If you’re living with chronic pain caused by CRPS or causalgia in your feet, knee, hips, or groin, dorsal root ganglion (DRG) therapy may help you get back to the life you want to live. The St. Jude Medical™ Invisible Trial System for DRG help you find out if DRG therapy is right for you before you commit to surgery. It works just like our implantable Proclaim™ DRG Neurostimulator System, but it’s temporary and easy to remove.

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DRG therapy is specifically designed to help manage focal chronic pain due to CRPS or causalgia. It works by sending mild electrical pulses to the nerves responsible for the painful sensations. This could reduce or completely block the pain from the affected nerve to the brain.

The St. Jude Medical™ Invisible Trial System for DRG lets you try DRG therapy to see if its right for you before committing to an implanted system.


DRG therapy has been proven to help manage focal chronic pain due to CRPS or causalgia. A long-term clinical study showed that DRG simulation provides1:

  • 7 out of 10 patients had their pain reduced by 80% at three months
  • 8 out of 10 patients felt less pain at twelve months
  • People felt an average of 81.4% less pain at twelve months



The St. Jude Medical™ Invisible Trial System for DRG lets you manage your therapy wirelelessly using an app on an Apple** iPod touch mobile digital device. The small external generator easily hides under your clothing. It’s so discreet, we call it the Invisible Trial System.


DRG therapy has helped many people manage their chronic pain, but it may not be right for everyone. Talk to your doctor to see if the St. Jude Medical™ Invisible Trial System for DRG may be the right choice for your pain.


Learn more about a trial evaluation of neurostimulation

The St. Jude Medical™ Invisible Trial System for DRG works by stimulating the dorsal root ganglia, a dense cluster of nerves along your spine. These nerve clusters act like traffic lights that control the signals and sensations traveling to your brain.

DRG therapy targets the nerve cluster connected to the area of your lower limbs where you experience pain. Stimulating that DRG can change the way it sends pain signals and potentially reduce the amount of pain you feel.


Neurostimulator Patient Controller icon


Length: 5:53

Find out how functional neurosurgeon Steven Falowski, M.D. used DRG stimulation to give Kam a whole new outlook on her daily life with chronic lower limb pain.


The St. Jude Medical™ Invisible Trial System for DRG includes just three components:

Generator: A compact, discreet battery-powered device that sends out mild electrical pulses. The St. Jude Medical™ Invisible Trial System for DRG features the smallest external pulse generator making the trial system nearly invisible under your clothes.

Leads: Thin insulated wires that carry the mild electrical pulses from the generator to a specific DRG. The leads are placed in your body in the area of the DRG.

Patient Controller: A handheld device that lets you adjust your therapy wirelessly. The St. Jude Medical™ Invisible Trial System for DRG uses an Apple** iPod touch** mobile digital device.


Abbott’s St. Jude Medical™ Invisible Trial System for DRG is built to be discreet, helping you incorporate your DRG therapy trial into your everyday life by being virtually invisible under clothing.

You can also learn more about how DRG therapy works and receiving a system.


Typically, a trial lasts from five to ten days. Your doctor can tell you more about the length of your trial.


While many doctors allow their patients to take medications during the evaluation, every doctor has a different approach. Ask your doctor about taking medication during your evaluation.


Most people receive medication to help with any discomfort and anxiety they may feel as the leads are inserted, so most report very little discomfort during the procedure. However, you may still feel sore at the insertion site afterward.


Yes. One of the benefits of the temporary evaluation is that it is designed to be reversible. The removal of a temporary system is simple and often takes less than a minute. It is frequently performed in a doctor’s office or day surgery center.


The purpose of the evaluation is to determine your response to neurostimulation and to find out if it controls your pain throughout the day. You may be encouraged to try light activities, such as walking, to see if neurostimulation relieves your pain during those activities. Your doctor may advise you to avoid physically challenging activities. If your job is very physical, you may or may not be able to return to work. Your doctor will determine what is best for you.


The evaluation procedure and implanted system are typically covered by most major insurance plans, Medicare and workers’ compensation programs. You will need to work with your doctor’s office and insurance company to determine your coverage.

What are the risks?

Talk to your doctor about complications related to the implant procedure and/or device, which include:

  • Infection
  • Swelling
  • Bruising
  • Undesirable changes in stimulation
  • The loss of strength or use in an affected limb or muscle group (e.g., paralysis)


See more risks.


See answers to more frequently asked questions about neurostimulation.

While DRG therapy has been proven successful in many patients, it may not be right for everyone. Talk to your doctor to see if the St. Jude Medical™ Invisible Trial System for DRG may help you manage your pain.


Brief SummaryPrior to using these devices, please review the User’s Guide for a complete listing of indications, contraindications, warnings, precautions, potential adverse events, and directions for use.  The system is intended to be used with leads and associated extensions that are compatible with the system.

Indications for Use:  Spinal column stimulation via epidural and intra-spinal lead access to the dorsal root ganglion as an aid in the management of moderate to severe chronic intractable* pain of the lower limbs in adult patients with Complex Regional Pain Syndrome (CRPS) types I and II.**

*Study subjects from the ACCURATE clinical study had failed to achieve adequate pain relief from at least 2 prior pharmacologic treatments from at least 2 different drug classes and continued their pharmacologic therapy during the clinical study.

**Please note that in 1994, a consensus group of pain medicine experts gathered by the International Association for the Study of Pain (IASP) reviewed diagnostic criteria and agreed to rename reflex sympathetic dystrophy (RSD) and causalgia, as complex regional pain syndrome (CRPS) types I and II, respectively.

ContraindicationsPatients who are unable to operate the system, who are poor surgical risks, or who have failed to receive effective pain relief during trial stimulation.

Warnings/PrecautionsDiathermy therapy, implanted cardiac systems or other active implantable devices, magnetic resonance imaging (MRI), computed tomography (CT), electrosurgery devices, ultrasonic scanning equipment, therapeutic radiation, explosive or flammable gases, theft detectors and metal screening devices, lead movement, operation of machinery and equipment, pediatric use, pregnancy, and case damage.

Adverse EffectsPainful stimulation, loss of pain relief, surgical risks (e.g., paralysis).  User’s Guide must be reviewed for detailed disclosure.

To review the full Impotant Safety Information (ISI), please click HERE

If you have any concerns about your neurostimulator system, contact your doctor during normal business hours.


*Based on 12-month data studied by Deer.1

†69.5 percent of patients experienced more than 80 percent pain relief.

**Apple is a trademark of Apple, Inc. Bluetooth is a registered trademark of Bluetooth SIG, Inc.

Study subjects from the ACCURATE clinical study had failed to achieve adequate pain relief from at least two prior pharmacologic treatments from at least two different drug classes and continued their pharmacologic therapy during the clinical study.

§Please note that in 1994, a consensus group of pain medicine experts gathered by the International Association for the Study of Pain (IASP) reviewed diagnostic criteria and agreed to rename reflex sympathetic dystrophy (RSD) and causalgia as complex regional pain syndrome (CRPS) types I and II, respectively.

1. Deer TR, Levy RM, Kramer J, et al. Dorsal root ganglion stimulation yielded higher treatment success rate for complex regional pain syndrome and causalgia at 3 and 12 months: a randomized comparative trial. Pain. 2017. 158(4): 669-681. (n=152)




Prescription and Safety Information

Read this section to gather important prescription and safety information.


This neurostimulation system is designed to deliver low-intensity electrical impulses to nerve structures. The system is intended to be used with leads and associated extensions that are compatible with the system.


This neurostimulation system is indicated for the management of chronic, intractable pain.


This system is contraindicated for patients who are

  • Unable to operate the system
  • Poor surgical risks
  • Pregnant
  • Under the age of 18

MRI Safety Information

Some models of this system are Magnetic Resonance (MR) Conditional, and patients with these devices may be scanned safely with magnetic resonance imaging (MRI) when the conditions for safe scanning are met. For more information about MR Conditional neurostimulation components and systems, including equipment settings, scanning procedures, and a complete listing of conditionally approved components, refer to the MRI procedures clinician’s manual for neurostimulation systems (available online at For more information about MR Conditional products, visit the Abbott product information page at


The following warnings apply to this neurostimulation system.

Pregnancy and nursing. Safety and effectiveness of neurostimulation for use during pregnancy and nursing have not been established.

Pediatric use. The safety and effectiveness of neurostimulation for pediatric use have not been established.

External defibrillatorsSafety for use of external defibrillator discharges on a patient receiving neurostimulation has not been established. External defibrillation can cause induced currents in the lead-extension portion of the neurostimulation system. After defibrillation, confirm the neurostimulation system is still working

Magnetic resonance imaging (MRI)Some patients may be implanted with the components that make up a Magnetic Resonance (MR) Conditional system, which allows them to receive an MRI scan if all the requirements for the implanted components and for scanning are met. A physician can help determine if a patient is eligible to receive an MRI scan by following the requirements provided by Abbott Medical. Physicians should also discuss any risks of MRI with patients.

Patients without an MR Conditional neurostimulation system should not be subjected to MRI because the electromagnetic field generated by an MRI may damage the device electronics, cause heating at the lead tip that could result in tissue damage, and induce voltage through the lead that could jolt or shock the patient.

Diathermy therapyDo not use short-wave diathermy, microwave diathermy, or therapeutic ultrasound diathermy (all now referred to as diathermy) on patients implanted with a neurostimulation system. Energy from diathermy can be transferred through the implanted system and cause tissue damage at the location of the implanted electrodes, resulting in severe injury or death.

Diathermy is further prohibited because it may also damage the neurostimulation system components. This damage could result in loss of therapy, requiring additional surgery for system implantation and replacement. Injury or damage can occur during diathermy treatment whether the neurostimulation system is turned on or off. Advise patients to inform their healthcare professional that they should not be exposed to diathermy treatment.

Electrosurgery. To avoid harming the patient or damaging the neurostimulation system, do not use monopolar electrosurgery devices on patients with implanted neurostimulation systems. Before using an electrosurgery device, place the device in Surgery Mode using the patient controller app or clinician programmer app. Confirm the neurostimulation system is functioning correctly after the procedure.

During implant procedures, if electrosurgery devices must be used, take the following actions:

  • Use bipolar electrosurgery only.
  • Complete any electrosurgery procedures before connecting the leads or extensions to the neurostimulator.
  • Keep the current paths from the electrosurgery device as far from the neurostimulation system as possible.
  • Set the electrosurgery device to the lowest possible energy setting.
  • Confirm that the neurostimulation system is functioning correctly during the implant procedure and before closing the neurostimulator pocket

Implanted cardiac systemsPhysicians need to be aware of the risk and possible interaction between a neurostimulation system and an implanted cardiac system, such as a pacemaker or defibrillator. Electrical pulses from a neurostimulation system may interact with the sensing operation of an implanted cardiac system, causing the cardiac system to respond inappropriately. To minimize or prevent the implanted cardiac system from sensing the output of the neurostimulation system, (1) maximize the distance between the implanted systems; (2) verify that the neurostimulation system is not interfering with the functions of the implanted cardiac system; and (3) avoid programming either device in a unipolar mode (using the device’s can as an anode) or using neurostimulation systemsettings that interfere with the function of the implantable cardiac system

Emergency proceduresInstruct patients to designate a representative (family member or close friend) to notify any emergency medical personnel of their implanted neurostimulation system if emergency care is required. Patients will receive an identification card to carry with them that will inform emergency medical personnel of their implanted system. Advise patients to use caution when undergoing any procedure that could include radiofrequency (RF) or microwave ablation, defibrillation, or cardioversion.

Ultrasonic scanning equipment. The use of ultrasonic scanning equipment may cause mechanical damage to an implanted neurostimulation system if used directly over the implanted system.

Therapeutic radiationTherapeutic radiation may damage the electronic circuitry of an implanted neurostimulation system, although no testing has been done and no definite information on radiation effects is available. Sources of therapeutic radiation include therapeutic X rays, cobalt machines, and linear accelerators. If radiation therapy is required, the area over the implanted IPG should be shielded with lead. Damage to the system may not be immediately detectable.

Restricted areasWarn patients to seek medical guidance before entering environments that could adversely affect the operation of the implanted device, including areas protected by a warning notice preventing entry by patients fitted with a pacemaker.

Component manipulation by patientsThe patient must be instructed to not rub or exert pressure on implanted components through the skin as this may cause lead dislodgement leading to stimulation at the implant site, IPG inversion leading to the inability to communicate with the device, or skin erosion that can lead to another surgical procedure or possible infection.

Lead movementPatients should be instructed to avoid bending, twisting, stretching, and lifting objects over 2 kg (5 lb) for at least six weeks after implantation. These activities may cause lead movement, resulting in under stimulation or overstimulation for the patient. Excessive lead migration may require reoperation to replace the leads.

Scuba diving and hyperbaric chambersInstruct patients to avoid scuba diving and entering hyperbaric chambers above 1.5 atmospheres absolute (ATA) because these activities might damage the neurostimulation system.

Operation of machines, equipment, and vehiclesIn the clinical experience with this device, patients have experienced few effects when moving from lying down to sitting up. Therefore, it is unlikely patients will need to adjust stimulation when changing positions or moving. However, advise patients who feel uncomfortable paresthesia during postural changes that they should not operate potentially dangerous equipment such as power tools, automobiles, or other motor vehicles. These patients should not climb ladders or participate in activities where postural changes or abrupt movements could alter the perception of stimulation intensity and cause patients to fall or lose control of equipment or vehicles or injure others.

Explosive and flammable gasesDo not use a clinician programmer or patient controller in an environment where explosive or flammable gas fumes or vapors are present. The operation of these devices could cause them to ignite, causing severe burns, injury, or death.

Keep the device dryProgrammer and controller devices are not waterproof. Keep them dry to avoid damage. Advise patients to not use their device when engaging in activities that might cause it to get wet, such as swimming or bathing.

Device componentsThe use of components not approved for use by Abbott Medical with this system may result in damage to the system and increased risk to the patient.

Device modificationThe equipment is not serviceable by the customer. To prevent injury or damage to the system, do not modify the equipment. If needed, return the equipment to Abbott Medical for service.

Application modificationTo prevent unintended stimulation, do not modify the operating system in any way. Do not use the application if the operating system is compromised (i.e., jailbroken).

Case damageDo not handle the IPG if the case is pierced or ruptured because severe burns could result from exposure to battery chemicals.

IPG disposal. Return all explanted IPGs to Abbott Medical for safe disposal. IPGs contain batteries as well as other potentially hazardous materials. Do not crush, puncture, or burn the IPG because explosion or fire may result.

Product materialsNeurostimulation systems have materials that come in contact or may come in contact with tissue. A physician should determine whether or not a patient may have an allergic reaction to these materials before the system is implanted.


The following precautions apply to this neurostimulation system.

General Precautions

Clinician training. Implanting physicians should be experienced in the diagnosis and treatment of chronic pain syndromes and have undergone surgical and device implantation training.

Patient selectionIt is extremely important to select patients appropriately for neurostimulation. Thorough psychiatric screening should be performed. Patients should not be dependent on drugs and should be able to operate the neurostimulation system.

InfectionFollow proper infection control procedures. Infections related to system implantation might require that the device be explanted.

Implantation of multiple leads. If multiple leads or extensions are implanted, the leads and extensions should be routed in close proximity. Nonadjacent leads and extensions have the possibility of creating a conduit for stray electromagnetic energy that could cause the patient unwanted stimulation.

High stimulation outputsStimulation at high outputs may cause unpleasant sensations or motor disturbances, or render the patient incapable of controlling the stimulator. If unpleasant sensations occur, the device should be turned off immediately.

Postural changesIn the clinical experience with this device, patients have experienced few effects when moving from lying down to sitting up. Therefore, it is unlikely patients will need to adjust stimulation when changing positions or moving. However, some patients may experience a decrease or increase in the perceived level of stimulation. Perception of higher levels of stimulation has been described by some patients as uncomfortable, painful, or jolting. Advise patients who experience these types of stimulation changes to turn down the amplitude or turn off the IPG before making extreme posture changes or abrupt movements such as stretching, lifting their arms over their heads, or exercising. If unpleasant sensations occur, the IPG should be turned off immediately.

Sterilization and Storage

Single-use, sterile deviceThe implanted components of this neurostimulation system are intended for a single use only. Sterile components in this kit have been sterilized using ethylene oxide (EtO) gas before shipment and are supplied in sterile packaging to permit direct introduction into the sterile field. Do not resterilize or reimplant an explanted system for any reason.

Storage environmentStore components and their packaging where they will not come in contact with liquids of any kind.

Handling and Implementation

Expiration dateAn expiration date (or “use-before” date) is printed on the packaging. Do not use the system if the use-before date has expired.

Package or component damageBefore opening any sterile package, verify the kit model number, that the kit is within its expiration (use-before) date, and that the packaging has not been damaged or compromised in any way. If the packaging has been compromised, the device is beyond its expiration date, or the sterile package or device show signs of damage, do not use the device as it may be compromised and could cause harm to the patient. Return any suspect components to Abbott Medical for evaluation.

Handle the device with careThe clinician programmer and patient controller are sensitive electronic devices that can be damaged by rough handling, such as dropping them on the ground.

Lead inspectionCarefully inspect the lead (in the sterile field) for damage after removing it from the sterile package. Damage to the lead body can cause improper function and stimulation or stimulation to areas other than the intended target.

Care and handling of componentsUse extreme care when handling system components prior to implantation. Excessive heat, excessive traction, excessive bending, excessive twisting, or the use of sharp instruments may damage and cause failure of the components.

Component handlingDo not bend, kink, or stretch the lead body, sheaths, or other components as this may result in damage to the component and poor function.

Using surgical instrumentsDo not use surgical instruments to handle the lead. The force of the instruments may damage the lead or stylet.

Component manipulationDo not over-manipulate the sheath and lead system as this may result in trauma within the epidural space.

Stylet handlingDo not bend, kink, or use surgical instruments on the stylet, as this may damage it. Use care when reinserting a stylet. Too much pressure on the stylet could damage the lead, resulting in intermittent or loss of stimulation. Remove the stylet from the lead only when satisfied with lead placement. If the stylet is removed from the lead, it may be difficult to reinsert it.

Sheath insertion precautionDo not insert the sheath into the epidural space without the lead or guidewire inserted, as this may cause injury to the dura.

Stabilizing the lead during insertionWhen inserting the lead-sheath assembly through the needle into the epidural space, tighten the lead stabilizer to prevent lead migration out of the sheath. Failure to do so may cause harm to the patient such as damage to the dura.

Bending the sheathDo not bend the sheath without the lead inside the sheath, as this will permanently kink it and make it difficult to deploy the lead.

Lead handlingIf the operating field is bloody, wipe gloves, lead, stylet, and sheath before handling the lead. Failure to do so may result in difficulty delivering the lead.

Exposure to body fluids or salinePrior to connection, exposure of the metal contacts, such as those on the connection end of a lead or extension, to body fluids or saline can lead to corrosion. If such exposure occurs, clean the affected parts with sterile, deionized water or sterile water for irrigation, and dry them completely prior to lead connection and implantation.

System testingTo ensure correct operation, always test the system during the implant procedure, before closing the neurostimulator pocket, and before the patient leaves the surgery suite.

Component disposalReturn all explanted components to Abbott Medical for safe disposal.

Hospital and Medical Environments

High-output ultrasonics and lithotripsyThe use of high-output devices, such as an electrohydraulic lithotriptor, may cause damage to the electronic circuitry of an implanted IPG. If lithotripsy must be used, do not focus the energy near the IPG.

Home and Occupational Environments

Electromagnetic interference (EMI)Some equipment in home, work, medical, and public environments can generate EMI that is strong enough to interfere with the operation of a neurostimulation system or damage system components. Patients should avoid getting too close to these types of EMI sources, which include the following examples: commercial electrical equipment (such as arc welders and induction furnaces), communication equipment (such as microwave transmitters and high-power amateur transmitters), high-voltage power lines, radiofrequency identification (RFID) devices, some medical procedures (such as therapeutic radiation, static magnetic field [SMF] therapy, and electromagnetic lithotripsy), and some medical devices (such as bone growth stimulators, transcutaneous electrical nerve stimulation [TENS] devices, dental drills, and ultrasonic probes).

Wireless use restrictions. In some environments, the use of wireless functions (e.g., Bluetooth® wireless technology) may be restricted. Such restrictions may apply aboard airplanes, in hospitals, near explosives, or in hazardous locations. If you are unsure of the policy that applies to the use of this device, please ask for authorization to use it before turning it on. (Bluetooth® is a registered trademark of Bluetooth SIG, Inc.)

Security, antitheft, and radiofrequency identification (RFID) devicesSome antitheft devices, such as those used at entrances or exits of department stores, libraries, and other public places, and airport security screening devices may affect stimulation. Additionally, RFID devices, which are often used to read identification badges, as well as some tag deactivation devices, such as those used at payment counters at stores and loan desks at libraries, may also affect stimulation. Patients who are implanted with nonadjacent multiple leads and patients who are sensitive to low stimulation thresholds may experience a momentary increase in their perceived stimulation, which some patients have described as uncomfortable or jolting. Patients should cautiously approach such devices and should request help to bypass them. If they must go through a gate or doorway containing this type of device, patients should turn off their IPG and proceed with caution, being sure to move through the device quickly.

Mobile phonesWhile interference with mobile phones is not anticipated, technology continues to change and interaction between a neurostimulation system and a mobile phone is possible. Advise patients to contact their physician if they are concerned about their mobile phone interacting with their neurostimulation system.



In addition to those risks commonly associated with surgery, the following risks are associated with using this neurostimulation system:

  • Unpleasant sensations or motor disturbances, including involuntary movement, caused by stimulation at high outputs (if either occurs, turn off your IPG immediately.)
  • Undesirable changes in stimulation, which may be related to cellular changes in tissue around the electrodes, changes in electrode position, loose electrical connections, or lead failure or breakage
  • Stimulation in unwanted places (such as stimulation of the chest wall)
  • Lead migration, causing changes in stimulation or reduced pain relief
  • Epidural hemorrhage, hematoma, infection, spinal cord compression, or paralysis from placement of a lead in the epidural space
  • Cerebrospinal fluid (CSF) leakage
  • Tissue damage or nerve damage
  • Paralysis, weakness, clumsiness, numbness, sensory loss, or pain below the level of the implant
  • Pain or bleeding where the needle was inserted
  • Persistent pain at the electrode or IPG site
  • Escalating pain
  • Seroma (mass or swelling) at the implant site
  • Headache
  • Allergic or rejection response to device or implant materials
  • Implant migration or skin erosion around the implant
  • Battery failure, leakage, or both
  • Hardware malfunction that requires replacing the neurostimulator
  • Pain from a noninjurious stimulus to the skin or an exaggerated sense of pain

Additional risks to the patients, as a result of the placement and stimulation of the lead in the area of the dorsal root ganglion (DRG), include pain from setting the stimulation parameters too high. This may occur once the lead is in place and is connected to the neurostimulator and activated. The neurostimulator is controlled by a trained operator and the starting point for the stimulation will be set to the lowest available settings. Additionally, all patients will be awake and conversant during the procedure to minimize the impact.