below is used to simulate the thickness of the cornea Instructions for using the CalBox are given in section VIII and they are also printed on the Calbox label TECHNOLOGY INC DGH gt DGH 500 PACHETTE CALIBRATION BOX OPERATING INSTRUCTIONS 1 With Pachette turned off connect probe to front panel 2 Enter the Demo mode by holding in the switch and turning on the Pachette 3 After power up is completed the display will indicate Positon 1 ActualData 0 BiasedData 0 4 Disconnectprobe and connect CalBoxto the Pachette 5 Press CalBox button until power LED lights If the LED fails to light or goes out before the test sequence is completed or if POORAPPL is displayed replacethe 9V alkaline battery If no measurements are taken within 2 minutes after the CalBox button is pressed the CalBox will turn off If Auto Mode is enabled the Pachete will begin taking measurements If Auto Mode is not enabled then use thefootpedalto take measurements 7 Observe actual measurement values of 200um thru 1000um in steps of 100um ALK units start at 1001m All values are based on a corneal velocity of 1640m s and should be within 5um If any measurements are outoftolerance contact DGH Technology Inc 8 Important Before taking any corneal me
8. cleared and the Pachette is ready for the next measurement session IX E Remote Control Interface Option The Remote Control interface option is a hardware software interface that allows a personal computer PC to control the operation of the Pachette The hardware interface that is utilized is the industry standard serial data communication protocol designated as RS232C A 25 pin connector on the rear panel of the Pachette conforms to the RS232C standard It is the operator s responsibility to provide a cable from this connector to a comparable RS232C connector on the operator s PC These cables are available from a variety of stores that retail computers The specific type of cable required depends upon the configuration of the RS232C interface of the particular computer Refer to appendix A for a technical description of the RS232C interface as it relates to the Pachette Software is also required to utilize the remote control mode All software required on the pachymeter end of the interface is supplied within the Pachette It is the operator s responsibility to provide the software for the PC end of the interface This software will 26 vary depending upon the type and configuration of PC as well as what the operator intends to do with the Pachette Appendix C provides all the information required by a programmer to determine the format of the commands used to control the Pachette When the remote control mode is ena
9. described in section 2 1 of the SII DPU 414 Operation Manual Plug the RS232C 25 pin D Type connector on the end of the printer cable into the mating connector on the rear of the Pachette Note If the printer is to be mated to the Pachette for extended periods of time it is recommended that the D Type connector be secured to the Pachette using the 2 screws on the connector Plug the RS232C 9 pin D Type connector on the opposite end of the printer cable into the mating connector on the rear of the SII DPU 414 printer Turn on the Pachette power switch Turn on the printer power switch When the SII DPU 414 printer is powered up for the first time the yellow OFF LINE LED will blink This indicates that paper needs to be loaded into the printer Load the thermal paper into the printer as described in section 2 2 of the SII DPU 414 Operation Manual When the paper is loaded correctly the OFF LINE LED stops blinking and remains on to indicate that the printer is still off line Bring the printer on line by pressing the ON LINE button The printer is now ready to accept data from the Pachette Note If the printer has been previously loaded with paper the printer will automatically be brought on line when the power switch is turned on Obtaining A Printout E Verify that the printer is on line the green ON LINE LED should be lit If the printer is off line it can be brought on line by pr
10. gain access to the data transfer parameters 1 Plug the probe into the front panel turn on the unit and wait until the unit is ready to take a measurement Press and hold the PQT switch until the message PACH CNFG appears on the front panel Press and release the PQT switch repetitively until the I1 designator appears in the Position display and INTF appears on the Actual Data display Use the TY cursor switches if necessary to obtain XFER on the Biased Data display Press and release the PQT switch to enable the interface The I2 designator will appear on the Position display and BAUD also appears on the Actual Data display Note To disable the interface follow steps 1 thru 3 above select NONE in step 4 press the PQT switch and then go to step 7 Use the TV cursor switches if necessary to select a baud rate for the Pachette 9600 is the default that matches the baud rate of the computer interface Press the CLEAR switch to save and exit the main configuration mode Connecting The Pachette To A Personal Computer Turn off the power switch on the Pachette and on the computer Plug the Pachette AC power cord into the back panel of the Pachette and into a three prong AC outlet Connect the computer AC power cord into a three prong AC outlet Connect the RS232C data cable between the Pachette and the computer A 25 PIN D Type connector mates to th
11. mode there are two parameters associated with the averaging option These parameters are designated as AT and A2 A1 allows the operator to select which of the three data types will be calculated BIAS AAVG or BAVG The A parameter will only appear when either the AAVG or BAVG data type is selected A2 permits the operator to specify which of the four independent averages A1 thru A4 will be associated with each measurement position P2 thru P33 Use the following procedure to enter the main configuration mode and configure the Measurement Averaging option 1 Plug the probe into the front panel turn on the unit and wait until the unit is ready to take a measurement 2 Press and hold the PQT switch until the message PACH CNFG appears on the front panel 3 Press and release the PQT switch repetitively until the A1 designator appears in the position display 4 Press and release the T switch until the desired data type appears in the Biased Data display then press and release the PQT switch to select that data type 20 Note If the BIAS data type is selected the averaging option is disabled As a result the unit will exit the main configuration mode and the operator should disregard the remaining steps However if either the AAVG or BAVG data type is selected the averaging option is enabled and the operator may continue with step 5 5 A2 sho
12. must configure the interface when a printer is connected to the Pachette 1 Plug the probe into the front panel turn on the unit and wait until the unit is ready to take a measurement 2 Press and hold the PQT switch until the message PACH CNFG appears on the front panel 3 Press and release the PQT switch repetitively until the I1 designator appears on the Position display and INTF appears on the Actual Data display 4 Use the TY cursor switches if necessary to obtain PRNT on the Biased Data display 5 Press and release the PQT switch to enable the interface The I2 designator will appear on the Position display and BAUD appears on the Actual Data display Note To disable the interface follow steps 1 thru 3 above select NONE in step 4 press the PQT switch and then go to step 7 6 Use the TY cursor switches if necessary to select a baud rate for the Pachette that matches the baud rate of the printer 9600 is the default setting for the SII DPU 414 printer 7 Press the CLEAR switch to save and exit the main configuration mode Connecting The Printer To The Pachette And Loading Paper 1 Turn off the power switch on the Pachette and the SII DPU 414 printer 2 Plug the Pachette AC power cord into the back panel of the Pachette and into a 22 three prong AC outlet Connect the printer AC adapter to the back of the SII DPU 414 printer and to an AC outlet as
13. the computer receives a response from the Pachette This appendix provides the necessary information for a programmer to interpret and utilize these data formats The format of the commands sent from the personal computer to the Pachette is shown in Figure XIV A The format of the Pachette responses to the commands is shown in Figure XIV B All data transferred to and from the Pachette are 7 bit ASCII encoded hexadecimal numbers The checksum is formed by performing an 8 bit sum of all hexadecimal values preceding the checksum and generating the twos complement of this sum Hence to verify the integrity of the transmitted data a checksum can be generated for the received data and compared to the received checksum If a mismatch occurs a data transmission error occurred and the data will have to be retransmitted Each transmission is terminated with ASCII carriage return and line feed characters Example ASCII Line Feed ASCII Carriage Return Checksum Command Identifier 01 Do PQT 02 Read Switches 03 Do Measurement 04 Retransmit Last Response Figure XIV A Format of remote control commands 40 D x o o x x x XP CRLF PQT FORMAT ASCII Line Feed ASCII Carriage Return Checksum Probe Quality Factor PQT Error Bits 00 Probe OK 01 No Probe 02 Check Probe 04 PQT Fail Status Byte READ SWITCHES FORMAT ASCII Line Fe
14. the left and right sides of the foot pedal A new measurement may be taken at any position by causing the appropriate position number to appear on the display and then retaking the new measurement 7 All measurements remain in memory until the CLEAR switch is pressed or the Pachette is turned off Press CLEAR to erase all measurements and re initialize the Pachette for a new measurement sequence starting at position 1 Obtaining Measurements In Manual Mode 1 Perform the Power Up Sequence as described in section IV 2 Position the Pachette for easy visibility during patient examination 3 With the patient in supine position and visualizing a fixation spot on the ceiling position the tip of the probe onto the cornea at a location that the operator has defined as position 1 Once the probe tip is aligned properly press the right side of the foot pedal to take a measurement 4 When a measurement is obtained a short beep will occur to indicate that the measurement has been stored in memory At the same time the measurement is shown on the Actual Data display If a measurement is not obtained within 3 seconds a long beep will occur to indicate that a poor applanation has happened At the same time the message POOR APPL is displayed Note The audible feedback is provided so that the operator can concentrate on probe tip alignment and positioning If the message of POOR APPL keeps appearing on the
15. um This permits the personal computer to establish the velocity Please note that the universally accepted velocity of sound through the cornea is 1640 m sec 4 Resend last transmission This command merely resends the last data response transmitted by the Pachette This gives the personal computer retry capability in the event it detected a checksum error Note In remote control mode all Pachette switches are disabled except for the CLEAR switch Pressing CLEAR temporarily returns the Pachette to its normal mode of operation Pressing CLEAR again changes the Pachette back to remote control mode 27 Configuring The Remote Control Interface Before the Pachette can accept any commands from a PC the remote control interface parameters must be properly set The interface must first be enabled and then the baud rate or data transmission rate must be set to match the RS232C interface on the PC Once configured it is not necessary to repeat this procedure since the parameter settings are stored in non volatile memory However if it becomes necessary to reset or check the initial configuration use the following procedure to enter the main configuration mode and gain access to the remote control parameters l Plug the probe into the front panel turn on the unit and wait until the unit is ready to take a measurement Press and hold the PQT switch until the message PACH CNFG appears on the front panel Pres
16. whenever the tip of the probe is properly applanated onto the cornea The exact method for obtaining pachymetry measurements will be different depending upon which mode has been enabled on the Pachette Section IX A explains how to switch between Auto and Manual modes for those units equipped with the Auto Mode option For convenience the procedures for using both measurement modes are given below Be sure to follow the appropriate procedure for how the Pachette is configured Obtaining Measurements In Auto Mode 1 Perform the Power Up Sequence as described in section IV 2 Position the Pachette for easy visibility during patient examination 3 With the patient in supine position and visualizing a fixation spot on the ceiling position the tip of the probe onto the cornea at the location the operator has defined as position 1 Once the probe tip is aligned properly the Pachette will automatically attempt to take a measurement 4 When a measurement is obtained a short beep will occur to indicate that the measurement has been stored in memory The measurement is shown on the Actual Data display for a time interval known as Delay 1 default 1 sec After Delay 1 expires the display will advance to position 2 and two short beeps will occur to indicate that the unit is ready to take the next measurement If a measurement is not obtained within 3 seconds a long beep will occur to indicate that a poor applana
17. PENDIX B DATA TRANSFER FORMAT e eeeeeeee ente ee nn tntn ntn tn tns n statu sins tatu sons ta ensi n statuo 38 XIV APPENDIX C REMOTE CONTROL COMMANDS FORMAT cssssssssssessrsessessrsessessesesees 39 LIST OF FIGURES Figure III A Figure III B Figure III C Figure XIII A Figure XIV A Figure XIV B Figure XIV C DGH 500 Front Panel Layout 4 2 eere eee etie Rend A e c tet 3 DGH 500 Back Panel Layout nite metet tre RU Et preter eds 3 Blectromc CALBOX zh died etia tite edo eri bd e eft s 6 Format of data stream sent by Pachette eesssessseseeeeeeeeeneneene nennen enne rennen 38 Format of remote control commandis eeseeseeseseseeeeee tentent nennen een rennen tenere 39 Format of data responses to remote control commands eee 40 Status Byte Format o ohegoten e oet ee e PRO re ep HERD eite Gee SERS 4l L INTRODUCTION Ultrasonic Pachymetry is an integral part of refractive corneal surgery The DGH 500 Pachette is an ultrasonic pachymeter that uses echo spike techniques to measure the thickness of the cornea This is the recommended method for obtaining corneal thickness measurements because it offers the following advantages e Reproducibility e High accuracy e Ability to take measurements anywhere on the cornea e Measurements are not dependent upon patient fixation e Ease of use After the corneal thickness has been obtained the measurement m
18. Pachette An RS232C standard serial interface is provided for this purpose A 25 pin D Type female connector is located on the rear panel of the Pachette This connector has the following pin out assignment PIN NAME EIA NAME FUNCTION 1 FG AA Frame ground 3 TD BA Transit data 2 RD BB Receive data 7 SG AB Signal ground 20 DTR CD Data terminal ready The Pachette is configured as a Data Communication Equipment DCE device as defined by the RS232C specification This means that data leaves the Pachette on pin 3 and enters the Pachette on pin 2 of the interface A third signal active in the interface is Data Terminal Ready DTR This is an input to the Pachette that when active indicates that the interface is ready to accept data from the Pachette When the signal is deactivated by the receiving device the Pachette will temporarily suspend data transmission until the DTR goes active again This allows slower devices such as printers and personal computers to hold off data transmission from the Pachette until they are ready to receive the data When the Pachette is attempting to transmit data across the RS232C interface and DTR remains inactive for more than 30 seconds the message NO INTF no interface will appear on the front panel display the alarm will sound and the transmission will be aborted This is usually an indication that the interface is not plugged in or that the printer is not on l
19. TECHNOLOGY INC DGH DGH 500 PACHETTE ULTRASONIC PACHYMETER OPERATOR S MANUAL SYS PA5 REV 05 2000 Sales 800 722 3883 Phone 610 594 9100 610 594 0390 DGH Technology Inc 110 Summit Drive Suite B www dghkoi com Exton PA 19341 Fax I iUn 1 II Unn 2 II GENERAL DESCRIPTION sscsssssssssssssessessssessessssessessssessessssessessssessssessessssessessssessesessessessesessesseseseesers 3 IV POWER UP SEQUENCE o 7 V CONFIGURING THE PACHETTE cscsssssssssssssessessssessessssesscssrsssessssessessssessessssessessesessesessessessrsesees 8 VI OBTAINING PACHYMETRY MEASUREMENTS cccsscsssssssscsssssssssnssscsssscsssssssssssnessessessessssesees 11 VII lg IOPPo 14 VIII VERIFYING PACHETTE CALIBRATION e eeeeeeee seen entente enses tn seta tu seta sone ta sens enses ense tatus eta an 15 IX OPTIONAL FEATURES FOR THE PACHETTHEM eese esee esee en enses enata sene ta sensn statu seen su seta sone 16 IX A Automatic Measurement Mode Option cece essssecssesecsesseceseeecsecseesecseesecnaeeeesaecaeesecaeeseeneeeeenaees 16 IX B Measurement Averaging Option sssi enee e e eiaei aaee E e EEE EE ESEESE ESEE RS a 18 IX C Printer Interface Option
20. asurements re connect the probe and exit the Demo mode by pressing CLEAR and then press PQT O x 4 o Figure III C Electronic CALBOX IV POWER UP SEQUENCE UM edu ie ure m Plug the AC cord into a three prong outlet Verify that the foot pedal is plugged into the rear panel Verify that the probe is connected to the front panel Turn on the unit The Pachette performs an internal self test function and then tests all the displays by sequencing through the numbers 0 to 9 The Pachette initiates a Probe Quality Test and then displays the results A probe of satisfactory quality should yield a Probe Quality Factor PQF of 100 This will be indicated on the display as PQF 100 for approximately two seconds Any other message indicates that the probe quality is not satisfactory and pachymetry measurements will be inhibited Refer to section VII for a detailed description of the Probe Quality Test The power up sequence is finished when the Position display is set to 1 and the Actual Biased Data displays are both set to 0 The Pachette is now ready to take corneal measurements If any default parameters need to be modified refer to section V Otherwise refer to section VI for a detailed description of the proper method for obtaining measurements V CONFIGURING THE PACHETTE Configuration Overview The Pachette
21. ay be used in different ways For example the measurement may be used to determine the appropriate blade depth when making partial thickness corneal incisions during radial keratotomy or to evaluate abnormalities in corneal function causing changes in the corneal thickness or to evaluate changes in corneal thickness due to various treatment modes including contact lenses and various surgical treatments The Pachette was designed to provide a means of obtaining fast accurate corneal thickness measurements with an instrument that is simple to use economical and ultra portable We invite you to read this manual carefully to discover how quickly and easily the Pachette can be integrated into your practice Il FEATURES The Pachette is manufactured with high quality components that are designed and built using the latest technological concepts The result is an advanced and powerful pachymeter that offers practicality and reliability The following features are just a sample of the characteristics and capabilities of the Pachette Standard Features Simple to use Turn on power and the Pachette is ready to take measurements Automatically stores up to 33 measurements Simultaneously displays actual and biased measurements by position location Large 2 inch LED character displays allow easy visibility from a distance over a large viewing angle and in all lighting conditions e Proven measurement algorithm which yields accu
22. bled the Pachette performs the normal display and probe quality tests whenever the unit is powered up However the Pachette will then display the message RMTE ON remote on to indicate that it is now prepared to accept commands from the PC At this point the Pachette will not function by itself The Pachette will only respond to one of four specific computer commands by performing the indicated function and then sending the results back to the PC The commands that the Pachette will respond to are as follows 1 Perform PQT test This command is identical to the front panel PQT switch If no error occurred the probe quality factor in 596 increments will be returned 2 Read Pachette switches This command is provided to allow the personal computer to read all front panel and foot pedal switches except the CLEAR switch For instance this may be used to read the foot switch and initiate a measurement Only the first switch closure encountered starting with PQT and ending with measure will be recognized in the event of multiple closures 3 Perform pachymetry measurement The measurement command functions identically to using the foot switch except that no alarm is sounded at the end of the measurement and no value is displayed on the front panel The value returned for a valid measurement is a count This count may be converted to microns via the following formula Velocity m sec x Count 10 000 Measurement
23. ch are functional as in the Manual Mode The T and 4 cursor switches may be used to manually scroll through each measurement position If the foot switch is installed it may also be used to step through the measurement positions The measure side of the foot switch will decrement the position numbers allowing the operator to review measurements The memory side of the foot switch will increment the position numbers allowing the operator to step over measurement points Configuring The Auto Mode To enable the Auto Mode option the operator must first enter the main configuration mode see procedure below Within the main configuration there are three parameters associated with the Auto Mode option These parameters are designated as M1 M2 and M3 M1 allows the user to select the mode of operation either MANL for manual foot switch operation or AUTO for automatic measurement operation M2 and M3 will only appear if the Auto Mode is enabled M2 is the designator for Delay 1 and M3 is the designator for Delay 2 Use the following procedure to enter the main configuration mode and adjust the Auto Mode settings 18 Plug the probe into the front panel turn on the unit and wait until the unit is ready to take a measurement Press and hold the PQT switch until the message PACH CNFG appears on the front panel Press and release the PQT switch repetitively until th
24. d that the cost of servicing replaceable and expandable items including parts and labor made in connection with the routine maintenance services as described in such Operator s Manual is not covered under this warranty and is the responsibility of the purchaser This warranty is strictly limited to replacement or repair of the part that is found to be defective in material and workmanship At the option of DGH said part shall be replaced or repaired free of charge F O B our factory by DGH DGH reserves the right to make changes in the design and material of Equipment without incurring any obligations to incorporate such changes in Equipment already completed on the effective date of any such change or changes This is the only warranty of this product and is expressly in lieu of all other warranties expressed or implied by law or otherwise including any implied warranties of merchantability and of fitness for a particular purpose Without regard to the alleged defect DGH does not under any circumstances assume any responsibility for the loss of time inconvenience or other consequential damages including but not limited to loss of damage of personal property or loss of revenue DGH has neither assumed nor authorized any other person including any distributor authorized to sell its Equipment to assume for it any other liability in the connection with the sale of Equipment X E Service If you are having problems with this unit pleas
25. display check to insure the probe tip actually touches the cornea and is perpendicular to the corneal surface If a measurement is still not obtained perform the Probe Quality Test by pressing the PQT switch The Probe Quality Test can be performed at any point in the measurement sequence Whenever an acceptable measurement has been made the Actual Data display will indicate the corneal thickness in microns All thickness measurements are based on a corneal velocity of 1640 m sec unless programmed differently by the operator Simultaneously the Biased Data display will indicate a biased corneal thickness in microns that is based on surgical requirements as defined by the operator Refer to section V for instructions on programming the corneal velocity bias type and or amount of bias After obtaining an acceptable measurement for position 1 press the left side of the foot pedal once to advance the display and the unit will be ready to take the next measurement at position 2 All measurements can be reviewed on the display by either using the T switch on the front panel or by pressing the left side of the foot pedal A new measurement may be taken at any position by causing the appropriate position number to appear on the display and then taking the new measurement at that position All measurements remain in memory until the CLEAR switch is pressed or the Pachette is turned off Press CLEAR to erase all measurements and re initial
26. e M1 designator appears in the Position display Depending upon how the Pachette was previously configured either MANL or AUTO will be visible in the Actual Data display If MANL is visible use the N switch to select AUTO Press and release the PQT switch and M2 designator for Delay 1 will appear in the Position display Use the TY switch to adjust the time period of Delay 1 The time is given in seconds and it can be adjusted in half second increments Press and release the PQT switch and M3 designator for Delay 2 will appear in the Position display Use the TY switch to adjust the time period of Delay 2 The time is given in seconds and it can be adjusted in half second increments Press and release the CLEAR switch to save and exit the main configuration mode IX B Measurement Averaging Option It is often desirable to form the average of multiple measurement positions such as a circumferential average The Measurement Averaging option automatically generates an average of a group of positions that the operator defines Up to four independent averages labeled Al A2 A3 and A4 may be utilized in the Pachette Each individual average can have any measurement position from 2 thru 33 associated with it The operator must define this association when configuring the averaging option Measurement position 1 may not be averaged because it is usually reserved for the optical center When
27. e rear of the Pachette and either a 9 pin or 25 pin D Type connector mates to the computer RS232C interface also called a COM port Note If the computer is to be mated to the Pachette for extended periods of time it is recommended that the D Type connectors be secured to the Pachette and the computer by using the 2 screws on each connector 25 5 Turn on the Pachette power switch and the computer power switch Transferring Pachymetry Data To A Computer As explained above DGH Technology Inc does not provide software for a personal computer that will accept a data transfer from the Pachette However no matter what software is developed by the operator or a third party the following general guidelines can be used when transferring pachymetry data to a personal computer 1 Start an appropriate computer software program that is capable of communicating with the Pachette through the designated COM port 2 Adjust the computer COM port settings to the following parity none data bits 8 stop bits 1 baud rate 9600 3 Obtain pachymetry measurements as described in section V 4 Start the data transfer by pressing and releasing the CLEAR switch on the Pachette front panel Note If no data transfer occurs and the display indicates NO INTF no interface check the data cable to make sure that it is properly mated 5 After the data transfer is completed the measurement memory is
28. e refer to the appropriate sections of this manual Most service calls result from a misinterpretation of the operation of the instrument as described in the manual However if you feel there is a problem with the unit or a probe please contact the Customer Service Department at the address below DGH Technology Inc can also be 31 contacted via our web page at www dghkoi com When contacting us please provide the model and serial number for the unit These numbers are located on the back panel DGH Technology Inc 110 Summit Drive Suite B TECHNOLOGY INC Exton PA 19341 Phone 610 594 9100 DGI I Fax 610 594 0390 32 XL IMPORTANT NOTES XLA Prescription Device The Pachette is a prescription device and is to be used only by or under the supervision of a licensed physician XLB Tissue Exposure To Ultrasound Energy The ultrasound energy emitted by the Pachette is low intensity and will have no adverse effects on the patient and or operator However the operator is still cautioned to perform examinations using the principle of ALARA As Low As Reasonably Achievable AII examinations should be done so that the patient receives as little ultrasound radiation as possible Do not hold the probe against the eye or other tissue with the system activated except when making a measurement Do not make unnecessary measurements XI C Ultrasonic Intensities The Pachette has only one mode and ultrasonic inte
29. ed ASCII Carriage Return Checksum Switch Status 00 No Switch Depressed 01 PQT Key Depressed 03 1 Key Depressed 04 4 Key Depressed 05 Measurement Footswitch Depressed Status Byte MEASUREMENT FORMAT ASCII Line Feed ASCII Carriage Return Checksum Measurement Count Status Byte Figure XIV B Format of data responses to remote control commands 41 Each data response by the Pachette is preceded by an 8 bit status byte encoded into two ASCI characters The format of this byte is shown in Figure XIV C The four most significant bits indicate errors that the Pachette detected in the last command received from the personal computer If any of these bits are set the command was not executed The least significant bit indicates that the last PQT test resulted in an error This error must be corrected before measurements can be performed The next to the least significant bit is used by the measurement command response to indicate poor applanation Bit 7 Bit 0 Bad PQT Poor Aplanation 0 Framing Error Invalid number or characters in received command Checksum Checksum received did not match data Unrecognized Command Command not between 01 amp 04 0 Figure XIV C Status Byte Format
30. es M2 DLY1 1 0 to 9 5 sec Period of time before the unit will Auto Mode 1 0 automatically store the current measurement and advance to the next measurement position M3 DLY2 1 0 to 9 5 sec Period of time after poor applanation occurs Auto Mode 2 0 before the unit will automatically advance to the next position Al DISP BIAS Selects mode of the Biased Average display Measurement BIA AAVG BIAS biased measurement calculated from Averagin BIAS ging BAVG the actual measurement no averaging AAVG actual average associated with the current measurement position BAVG biased average associated with the current measurement position EN IP 2 P 2 to 33 Permits the operator to specify which average Measurement A1 A 1to4 number A1 to A4 is to be associated with a Averaging given measurement position P2 to P33 Depending upon the selection of a previous parameter value these parameters may not appear 10 The Velocity Configuration Mode The Velocity Configuration Mode is accessible on every Pachette This mode permits the operator to modify the corneal velocity setting of the pachymeter Corneal velocity is used in the calculation of all corneal measurements Therefore it is important that the value for the corneal velocity setting be correct The currently accepted value for the speed of sound through the cornea is 1640m s This is also the default value for the corneal velocity setting in the Pachet
31. essing the ON LINE button Obtain pachymetry measurements as described in section V Initiate the printout by pressing and releasing the CLEAR switch on the Pachette front panel During the printout the Pachette display will indicate PLSE WAIT please wait Note If no printout occurs and the display indicates NO INTF no interface check the printer cable to make sure that it is properly mated Also make sure that the printer is on line as explained above 23 4 After the printout is completed the measurement memory is cleared and the Pachette is ready for the next measurement session Printer Troubleshooting If the printer malfunctions or does not operate at all go to the troubleshooting guide that is given in section 7 of the SII DPU 414 Operation Manual In addition the printer can also perform a self test printout to verify that the print head is operating properly Refer to section 2 6 of the SII DPU 414 Operation Manual to run the test print IX D Data Transfer Interface Option The data transfer interface option is a software hardware interface that allows the Pachette to transfer pachymetry data to a personal computer PC The hardware interface that is utilized is the industry standard serial data communication protocol designated as RS232C A 25 pin connector on the rear panel of the Pachette conforms to the RS232C standard It is the operator s responsibility to provide a cable from this con
32. ine All signals within the interface are RS232C standard loads and 10V levels All other pins on the connector have no connection 36 WARNING Interfacing the Pachette with voltages in excess of 10V will cause permanent damage to the Pachette DGH Technology Inc assumes no liability for damage to the Pachette or any user equipment in the event of improper use of the RS232C interface RS232C Interface Cables There are generally two different interface cables that are used with the Pachette The first cable is needed when connecting the Pachette to the SII DPU 414 printer This cable can be purchased from DGH Technology Inc when the SII DPU 414 printer is ordered The second cable is used when connecting the Pachette to a personal computer It is usually the operator s responsibility to obtain this cable from a computer outlet store For reference the wiring diagrams for both of these cables are given in Figure XII A andFigure XII B Note If a printer other than the SII DPU 414 is used with the Pachette or if the Pachette is interfaced to a personal computer that uses a non standard RS232C port than a different interface cable may be required in each case 37
33. ize the Pachette for a new measurement sequence starting at position 1 14 VI PROBE QUALITY TEST Probe Quality Test Overview The purpose of the Probe Quality Test PQT is to allow the operator to check the quality of the ultrasonic probe when connected to the front panel When the PQT switch is pressed ultrasonic waves are emitted from the piezoelectric element in the transducer housing and transmitted through the plastic cone A return signal echo is created when the ultrasonic waves pass through the end of the plastic cone into free air This echo signal is received by the piezoelectric element and then amplified and measured within the unit The magnitude of the echo signal is compared to the magnitude of the echo signal when the unit was originally calibrated at the factory Depending on the results of this comparison a message stating the quality of the probe is displayed on the front panel 1 Ifinstalled remove the plastic protective sleeve from the probe tip 2 Connect the probe to the front panel connector labeled PROBE 3 Press and release the PQT switch The results of the test will be shown on the front panel by displaying one of the following four messages PQF 100 This indicates that the Probe Quality Factor is optimum and the probe has passed the Probe Quality Test Pachymetry measurements may now be taken CHK PRBE This message usually means the tip of the probe is wet Howeve
34. ment options Therefore the biometric measurement capabilities of a particular unit will depend upon which option is installed The following table shows the measurement range for each option Measurement Option Range um Accuracy um Display Resolution um Standard Unit 200 1300 5 1 ALK Unit 95 1100 5 1 Extended Unit 200 2000 5 1 XLE Classification According to the degree of protection against electric shock the Pachette is classified as type B equipment as indicated by the R symbol on the back panel 34 XLF EMI EMC Compliance CE Units Only The Electro Magnetic Interference and Compatibility testing of the DGH 500 Ultrasonic Pachymeter Pachette V was performed in accordance with the applicable requirements of EN60601 2 The following tests were performed yielding the test results as indicated IEC 601 1 2 Para 36 201 1 Para 36 202 2 Para 36 202 2 Para 36 202 3 1 Para 36 202 3 2 Test Description Radio Frequency RF Emissions Electrostatic Discharge Radiated Radio Frequency Electromagnetic Fields Transient Bursts Transient Surges Test Results Passed Passed Passed 3V m Passed Passed 35 XII APPENDIX A RS232C HARDWARE INTERFACE There are three interface options currently available for the Pachette 1 printer interface 2 data transfer interface and 3 remote control interface Utilization of one or more of these options requires a hardware interface to the
35. nd interface cable can either be purchased from DGH Technology Inc or the operator can supply them DGH currently offers the SII DPU 414 thermal printer by Seiko Instruments Inc for use with the Pachette Please contact DGH before attempting to interface your own printer DGH maintains a list of printers that have already been tested for compatibility with the Pachette The intent of this section is to provide the operator with information for using the SII DPU 414 printer with the Pachette Where applicable the SII DPU 414 User s Guide that was shipped with the printer will be referenced 21 Configuring The Printer Interface Before the Pachette can send any data to a serial printer the printer interface parameters must be properly set The interface must first be enabled and then the baud rate or data transmission rate must be set to match the RS232C interface on the printer Once configured it is not necessary to repeat this procedure since the parameter settings are stored in non volatile memory However if it becomes necessary to reset or check the initial configuration use the procedure below to enter the main configuration mode and gain access to the printer interface parameters Note When the SII DPU 414 printer is purchased along with the printer interface option the interface will already be configured by DGH Technology Inc However if no printer is purchased with the printer interface option then the operator
36. neal position saving the last measurement that was obtained 17 With Auto Mode enabled the Pachette will immediately be ready to take a measurement upon power up The moment the probe is applanated to the cornea a measurement will be initiated As with the initiation of a measurement with the foot switch the Pachette will attempt to get a valid measurement for 3 seconds before displaying the error message POOR APPL Once a valid measurement has been obtained and the probe is removed from the cornea the Pachette will wait between 1 0 and 9 5 seconds before automatically storing the current measurement and advancing to the next measurement position This delay referred to as Delay 1 is user configurable When the Pachette advances to the next position a short double beep is sounded to inform the operator that the advancement has occurred If poor applanation occurs and the probe is removed from the eye the Pachette will again wait between 1 0 and 9 5 seconds before advancing to the next measurement position This delay referred to as Delay 2 is also user configurable No measurement storage occurs in the case of a poor applanation With careful selection of delay times the operator may very rapidly perform a measurement session yet still have enough time to monitor measurements before the Pachette advances to the next measurement position During the Auto Mode all front panel switches and the foot swit
37. nector to a comparable RS232C connector on the operator s PC These cables are available from a variety of stores that retail computers The specific type of cable required depends upon the configuration of the RS232C interface of the particular computer Refer to appendix A for a technical description of the RS232C interface as it relates to the Pachette Software is also required to implement the data transfer All software required on the pachymeter end of the interface is supplied within the Pachette It is the operator s responsibility to provide the software for the PC end of the interface This software will vary depending upon the type and configuration of PC as well as what the operator intends to do with the data transferred from the Pachette All information required by a programmer to determine the format of the data sent by the Pachette is given in appendix B Configuring The Data Transfer Interface Before the Pachette can transfer any data to a PC the data transfer interface parameters must be properly set The interface must first be enabled and then the baud rate or data transmission rate must be set to match the RS232C interface on the PC Once configured it is not necessary to repeat this procedure since the parameter settings are 24 stored in non volatile memory However if it becomes necessary to reset or check the initial configuration use the following procedure to enter the main configuration mode and
38. nsity settings are not under the control of the operator Thus the values below are the values to be expected for a typical transducer In Water In the Eye I SPTA mw cm 2 8 17 7 47 I SPPA W cm 13 10 12 00 IM W cm 22 90 20 90 At transducer focus 1 mm from probe tip Since the Pachette is a contact scanner the energy will always be attenuated by the tissue when used as recommended However since the focal length point of maximum intensity is very short 1 mm and thus penetration into the eye is limited the water values are effectively the same as the tissue values for all practical purposes 33 If more accuracy is desired the intensity in the eye at the transducer focus corresponding to maximum intensity may be calculated according to the formula recommended by the FDA Hews e 0969 x f xz where It is the estimated in situ intensity w is the measured intensity in water at the focus of the transducer indicated in the above chart fis the ultrasonic frequency and z is the distance from the face of the probe to the transducer focus which is the point of measurement 1 millimeter The nominal frequency of these transducers is 20 MHz The actual frequency of a particular transducer may vary from this value The tissue calculations above were done with the measured frequency of the transducer used for the tests XI D Biometric Measurement Capabilities The DGH 500 can be ordered with one of three different measure
39. plemented a specific data format is used to transfer data from the Pachette to a personal computer This appendix provides the necessary information for a programmer to interpret and utilize the data stream sent by the Pachette The format of the data sent to the personal computer is shown in Figure XIII A Each character in the data stream represented by X is a 7 bit ASCII encoded decimal digit e g 1 is encoded as 31 hex 2 as 32 hex etc The first value transmitted is a four digit number representing the current setting of the velocity parameter The next two digit number represents the number of measurements to be transmitted Following this will be one to thirty three four digit pachymetry measurements represented in microns The number of measurements depends upon the number of positions for which the Pachette V was programmed The data stream is terminated with ASCII carriage return and line feed characters X X X XIX XIX X X x X X X X CR LF ASCII Line Feed ASCII Carriage Return Measurement N Measurement 1 Number of Measurement Positions N Velocity Figure XIII A Format of data stream sent by Pachette 39 XIV APPENDIX C REMOTE CONTROL COMMANDS FORMAT When the remote control interface is implemented a specific data format is used to send commands from a personal computer to the Pachette Likewise a similar data format is used when
40. r if drying the tip of the probe fails to produce an acceptable probe quality test this message may indicate that the probe has degraded and will require replacement NO PRBE This message occurs when 1 the probe connector is not mated or is improperly mated to the connector on the front panel or 2 the probe is defective PQT FAIL This message usually indicates a hardware failure occurred within the unit and the unit must be returned for repair VIII VERIFYING PACHETTE CALIBRATION Pachymeter calibration is verified by using the electronic calibration box CalBox that is supplied with the Pachette see Figure III C It is important to realize that the CalBox does not calibrate the pachymeter The CalBox generates a sequence of precise predetermined thicknesses that can be measured by the pachymeter The values of these thicknesses have been purposely selected to span the full measurement range of the unit Therefore by measuring these predetermined thicknesses the operator can quickly verify that the pachymeter is properly calibrated Procedure For Verifying Calibration 1 With the Pachette turned off connect the probe to the front panel 2 Enter the Demo mode by holding in the switch and turning on the Pachette 3 After power up is completed the display will indicate Position 1 Actual Data 0 Biased Data 0 4 Disconnect the probe and connect the Calbox to the Pachette 5 Press the
41. rate reproducible measurements in a fraction of a second e Ultra Portable Compact and light weight to allow easy transfer from the office to the hospital Adjustable tilt stand handle for ease of viewing e Operator feedback Audible signal indicates when a valid measurement is complete e Dual position foot switch for initiating measurements and memory storage e Personalized configuration User friendly front panel allows selection of number of positions to be measured speed of sound used to calculate corneal thickness and type and amount of bias based on incision depth factor e Configuration memory Once personally configured for the operator non volatile memory provides permanent storage of configuration data even when the Pachette is turned off Optional Features e Automatic measurement mode for operation without a foot switch e Measurement averaging of corneal positions designated by the operator e Printer interface for sending pachymetry data to a serial printer e Data transfer interface for sending pachymetry data to a personal computer e Remote control interface for operating the Pachette from a personal computer Il GENERAL DESCRIPTION Front Panel i LTRASONIC PACHYMETER ii ACTUAL DATA B POSITION CLEAR i POWER li PROBE DGI i TECHNOLOGY INC Figure III A DGH 500 Front Panel Layout BIASED DATA
42. ress and hold the T or 4 cursor switch 4 To advance to the next parameter press and release the PQT switch 5 Repeat steps 3 and 4 to modify any remaining parameter values 6 To save the new parameter values and exit the main configuration mode press and release the CLEAR switch 7 Pachymetry measurements may now be taken Refer to section VI for a detailed description of the proper method for obtaining measurements Table 1 Parameters Of The Main Configuration Mode And Associated Options DERI Parameter R D ipti Associated SOROR default value ae a Lee Option s P1 TYPE Selects the type of bias to be implemented Basic Percentage of the Actual Data Pachette Fixed offset added to the Actual Data Fixed offset subtracted from Actual Data P2 BIAS 1 to 199 Selects the amount of bias Basic 100 Pachette M P3 PNTS 1 to 33 Selects the number of measurement points Basic 33 Pachette Il INTF NONE RS232C serial interface mode of operation Printer NONE PRNT NONE interface is disabled Data Transfer XFER PRNT connection to printer Remote RMTE XFER data transfer to a computer RMTE remote operation from a computer Pa BAUD 300 Sets the data transfer rate in bits per second Printer 9600 600 bps for the RS232C serial interface Data Transfer 1200 Remote 2400 4800 9600 M1 MODE MANL Selects between the Automatic and Manual Auto Mode MANL AUTO measurement mod
43. s moraru re e eu p ERE RE ert Rire ie eed 20 IX D Data Transfer Interface Option eei ns etre ce eee re ee Ent d CEAN ene Lo Eee 23 IX E Remote Control Interface Option essent nennen enne enne nren etre nein ennt nnenne 25 X CARE AND MAINTENANCE eese restes nente enata snas tatu sons tatus sosiedade eiiaoe tiroirs ta sta sn an 29 XA Cleaning Instructions vis Heat Ae Rn ea leet ipea rte 29 X B Transport and Storage Conditions eese enne enne nre enne enne 29 XC Operai Conditions ve aceasta te de t dede haa ae ies 29 XD Warranty sce ne eie it etie ree dide Re pite e 30 XE Service essen bie baie wipe a ee ae diee OD BEEN E UI 30 XI IMPORTANT NOTES ccssssssssssrserscssssersessrsessessssessessssessessnsessessssessssessessssessassnsessesessessessesessessesersesees 32 XLA Prescription Device unorder te Ae Wale Apt te d ts 32 XLB Tissue Exposure To Ultrasound Energy eese eren ener 32 XLC Ultrasonic Intensities prete tee nte Der eec de eee rettet te epe bero en Lene tore nn 32 XLD Biometric Measurement Capabilities eese reete nnen rennen innen en nenne 33 XIE Classification ps uite et tea e i hr ie t rede hot etui oeste 33 XI F EMI EMC Compliance CE Units Only esee enne ener trennen nre 34 XII APPENDIX A RS232C HARDWARE INTERFACE e eeeeee seen eee ee tenens tn senses ense esto se ta suue 35 XIII AP
44. s and release the PQT switch repetitively until the I1 designator appears in the Position display and INTF appears on the Actual Data display Use the TV cursor switches if necessary to obtain RMTE on the Biased Data display Press and release the PQT switch to enable the interface The I2 designator appears on the Position display and BAUD appears on the Actual Data display Note To disable the interface follow steps 1 thru 3 above select NONE in step 4 press the PQT switch and then go to step 7 Use the TV cursor switches if necessary to select a baud rate for the Pachette 9600 is the default that matches the baud rate of the computer interface Press the CLEAR switch to save and exit the main configuration mode Connecting The Pachette To A Personal Computer Turn off the power switch on the Pachette and on the computer Plug the Pachette AC power cord into the back panel of the Pachette and into a three prong AC outlet Connect the computer AC power cord into a three prong AC outlet Connect the RS232C data cable between the Pachette and the computer A 25 PIN D Type connector mates to the rear of the Pachette and either a 9 pin or 28 25 pin D Type connector mates to the computer RS232C interface COM port Note If the computer is to be mated to the Pachette for extended periods of time it is recommended that the D Type connectors be secured to
45. te If the operator wishes to modify the default value for any reason the following procedure can be used to enter the velocity configuration mode and change the corneal velocity parameter 1 Press and hold the CLEAR switch until the message VEL appears on the Actual Data display 2 Release the CLEAR switch The default corneal velocity of 1640m s should now be displayed unless an operator had previously changed this value 3 To modify the corneal velocity press and release the T or cursor switch to increase or decrease the number being displayed Pressing and releasing the switch changes the display in one count steps Pressing and holding the switch enables the scroll mode The range of values for this parameter is 1000 to 1999m s 4 To save and exit the velocity configuration mode press and release the CLEAR switch 5 Pachymetry measurements may now be taken Refer to section VI for a detailed description of the proper method for obtaining measurements Vi OBTAINING PACHYMETRY MEASUREMENTS The basic Pachette obtains pachymetry measurements by using a foot pedal to initiate the measurement sequence This method of obtaining measurements is referred to as the Manual Mode If it is desired an option is available from the factory that allows measurements to be taken without the use of a foot pedal This option is referred to as the Auto Mode When the Auto Mode is enabled measurements are taken automatically
46. the Pachette and the computer by using the 2 screws on each connector 5 Turn on the Pachette power switch and the computer power switch Operating The Pachette From A Personal Computer As explained above DGH Technology Inc does not provide software for a personal computer that will control the operations of the Pachette However no matter what software is developed by the operator or a third party the following general guidelines can be used when controlling the Pachette from a personal computer 1 Start an appropriate computer software program that is capable of communicating with the Pachette through the designated COM port 2 Adjust the computer COM port settings to the following parity none data bits 8 stop bits 1 baud rate 9600 3 Use the computer software program to send one of the four remote control commands to the Pachette M 4 Responses to the remote control commands should be indicated in the computer software program 29 X CARE AND MAINTENANCE X A Cleaning Instructions Keep the probe tip clean To prevent patient to patient infection after each patient wipe the probe with a Q tip soaked in 70 isopropyl alcohol and then immerse the probe tip for 10 minutes in 70 isopropyl alcohol The tip should be rinsed in sterile distilled water before using The electronic console can be cleaned by wiping with a damp cloth with mild soap Do not immerse in water CAUTION
47. the averaging option is installed the Biased Average display will present one of three data types during a measurement session These data types are 1 BIAS the normal biased measurement averaging is disabled 2 AAVG the actual average that is associated with the current measurement position 19 3 BAVG a biased average that is associated with the current measurement position Two discrete LEDs above the Biased Average display are used to indicate which of the three types of data is being displayed The left hand LED is associated with the word BIASED The right hand LED is associated with the word AVERAGE Hence if the biased measurement is being displayed only the BIASED LED will be illuminated If the average is being displayed only the AVERAGE LED will be illuminated If the biased average is being displayed then both BIASED and AVERAGE LEDs will be illuminated With the Measurement Averaging option enabled the Biased Average display will show the average associated with each measurement position In addition to viewing the averages on the front panel during the measurement session the measurement averages can also be printed if the printer interface option is installed and selected Configuring The Measurement Averaging Option To enable the Measurement Averaging option the operator must first enter the main configuration mode see procedure below Within the main configuration
48. tion has happened A message of POOR APPL is also displayed for a time interval known as Delay 2 default 2 sec After Delay 2 expires the display will advance to position 2 and two short beeps will occur to indicate that the unit is ready to take the next measurement Notes The audible feedback is provided so that the operator can concentrate on probe tip alignment and positioning For instructions on changing the length of 12 Delay 1 and or Delay 2 refer to section IX A If the message of POOR APPL keeps appearing on the display check to insure the probe tip actually touches the cornea and is perpendicular to the corneal surface If a measurement is still not obtained perform the Probe Quality Test by pressing the PQT switch The Probe Quality Test can be performed at any point in the measurement sequence 5 Whenever an acceptable measurement has been made the Actual Data display indicates the corneal thickness in microns All thickness measurements are based on a corneal velocity of 1640 m sec unless programmed differently by the operator Simultaneously the Biased Data display indicates a biased corneal thickness in microns that is based on surgical requirements as defined by the operator Refer to section V for instructions on programming the corneal velocity bias type and or amount of bias 6 All measurements can be reviewed on the display by either using the switch on the front panel or by pressing
49. uld now be visible on the position display Press and release the TY switch to select the desired average number in the Biased Data display that will be associated with the measurement position shown in the Actual Data display 6 Press and release the PQT switch to assign the average number to the current measurement position The Actual Data display will advance to the next measurement position 7 Repeat steps 5 and 6 until all the desired measurement positions are associated with the correct average number s 8 When the PQT switch is pressed after the last measurement position has been set the measurement position number will roll around back to position 2 This permits reviewing the selected average number s by stepping through the measurement positions with the PQT switch making any corrections that may be required To exit the main configuration mode press the CLEAR switch IX C Printer Interface Option The printer interface option is a software hardware interface that allows the Pachette to be connected to a serial printer The hardware interface that is utilized is the industry standard serial data communication protocol designated as RS232C Refer to appendix A for a technical description of the RS232C interface as it relates to the Pachette Once the printer interface is installed a serial printer and interface cable must also be purchased before a hardcopy of pachymetry data can be obtained A compatible printer a
50. urement Mode Option Allows measurements to be taken without the use of a foot switch 2 Measurement Averaging Option Permits the averaging of a group of measurements that are defined by the operator 3 Printer Interface Option Allows a serial printer to be connected to the Pachette for obtaining a hard copy of pachymetry data 4 Data Transfer Interface Option Allows pachymetry data to be transferred to a personal computer for the purpose of archiving display formatting predictability computations etc 5 Remote Control Interface Option Permits the Pachette to be controlled externally by a personal computer This option is intended primarily for refractive surgery software packages resident on a personal computer that require access to pachymetry data The following sections give a description of each option and also explain how to use them IX A Automatic Measurement Mode Option The Automatic Measurement Mode or Auto Mode is a unique operating feature of the Pachette Auto Mode allows corneal measurements to be obtained and stored without the use of a foot switch This is achieved by sensing when the probe is placed on the cornea and when it is removed With the assistance of two user programmable time delays the operator may customize the Auto Mode to permit rapid corneal mapping while still reviewing measurements during the process Auto Mode also permits taking multiple measurements at the same cor
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