"Electromagnetical Stimulation of Phrenic Nerve to Generate Contraction of the Diaphragm"

"Electromagnetical Stimulation of the Phrenic Nerve to Generate Contraction of the Diaphragm in Healthy Subjects and Anaesthetized and Intubated Patients - a Feasibility Study"

The scientific study is intended to show that external non-invasive electromagnetic stimulation can be used to safely and effectively stimulate the phrenic nerve in awake healthy subjects as well as in ventilated, anesthetized patients and that the stimulation can generate a diaphragmatic contraction that generates significant breath volume - a Controlled Own Breath (COB).

Also of interest is the reproducibility of the generated diaphragmatic movements and the reliability of different feedback signals for detecting the generated diaphragmatic contraction. This applies to inspiration and expiration detection for subsequent synchronization mechanisms of the magnetic stimulator for patient-initiated breathing as well as to contraction intensity. Further, the characterization of the position finding process is of great importance, so that technical developments can further simplify the process of coil positioning in the future. The possible occurrence of discomfort and pain sensation will also be investigated in awake healthy volunteers. Different stimulation protocols will be used.

Finally, it will be investigated whether an adjusted coil position still triggers reproducible diaphragmatic contractions after removal and repositioning in the same configuration. The knowledge gained will be used to further develop the technique and to prepare a study in critically ill, ventilated patients where the diaphragmatic muscle is to be treated preventively by stimulating the phrenic nerve, in order to prevent atrophy of the muscle.

Study Overview

• Status: Completed
• Conditions: Healthy Subjects; Elective Surgical Procedure
• Intervention / Treatment: Device: Stimit Activator

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Nottwil, Switzerland
    • Swiss Paraplegic Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Persons aged > 18 years
• Applicable for Group 2: planned for elective surgery
• No relevant pre-existing conditions - corresponding to American Society of Anesthesiologists (ASA) level of I-II.
• Written informed consent by the patient for participation in the study given

Exclusion Criteria:

• chronic lung diseases (bronchial asthma, COPD)
• known diaphragmatic weakness
• known neurological conditions with motor muscle weakness
• known paralysis of the phrenic nerve
• conditions that limit the mobility of the diaphragm (high intra-abdominal pressure, ascites, BMI >30)
• not able to read and understand the national language German
• skin lesions, infections or strictures in the neck area
• persons with Implanted cardiac support systems (pacemaker, implanted defibrillator)
• persons with implanted medical pumps
• pregnant women
• persons deprived of liberty by administrative or judicial decision or under legal guardianship.
• Participation in another clinical trial

• Applicable for group 2 (intubated and mechanically ventilated) patients: Exclusion criteria at the time of stimulation:

  • Unstable patient after induction of anesthesia and intubation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: OTHER
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Phrenic nerve stimulation with Stimit Activator	Device: Stimit Activator; The Stimit Activator Device is composed of three components.; A magnetic stimulator generating current pulses; A novel Stimit coil design optimized for phrenic nerve stimulation; A coil positioning device for quick, easy and reproducible coil positioning

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in airway pressure / endpoint Group 1:	The primary outcome / endpoint is the change in airway pressure at the mouth during stimulation as seen with or without the use of the ventilator	During stimulation
Discomfort / pain during stimulation measured by Visual Analogue Scale / endpoint Group 1:	The primary outcome / endpoint is the level of discomfort / pain during stimulation, measured by Visual Analogue Scale(0-100, with 100 being worst pain / discomfort)	During stimulation
Change in airway pressure / endpoint Group 2:	The primary outcome / endpoint is the change in airway pressure during stimulation as seen with or without the use of the ventilator during stimulation.	During stimulation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diaphragmatic contraction	Diaphragmatic contraction at 20 percent / 30 percent / 40 percent stimulation intensity at the optimal stimulation site, at 25 Hz and 2s stimulation time	During stimulation
Feedback signals	Change of the maximum value of the feedback signals in percent of the maximum depending on the coil position (in 0.5 cm steps; at least 3 steps in each direction)	During stimulation
Time stimulation start to end	Time (mean value & standard deviation) between stimulation start and stimulation end (trigger signal start and end) until the feedback signals from: the abdominal belt,; the Diaphragm Thickening Fraction ((TFdi) according to standard procedure, measured via ultrasound during stimulation), and; the Diaphragm Excursion Signal "respons" (measured by ultrasound during stimulation)	During stimulation
Correlation stimulation intensity and diaphragm contraction	Correlation between stimulation intensity (power output in percent) and diaphragm contraction, measured by tidal volume, at the optimal coil position at given frequency (25 Hz) and given stimulation duration	During stimulation
Optimal stimulation site - distance	Distance from anatomical landmark (a) to optimal stimulation site (b) and phrenic nerve (c) using ultrasound and between b and c	During stimulation
Optimal stimulation site - time	Time from the start of coil positioning to finding a coil positioning which produces the maximum diaphragmatic contraction at a given stimulation intensity and frequency of 25 Hz	During stimulation
Tidal volumes	The mean and standard deviation of generated tidal volumes for ten stimulations performed without the subject being ventilated	During stimulation
Skin reactions / musle activation	For Group 1: evaluation of stimulation-induced local skin reactions or muscle activation leading to paresthesia in the dental area	During stimulation
Safety outcome	The safety outcome/ endpoint is the occurrence of the following events during stimulation: Device related Adverse Events; Device related Serious Adverse Events	During stimulation and postoperatively, usually within 2-3 hours

Collaborators and Investigators

• Sponsor: Stimit AG
• Investigators: Principal Investigator: Michael Baumberger, MD, Swiss Paraplegic Center Nottwil

Study record dates

Study Major Dates

• Study Start (ACTUAL): June 25, 2021
• Primary Completion (ACTUAL): December 13, 2021
• Study Completion (ACTUAL): December 13, 2021

Study Registration Dates

• First Submitted: April 30, 2021
• First Submitted That Met QC Criteria: May 10, 2021
• First Posted (ACTUAL): May 13, 2021

Study Record Updates

• Last Update Posted (ACTUAL): January 6, 2022
• Last Update Submitted That Met QC Criteria: January 5, 2022
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: Stimit swiss I

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No