Compact, optical sensor device to measure forces on mitral valve structures prior to surgical repair or replacement

A team of interdisciplinary researchers at Stanford have developed a small, lightweight optical strain sensor device to sensitively measure forces within the mitral valve apparatus to help determine the appropriate repair technique for patients undergoing valvular surgery for degenerative mitral regurgitation. This force-sensing neochord (FSN) device measures the forces experienced by individual chordae tendineae within the mitral valve using a Fiber Bragg grating (FBG) core encased in a flexible coil sheath. This design mimics the natural shape and movement of natural chordae as much as possible while maintaining a compact physical footprint that minimizes interference with mitral valve leaflet motion. The FSN technology provides an extremely sensitive method for measuring the force generated by mitral valve cordae, either in vitro or in vivo. This could provide a more comprehensive understanding of mitral valve pathology for both research into heart muscle function (including for medical device and drug development) or as a clinical device for cardiovascular surgery and intervention.

Prototype FBG-based force sensing nechord (green arrow) implanted ex vivo via suture (white arrow) to measure the chordae of interest (orange arrow). APM: anteriolateral papillary muscle; PPM: posteriomedial papillary muscle, AL: anterior leaflet.

Force tracing of chordae tendineae at baseline (left) and during hypertensive conditions (right), demonstrating proper function of FBG sensor.

Stage of Research
The inventors have developed a prototype Force Bragg Grating (FBG) sensor device and a 3D printed left heart simulator model. They have demonstrated that the FBG sensors provided high-fidelity force measurements of mitral valve cordae tendineae at a temporal resolution of 1000Hz.