Electrical Activation of The Diaphragm for Ventilatory Assist

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00010374
Recruitment Status : Unknown
Verified September 2008 by Synapse Biomedical.
Recruitment status was:  Active, not recruiting
First Posted : February 2, 2001
Last Update Posted : September 16, 2008
University Hospitals Cleveland Medical Center
Shepherd Center, Atlanta GA
Information provided by:
Synapse Biomedical

Brief Summary:


The objectives of this study are to test the Diaphragm Pacing Stimulation (DPS) System for treating chronic ventilatory insufficiency in persons with respiratory muscle paralysis. The hypothesis being tested in the clinical trial is that laparoscopic stimulation of the diaphragm at the motor point with intramuscular electrodes is safe and effective in providing significant ventilatory support to individuals who are otherwise dependant on a mechanical ventilator. Patients in our initial study group have all suffered from high-level spinal cord injury and were full-time dependant on positive pressure mechanical ventilation prior to inclusion.

Condition or disease Intervention/treatment Phase
Spinal Cord Injury Quadriplegia Device: intramuscular diaphragm electrodes Device: Intramuscular diaphragm electrodes Not Applicable

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Detailed Description:

System: NeuRx RA/4 Diaphragm Pacing Stimulation System


The NeuRx-RA/4 is intended to be used by individuals that have sustained a spinal cord injury, requiring aid with respiration. The device connects to the diaphragm which delivers current to stimulate muscle contractions to aid in respirations.

This device currently holds an Investigational Device Exemption No. G920162 in the United States and is currently undergoing clinical trials at University Hospitals (Cleveland), Shepherd Center (Atlanta) and Vancouver (Canada).


The purpose of the study is to determine if a new, investigational diaphragm pacing system can provide part or full time respiratory support to spinal cord injured persons who normally need a mechanical ventilator. Patients with high-level spinal cord injuries typically experience chronic ventilatory insufficiency due to respiratory muscle paralysis; these patients must be supported predominantly through positive pressure mechanical ventilation with a ventilator.

The diaphragm pacing system (NeuRx-RA/4) provides an electrical signal to the motor point of the muscle that causes the diaphragm to contract and allows patients to breathe more naturally.

Synapse Biomedical, in conjunction with Case Western Reserve University and University Hospitals of Cleveland, are evaluating activating the diaphragm with percutaneous intramuscular electrodes implanted laparoscopically. This eliminates any direct contact with the phrenic nerve, allows all circuitry and electronics to remain outside the body, and provides direct, selective activation to each hemidiaphragm.

The NeuRx RA/4 Diaphragm Pacing Stimulation (DPS) System has been implanted in over 25 individuals with high-level spinal cord injury, resulting in over 20 years of cumulative active implantation time. The longest term patient was implanted March 6, 2000 and has been using the DPS System as his sole means of respiratory support for over five years. With the exception of the second patient, who does not meet our revised inclusion criteria and has gained no benefit from the implant, all of the remaining patients have been able to achieve significant tidal volumes with the DPS System. Based on the current results, the NeuRx RA/4 DPS System has demonstrated safety and efficacy in patients with high-level spinal cord injury.

Given the results to date the study has demonstrated preliminary efficacy in this patient population. With no unexpected significant adverse events reported the NeuRx RA/4 DPS System has performed reliably and safely in this patient population.

Device Description: The NeuRx RA/4 Respiratory System is manufactured by Synapse Biomedical. The NeuRx RA/4 System comprises the following components: an external, battery powered Stimulator Device, an associated Programmer/Controller, Intramuscular Electrodes, associated percutaneous Lead Wires, a Surgical Placement Tool Set, and a surgical Mapping Station.

Inclusion Criteria:

  • Age 18 years or older
  • Cervical spinal cord injury dependant on mechanical ventilation
  • Clinically stable following acute spinal cord injury
  • Bilateral phrenic nerve function clinically acceptable as demonstrated with EMG recordings and nerve conduction times
  • Diaphragm movement with stimulation visible under fluoroscopy
  • Clinically acceptable oxygenation on room air (>90%)
  • Hemodynamically stable
  • No medical co-morbidities that would interfere with the proper placement or function of the device
  • Committed primary caregiver
  • Negative pregnancy test in females of child-bearing potential
  • Informed consent from patient or designated representative

Exclusion Criteria:

  • Co-morbid medical conditions that preclude surgery
  • Active lung disease (obstructive, restrictive or membrane diseases)
  • Active cardiovascular disease
  • Active brain disease
  • Hemodynamic instability or low oxygen levels on room air
  • Hospitalization for or a treated active infection within the last 3 months
  • Significant scoliosis or chest deformity
  • Marked obesity
  • Anticipated poor compliance with protocol by either patient or primary caregiver.
  • Currently breastfeeding

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 50 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Multi-Center Pivotal Study of NeuRx RA/4 Ventilatory Assist Device
Study Start Date : February 2000
Estimated Primary Completion Date : October 2008
Estimated Study Completion Date : October 2008

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arm Intervention/treatment
Experimental: 1
The objective of this study is to assess the safety and efficacy of the NeuRx RA/4 for diaphragm pacing compared to mechanical ventilator support.
Device: intramuscular diaphragm electrodes
Conditioning of the diaphragm
Experimental: 2
To test the safety, efficacy and clinical utility of diaphragm pacing using IM electrodes placed through a laparoscopic approach to achieve artificial ventilation in spinal cord injured patients who have an internal cardiac pacemaker and require full-time ventilator support.
Device: intramuscular diaphragm electrodes
Conditioning of the diaphragm
Device: Intramuscular diaphragm electrodes
to test the safety, efficacy and clinical utility of diaphragm pacing using IM electrodes placed through a laparoscopic approach to achieve artificial ventilation in spinal cord injured patients who have an internal cardiac pacemaker and require full-time ventilator support.

Primary Outcome Measures :
  1. Clinically acceptable tidal volume sustained over a continuous 4 hour period. [ Time Frame: Within one year after implantation ]

Secondary Outcome Measures :
  1. Adverse event rate from time of electrode implant compared to published adverse event rates in a similar patient population using ventilator support. [ Time Frame: After completion of the study ]
  2. Reduction of dependence on mechanical ventilation. Improvement in the quality of life for patient and caregiver. [ Time Frame: Within one year of implantation ]

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Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No


--Disease Characteristics--

  • High cervical spinal cord injury resulting in tetraplegia
  • Respiratory failure that requires chronic mechanical ventilatory support
  • Failure of vigorous attempts to wean from ventilatory support

Normal bilateral phrenic nerve function required

--Patient Characteristics--

Performance status: Stable condition

Cardiovascular: No active cardiovascular disease

Pulmonary: No active lung disease


  • No active brain disease
  • No significant scoliosis, chest wall deformity, or obesity

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00010374

United States, Colorado
Craig Hospital
Englewood, Colorado, United States, 80113-2811
United States, Georgia
Shepherd Center
Atlanta, Georgia, United States, 30309-1465
United States, Ohio
University Hospital Of Cleveland
Cleveland, Ohio, United States, 44106
United States, Texas
The Methodist Hospital
Houston, Texas, United States, 77030
Canada, British Columbia
Vancouver CoastHealth
Vancouver, British Columbia, Canada, V5Z 1M9
Sponsors and Collaborators
Synapse Biomedical
University Hospitals Cleveland Medical Center
Shepherd Center, Atlanta GA
Principal Investigator: Raymond Onders, MD University Hospitals Cleveland Medical Center

Responsible Party: Raymond Onders, MD, University Hospitals of Cleveland Identifier: NCT00010374     History of Changes
Other Study ID Numbers: CLIN 20-0000-0009
First Posted: February 2, 2001    Key Record Dates
Last Update Posted: September 16, 2008
Last Verified: September 2008

Keywords provided by Synapse Biomedical:
Diaphragm for Ventilatory Assist
environmental/toxic disorders
neurologic and psychiatric disorders
rare disease
spinal cord injury

Additional relevant MeSH terms:
Spinal Cord Injuries
Spinal Cord Diseases
Central Nervous System Diseases
Nervous System Diseases
Trauma, Nervous System
Wounds and Injuries
Neurologic Manifestations
Signs and Symptoms