US-based Synapse Biomedical has received approval from the Health Canada for its NeuRx diaphragm pacing system (DPS), designed to assist ventilator-dependent spinal cord injury (SCI) patients who lack control of their diaphragms.

The approval is based on patient data supplied from clinical trials at hospitals in the US and Canada, including Vancouver General Hospital.

NeuRx DPS is implanted through minimally invasive laparoscopic surgery and provides electrical stimulation of the muscles of the diaphragm.

During the procedure, a surgeon creates small holes in the abdomen and inserts a laparoscope so the diaphragm muscle can be seen. The surgeon then places small electrodes in the diaphragm.

Electrodes are then attached to a small external battery powered pulse generator, which stimulates the diaphragm, causing a contraction of muscle.

This allows air to fill the upper and lower parts of the lungs rather than forcing air in with a mechanical ventilator.

The stimulation is then used to condition the diaphragm, enabling the patient to breathe longer without the need of ventilator.

The device is controlled through a four-channel, battery-powered external pulse generator and eliminates the need for a source of electricity and concern for power outages.

"Although results may vary, some patients are provided the greatest freedom and are ventilator free for up to 24 hours a day."

Diaphragm dysfunction can result in abnormal or absent respiration in patient populations of high-level SCI and other injuries or diseases affecting the neuromuscular respiratory pathways.

In the US clinical trial, more than 50% of the eligible participants were able to completely eliminate their need for mechanical ventilation.

In November 2007, the NeuRx DPS received CE Mark for treating patients with diaphragm dysfunction and received the US Food and Drug Administration (FDA) approval for ventilator dependency from spinal cord injury in June 2008.

The Lung Centre Vancouver British Columbia respirologist and professor of Medicine UBC Dr Jeremy Road said: "Although results may vary, some patients are provided the greatest freedom and are ventilator free for up to 24 hours a day."

This new approval enables SCI patients throughout Canada to access this technology that was only previously available to clinical trial participants or through the Medical Devices Special Access Programme.

According to GlobalData estimates, the neurostimulation devices market in Canada was valued at $18.1m in 2012 and is expected to grow at a CAGR of 9.8% to reach $35m by 2019.

Image: A diaphragm stimulator. Photo: courtesy of Synapse Biomedical Inc.