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Final Program


Final Program

1203 - A closed-loop diaphragm pacing system

Thursday, February 27, 2025
5:00 PM - 6:30 PM MST
Objectives: Diaphragm paralysis is secondary to many diseases and most of them are attributed to neurological etiology that can be treated by diaphragm pacing. We are showing a novel closed-loop diaphragm pacing system working on rats and patients.

Design: The pacing system has a wireless battery-free highly stretchable implantable pacer on hemidiaphragm, receiving power by a sticker size wireless external powering device; five wearable broadband acousto-mechanical sensors on the chest recording both breathing sound and movements, analyzing in real-time; an app installed on smartphones integrating inputs and control the pacer through Bluetooth accordingly. The system has unilateral vs bilateral pacing options, permanent vs transient (bioresorbable) versions for clinicians choosing. The system was tested on rats and patients with cervical spinal cord injury or phrenic neuropathy.

Results:

Preclinically, the pacing system restored deminished abdominal movements in both high spinal cord injury model and phrenic neuropathy model meatured by movement sensors. The average delay time was 4 ms on unilateral hemidiaphragm pacing triggered by the intact side. In patients, the system can correctly sensed breathing sound differences among five sensors and firing the pacer accordingly (not implanted on patients in this study).

Conclusions:

We created a diaphragm pacing system that 1) with self-adaptive setting catching up respiratory rate based on metabolic need; 2) fully implantable and wireless with no in-body battery; 3) has permanent/transient versions based on individual’s need; 4) achieved great synchronization when pacing unilaterally.