Troubleshooting

Trouble Shooting

Voor vragen kunt u onderstaande informatie raadplegen.

Problemen tijdens implantatie
In geval van onoplosbare problemen

Bel Hilco Bremmer van LivaNova: 06 – 8271 3794.

Communicatieproblemen tussen de programmeerkop en de pulsgenerator.
Meestal hebben communicatieproblemen te maken met de omgeving of met de programmeerkop. Slechts zelden houden ze verband met de pulsgenerator (door buiten het steriele veld de patiëntengegevens te programmeren kan je dit al uitsluiten).

Wanneer de melding verschijnt dat er een ‘communication error’ is, controleer dan in ieder geval of:

  • de programmeerkop goed contact maakt met de pulsgenerator;
  • de batterijen in de programmeerkop nog goed zijn;
  • de kabel tussen de programmeerkop en de handheld programmer goed aangesloten en in orde is;
  • de stekker die de handheld oplaad uit het stopcontact is;
  • er geen interferentie in de buurt is van bv. röntgenapparaten ed.

Controle batterijen
Het controleren van de batterijen in de programmeerkop kan door kort en gelijktijdig de twee rode RESET-knoppen in te drukken. Als het goed is gaat dan het groene lampje POWER branden en blijft deze nog 25 seconden branden. Als dat niet het geval is, moeten de batterijen (9V) vervangen worden door nieuwe batterijen.

Wanneer een pulsgenerator volledig leeg is (end of service: EOS), is er geen communicatie tussen de pulsgenerator en programmeerkop meer mogelijk.

Hoge weerstand (lead impedance = high) en/of lage weerstand (lead impedance = low)
Een hoge systeemweerstand (melding ‘lead impedance = high’ ) in de OK kan worden veroorzaakt door de volgende situaties:

  • incorrecte plaatsing van de elektrode op de nervus vagus;
  • niet helemaal schone nervus vagus;
  • materiaal met een hoge weerstand tussen elektrodecontact en de zenuw;
  • incorrecte aansluiting van de elektrode op de pulsgenerator (connector-pin niet ver genoeg in pulsgenerator, of schroef niet goed genoeg vastgedraaid);
  • een defecte pulsgenerator (te testen m.b.v. de testweerstand uit de verpakking);
  • een defecte elektrode.
Technische problemen tijdens implantatie en instellen

Wat te doen bij meten van hoge weerstand > 7000: 

  1. NVS uitzetten
  2. Anteroposteriore(AP)- en laterale X foto van thorax en nek laten maken
  3. Contact LivaNova. Foto’s naar Clinical Technical Support om te beoordelen of de leadpin goed is ingebracht en of er potentiele leadbreuken zijn (cservises@livanova.com )
  4. Overleg neurochirurg.

Technische problemen tijdens implantatie en instellen

Onderstaande informatie (English) is geëxtraheerd uit interne Cyberonics handleidingen.

Clinical Technical Support (CTS)

+ 32 2 720 95 93 (Europe)
europecomplaints@cyberonics.com

A $LEADIMPEDANCE: ($ZVALUE:) lead impedance has been detected. Impedance is lower than expected. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

LOW Impedance

 

(25)

A $LEADIMPEDANCE: ($ZVALUE:) lead impedance has been detected. This could indicate a possible discontinuity of the lead, or fibrosis between the nerve and the lead, or other problems. If you have questions, please consult the Physician’s
Manual or contact Cyberonics.

Note: $ZVALUE: can be one of the following:

  • For values >= 7000 Ohms and < 10000 Ohms, $ZVALUE: will be the measured value.
  • For values >= 10000 Ohms, $ZVALUE: will be “>= 10000”.
HIGH Impedance

 

(14) or (16)

A HIGH (>=7000oms) lead impedance has been detected. Verify that the test resistor is properly connected to the generator. If you have questions, please consult the Physician’s Manual or contact Cyberonics. HIGH Impedance

(21)

 

An invalid serial number or generator reset has been detected. If you know the serial number of the generator enter it now. The serial number must be in the range of $RANGE:

Reference Troubleshooting Option # (4) for “$RANGE” values.

Programming Settings/Generator Status

 

(5)
Backup or Recovery Error

Data Storage

 

(2)
Cannot use future date for Implant Date! HHD Configuration (3)
Caution! Frequency settings of 1Hz, 2Hz, or 5Hz are provided for diagnostic use only. Prolonged use of these settings will decrease the battery life of the implanted device.

Programming Settings

 

(9)
Checksum byte not received. Communication  (6)
Checksum error. Communication  (6)
“”Data end “” character was incorrect. Communication  (6)
“”Data start”” character was incorrect. Communication  (6)
Diagnostic Failed. The device parameters were potentially reprogrammed for the diagnostic mode. It is recommended that the generator be interrogated to verify the parameter settings.

Communication

 

 (5) followed by (6)

Diagnostic Failed. The generator parameters were potentially reprogrammed to unintended settings.Try the following and select Retry.

  • Unplug the handheld from the power outlet
  • Check the wand battery
  • Reposition the wand over the generator
 Communication  (5) followed by (12)
if needed
Error executing SQL statement HHD Corruption (2) If problem persists, (24)
Error initiating Interrogation Communication (6)
Error initiating Programming  Communication (6)
Failed CoCreateInstance. Communication (6)
Failed to initialize output current to zero prior to programming. Communication (6)
Failed to initiate start of Diagnostics Mode. Communication (6)
Failed to program proper output current value. Communication (6)
Failed to receive “”Data end”” character Communication (6)
Failed to receive “”Data start”” character. Communication (6)
Failed to receive all bytes in sequence. Communication (6)
Failed to receive model ID from generator Communication (6)
Failed to receive program acknowledgment. The generator may or may not have been programmed to the desired settings. It is recommended that the generator be interrogated to verify the parameter settings. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

Communication

 

(5) and (6)

 

Failed to resolve ClassID from ProgID Communication (6)
Failed to respond to Interrogation Communication (6)
Failed to retrieve diagnostic data. Communication (6)
Failed to send checksum Communication (6)
Failed to send END OF PROGRAM  Communication (6)
Failure in programming data sequence. Communication (6)
Generator failed to respond to programming initialization.  Communication (6)
Generator settings were altered due to an interrupted programming attempt. Select Proceed and program the Generator
to desired settings.
Communication

(5)

 

Impedance cannot be assessed. Reprogram the Pulse Generator for parameters at least set to:
Output/Mag Current: 0.75 mA
Frequency: 15 Hz
Signal/Mag ON Time: 30 sec
If you have questions, please consult the Physician’s Manual or contact Cyberonics.

Programming Settings

 

(5)
Impedance is higher than expected. Indicates a possible discontinuity of the lead, or fibrosis between the nerve and lead.
If you have questions, please consult the Physician’s Manual or contact Cyberonics.

HIGH Impedance

 

 (14) if in the OR (15)
for all other cases with
pre-Demipulse models (16)
for all other cases with
Demipulse models
Impedance is higher than expected. Verify that the test resistor is properly connected to the generator. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

HIGH Impedance

 

(21)

 

Impedance is lower than expected. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

LOW Impedance

 

(25)

 

Invalid data was received from the generator. Communication (6)
Invalid Interrogation Response Communication (6)
Invalid Programming Response. Communication (6)
It is recommended that you DO NOT operate this software without the Flash Card! Please consult the operator manual or Cyberonics before proceeding.

HHD Configuration

 

(28)
Memory on the computer is low. Recording to the database will be suspended until more memory is available. All other features will continue to work normally. Please contact Cyberonics for further assistance.

HHD Status

 

(2) followed by (31) if
problem persists
Model number does not match model number from last interrogation. Communication (6)
Model number echoed from generator was incorrect. Communication (6)
No Database exists! Creating an Empty Database. Data Storage (5)
Note that the Pulse Generator has been re-programmed to Standard Values.
Output Current (mA): 0
Signal Frequency (Hz): 30
Pulse Width (uSec): 500
Signal On Time (Sec): 30
Signal Off Time (min): 5
Mag. Current (mA): 0
Mag. On Time (Sec): 60
Mag. Pulse Width (uSec): 500

Programming Settings

 

(12)

 

One or more of the following values are out of range and must be reprogrammed: Programming Settings (8)
Programmed current is possibly not being delivered at the specified level (possibly limited by battery voltage, lead impedance, or other reason). If you have questions, please consult the Physician’s Manual or contact Cyberonics.

LIMIT Status

 

(14) for OR, (15) Clinic or
(16) Clinic if detected with a
High impedance
(22) all other cases
Programmed current is possibly not being delivered at the specified level (possibly limited by battery voltage, lead impedance, or other reason). Reprogram the Pulse Generator to a lower output current and a wider pulse width. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

LIMIT Status

 

(14), (15), or (16)
if detected with a High
impedance (5) all other
cases, then reperform
diagnostic testing

 

Programmed current is possibly not being delivered at the specified level. Verify that the test resistor is properly connected to the generator. If you have questions, please consult the Physician’s Manual or contact Cyberonics.

LIMIT Status

 

(21)
Self Test Failed on this Program! Aborting execution immediately! HHD Corruption (2)
The Backup database is more recent! Press OK if you are sure you wish to proceed

Data Storage

 

(17)
The backup or restore operation could not be completed. Data Storage (2)
The computer battery is running low. Connect the computer to the AC adapter to recharge the battery and eliminate the possibility of the computer turning off.

HHD Status

 

(5)

 

The database is empty. HHD Status (29)
The Device Frequency must be greater than 10 Hz to run Normal or Magnet Diagnostics. Please reprogram the device before using Normal or Magnet mode diagnostics.

Programming Settings

 

(5)

 

The generator did not send the model number. Communication (6)

The Generator settings were altered due to an interrupted programming attempt. Try the following and select Retry.

  • Unplug the handheld from the power outlet
  • Check the wand battery
  • Reposition the wand over the generator

Communication

 

(5) and (12)

 

The generator was partially programmed. The generator output has been turned off.

Communication

 

(12)
The Intensified Follow-up Indicator (IFI) has been set for the Pulse Generator. More frequent clinical monitoring is recommended. If you have any questions, please consult the Physician’s Manual or contact Cyberonics.

Generator Status

 

(13)

 

The Local database is more recent! Press OK if you are sure you wish to proceed Data Storage

(18)

 

The Magnet On-Time must be at least 30 seconds to run Magnet Mode Diagnostics. Please reprogram the device before using Normal or Magnet Mode Diagnostics.

Programming Settings

 

(5)
The Pulse Generator battery is nearing end of service. If VNS therapy is to be continued, it is suggested that the Pulse Generator be replaced as soon as possible. If you have questions, please refer to the Physician’s Manual or contact Cyberonics.

Generator Status

 

(5)

 

The Pulse Generator battery is nearing end of service. Please execute System Diagnostics to verify. If you have any questions, please consult the Physician’s Manual or contact Cyberonics.  Generator Status

(5)

 

The Pulse Generator battery is PAST projected end of service (EOS). If VNS therapy is to be continued, it is suggested that the Pulse Generator be replaced as soon as possible. If you have questions, consult the Physician’s Manual or contact Cyberonics.

Generator Status

 

(20) if prior to surgery,
outside of the sterile field
(5) for all other cases
The Pulse Generator did not sense a magnet swipe during the execution of the Magnet Mode Diagnostics. Please execute the diagnostic again and verify that the Pulse Generator is swiped with the magnet before starting the diagnostics. If you have any questions, please consult the Physician’s Manual or contact Cyberonics.

Diagnostic Technique

 

(5)
This Pulse Generator has been reset. The existing serial number can be used or a new serial number can be programmed.
The serial number must be in the range of $RANGE:
Reference Troubleshooting Option # (4) for “$RANGE” values.

Programming Settings

 

(5)

 

The Pulse Generator has reached End of Service (EOS) and is NOT supplying stimulation. It is recommended that the Pulse Generator be replaced immediately. If you have any questions, please consult the Physician’s Manual or contact Cyberonics.

Generator Status

 

(20) if prior to surgery,
outside of the sterile field
(5) for all other cases
The Pulse Generator is currently disabled due to $CAUSE:. Note that the generator is NOT supplying stimulation. It is
recommended that you contact Cyberonics or refer to the Physician’s Manual.
Note: $CAUSE: can be one of the following:
––an unknown reason
––a wand reset
––a pulse watchdog timeout
––a flash key violation
––a nonmaskable interrupt reset
––an oscillator fault
––a flash access violation
––a commCommand reset
––a Vbat < EOS threshold
––a direct disable

Generator Status

 

(19)

 

The Pulse Generator is nearing End of Service (N EOS). It is recommended that the Pulse Generator be replaced as soon as possible. If you have any questions, please consult the Physician’s Manual or contact Cyberonics.

Generator Status

 

(13)

 

The Pulse Generator may not be able to deliver the output current as programmed. The output current may be too high for the lead impedance. If you have question, please consult the Physician’s Manual or contact Cyberonics. LIMIT Status If detected with a High
Impedance: (14) if in the OR
(15) for all other cases with
pre-Demipulse models
(16) for all other cases with
Demipulse models For all
other cases, perform (22)
The Serial Number you have entered is not within the specified range. Programming Settings (4)
The Signal On-Time must be at least 30 seconds to run Normal Mode Diagnostics. Please reprogram the device before using Normal or Magnet mode diagnostics.

Programming Settings

 

(5)

 

The timestamp for this interrogation has expired. You must re-interrogate the device in order to continue.

HHD Configuration

 

(5)

 

The timestamp for this interrogation has expiried. You must re-interrogate the device in order to continue. The device will power down in less then one minute if no activity takes place.

HHD Configuration

 

(5)

 

The treatment time per day for this device is set to less than 24 hours. The next time programming or diagnostics are attempted communications with the VNS generator may become impossible. If you attempt to program, the software will set the treatment time per day to 24 hours automatically. Please consult your physicians manual or contact Cyberonics.

Programming Settings

 

(26)

 

There is an error establishing communications with the device. Please try repositioning the programming wand.

Communication

 

(6)

 

This Pulse Generator has been reset. The existing serial number can be used or a new serial number can be programmed. The serial number must be in the range of $RANGE:
Reference Troubleshooting Option # (4) for “”$RANGE”” values.

Programming Settings

 

(5)
This software is not compatible with this model of generator. Compatibility/Communication (7) followed by (6)
Unable to configure the serial port: HHD Software Failure (2)
Unable to create the read thread: HHD Software Failure (2)
Unable to open the port: HHD Software Failure (2)
Unable to send read request. Communication (6)
Unable to set the time-out parameters: HHD Software Failure (2)

You are only allowed to view $DBLIMIT: records at a time. You should narrow your selection using Date, Serial Number,
or Patient ID criteria. Note: $DBLIMIT: can be one of the following:
25
50
75
100

 

HHD Configuration

 

(5)

 

You have selected an Output Current change greater than a 0.25 mA-step increase. It is recommended to increase
Output Current in 0.25 mA steps to allow for accommodation of current changes.

Programming Settings

 

(5)

 Number  Action steps
 1 Fully charge the HHD
 2

Perform a hard reset:

For Dell x5 (applies to both PPC 2002 and PPC 2003 OS)
1) Plug the HHD into an appropriate power source;
2) Press and hold both the “Power” button and the “Reset” button (on the side of the HHD) for at least 5 seconds;
3) Select “Yes” to clear all data when prompted;
4) Complete the screen alignment, Windows tutorial, and set the date and time upon request;
5) Unplug the HHD from its power source once the VNS software has loaded and continue with session.

For Dell x50
1) Plug the HHD into an appropriate power source and verify that the Screen Lock button on the side of the HHD is not set;
2) Press and hold both the “Power” button and the “Reset” button (on the back of the HHD) for at least 5 seconds;
3) Select “Yes” to clear all data when prompted;
4) Complete the screen alignment, Windows tutorial, and set the date and time upon request;
5) Unplug the HHD from its power source once the VNS software has loaded and continue with session.

 3 1) Return to the main menu of the VNS software by selecting “Main Menu” from the Parameter Menu;
2) Select “User Preferences”;
3) Select “Set Time”;
4) Correct the Date and Time so that it shows today’s information;
5) Select “Accept Changes”;
6) Continue with session.
 4 Ensure the serial number for the device is within the specified ranges below:
Model, Letter, SN
100B, B, 1 to 9,999 (version v8.0 software does not support 100B)
100C, C, 10,000 to 65535
101, F, 100 to 65535
102, J, 1 to 999,999
102R, J, 1,000,000 to 16,777,215
103, no letter, 1 to 16,777,215
104, no letter, 1 to 16,777,215
105, no letter, 1 to 16,777,215
 5 Troubleshooting provided in message.
 6

Perform the following communication troubleshooting:

1) Verify that the HHD is not plugged into a wall outlet. If it is, unplug the HHD and attempt communication again. If communication is still unsuccessful, proceed to Step 2;
2) Test the wand battery by pressing and releasing both “Reset” buttons at the same time. The green power light should remain illuminated for >25 sec, if it does not, the 9V alkaline battery is depleted;
3) If the wand battery appears depleted, replace it with another 9V alkaline battery and attempt communication again. If communication is still unsuccessful, proceed to Step 4;
4) Verify that all connections between the wand and HHD cables are secure. If communication is still unsuccessful, proceed to Step 5;
5) Verify that the wand is directly over the generator, whose implant depth should be no greater than 1 inch, and that the wand is 3-4 feet away from any other electronic equipment. Rotate the wand 45 degrees and attempt communication again (slight pressure may be applied). If communication is still unsuccessful, proceed to Step 6;
6) Consider using alternative equipment. If communication is successful with other equipment, replace the product in question with known functional product (i.e. such as an alternate wand, serial adapter cable, etc) to isolate the suspect piece of equipment; If communication is still unsuccessful, proceed to Step 7;
7) For messages received upon attempted interrogation, consider other clinical symptoms that may suggest an EOS condition. A battery life calculation can be performed in order to evaluate the possible end of service condition of the generator (Note: Battery life calculations are not available for all generator models). Contact CTS for assistance.

 7 If attempting to interrogate following a generator reset:
1) Ensure that interrogation is not attempted until at least 30 seconds have elapsed following the generator reset;
2) Reinterrogate the generator;
Otherwise:
1) Verify that the model 250 software is at least version 7.0, as Demipulse generators cannot be interrogated by previous versions of software. Also, v8.0 is not compatible
with model 100B generators.
 8 If desired, reprogram the stated parameter to one of the available values in the drop-down box on the parameters screen.
 9 Reprogram the generator to a signal frequency setting of 10 Hz or greater to avoid excessive battery depletion.
 10 This step does not apply to V8.0 software
 11

Perform a generator reset:

1) Place a VNS Therapy Magnet and the Programming Wand over the Pulse Generator, and press down continuously on the two red “Reset” buttons for at least 30 seconds;
2) Wait an additional 30 seconds, then interrogate the Pulse Generator;
3) For models 100, 101, and 102/102R, reprogram the serial number, patient ID, and implant date. This step is not necessary for later models.
4) Reprogram the Pulse Generator to the desired parameters.

 12 Interrogate the device and reprogram to intended settings.
 13 Troubleshooting not needed. Action is described in the error message.
 14

Perform the following high impedance troubleshooting steps in the OR:

1) Back out the setscrew(s), remove lead pin(s), and allow the hex screwdriver to remain engaged with the setscrew(s);
2) Verify that the setscrew(s) is not visible in the Lead receptacle(s);
3) Insert Lead connector pin(s) and tighten setscrew(s) until the hex screwdriver clicks;
4) Visually inspect the Lead receptacle(s) and verify that the Lead pin(s) is past the back end of the connector block;
5) For model 102 and 103, ensure the end of connector ring is inside of Lead receptacle;
6) Tighten setscrew(s) until the hex screwdriver clicks
7) For initial implant only: If nerve site is dry, irrigate the nerve and remove pooled fluid;
8) Retry System Diagnostics.

If high impedance resolves, continue with implant; otherwise:
1) Back out setscrew(s) and remove Lead pin(s);
2) Insert test resistor into Pulse Generator and tighten setscrew(s) with hex screwdriver until the screwdriver clicks;
3) Perform Generator Diagnostics.

If a high impedance is detected while performing the generator test, there may be a generator issue; otherwise:
1) Back out the setscrew(s) and remove the test resistor;
2) Verify the setscrew(s) is not visible in the Lead receptacle(s);
3) Insert the hex screwdriver, through the generator septum, so that it properly engages with the setscrew(s);
4) Insert connector pin(s) and visually insepct the Lead receptacle(s) in order to verify that the Lead pin(s) is past the back end of the connector block
5) Tighten setscrew(s) until the hex screwdriver clicks;
6) Retry System Diagnostics.

If high impedance resolves, continue with implant; otherwise, there may be a lead issue (eg. lead fracture, fibrosis, etc.) and a lead revision may be appropriate. Contact CTS for assistance.

 15

Perform the following high impedance troubleshooting when detected outside of the OR (e.g. clinic setting):

1) Perform System Diagnostics and record results;
– DCDC codes 0-3: no intervention is needed. Consider re-running System Diagnostics to confirm result. Exception: DCDC code of 0, or a sudden drop in DCDC code from previous baseline (i.e. from 3 to a 0), accompanied with clinicals symptoms such as pain, increased seizures, etc. may indicate the presence of a possible short circuit condition; in those cases further assessment is required and surgical intervention may be needed.
– DCDC codes 4-7: there is likely an issue with the continuity of the system, such as fibrosis, lead fracture, lead pin’s not being fully inserted, etc. Surgical intervention is likely required. Device disablement (output current programmed to 0 mA) is recommended. Contact CTS for further assistance.

2) Perform Normal Mode Diagnostics and records results;
– DCDC codes 0-6 or 7 with Output Status “OK”: no intervention is needed. Consider re-running Normal Mode Diagnostics to confirm result;
– DCDC code 7 and Output Status “LIMIT”: If observed with DCDC codes of 4-7 on System Diagnostics, there is likely an issue with the continuity of the system and
surgical intervention is likely required. If observed with DCDC codes of 0-3 on System Diagnostics, the Generator cannot deliver the programmed output current. Consider
reducing output current or pulse width.

 

 16

Perform the following troubleshooting steps when high impedance is detected outside of the OR (e.g. clinic setting):

1) Perform System or Normal Mode Diagnostics and record results;
– Impedance values =7000 Ohms: there is likely an issue with the continuity of the system, such as fibrosis, lead fracture, lead pin(s) not fully inserted, etc. and
surgical intervention is likely required. Device disablement (output current programmed to 0 mA) is recommended. Contact CTS for further assistance.

 17

The latest update of parameter or diagnostic data present on the Flashcard is more recent than the HHD
(NOTE: THIS DOES NOT MEAN THERE IS NECESSARILY MORE DATA ON THE FLASHCARD):

1) Verify that the current Flashcard is the backup source normally used with the current HHD;
– If it is not, inset the correct Flashcard into the HHD. If writing to a Flashcard from a different operating system is continued, the software will present an SQL error.
– If it is, do not proceed with Backing up to Flashcard and proceed to Step 2 if it is desired to keep the more recent data;
2) Consider copying the Flashcard data by performing the following, then proceed to Step 3:
– Using a blank Flashcard, or…
– Send the current Flashcard back to Cyberonics where the information can be downloaded. An Excel sheet of the Flashcard can be sent back to the user;
3) Continue with the Back up to Flashcard operation if desired.

 18

The latest update of parameter or diagnostic data present on the HHD is more recent than the Flashcard
(NOTE: THIS DOES NOT MEAN THERE IS NECESSARILY MORE DATA ON THE HHD):

1) Verify that the current Flashcard is the backup source normally used with the current HHD;
– If it is not, insert the correct Flashcard into the HHD. If writing to a Flashcard from a different operating system is continued, the software will present an SQL error.
– If it is, proceed to Step 2;
2) The current Flashcard has been removed from the HHD during interrogations or diagnostic tests OR the data on the Flashcard has been deleted. Cancel the Restore from
Flashcard operation if the HHD data information is to be preserved.

 19

If the reason states “a wand reset”:

1) Proceed with interrogation and input the correct generator information (e.g. patient initials, generator serial number, implant date) for pre-demipulse models;
2) Reprogram the generator to desired settings.

If the reason states “Vbat < EOS threshold”:

1) If the event is believed to be related to EOS, replacing the generator is recommended if the continuation of VNS therapy is desired;
2) If the event is not believed to be related to EOS , contact CTS for additional information.

If the reason is not “a wand reset” or “Vbat < EOS threshold”:
1) Obtain copy of all relevant Flashcard data;
2) Notify Clinical Technical Services (CTS).

 20 1) Perform System or Generator Diagnostics with the device in sterile package and output current set to 0mA;
– IFI = “No” (on V8.0 software), proceed with implant;
– IFI = “Yes”, or N EOS = “Yes”, or EOS = “Yes”, or another EOS warning message appears (on V8.0 software), proceed to Step 2;
2) Wait approximately 30 minutes with Generator at room temperature;
3) Repeat Step 1. IFI = “Yes”, or N EOS = “Yes”, or EOS = “Yes”(on V8.0 software) after the 30 minutes of waiting, contact CTS for additional information.
 21 1) Back out the test resistor by loosening the setscrew(s);
2) Verify that there is no debris or other obstructions within the lead receptacle and that the setscrew(s) are not obstructing the resistor’s insertion path;
3) Re-insert the test resistor;
4) Verify that the test resistor is properly inserted (past the back end of the connector block) into the lead receptacle(s);
5) Repeat Generator Diagnostics;
6) If problem persists, contact CTS and arrange for product return.
 22 1) Reprogram the Pulse Generator to a lower output current and a wider pulse width;
2) Repeat diagnostic testing.
 23 1) Remove Flashcard from the HHD and reseat it;
2) Repeat the data operation;
3) If problem persists, contact CTS and arrange for product return.
 24 Contact CTS and arrange for product return.
 25

If in the OR and during an initial implant:
1) Remove any excess liquid that may have pooled around the leads;
2) Repeat diagnostics;
3) If problem persists, contact CTS as there may be a lead issue and lead replacement may be necessary.

All other cases:
1) Repeat diagnostics testing to verify result;
2) If problem persists, contact CTS as there may be a lead issue and lead replacement may be necessary.

 26

Contact CTS for further information.

If the generator was part of a clinical or other study:
1) Use the corresponding software to program the device as desired;

If the generator was not part of a clinical or other study:
1) Proceed with programming the generator to correct the setting if desired;
2) Obtain information on where the patient was seen in the past and obtain any relevant Flashcard data if possible.

 27 This step does not apply to V8.0 software
 28

The Flashcard serves as a data backup for the VNS Therapy System. If the Flashcard is removed, data from the HHD will not be transferred to it. Consequently, the Flashcard may not contain all of the HHD’s information once it is replaced if HHD operations are performed with the Flashcard removed.
(NOTE: It is not possible to run V8.0 VNS software without a VNS Flashcard in the HHD)

1) If the user does not have a VNS Flashcard, arrange for a new one to be sent;
2) If the user does have a VNS Flashcard, reinsert it and proceed with session.

 29 No troubleshooting needed – session can proceed as normal. This message should not be seen unless the user has deleted the database files off of the Flashcard and in the persistent memory in the HHD.
 30 Interrogate the generator before attempting Magnet Mode Diagnostic tests.
 31 Persistent memory on the HHD may be running low. If recording to the database is desired:
1) Contact CTS and arrange for product return and replacement. CTS can also provide guidance for copying handheld data onto an alternate source.

 

Vervanging, revisie of verwijdering

Vervanging, revisie of verwijdering van het NVS systeem of onderdelen van dit systeem kan om diverse redenen gewenst zijn:

  • Vervanging van de pulsgenerator is nodig als het einde van de gebruiksduur van de pulsgenerator (bijna) bereikt is en de pulsgenerator niet meer kan communiceren en/of geen therapie meer verstrekt.
  • Revisie/vervanging van de elektrode kan vereist zijn als wordt vermoed dat de geleider gebroken of beschadigd is. Dit moet blijken uit diagnostische tests en/of een röntgenopname en/of anamnese.
  • Verwijderen van het gehele NVS systeem kan vereist zijn in gevallen van infectie of in geval van bepaalde medische omstandigheden die volgens de documentatie van het product een contra-indicatie vormen.

LivaNova (voorheen Cyberonics) vraagt om geëxplanteerde onderdelen van het NVS systeem aan het bedrijf te retourneren ter analyse en recycling.

Vervanging pulsgenerator

  1. Indien nog communicatie mogelijk is, lees de huidige instellingen van de pulsgenerator uit.
  2. Verwijder de pulsgenerator uit de pocket, met de connector-pin nog steeds aangesloten.
  3. Gebruik de schroevendraaier uit de verpakking van de nieuwe pulsgenerator om de connector-pin van de elektrode los te maken uit de te verwijderen pulsgenerator.
  4. Sluit de nieuwe pulsgenerator aan op de elektrode en controleer of de connector-pin volledig is ingebracht. Draai het schroefje vast met de schroevendraaier uit de verpakking (tot twee keer een klik gehoord is).
  5. Zet de patiëntgegevens in de pulsgenerator en doe een systeemdiagnose.
  6. Plaats de pulsgenerator in de pocket.
  7. Sluit de incisie.
Bijwerkingen NVS

De ongewenste voorvallen die tijdens de klinische onderzoeken als statistisch significant zijn gemeld, zijn in alfabetische volgorde hieronder vermeld:

Meest voorkomend:

  • Dyspneu (problemen met ademhalen, kortademigheid)
  • Paresthesie (prikkelende huid)
  • Stemverandering (heesheid)
  • Vaker hoesten

Verder worden onderstaande bijwerkingen wel eens gemeld:

  • Ataxie (verlies van de mogelijkheid om spierbewegingen te coördineren)
  • Apneu
  • Braken
  • Dyspepsie (indigestie)
  • Faryngitis (ontsteking van de farynx, keel)
  • Hypesthesie (verminderde gevoeligheid)
  • Infectie
  • Insomnie (slapeloosheid)
  • Laryngisme (spasmen van de keel, larynx)
  • Misselijkheid
  • Pijn

Andere mogelijke ongewenste voorvallen in verband met:

De voorvallen met * komen in beide groepen voor

Chirurgie

  • Aspiratie (vloeistof in de longen) *
  • Bloedstolsels
  • Gezichtsverlamming, parese
  • Koorts met lage temperatuur
  • Maagpijn *
  • Migratie of uitstoting van de generator en/of geleider
  • Nekpijn *
  • Ongebruikelijke littekenvorming op de incisieplaats
  • Paralyse van linkerstemband
  • Pijn op de plaats van incisie *
  • Reactie op lichaamsvreemd implantaat, waaronder de mogelijkheid tot tumorvorming
  • Schade aan zenuwen of bloedvaten in het operatiegebied, waaronder de carotis en de v. jugularis
  • Verlamming van de nervus vagus
  • Verlamming van linker hemidiafragma
  • Vorming van vezelachtig weefsel, vloeistofzakjes
  • Zenuwletsel

Stimulatie:

  • Duizeligheid *
  • Dysfagie (moeilijkheden met slikken)
  • Geïrriteerdheid
  • Gewichtsverandering
  • Hikken
  • Irritatie van de larynx (geïrriteerde, pijnlijke keel) *
  • Keelknijpen, gevoel van stikken
  • Oorpijn
  • Opvliegers in gezicht
  • Pijnlijke of onregelmatige stimulatie
  • Reactie van huid, weefsel *
  • Recidiverend letsel van linker larynxzenuw
  • Spierpijn *
  • Tandpijn
  • Tinnitus (oorsuizen)
  • Urinaire retentie *
  • Verergering van astma en bronchitis
  • Wijzigingen in hartslag en -ritme
  • Zweer in twaalfvingerige darm, maagzweer
Suggesties bij bijwerkingen

Algemeen

Bijwerkingen treden in de regel alleen op tijdens stimulatie en verdwijnen meestal in de loop van de tijd, door gewenning.

Heesheid, hoesten, keelknijpen en kortademigheid

Mochten bijwerkingen na verloop van tijd niet minder worden dan kunnen die mogelijk op de volgende manier worden verholpen:

  1. Verlagen van de frequentie van 25 naar 20 Hz (vooral effectief bij hinderlijke heesheid).
  2. Staat pulsbreedte al 250 microseconden (vooral effectief bij gevoel van keelknijpen en kortademigheid) evt tijdelijk naar 130 msec.
  3. Indien stap 1 of 2 geen verbetering geeft: frequentie naar 20 Hz én pulsbreedte naar 250 microseconden.
  4. Indien stap 1 t/m 3 geen verbetering geeft: frequentie naar 30 Hz, pulsbreedte naar 500 microseconden en output met 0.25 mA verlagen.
  5. Heesheid kan ook verminderen door instellen op rapid cycling met een hoge bedrijfscyclus (bijvoorbeeld 7 seconden aan, 1,8 minuten uit of nog korter) bij 250Hz en 30Hz (bij mensen die het niet verdragen of zich niet kunnen uiten naar 25-20 Hz).

Apneu

Bij vermoeden van centrale/obstructieve apneu: slaaponderzoek uitvoeren (één nacht NVS aan, één nacht NVS uit). Indien apneu wordt vastgesteld: frequentie en pulsbreedte verlagen naar resp. 20 Hz en 250 microseconden. Zonodig ook output verlagen. Ook afplakken van de stimulator met de magneet (gedurende de nacht) is een te overwegen mogelijkheid.

 

 

 

Melden van bijwerkingen

Afgesproken is om onverwachte bijwerken, incidenten en calamiteiten te melden bij:

– de landelijke werkgroep

– de fabrikant van het NVS-apparaat

het meldpunt bijwerkingen implantaten  

Patiënten kunnen naast melding doen van bijwerking bij de behandelaar ook melden bij het meldpunt NVS’ van de EVN en bij het RIVM.