Ultrasound-coupled electrical impedance tomography for assessment of neuromuscular disorders

PROJECT SUMMARY ABSTRACT Clinical NeedThe coming decades promise a revolution in the therapies available for patients with generalized neuromuscular diseasesGNMDsincluding muscular dystrophyamyotrophic lateral sclerosisspinal muscular atrophymyasthenia gravisand a variety of acquired myopathiesHoweverin order to help facilitate thisthe academic and industrial clinical research communities need improved biomarkers to assess the impact of their new potential therapiesIn additiononce these therapies become approvedthese tools will be needed to help in tailoring therapy to the needs of individual patientsLimitationsCurrent approaches for evaluating GNMD are very limitedwith modest sensitivity and uncertain reliabilityThese methods typically include simple force measurementselectromyographyEMGor imaging with MRI or ultrasoundUSFor exampleforce measurements require patient cooperation making them very subject dependent with low reliabilityEMG is invasivepainfuland generally only provides qualitative outcomesMRI is very expensive and not able to be performed in a routine clinic visitFinallyUS is extremely convenient since it can be used directly in the clinichoweverit is qualitative and very challenging to perform meaningful quantitative image assessmentOur ProductUltrasound coupled Electrical Impedance TomographyUS EITis an electrical property imaging device that integrates with a standard ultrasound probe to provide augmented US imagingSimilar to Doppler imaging for blood flow mappingour device will be able to beflipped onto provide a map of the electrical properties of the underlying muscle tissueElectrical properties of muscle have been shown through many studies to discriminate healthy from diseased tissueIn factelectrical impedance myographyEIMhas been extensively used for diagnosing and assessing GNMDhoweverthis approach is a single local measurement and provides no spatial information regarding muscle pathophysiologyWe plan to combine for the first time ever in a commercial settingelectrical impedance imaging with standard US for assessing NMDWe hypothesize that this device will be sufficiently sensitive and specific so as to provide a highly reliable output on muscle healthSpecific ObjectivesWe specifically propose to design a sonolucent electrode array and housing that seamlessly integrates to a standard US probeSecondlywe will evaluate our technology s repeatability and ability to evaluate muscular dystrophyi edistinguish healthy from diseased musclein a small feasibility trial in humansFuture DirectionsRyTek Medical is a small company developing bioimpedance sensing devices for a variety of clinical applicationsThis device will complement our existing effortsBy the end of this Phaseeffortwe will have demonstrated that the US EIT probe is functional in a human population and we will have provided evidence that this approach can distinguish healthy from diseased muscleThis will position us for Phasefunding focused on conducting a clinical trial aimed at assessing muscular dystrophy progression and preparing for akor IDE application to the FDA PROJECT NARRATIVE Treatment efficacy of generalized neuromuscular disordersGNMDis currently assessed via single point measurements using electromyographyquantitative strength testingor via imaging with MR systems or in clinic ultrasoundUSunfortunatelythese systems are not cost effective and unable to be used in the clinicMRIor have a low specificity in terms of assessment information providedUSWe propose to couple a highly specific electrical impedance imaging modality to standard in clinic ultrasound probes in order to improve therapeutic efficacy assessment metrics currently provided via US imagingelectrical impedance has been shown by our team to be highly sensitive and specific to neuromuscular disease and for the first time we propose to image these properties in tandem with US based GNMD imagingThis novel technology will provide highly specific spatial information regarding the heterogeneity of neuromuscular function and health in an easy to use bedside device that is directly coupled to standard ultrasound probes! !