title: Ambulatory diffuse optical tomography and multimodality physiological monitoring system for muscle and exercise applications.
abstract: Ambulatory diffuse optical tomography (aDOT) is based on near-infrared spectroscopy (NIRS) and enables three-dimensional imaging of regional hemodynamics and oxygen consumption during a person’s normal activities. Although NIRS has been previously used for muscle assessment, it has been notably limited in terms of the number of channels measured, the extent to which subjects can be ambulatory, and/or the ability to simultaneously acquire synchronized auxiliary data such as electromyography (EMG) or electrocardiography (ECG). We describe the development of a prototype aDOT system, called NINscan-M, capable of ambulatory tomographic imaging as well as simultaneous auxiliary multimodal physiological monitoring. Powered by four AA size batteries and weighing 577 g, the NINscan-M prototype can synchronously record 64-channel NIRS imaging data, eight channels of EMG, ECG, or other analog signals, plus force, acceleration, rotation, and temperature for 24+ h at up to 250 Hz. We describe the system’s design, characterization, and performance characteristics. We also describe examples of isometric, cycle ergometer, and free-running ambulatory exercise to demonstrate tomographic imaging at 25 Hz. NINscan-M represents a multiuse tool for muscle physiology studies as well as clinical muscle assessment.
authors.affiliation: Harvard Medical School, Massachusetts General Hospital, Neural Systems Group, Building 149, 13th Street, Charlestown, Massachusetts 02129, United States.
authors.forename: Gang
authors.initials: G
authors.lastname: Hu
authors.affiliation: Harvard Medical School, Massachusetts General Hospital, Neural Systems Group, Building 149, 13th Street, Charlestown, Massachusetts 02129, United StatesbBaylor College of Medicine, Center for Space Medicine, 6500 Main Street, Houston, Texas 77030, United.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Harvard Medical School, Massachusetts General Hospital, Neural Systems Group, Building 149, 13th Street, Charlestown, Massachusetts 02129, United States.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Ivkovic
authors.affiliation: Harvard Medical School, Massachusetts General Hospital, Neural Systems Group, Building 149, 13th Street, Charlestown, Massachusetts 02129, United StatesbBaylor College of Medicine, Center for Space Medicine, 6500 Main Street, Houston, Texas 77030, United.
authors.forename: Gary E
authors.initials: GE
authors.lastname: Strangman
mesh_terms: D015716:Electrocardiography, Ambulatory / Q000295:instrumentation / Q000379:methods; D004576:Electromyography / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D015444:Exercise / Q000502:physiology*; D006801:Humans; D018670:Monitoring, Ambulatory / Q000295:instrumentation* / Q000379:methods; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D041622:Tomography, Optical / Q000295:instrumentation* / Q000379:methods