Biomedical Engineering and Bioengineering Commons^™

Biomechanical Tolerance Of Whole Lumbar Spines In Straightened Posture Subjected To Axial Acceleration, Brian D. Stemper, Sajal Chirvi, Ninh Doan, Jamie L. Baisden, Dennis J. Maiman, William H. Curry, Narayan Yoganandan, Frank A. Pintar, Glenn Paskoff, Barry S. Shender

Biomedical Engineering Faculty Research and Publications

Quantification of biomechanical tolerance is necessary for injury prediction and protection of vehicular occupants. This study experimentally quantified lumbar spine axial tolerance during accelerative environments simulating a variety of military and civilian scenarios. Intact human lumbar spines (T12‐L5) were dynamically loaded using a custom‐built drop tower. Twenty‐three specimens were tested at sub‐failure and failure levels consisting of peak axial forces between 2.6 and 7.9 kN and corresponding peak accelerations between 7 and 57 g. Military aircraft ejection and helicopter crashes fall within these high axial acceleration ranges. Testing was stopped following injury detection. Both peak force and acceleration were significant …

Optimizing Filter-Probe Diffusion Weighting In The Rat Spinal Cord For Human Translation, Matthew D. Budde, Nathan P. Skinner, L. Tugan Muftuler, Brian D. Schmit, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

No abstract provided.

The Temporal Expression Of Adipokines During Spinal Fusion, Sohrab Virk, Alicia L. Bertone, Hayam Hamaz Hussein, Jeffrey M. Toth, Mari Kaido, Safdar Khan

Biomedical Engineering Faculty Research and Publications

Background Context

Adipokines are secreted by white adipose tissue and have been associated with fracture healing. Our goal was to report the temporal expression of adipokines during spinal fusion in an established rabbit model.

Purpose

Our goal was to report the temporal expression of adipokines during spinal fusion in an established rabbit model.

Study Design

The study design included a laboratory animal model.

Methods

New Zealand white rabbits were assigned to either sham surgery (n=2), unilateral posterior spinal fusion (n=14), or bilateral posterior spinal fusion (n=14). Rabbits were euthanized 1–6 and 10 weeks out from surgery. Fusion was evaluated by …

Macroscopic Anisotropic Bone Material Properties In Children With Severe Osteogenesis Imperfecta, Carolyne Albert, John Jameson, Sergey Tarima, Peter Smith, Gerald Harris

Biomedical Engineering Faculty Research and Publications

Children with severe osteogenesis imperfecta(OI) typically experience numerous fractures and progressive skeletal deformities over their lifetime. Recent studies proposed finite element models to assess fracture risk and guide clinicians in determining appropriate intervention in children with OI, but lack of appropriate material property inputs remains a challenge. This study aimed to characterize macroscopic anisotropic cortical bone material properties and investigate relationships with bone density measures in children with severe OI. Specimens were obtained from tibial or femoral shafts of nine children with severe OI and five controls. The specimens were cut into beams, characterized in bending, and imaged by synchrotron …

Robotic Resistance Treadmill Training Improves Locomotor Function In Children With Cerebral Palsy: A Randomized Controlled Pilot Study, Ming Wu, Janis Kim, Deborah J. Gaebler-Spira, Brian D. Schmit, Pooja Arora

Biomedical Engineering Faculty Research and Publications

Objective

To determine whether applying controlled resistance forces to the legs during the swing phase of gait may improve the efficacy of treadmill training as compared with applying controlled assistance forces in children with cerebral palsy (CP).

Design

Randomized controlled study.

Setting

Research unit of a rehabilitation hospital.

Participants

Children with spastic CP (N=23; mean age, 10.6y; range, 6–14y; Gross Motor Function Classification System levels, I–IV).

Interventions

Participants were randomly assigned to receive controlled assistance (n=11) or resistance (n=12) loads applied to the legs at the ankle. Participants underwent robotic treadmill training 3 times a week for 6 weeks (18 …

Sagittal Subtalar And Talocrural Joint Assessment During Ambulation With Controlled Ankle Movement (Cam) Boots, Ben Mchenry, Emily L. Exten, Janelle A. Cross, Karen M. Kruger, Brian Law, Jessica M. Fritz, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background: The purpose of the current study was to determine sagittal plane talocrural and subtalar kinematic differences between barefoot and controlled ankle movement (CAM) boot walking. This study used fluoroscopic images to determine talar motion relative to tibia and calcaneal motion relative to talus.

Methods: Fourteen male subjects (mean age 24.1 ± 3.5 years) screened for normal gait were tested. A fluoroscopy unit was used to collect images at 200 Hz during stance. Sagittal motion of the talocrural and subtalar joints were analyzed barefoot and within short and tall CAM boots.

Results: Barefoot talocrural mean maximum plantar and dorsiflexion were …

Protection By Inhaled Hydrogen Therapy In A Rat Model Of Acute Lung Injury Can Be Tracked In Vivo Using Molecular Imaging, Said H. Audi, Elizabeth R. Jacobs, Xiao Zhang, Amadou K.S. Camara, Ming Zhao, Meetha M. Medhora, Benjamin Michael Rizzo, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

Inhaled hydrogen gas (H₂) provides protection in rat models of human acute lung injury (ALI). We previously reported that biomarker imaging can detect oxidative stress and endothelial cell death in vivo in a rat model of ALI. Our objective was to evaluate the ability of ^99mTc-hexamethylpropyleneamineoxime (HMPAO) and ^99mTc-duramycin to track the effectiveness of H₂ therapy in vivo in the hyperoxia rat model of ALI. Rats were exposed to room air (normoxia), 98% O₂ + 2% N₂ (hyperoxia) or 98% O₂ + 2% H₂ (hyperoxia+H₂) for up to 60 …

Treating A 20 Mm Hg Gradient Alleviates Myocardial Hypertrophy In Experimental Aortic Coarctation, David C. Wendell, Ingeborg Friehs, Margaret M. Samyn, Leanne Harmann, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Background

Children with coarctation of the aorta (CoA) can have a hyperdynamic and remodeled left ventricle (LV) from increased afterload. Literature from an experimental model suggests the putative 20 mm Hg blood pressure gradient (BPG) treatment guideline frequently implemented in CoA studies may permit irreversible vascular changes. LV remodeling from pressure overload has been studied, but data are limited following correction and using a clinically representative BPG.

Materials and methods

Rabbits underwent CoA at 10 weeks to induce a 20 mm Hg BPG using permanent or dissolvable suture thereby replicating untreated and corrected CoA, respectively. Cardiac function was evaluated at …

A Spectral Ct Method To Directly Estimate Basis Material Maps From Experimental Photon-Counting Data, Tal Gilat Schmidt, Rina Foygel Barber, Emil Y. Sidky

Biomedical Engineering Faculty Research and Publications

The proposed spectral CT method solves the constrained one-step spectral CT reconstruction (cOSSCIR) optimization problem to estimate basis material maps while modeling the nonlinear X-ray detection process and enforcing convex constraints on the basis map images. In order to apply the optimization-based reconstruction approach to experimental data, the presented method empirically estimates the effective energy-window spectra using a calibration procedure. The amplitudes of the estimated spectra were further optimized as part of the reconstruction process to reduce ring artifacts. A validation approach was developed to select constraint parameters. The proposed spectral CT method was evaluated through simulations and experiments with …

A Long-Term Follow-Up Of Young Adults With Idiopathic Clubfoot: Does Foot Morphology Relate To Pain?, Adam Graf, Ken N. Kuo, Nikhil T. Kurapati, Joseph J. Krzak, Sahar Hassani, Angela Caudill, Ann Flanagan, Gerald F. Harris, Peter A. Smith

Biomedical Engineering Faculty Research and Publications

Background:

Individuals with clubfoot, treated in infancy with either the Ponseti method or comprehensive clubfoot release, often encounter pain as adults. Multiple studies have characterized residual deformity after Ponseti or surgical correction using physical exam, radiographs and pedobarography; however, the relationship between residual foot deformity and pain is not well defined. The purpose of the current study was 2-fold: (1) to evaluate the relationship between foot morphology and pain for young adults treated as infants for idiopathic clubfoot and (2) to describe and compare pedobarographic measures and outcome measures of pain and morphology among surgically treated, Ponseti treated, and typically …

Open Source Software For Automatic Detection Of Cone Photoreceptors In Adaptive Optics Ophthalmoscopy Using Convolutional Neural Networks, David Cunefare, Leyuan Fang, Robert F. Cooper, Alfredo Dubra, Joseph Carroll, Sina Farsiu

Biomedical Engineering Faculty Research and Publications

Imaging with an adaptive optics scanning light ophthalmoscope (AOSLO) enables direct visualization of the cone photoreceptor mosaic in the living human retina. Quantitative analysis of AOSLO images typically requires manual grading, which is time consuming, and subjective; thus, automated algorithms are highly desirable. Previously developed automated methods are often reliant on ad hoc rules that may not be transferable between different imaging modalities or retinal locations. In this work, we present a convolutional neural network (CNN) based method for cone detection that learns features of interest directly from training data. This cone-identifying algorithm was trained and validated on separate data …

Inter-Joint Coordination Deficits Revealed In The Decomposition Of Endpoint Jerk During Goal-Directed Arm Movement After Stroke, Jozsef Laczko, Robert A. Scheidt, Lucia Simo, Davide Piovesan

Biomedical Engineering Faculty Research and Publications

It is well documented that neurological deficits after stroke can disrupt motor control processes that affect the smoothness of reaching movements. The smoothness of hand trajectories during multi-joint reaching depends on shoulder and elbow joint angular velocities and their successive derivatives as well as on the instantaneous arm configuration and its rate of change. Right-handed survivors of unilateral hemiparetic stroke and neurologically-intact control participants held the handle of a two-joint robot and made horizontal planar reaching movements. We decomposed endpoint jerk into components related to shoulder and elbow joint angular velocity, acceleration, and jerk. We observed an abnormal decomposition pattern …

Quantitative Optical Measurement Of Mitochondrial Superoxide Dynamics In Pulmonary Artery Endothelial Cells, Zahra Ghanian, Girija G. Konduri, Said H. Audi, Amadou K.S. Camara, Mahsa Ranji

Biomedical Engineering Faculty Research and Publications

No abstract provided.

The Arm Movement Detection (Amd) Test: A Fast Robotic Test Of Proprioceptive Acuity In The Arm, Leigh A. Mrotek, Maria Bengtson, Tina M. Stoeckmann, Lior Botzer, Claude Ghez, John Mcguire, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Background

We examined the validity and reliability of a short robotic test of upper limb proprioception, the Arm Movement Detection (AMD) test, which yields a ratio-scaled, objective outcome measure to be used for evaluating the impact of sensory deficits on impairments of motor control, motor adaptation and functional recovery in stroke survivors.

Methods

Subjects grasped the handle of a horizontal planar robot, with their arm and the robot hidden from view. The robot applied graded force perturbations, which produced small displacements of the handle. The AMD test required subjects to respond verbally to queries regarding whether or not they detected …

Identity And Function Of A Cardiac Mitochondrial Small Conductance Ca2+-Activated K+ Channel Splice Variant, Meiying Yang, Amadou K. S. Camara, Mohammed Aldakkak, Wai-Meng Kwok, David F. Stowe

Biomedical Engineering Faculty Research and Publications

We provide evidence for location and function of a small conductance, Ca²⁺-activated K⁺ (SK_Ca) channel isoform 3 (SK3) in mitochondria (m) of guinea pig, rat and human ventricular myocytes. SK_Ca agonists protected isolated hearts and mitochondria against ischemia/reperfusion (IR) injury; SK_Ca antagonists worsened IR injury. Intravenous infusion of a SK_Ca channel agonist/antagonist, respectively, in intact rats was effective in reducing/enhancing regional infarct size induced by coronary artery occlusion. Localization of SK3 in mitochondria was evidenced by Western blot of inner mitochondrial membrane, immunocytochemical staining of cardiomyocytes, and immunogold labeling of isolated mitochondria. …

Erratum To: Supplemental Vibrotactile Feedback Control Of Stabilization And Reaching Actions Of The Arm Using Limb State And Position Error Encodings, Alexis Krueger, Psiche Giannoni, Valay Shah, Maura Casadio, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

The original article contained omissions mistakenly carried forward by the Production department handling this journal; these omissions related to missing ‘λ’ symbols throughout the article body, thus inaccurately representing the meaning of the associated text.

The article has now been updated to include these symbols in the appropriate sections of text to accurately reflect the conveyed implications.

Supplemental Vibrotactile Feedback Control Of Stabilization And Reaching Actions Of The Arm Using Limb State And Position Error Encodings, Alexis Krueger, Psiche Giannoni, Valay Shah, Maura Casadio, Robert A. Scheidt

Biomedical Engineering Faculty Research and Publications

Deficits of kinesthesia (limb position and movement sensation) commonly limit sensorimotor function and its recovery after neuromotor injury. Sensory substitution technologies providing synthetic kinesthetic feedback might re-establish or enhance closed-loop control of goal-directed behaviors in people with impaired kinesthesia.

Biplane Fluoroscopy For Hindfoot Motion Analysis During Gait: A Model-Based Evaluation, Janelle A. Cross, Ben Mchenry, Robert C. Molthen, Emily Exten, Taly Gilat-Schmidt, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

The purpose of this study was to quantify the accuracy and precision of a biplane fluoroscopy system for model-based tracking of in vivo hindfoot motion during over-ground gait. Gait was simulated by manually manipulating a cadaver foot specimen through a biplane fluoroscopy system attached to a walkway. Three 1.6-mm diameter steel beads were implanted into the specimen to provide marker-based tracking measurements for comparison to model-based tracking. A CT scan was acquired to define a gold standard of implanted bead positions and to create 3D models for model-based tracking. Static and dynamic trials manipulating the specimen through the capture volume …

Segmental Kinematic Analysis Of Planovalgus Feet During Walking In Children With Cerebral Palsy, Karen M. Kruger, Katherine A. Konop, Joseph Krzak, Adam Graf, Haluk Altiok, Peter A. Smith, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Pes planovalgus (flatfoot) is a common deformity among children with cerebral palsy. The Milwaukee Foot Model (MFM), a multi-segmental kinematic foot model, which uses radiography to align the underlying bony anatomy with reflective surface markers, was used to evaluate 20 pediatric participants (30 feet) with planovalgus secondary to cerebral palsy prior to surgery. Three-dimensional kinematics of the tibia, hindfoot, forefoot, and hallux segments are reported and compared to an age-matched control set of typically-developing children. Most results were consistent with known characteristics of the deformity and showed decreased plantar flexion of the forefoot relative to hindfoot, increased forefoot abduction, and …

Assessment Of Kinematics And Electromyography Following Arthroscopic Single-Tendon Rotator Cuff Repair, Jessica M. Fritz, Ryan R. Inawat, Brooke A. Slavens, John R. Mcguire, Dean W. Ziegler, Sergey S. Tarima, Steven I. Grindel, Gerald F. Harris

Biomedical Engineering Faculty Research and Publications

Background

The increasing demand for rotator cuff (RC) repair patients to return to work as soon as they are physically able has led to exploration of when this is feasible. Current guidelines from our orthopedic surgery clinic recommend a return to work at 9 weeks postoperation. To more fully define capacity to return to work, the current study was conducted using a unique series of quantitative tools. To date, no study has combined 3-dimensional (3D) motion analysis with electromyography (EMG) assessment during activities of daily living (ADLs), including desk tasks, and commonly prescribed rehabilitation exercise.

Objective

To apply a quantitative, …

Rapid In Vivo Detection Of Rat Spinal Cord Injury With Double-Diffusion-Encoded Magnetic Resonance Spectroscopy, Nathan P. Skinner, Shekar N. Kurpad, Brian D. Schmit, L. Tugan Muftuler, Matthew D. Budde

Biomedical Engineering Faculty Research and Publications

Purpose

Diffusion-weighted imaging is a common experimental tool for evaluating spinal cord injury (SCI), yet it suffers from complications that decrease its clinical effectiveness. The most commonly used technique, diffusion tensor imaging (DTI), is often confounded by effects of edema accompanying acute SCI, limiting its sensitivity to the important functional status marker of axonal integrity. The purpose of this study is to introduce a novel diffusion-acquisition method with the goal of overcoming these limitations.

Methods

A double diffusion encoding (DDE) pulse sequence was implemented with a diffusion-weighted filter orthogonal to the spinal cord for suppressing nonneural signals prior to diffusion …

Evaluation Of Whole-Brain Resting-State Functional Connectivity In Spinal Cord Injury - A Large-Scale Network Analysis Using Network Based Statistic, Mayank Kaushal, Akinwunmi Oni-Orisan, Gang Chen, Wenjun Li, Jack Leschke, B. Douglas Ward, Benjamin Kalinosky, Matthew D. Budde, Brian D. Schmit, Shi-Jiang Li, Viashnavi Muqeet, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

Large-scale network analysis characterizes the brain as a complex network of nodes and edges to evaluate functional connectivity patterns. The utility of graph-based techniques has been demonstrated in an increasing number of restingstate functional MRI (rs-fMRI) studies in the normal and diseased brain. However, to our knowledge, graph theory has not been used to study the reorganization pattern of resting-state brain networks in patients with traumatic complete spinal cord injury (SCI). In the present analysis, we applied a graph-theoretical approach to explore changes to global brain network architecture as a result of SCI. Fifteen subjects with chronic (> 2 years) …

Spatio-Temporal Patterning In Primary Motor Cortex At Movement Onset, Matthew D. Best, Aaron J. Suminski, Kazutaka Takahashi, Kevin A. Brown, Nicholas G. Hatsopoulos

Biomedical Engineering Faculty Research and Publications

Voluntary movement initiation involves the engagement of large populations of motor cortical neurons around movement onset. Despite knowledge of the temporal dynamics that lead to movement, the spatial structure of these dynamics across the cortical surface remains unknown. In data from 4 rhesus macaques, we show that the timing of attenuation of beta frequency local field potential oscillations, a correlate of locally activated cortex, forms a spatial gradient across primary motor cortex (MI). We show that these spatio-temporal dynamics are recapitulated in the engagement order of ensembles of MI neurons. We demonstrate that these patterns are unique to movement onset …

Diffusion Tensor Imaging Correlates With Short-Term Myelopathy Outcome In Patients With Cervical Spondylotic Myelopathy, Aditya Vedantam, Avinash Rao, Shekar N. Kurpad, Michael B. Jirjis, Gerald Eckardt, Brian D. Schmit, Marjorie C. Wang

Biomedical Engineering Faculty Research and Publications

Objective

To determine if spinal cord diffusion tensor imaging indexes correlate with short-term clinical outcome in patients undergoing elective cervical spine surgery for cervical spondylotic myelopathy (CSM).

Methods

A prospective consecutive cohort study was performed in patients undergoing elective cervical spine surgery for CSM. After obtaining informed consent, patients with CSM underwent preoperative T2-weighted magnetic resonance imaging and diffusion tensor imaging of the cervical spine. Fractional anisotropy (FA) values at the level of maximum cord compression and at the noncompressed C1-2 level were calculated on axial images. We recorded the modified Japanese Orthopaedic Association (mJOA) scale, Neck Disability Index, and …

Lessons Learned From A 10-Year Collaboration Between Biomedical Engineering And Industrial Design Students In Capstone Design Projects, Jay R. Goldberg, Pascal Malassigné

Biomedical Engineering Faculty Research and Publications

Engineers and industrial designers have different approaches to problem solving. Both place heavy emphasis on identification of customer needs, manufacturing methods, and prototyping. Industrial designers focus on aesthetics, ergonomics, ease of use, manufacturing methods, and the user’s experience. They tend to be more visual and more concerned with the interaction between users and products. Engineers focus on functionality, performance requirements, analytical modeling, and design verification and validation. They tend to be more analytical and more concerned with the design of internal components and product performance. Engineers and industrial designers often work together on project teams in industry. Collaboration between the …

Limb Stabilization In Older Adults And Chronic Stroke Survivors: A Pilot Study, Raymond C. Doudlah, Robert A. Scheidt, Aaron J. Suminski

Biomedical Engineering Faculty Research and Publications

Visual fidelity influences many aspects of daily living, including stabilizing wrist movements against environmental perturbations. Here, we present a pilot investigation to determine how visual feedback impacts wrist stabilization for populations with age related declines in motor function and chronic stroke. To quantify these interactions, behavioral performance and local brain activation were observed during a task requiring stabilization of the wrist against constant and stochastic extensor torque perturbations. All subjects were better able to stabilize their wrist when veridical visual feedback of their limb was provided. Examination of the neural activation maps in the Control and Aging populations revealed patterns …

Effects Of Training Intensity On Locomotor Performance In Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study, Gabrielle Brazg, Meghan Fahey, Carey L. Holleran, Mark Connolly, Jane Woodward, Patrick W. Hennessy, Brian D. Schmit, T. George Hornby

Biomedical Engineering Faculty Research and Publications

Background. Many physical interventions can improve locomotor function in individuals with motor incomplete spinal cord injury (iSCI), although the training parameters that maximize recovery are not clear. Previous studies in individuals with other neurologic injuries suggest the intensity of locomotor training (LT) may positively influence walking outcomes. However, the effects of intensity during training of individuals with iSCI have not been tested. Objective. The purpose of this pilot, blinded-assessor randomized trial was to evaluate the effects of LT intensity on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI >1 year duration performed either …

How A Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review Of Nidilrr’S Rehabilitation Engineering Research Centers, David J. Reinkensmeyer, Sarah Blackstone, Cathy Bodine, John Brabyn, David Brienza, Kevin Caves, Frank Deruyter, Edmund Durfee, Stefania Fatone, Geoff Fernie, Steven Gard, Patricia Karg, Todd A. Kuiken, Gerald F. Harris, Mike Jones, Yue Li, Jordana Maisel, Michael Mccue, Michelle A. Meade, Helena Mitchell, Tracy L. Mitzner, James L. Patton, Philip S. Requejo, James H. Rimmer, Wendy A. Rogers, W. Zev Rymer, Jon A. Sanford, Lawrence Schneider, Levin Sliker, Stephen Sprigle, Aaron Steinfeld, Edward Steinfeld, Gregg Vanderheiden, Carolee Winstein, Li-Qun Zhang, Thomas Corfman

Biomedical Engineering Faculty Research and Publications

Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their …

Structurofunctional Resting-State Networks Correlate With Motor Function In Chronic Stroke, Benjamin Kalinosky, Reivian B. Barillas, Brian D. Schmit

Biomedical Engineering Faculty Research and Publications

Purpose

Motor function and recovery after stroke likely rely directly on the residual anatomical connections in the brain and its resting-state functional connectivity. Both structural and functional properties of cortical networks after stroke are revealed using multimodal magnetic resonance imaging(MRI). Specifically, functional connectivity MRI (fcMRI) can extract functional networks of the brain at rest, while structural connectivity can be estimated from white matter fiber orientations measured with high angular-resolutiondiffusion imaging (HARDI). A model that marries these two techniques may be the key to understanding functional recovery after stroke. In this study, a novel set of voxel-level measures …

Smartphone Based Optical Spectrometer For Diffusive Reflectance Spectroscopic Measurement Of Hemoglobin, Perry Edwards, Chenji Zhang, Baigang Zhang, Xiangqian Hong, Vivek K. Nagarajan, Bing Yu, Zhiwen Liu

Biomedical Engineering Faculty Research and Publications

We report a miniature, visible to near infrared G-Fresnel spectrometer that contains a complete spectrograph system, including the detection hardware and connects with a smartphone through a microUSB port for operational control. The smartphone spectrometer is able to achieve a resolution of ~5 nm in a wavelength range from 400 nm to 1000 nm. We further developed a diffuse reflectance spectroscopy system using the smartphone spectrometer and demonstrated the capability of hemoglobin measurement. Proof of concept studies of tissue phantoms yielded a mean error of 9.2% on hemoglobin concentration measurement, comparable to that obtained with a commercial benchtop spectrometer. The …