Cervical Spinal Cord Stimulation for Activity-Responsive Breathing
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Solution Overview
Problem
Current respiratory stimulation technologies, such as phrenic nerve stimulators, fail to react to changes in a patient's activity state and only activate the diaphragm during the inspiratory phase, failing to fully recapitulate normal breathing patterns in diseased states.
Innovation Solution
Stimulating the cervical, thoracic, and/or lumbar spinal cord with electrical current at specific frequencies (30-60 Hz) and combining this with serotonin agonist medication to modulate breathing, along with epidural or transcutaneous electrical stimulation, to activate a respiratory drive responsive to normal feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phrenic nerve stimulators are used to stimulate the diaphragm muscle, then the inspiratory phase of respiration is activated, but the system cannot react to changes in patient activity state and only activates the diaphragm
Solution Approach 1:
The patent applies feedback by using sensors to detect patient activity state and respiratory parameters, then adjusting stimulation parameters accordingly. The system monitors respiratory rate, effort, and other parameters to dynamically modify diaphragm stimulation, enabling it to react to changes in patient activity state while maintaining reliable respiratory function.
Solution Approach 2:
The system transitions from static diaphragm activation to dynamic stimulation that adapts to changing patient conditions. By continuously adjusting stimulation intensity and timing based on real-time sensor data about patient activity and respiratory state, the system becomes versatile and responsive to various physiological conditions.
2Productivity
If diaphragm stimulation is applied, then inspiration is enhanced, but normal breathing patterns including coughing, airway opening, and swallowing are not fully recapitulated
Solution Approach 1:
The patent makes the diaphragm stimulation system multi-functional by enabling it to perform not only inspiration but also coughing, airway opening, and swallowing functions. By varying stimulation parameters (intensity, frequency, duration, and pattern) the same diaphragm can execute multiple respiratory-related actions, greatly enhancing the system's versatility and respiratory output.
Solution Approach 2:
The system uses periodic variation in stimulation patterns to produce different respiratory functions. By applying rhythmic, pulsatile, or intermittent stimulation rather than continuous stimulation, the system can elicit coughing bursts, swallowing movements, and other periodic respiratory actions in addition to normal breathing.
3Reliability
If spinal cord stimulation is applied to activate respiratory network, then breathing patterns are improved, but the system complexity increases compared to simple diaphragm stimulation
Solution Approach 1:
The patent introduces the spinal cord as an intermediary target between the stimulation device and the diaphragm. Rather than directly stimulating the diaphragm or using complex brainstem stimulation, the system applies stimulation to the spinal cord (specifically cervical and/or thoracic regions) which then activates the respiratory network and diaphragm through existing neural pathways, simplifying the overall system while improving reliability.
Solution Approach 2:
The system replaces complex mechanical or direct neural stimulation approaches with electrical stimulation of the spinal cord. By using electrical currents delivered through electrodes positioned over the spinal cord, the system achieves reliable respiratory drive activation without requiring complex mechanical interfaces or direct brainstem manipulation, thus reducing overall system complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The described methods fully recapitulate normal breathing patterns by activating the respiratory network, enabling coughing, airway opening, and swallowing, and potentially replacing ventilators as respiratory 'pacemakers' for patients with reduced respiratory drive due to brain or spinal injuries, neurodegenerative disorders, or medication overdose.
Implementation Method 1
Stimulating the cervical, thoracic, and/or lumbar spinal cord with electrical current at specific frequencies (30-60 Hz)
Implementation Method 2
epidural or transcutaneous electrical stimulation
Implementation Method 3
transcutaneous electrical stimulation of the spinal cord or a region thereof
Implementation Method 4
neuromodulating the cervical spinal cord of subject with magnetic stimulator at frequency and intensity sufficient to regulate and to restore respiration
Data Source
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AI summary
In various embodiments, methods are provided for improving, and/or regulating, and/or restoring respiration in a subject with a respiratory deficiency. In certain embodiments the methods involve neuromodulating the cervical spinal cord of a subject by administering transcutaneous stimulation to the cervical spinal cord or a region thereof at a frequency and intensity sufficient to regulate and/or to restore respiration; and/or neuromodulating the cervical spinal cord of a subject by administering epidural stimulation to the cervical spinal cord or a region thereof at a frequency and intensity sufficient to regulate and/or to restore respiration; and/or neuromodulating the cervical spinal cord of a subject with a magnetic stimulator at a frequency and intensity sufficient to regulate and/or to restore respiration.