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Rapid-Fire Presentations


The following are presentations from the 2020 Call for Papers. The papers have been published in the 2020 Proceedings of the Design of Medical Devices Conference in the ASME Digital Collection.

Underlined poster titles are links to online videos. The entire playlist can be found on our DMD YouTube Playlist (https://z.umn.edu/RapidFireYT).

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Track 1 - Cardiovascular

"Pulmonary Artery Stenosis: Early Interventions With Low Profile Stents Versus Delayed Interventions With Large Diameter Stents" DMD2020-9005
Ryan Pewowaruk, Kevin Pettit, Carolina Larrain, Cody Johnson, Christopher Francois, Luke Lamers and Alejandro Roldán-Alzate, University of Wisconsin - Madison

Abstract: Pulmonary artery stenosis (PAS) is a common complication of heart surgery in infancy. With recent advances in low profile-small diameter stent technology, PA stenting is now often performed in infants. While PAS stenting in older children does not impact distal PA growth and multiplication, in infants still undergoing significant PA growth, the impact of PA stent timing on long term PA development is unknown and potentially important. In a swine PAS model, the effects of early and delayed stent interventions on PA growth and cardiac function were comprehensively assessed. PA stenting had a positive impact on hemodynamics, lung perfusion, and histology, but the timing of intervention, either early or late, does not make a significant difference.


Track 1 - Cardiovascular

"Classification of Left Atrial Appendage Morphology Using Deep Learning" DMD2020-9018
Mikayle Holm, Alex Deakyne, Erik Gaasedelen, Weston Upchurch and Paul Iaizzo, University of Minnesota

Abstract: Atrial fibrillation, a common cardiac arrhythmia, can lead to blood clots in the left atrial appendage (LAA) of the heart, increasing the risk of stroke. Understanding the LAA morphology can indicate the likelihood of a blood clot. Therefore, a classification convolutional neural network was implemented to predict the LAA morphology. Using 2D images of 3D models created from MRI scans of fixed human hearts and a pre-trained network, an 8.7% error rate was achieved. The network can be improved with more data or expanded to classify the LAA from the automatically segmented1 DICOM datasets and measure the LAA ostia.


Track 1 - Cardiovascular

"A Novel Transcatheter Edge-to-Edge Suturing Technique and Prototype for Repairing Tricuspid Valve Regurgitation" DMD2020-9033
Jorge Zhingre Sanchez and Paul Iaizzo, University of Minnesota

Abstract: Tricuspid valve regurgitation is a major clinical issue that continues to attract interest from interventional cardiologists and medical device designers due to its rising prevalence and progressive nature. This disease impact is exacerbated among the aging population, considered as high risk of mortality for open-heart surgical procedures. Furthermore, early intervention for tricuspid regurgitation post left-sided heart procedures continues to increase. Thus, percutaneous or transcatheter interventions have emerged as the new frontier for tricuspid valve therapy. Specifically, tricuspid leaflet plication, or edgeto- edge repair, is a valvular procedure to enhance the coaptation of the leaflets and reduce regurgitation. The current landscape of approved transcatheter devices for leaflet coaptation are exclusive to the mitral valve or being investigated for tricuspid treatment. However, most of these transcatheter systems are designed with high procedure specificities, are expensive, and require extensive procedural training. Hence, there is an opportunity to percutaneously plicate the tricuspid leaflets using commonly available right-heart catheter equipment. This study details a novel transcatheter repair procedure that can plicate the tricuspid valve leaflets solely using current market released catheters and/or surgical equipment. Testing and evaluation of this prototype procedure was performed using Visible Heart® methodologies.


Track 1 - Cardiovascular

"Selectively Compliant Annuloplasty Ring to Enable Annular Dynamics in Mitral Valve Repair Evaluated by In-Vitro Stereovision" DMD2020-9034
Samuel Frishman, Annabel Imbrie-Moore, Mark Cutkosky, Ali Kight, Ileana Pirozzi, Michael Paulsen and Joseph Woo, Stanford University

Abstract: Mitral valve (MV) annular dynamics are critical to the long term efficacy of MV repair. Today's annuloplasty rings, used to restore MV function, impose significant constraints on the motion profile of the MV annulus. We present a selectively compliant ring that provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Ring design is informed by a finite element analysis and experimentally evaluated with in-vitro stereophotogrammetry. We compare the ring dynamics to commercially available semi-rigid rings as well as values found in literature for healthy annuli. The results demonstrate that motion of the selectively compliant ring is significantly closer to that of a healthy annulus based on standard metrics that define MV annular movement. Specifically, the metrics for the new ring compare to those in literature as follows: change in orifice area 12.5±3% vs. 10±2%; change in anterior-posterior diam. 5.4±0.3% vs. 7±1%; change in inter-commissural diam. 6.6±1.3% vs.5±1%.


Track 1 - Cardiovascular

"A Novel Tool for Improved Control and Maneuverability in Pediatric Cardiac Catheter Ablation Procedures" DMD2020-9039
Paige Mass, Rohan Kumthekar, Charles Berul and Justin Opfermann, Children's National Hospital

Abstract: Cardiac ablation catheters commonly used for the diagnosis and treatment of arrhythmias are small in diameter and require extensive finger grip and dexterity for safe maneuverability during procedures. This is especially important in the pediatric population where the cardiac structures are smaller and potentially more variable as a result of congenital anatomic anomalies. We developed a novel catheter grip accessory tool for improved control and maneuverability of cardiac ablation catheters. Mechanical testing of the tool demonstrated it could grip the catheter with an average force of 0.031 kN and transfer an average torque of 0.0392 N-m before slipping, both well above forces experienced in normal clinical use. During tensile testing, the tool fractured at an average force of 0.554 kN. At the point of failure, testing found that the electrical conduction and resistance of the catheter remained unchanged. In simulated use testing, the tool was able to translate torque more accurately to the catheter tip compared to manual manipulation of the catheter. This novel tool has the potential to reduce physician muscle exertion in ablation procedures and increase the safety profile when manipulating catheters within the heart.


Track 1 - Cardiovascular

"A Flow Cytometry Method for Characterizing Platelet Activation" DMD2020-9070
Brian Alzua, Mark Smith and Yan Chen, American Preclinical Services

Abstract: Hemocompatibility testing is critical for assessing the safety of blood-contacting medical devices. Comprehensive hemocompatibility testing requires examining a wide range of possible adverse effects cause by direct or indirect blood contact, such as hemolysis, complement activation, and thrombus formation [1]. Moreover, these domains each encompass complex intercellular processes with many potential targets for analysis. For example, the current testing paradigm of platelet function may involve exposing the device to human whole blood and performing simple blood counts and/or macroscopic evaluation to determine the extent of platelet activation and clot formation as described in ASTM F2888-19. However, this approach does not capture any observations for device-mediated initiation of any steps in the platelet activation pathway prior to aggregation. We have validated a method to evaluate platelet activation by quantifying surface p-selectin expression after exposure to various materials. This method will provide an additional level of detail about potential platelet activating properties of a medical device. Flow cytometry has been used previously to measure platelet activation for clinical and research purposes. We sought to adapt this method to test for platelet activation induced by exposure of blood to medical devices or materials. We determined that processing fresh whole blood to platelet-rich plasma (PRP) by gentle centrifugation enhanced the signal compared to fresh blood itself. In each experiment, devices were exposed to PRP according to an extraction ratio of 6 cm2/mL for 1 hour. A blank control consisting of untreated PRP, and a positive control consisting of ADP, a potent agonist, were also used. After the exposure, excess plasma was removed from the articles and combined with anti-CD61 (to stain for platelets) and anti-CD62P (to stain for activated platelets) antibodies. Flow cytometry was then performed to quantify the percentage of CD62P+ over the total CD61+ cells to measure the percentage of activated platelets. In order to optimize the method, we investigated the effect of several experimental factors, including anticoagulant usage, donor variability, and selection of reference materials to serve as controls. Our results indicate that the flow cytometry-based method is consistent and reproducible, quick and easy to perform, and is well-correlated with results from the standard platelet and leukocyte count assay. The flow cytometry-based platelet activation method is a powerful supplement to the standard regimen of medical device hemocompatibility testing.


Track 1 - Cardiovascular

"Thrombogenicity Testing Results for Legally Marketed Comparator Devices (Lmcd): Comparison Between the Traditional Non-Anticoagulated Venous Impllant Assay and an in Vitro Ovine Blood Loop Test" DMD2020-9073
Mark Smith and Yan Chen, American Preclinical Services

Abstract: Legally marketed comparator devices (LMCD) are required by many regulatory bodies in as a control for thrombogenicity testing when evaluating new devices. It is assumed by both the medical device manufacturing industry and regulatory bodies that these LMCD's have good clinical history and should perform with no to minimal thrombus accumulation and thereby serve as valid negative controls for the assay. APS regularly performs these assays for many medical device manufacturers, all of whom select a predicate comparator device (required by FDA to be an LMCD), for both the in vivo Non-Anticoagulated Venous Implant (NAVI) assay as well as a custom in vitro blood loop AVI. In this retrospective analysis, we have compiled thrombogenicity scores of control/predicate devices (limited to assays which used LMCD's), both the discrete score from the classification standard scoring scheme and the continuous values obtained from the percent surface area associated with thrombus. We have compared results from 37 NAVI studies and 22 in vitro blood loop studies. These compiled results show ~25% of LMCDs score ≥3 (>50% of the surface covered in thrombus) in the NAVI model while <5% of LMCDs score ≥3 (>50% thrombus) in the Blood-Loop assay. In addition, the median score and mean % thrombus for LMCD in the blood loop assay is substantially lower than the median and mean scores for LMCD in the NAVI assay. This retrospective assessment highlights a high proportion of false-positive scores for LMCD in a large number of NAVI assays.


Track 1 - Cardiovascular

"Potential of Weight Scale Based Ballistocardiography for Identifying Orthostatic Intolerance: A Tilt Table Study" DMD2020-9074
Stian Henriksen and Parshuram Aarotale, University of North Dakota

Abstract: Autonomic cardiovascular control is critical in regulating blood pressure during postural transition, failure of which could lead to dizziness and fall (orthostatic intolerance). In this study, the feasibility of Ballistocardiography (BCG) for quantifying autonomic nervous system activity in relation to gold standard electrocardiogram (ECG) was tested. Simultaneous ECG, blood pressure, photoplethysmography (PPG), and BCG were continuously acquired during 5-minutes of stand tests (before and after tilt test up to 60°) from 10 participants. Heart period was derived from ECG and BCG represented as RR and JJ intervals, respectively. Spectral analysis of heart period (both RR and JJ) was performed by calculating power distributed in low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.4 Hz) bands. Strong correlation (r>0.87 for Pre-tilt and r>0.97 for Post-tilt, p<0.001) between ECG and BCG derived LF, HF, and LF/HF was observed, except for LF/HF(r>0.63 for Pre-tilt). The Wilcoxon rank sum test revealed no difference (p>0.10) in BCG or ECG LF, HF, and LF/HF during the two stand tests. The findings of the study highlighted the feasibility of monitoring cardiovascular control via weight-scale BCG. Therefore, the developed system can gain utility as a portable and cost-effective system for early detection and mitigation of falls associated with autonomic dysfunction.


Track 1 - Cardiovascular

"Design of a Miniaturized, Affordable, and Quantifiable Vascular Doppler" DMD2020-9080
Matthew Kubalaubala, Jack Doenges, Brooks Hodenfield and Jeremy Wales, Vibha Mavanji, University of Minnesota

Abstract: Peripheral artery disease (PAD) results from atherosclerotic plaque deposition on arterial walls causing stenosis, reduced blood flow to affected tissue areas, and can result in pain, tissue loss, poor wound healing, limb loss, and death. PAD affects an estimated 200 million people [4]. One of the most common ways to diagnose PAD is with a vascular doppler. This is a device that reflects ultrasound signals off of the moving blood particulate in a vessel and produces an audible signal relating to blood flow parameters. As shown through multiple rounds of clinician interviews, current vascular dopplers are expensive, bulky, and many lack objective signal analysis. An improved, consolidated vascular doppler was designed and prototyped in order to meet these needs. This prototype showed a reduction in cost and showed promise for intensive waveform analysis and size reduction.


Track 2 - Neuroengineering

"Usdl: Inexpensive Medical Imaging Using Deep Learning Techniques and Ultrasound Technology" DMD2020-9109
Manish Balamurugan, Kathryn Chung and Venkat Kuppoor, Fairfax High School; Smruti Mahapatra, Aliaksei Pustavoitau and Amir Manbachi, Johns Hopkins University

Abstract: In this study, we present USDL, a novel model that employs deep learning algorithms in order to reconstruct and enhance corrupted ultrasound images. We utilize an unsupervised neural network called an autoencoder which works by compressing its input into a latent-space representation and then reconstructing the output from this representation. We trained our model on a dataset that compromises of 15,700 in vivo images of the neck, wrist, elbow, and knee vasculature and compared the quality of the images generated using the structural similarity index (SSIM) and peak to noise ratio (PSNR). In closely simulated conditions, the architecture exhibited an average reconstruction accuracy of 90% as indicated by our SSIM. Our study demonstrates that USDL outperforms state of the art image enhancement and reconstruction techniques in both image quality and computational complexity, while maintaining the architecture efficiency.


Track 3 - Orthopedics & Rehabilitation

"Improving Footwear Options for Persons With Lower Limb Amputations" DMD2020-9044
Eric Nickel, Gregory Voss and Billie Slater, Minneapolis VA Health Care System; Emily Mueller and Andrew Hansen, Minneapolis VA Health Care System and University of Minnesota

Abstract: Men and women with lower limb amputations struggle with managing the balance between prosthesis alignment and shoe heel rise. A novel prosthetic ankle-feet system is being developed to support a wider range of footwear options for men and women with lower limb amputations. Each rigid foot is customized to fit the footwear of choice and can be rapidly attached to (or released from) an ankle unit which remains attached to the prosthesis. The ankle unit has a mass of 318g and is small enough to fit in the design volume of a 22cm foot across a range of heel rises. The ankle uses elastomeric bumpers arranged in a wiper design to maximize space efficiency. Structural testing has shown that the 3D printed custom Nylon 12 feet withstood 4584N of forefoot loading without failure based on the ISO 10328 loading parameters, indicating suitable strength to support safe human use in the laboratory. The feet have a mass of 446g. Feedback from two women Veterans with lower limb amputations reinforced the importance of improving access to shoes with different heel rises. Future activities will include cyclic fatigue testing, additional weight reduction, and incorporating suggested design refinements.


Track 3 - Orthopedics & Rehabilitation

"A Hydraulic Bimodal Ankle to Improve Mobility and Stability for Prosthesis Users" DMD2020-9061
Sara Koehler-McNicholas, Minneapolis VA Health Care System and University of Minnesota; Gregory Voss, Minneapolis VA Health Care System; Evandro Ficanha, WillowWood; John Looft and Nicole Walker, Minneapolis VA Health Care System; James Colvin, WillowWood; Andrew Hansen, Minneapolis VA Health Care System and University of Minnesota; Matthew Wernke, WillowWood

Abstract: A bimodal prosthetic ankle-foot system has been developed to support the demands of both walking mobility and standing balance. Using a novel hydraulic locking mechanism, this system provides a curved effective rocker shape for walking and a flat effective rocker shape for standing and swaying on non- level surfaces. To date, the hydraulic cylinder sub-assembly has been cycle tested to 1.2 million cycles. Future testing with lower-limb prosthesis users is planned, which will reveal the extent to which this new hydraulic ankle-foot design improves standing balance on both level and non-level surfaces. The capacity for an automatic switching algorithm, designed to appropriately detect and switch between modes as users transition between walking and standing tasks, will also be evaluated.


Track 3 - Orthopedics & Rehabilitation

"Evaluating the Fit of Current Anatomical Scapula Reconstruction Plates: A Study Using Fifty Scapula" DMD2020-9079
Roopam Dey, Sudesh Sivarasu, Johan Charilaou, Stephen Roche and Frida Hansson, University of Cape Town

Abstract: Open Reduction and Internal Fixation (ORIF) of scapula shoulder [3]. Moreover, there is no consensus regarding the fractures have increased in numbers recently. This is due to optimum way to provide the non-invasive treatment to scapula better functional outcomes achieved post-ORIF than non-facture patients. These drawbacks have led the surgeons to adapt operative management techniques. In South Africa, there is only the ORIF option to manage fractured scapula with displaced one available supplier for anatomical contoured scapula plates fracture fragments [3]. used in the ORIF. This study examines the fit of these plates on the bony topology of fifty healthy scapula. It was observed that the short medial body plate performed the best in adhering to the bone topology followed by the short acromion plate. The glenoid plate and the long acromion and body plates were not adequately designed to fit their intended regions on the scapula. In conclusion, this study highlights the drawbacks in design of current commercial plates available for ORIF of scapula. Further studies are needed in order to evaluate the quantitative- fit performance of these plates on fracture scapula surfaces.


Track 4 - MEMS & Nano

"Label Free Cell Purifcation Following Electroporation" DMD2020-9037
Beth Ringwelski, North Dakota State University

Abstract: Cell transfection by electroporation is a biological assay that has been utilized to inject exogenous molecules (e.g.: RNA, DNA and protein) into live cells. Recently, electroporation has been utilized in developing cell therapy for cancer. One of the major drawbacks in current electroporation methods is the cell death during the process. These dead cells can be detrimental, if injected back to the patients. Current cell filtering methods are unable purify T-cells following electroporation, this is due to the lack of unique biomarkers that target the apoptosis and necrosis of T-cells. To address this issue, we have developed a method using dielectrophoresis and microfluidics, where no prior labeling is needed to isolate dead cells from live cells. Upon electroporation, the cell sample has to be flowed through the microfluidic chip where a selective electric field is applied through specially designed electrodes so that the dead cells are trapped on the electrodes, and the live cells are able to flow through and are collected at the end. Results after purification of the cells using our method reveal that it is possible to achieve ~100% of purity in filtering of the live cells. This method presents a viable solution to a critical concern regarding CAR T-cell manufacturing. This paper presents an extended study of the variation of efficacy in the design with the time from the electroporation.


Track 4 - MEMS & Nano

"Laser Micromachining of Thin-Film Polyimide Microelectrode Arrays: Alternative Processes to Photolithography" DMD2020-9057
Hsiang-Lan Yeh, Iowa State University; Jonathan Garich, Ian Akamine and Jennifer Blain Christen, Arizona State University; Seth Hara, Mayo Clinic

Abstract: Thin-film microelectrode arrays have a wide variety of applications in research and medical devices. Conventionally, these arrays are fabricated through the use of photolithography, which can be problematic for innovative medical device fabrication due to long process times, inflexibility to design changes, and the reliance on potentially harmful chemicals. Here, we present the use of laser micromachining as an alternative to photolithography processes to fabricate thin-film polyimide microelectrode arrays. This fabrication method lends itself to an iterative design process as it can reduce fabrication steps and is attractive for medical devices since it can be used without harmful chemicals. Several process parameters were explored and the performance of the fabricated electrodes was compared to similar electrodes that were fabricated with conventional photolithography processes.


Track 5 - Sensors

"An Integrated I2c Sensor Network for Transcatheter Heart Valves" DMD2020-9016
Thomas Secord, Lucas Koerner and Robert Kopas, University of St. Thomas

Abstract: Transcathether aortic heart valve replacement (TAVR) is a widespread approach to treating patients with severe aortic stenosis. A TAVR implant is ideally positioned to access numerous clinically relevant signals including arterial blood pressure, pulse wave velocity, electrocardiogram (ECG), patient motion, heart rate, respiration, and blood oxygenation. Unlike medical devices such as pacemakers, TAVR implants are purely mechanical structures with no sensing capabilities. In this work, we address this unmet clinical need by incorporating an Inter-Integrated Circuit (I2C) sensor network within a TAVR stent frame and designing sensor modules that can physically connect to the network at various landing zones. To illustrate this approach, we designed and built a sensor circuit board populated with a commercial inertial measurement unit (IMU) that can detect numerous clinically useful metrics including pulse wave velocity at the aortic root. We demonstrate two spatially separated accelerometers to measure pulse wave propagation time with a standard deviation of 140 µs, which translates to an uncertainty of the pulse wave velocity of ±0.2 m/s. These sensor modules connect to a customized stent frame containing the necessary I2C conductors. Our data suggest that a fully instrumented TAVR paradigm is feasible using this frame design and modular sensor approach.


Track 5 - Sensors

"A Smartphone Enabled Phototherapy Irradiance Meter for the Care of the Jaundiced Neonates in Low-Resource Regions" DMD2020-9040
Patrick Powell, Arbor Grace; Isa Abdulkardir, Abmadu Bellow University; Tina Slusher, University of Minnesota and HRRI; Katie Satrom, University of Minnesota; Gary DeWitt, Internet Mobility Cellular

Abstract: Smartphones have become near ubiquitous on the global stage placing the power of both computational analytics and communication into the hands of users in both high and low- resource regions alike. The potential to leverage these devices to address inequities in healthcare are enormous. Our development team theorizes that we can create a medical device blending a traditional pediatric phototherapy irradiance meter for the treatment of neonatal jaundice with a mobile smartphone to create a reasonably priced irradiance meter with improved performance specifically for low-resource regions. The result of our work is a minimum viable prototype based on an Android operating system tethered wirelessly to a remote sensor that incorporates a clinical training feature. Based on laboratory tests simulating a clinical environment, the results were equivalent to standard phototherapy meters with additional expected benefits of cost, mobility, access and clinical training.


Track 5 - Sensors

"Respiratory Arrest Monitoring; a Non-Invasive Approach for Early Detection of Breathing Complexities in Psychiatric Patients" DMD2020-9087
Moein Enayati and Marjorie Skubic, Mayo Clinic

Abstract: Background: Current protocol for monitoring high-risk patients in psychiatric hospital calls for a staff member to enter each room every 15 minutes to visually ensure that each patient is still breathing. This protocol has been set up for fast intervention in the case of a patient self-inflicting harm. However, this procedure is disruptive to the patients and a burden for the care providers. Objective: Continuous and automated overnight monitoring of psychiatric patients for a complete cessation of breath, that eliminates the need for frequent in-person checks. Method: An IRB approved study conducted in a simulated lab environment, with a radar device placed in the ceiling above the bed. 14 volunteers simulated episodes of respiratory arrest. Results: Extracted radar signal not only tracks the episodes of complete breath cessation but also estimates the respiration rate with more than 92% accuracy, during normal breathing. Conclusion: Our proposed approach provides the means for care providers in psychiatric hospitals to ensure the patients can breathe without disturbing the patients' sleep.


Track 6 - Surgical Tools

"Design of a Modular Cost-Effective Robot Arm for Increased Dexterity in Laparoscopic Surgery" DMD2020-9010
John Lowery and Carl Nelson, University of Lincoln, Nebraska

Abstract: This paper outlines the design of a reconfigurable, partially disposable, tendon-driven robotic arm for providing assistance in laparoscopic surgery. The rationale for its development and design objectives are provided, followed by a description of its mechanical design. Kinematic simulations to assess workspace are presented, and a first-stage assessment of the functionality of a prototype using a custom test bench is also included.


Track 6 - Surgical Tools

"Incremental Needle Insertion System for Force and Position Sensing" DMD2020-9012
Dailen Brown and Jessica Gonzalez-Vargas, The Pennsylvania State University; David Han, Penn State Heart and Vascular Institute; Scarlett Miller and Jason Moore, The Pennsylvania State University

Abstract: An incremental needle insertion system (INIS) which simultaneously measures the force and position of a needle during insertion was designed and fabricated for use in a tissue deformation study to improve realism in medical simulation. The INIS was tested in a fresh frozen cadaver experiment and the position of the needle was plotted and compared to the expected needle path. It was found that the INIS is sufficiently accurate with an average path deviation of 1.55 mm. In addition, INIS was shown to accurately measure the maximum Central Venous Catheterization needle insertion force which ranged from 3.02 N to 3.73 N.


Track 6 - Surgical Tools

"A Wire-Driven Multifunctional Manipulator for Single Incision Laparoscopic Surgery" DMD2020-9015
A M Masum Bulbul Chowdhury, Kent State University; Michael Cullado, Summa Health System; Tao Shen, Kent State University

Abstract: Minimally Invasive Surgery (MIS) has gained popularity in current abdominal surgical procedures due to its reduced skin incision length, shortened recovery time and decreased postoperative complications. One trend is to enhance these benefits by developing technologies to expand the application of single incision laparoscopic surgery (SILS) which has even less incision and incision-related complication. However, the practical application of SILS has been constrained by many complexities, including fundamental procedure issues (e. g. limited space), as well as the issues related to surgical tools, such as lack of actuation force, weak tool tips, poor visualization and lack of dexterous multitasking tools. Due to this lack of multitasking tools, the surgical tools or robots have to be retracted, exchanged and reset multiple times during the surgery, increasing the surgical time, the risk of injury and the surgeon's level of fatigue. This paper focuses on developing a multifunctional manipulator with an automatic tool changing capability to boost practical application of SILS. The manipulator uses a wire-driven method that minimizes the potential damage from sterilization since the electronic actuation and sensing components are located remotely from the end-effector which needs heat or chemical sterilization before surgery. The feasibility of the tool tip changing method has been demonstrated by experiments.


Track 6 - Surgical Tools

"Towards Manufacturing Scale-Up of an Air Retention Device for Colonoscopy" DMD2020-9022
Carl Nelson and Pin Hao Cheng, University of Nebraska-Lincoln; Joy Wolfe, Daykin

Abstract: Colonoscopy is a very common diagnostic procedure and is considered relatively safe. Air insufflation is often used to increase the effectiveness of the procedure and decrease its duration. However, it is not uncommon for poor sphincter tone to cause loss of insufflation gas, thus complicating the workflow and lengthening the procedure. Air retention devices may address this shortcoming. In this paper, we present an improved air retention device for colonoscopy and demonstrate its effectiveness through testing.


Track 6 - Surgical Tools

"Minimizing Cotton Ball Retention in Neurological Procedures" DMD2020-9042
Raphael Bechtold, Benjamin Garlow, Arushi Tandon, Alexandra Szewc, Renee Liu, William Zhu and Olivia Musmanno, Johns Hopkins University; George Coles, Noah Gorelick, Ian Suk, Judy Huang, Henry Brem and Amir Manbachi, Johns Hopkins Medical Institution

Abstract: Neurosurgical operations are long and intensive medical procedures, during which the surgeon must constantly have an unobscured view of the brain in order to be able to properly operate, and thus must use a variety of tools to clear obstructions (like blood and fluid) from the operating area. Currently, cotton balls are the most versatile and effective option to accomplish this as they absorb fluids, are soft enough to safely manipulate the brain, act as a barrier between other tools and the brain, and function as a spacer to keep anatomies of the brain open and visible during the operation. While cotton balls allow neurosurgeons to effectively improve visibility of the operating area, they may also be accidentally left in the brain upon completion of the surgery. This can lead to a wide range of post-operative risks including dangerous immune responses, additional medical care or surgical operations, and even death. This project seeks to develop a unique medical device that utilizes ultrasound technology in order to minimize cotton retention after neurosurgical procedures in order to reduce undesired post-operative risks, and maximize visibility.


Track 6 - Surgical Tools

"An Evaluation of Sensing Technologies to Measure Intraoperative Leg Length for Total Hip Arthroplasty" DMD2020-9056
Akash Chaurasia, Jerry Yan, Robert Li, Kate McCarren, Claire State, Hannah Takasuka, Evan Bender, Aditi Jithendra, Julius Oni and Amir Manbachi, Johns Hopkins Bayview Medical Center

Abstract: Total hip arthroplasty (THA) procedures have been identified as high-volume procedures with growing prevalence. During the procedure, orthopedic surgeons largely rely solely on qualitative assessment to ensure an excessive limb length discrepancy (LLD) is not introduced from the implant selection. LLD can result in back pain and gait complications, with some cases of LLD requiring a revision procedure to mitigate. To address this issue, we evaluated several methods of sensing distance intraoperatively to determine the best approach to measure leg length during the THA procedure. A testing setup using a sawbones model of hip anatomy in the decubitus position was used as a simulation of the THA procedure to test the accuracy of each of the sensing modalities.


Track 6 - Surgical Tools

"Cable-Driven 3d Steerable Surgical Needle for Needle-Based Procedures" DMD2020-9072
Zahra Khashei Varnamkhasti and Bardia Konh, University of Hawaii at Manoa

Abstract: Surgical needles have been used in many percutaneous needle-based procedures such as biopsy and brachytherapy in recent years. The needle-based procedures have replaced open surgeries to perform the tasks with minimal invasiveness to the tissue. Precise needle insertion at target position in cancer diagnostic and therapeutic procedures governs the success of such procedures. This work presents a cable-driven 3D steerable needle for improved guidance inside the tissue towards the target. The needle is manipulated by pulling cable tendons via programmed stepper motors. Feasibility tests in air and in a tissue-mimicking phantom showed an average 3D needle deflection of 11.06mm and 10.49mm, respectively. The controlled 3D deflection of this needle is expected to assist surgeons in trajectory tracking and to improve targeting accuracies.


Track 6 - Surgical Tools

"Design of a Handheld Tissue Grasping Device to Measure Tissue Mechanical Properties In-Vivo or in a Laboratory Setting" DMD2020-9089
Bradley Drahos, Amer Safdari, Faizan Malik, Rebecca Smith, Matt Kubala, Shikha Goodwin and Timothy Kowalewski, University of Minnesota

Abstract: With medical institutions increasing the use of medical simulators for educational purposes it is necessary that the knowledge gap regarding tissue mechanical properties be researched further in depth. In order to assist with the testing of the mechanical properties, a grasper device was designed. The grasper device discussed throughout this paper aims to provide researchers a handheld device capable of testing soft organs and tissue in-vivo minimally invasive and ex-situ in a laboratory setting. The device consists of two load cells on the inner jaws of the grasper to measure compressive force and an encoder to monitor the graspers angular position which yields tissue position and strain. Accompanying the grasper is a GUI written in Rust which is capable of data file management and providing a 10 second live feed of load cell and encoder readings. The grasper device is currently being employed in a study testing the tissue mechanical response of porcine tissue at states ranging from in-vivo to ex-situ post freeze. The results from this test, and subsequent tests using the grasper have the capability of providing much needed knowledge regarding tissue mechanic properties to improve medical simulators and medical education as a whole.


Track 6 - Surgical Tools

"Dynamic Characteristics Analysis and Fem Modeling in Control of an Sma-Activated Flexible Multi-Joint Needle" DMD2020-9097
Saeed Karimi and Bardia Konh, University of Hawaii at Manoa

Abstract: Minimally invasive percutaneous needle-based procedures such as brachytherapy, ablation, and biopsy are standard clinical procedures in cancer interventions. Active needle steering increases the target placement accuracy, and consequently improves the clinical outcome. In this work, kinematic characteristics and dynamical analysis of a 3D steerable active surgical needle prototype with flexible joints, and three Shape Memory Alloy (SMA) actuators are studied. The Shape Memory Effect (SME) and Pseudoelasticity (PE) of the SMA actuators, and their biocompatibility, and high corrosion resistance, have made SMAs appropriate alternatives in biomedical applications. Modelling the dynamics of the flexible active needle in actuation is essential in predictions of the needle-tissue interactions, navigation, and control of the active needle in the tissue during the insertion.


Track 6 - Surgical Tools

"Characterization of Acetabular Cup Insertion Forces in Cancellous Bone Proxy for Validation of an Invasive Sensing Model and Development of Automatic Intelligent Prosthesis Installation Device" DMD2020-9098
Kambiz Behzadi and Jesse Rusk, Behzadi Medical Device LLC

Abstract: Total hip replacement is a widespread medical procedure, with over 300,000 surgeries performed each year in the US alone. The vast majority of total hip replacements utilize press fit fixation, where the implant cup is physically impacted into the patient's acetabular cavity. Successful seating of the implant requires a delicate balance between inserting the implant deep enough to obtain sufficient primary stability, while avoiding fracture of bone, which causes pain, complications during recovery, and revision surgery. To improve patient outcomes, this surgical field needs assistive technologies that can measure the forces applied during press fit fixation, and provide real-time feedback to guide how much force to apply, and when to stop applying additional forces. The development of such technology, however, requires a greater understanding of the forces experienced at the implant-acetabular cup interface, and the resulting cup insertion and implant stability. Here, we present a preliminary study of acetabular cup insertion into bone proxy samples. We find that as the magnitude of force on the acetabular cup increases, the cup displacement and axial extraction force increase linearly and then plateau. For repeated impacts of a given force, cup insertion and force experienced in bone increase correspondingly and reach a plateaued value over certain number of impacts, which represents rate of insertion. These finding suggest the plausibility of a feedback mechanism that utilizes measured force patterns in bone, implant/bone interface, and impaction tool in relation to rate of insertion to infer optimal primary implant stability in arthroplasty.


Track 7 - Computer Modeling & Simulation

"Development of Anaglyph 3d Functionality for Cost-Effective Virtual Reality Anatomical Education Tool" DMD2020-9014
Alex Deakyne, Erik Gaasedelen, Tinen Iles and Paul Iaizzo, University of Minnesota

Abstract: Virtual reality (VR) is becoming more widely available and accessible as a technology due to the affordability of cheap computing power. Thus, it has made it possible for virtual reality systems to capture audiences in industry and education, as well as for personal use. Currently, a major limitation of VR headsets is that the user's vision is completely occluded, making it difficult for them to interact with others. This is problematic in an educational setting since it is difficult for the given instructor and students to have a shared learning experience. Here, we have developed anaglyph 3D functionalities into the Visible Heart® Laboratories anatomical virtual reality platform. These functionalities augment what is viewed by the virtual reality user with an anaglyph shader which in turn projects it to an external display. This allows a multitude of users to wear anaglyph "red/blue 3D glasses" and view the same anatomy as the VR instructor is viewing in 3D, but while preserving the important 3D anatomical spatial relationships.


Track 7 - Computer Modeling & Simulation

"A Pediatric Supracondylar Humerus Fracture Wire Navigation Simulator" DMD2020-9031
Zane Johnson, Geb Thomas, Steven Long and Donald Anderson, The University of Iowa

Abstract: Orthopedic trainees are required to receive dedicated laboratory-based surgical skills training in their first year of residency. Simulators are often used in this training. Our group has developed a hip fracture wire navigation simulator to train and assess residents' skills in placing a K wire within a femur bone surrogate using planar pseudo-fluoroscopic images to aid in navigation. In this paper, we describe design considerations and challenges in modifying the existing simulator to train the multi-wire pinning of a pediatric supracondylar humerus simulator. The design involves changing the bone of interest from the femur to the humerus, while using the same platform technology. Considerations include ease of use, minimizing motion of the fixed bone, and minimizing materials used. The robustness of the bone mounting was tested by running an experiment using 3D scans and surface deviation analysis to test the repeatability of bone placement and its resistance to rotational motion after being placed in the fixture. After the design was developed and proved to hold the bone rigidly, the new simulator was used in a pilot study to confirm that the surgeons and residents consider the simulator experience as being a valid representation of the actual surgical skill.


Track 7 - Computer Modeling & Simulation

"A Novel Nonparametric Technique for Segmenting Multimode Hyperspectral Images Obtained From Non-Melanoma Skin Cancer Lesions" DMD2020-9045
Gamal Geweid, Benha University and University of North Dakota; Fartash Vasefi, Wound Exam Corp; Kouhyar Tavakolian, University of North Dakota

Abstract: Keratinocyte Carcinoma, more traditionally known as Non-melanoma skin cancer (NMSC), is the most common cancer in humans. Incidence continues to increase despite increased public awareness of the harmful effects of solar radiation. In this paper, a non-parametric technique based on image registration will be applied to the multimode hyperspectral imaging system to segment Basal carcinoma (BCC) and Squamous cell carcinoma lesions (SCC). The aim is to enhance Mohs surgery by determining the actual borderlines of the desired area in the patient's images, leading to increased efficiency and efficacy of the Mohs surgery. The proposed algorithm was applied to four sets of different Multimode Hyperspectral Images with Non-Melanoma Skin. The experimental findings showed that the proposed algorithm is effective in Non-Melanoma skin detection. This could lead to improved image-guided excision of cancerous lesions with potential applications in robotic interventions.


Track 7 - Computer Modeling & Simulation

"Virtual Reality Tools for Deep Brain Stimulation: A Framework and Design Concepts for Procedural Planning" DMD2020-9059
Bethany Juhnke, Muhammad Ahsan, Paul Rothweiler and Arthur Erdman, University of Minnesota

Abstract: Virtual reality tools have been theorized to revolutionize medicine. Many tools on the market today fail to provide value in a clinical setting. Virtual reality tools must emulate existing clinical workflows to add value to a doctor's process. Usability studies provide evidence to validate if a specific virtual reality tool design improves a clinical process. A framework is created to capture the clinical workflow by defining user tasks, graphical user interface functionalities and backend software functionalities. Two virtual reality tool designs are presented based on the workflow captured in the framework. The first virtual reality tool is designed for communication and collaboration, while the second tool is designed with a full immersive experience.


Track 7 - Computer Modeling & Simulation

"A Precise Scale-Up Method to Predict Particle Delivered Dose in a Human Respiratory System Using Rat Deposition Data: An in Silico Study" DMD2020-9060
Hamideh Hayati and Yu Feng, Oklahoma State University

Abstract: As surrogates to human beings, rats are used occasionally to study the therapeutic impact of inhaled pulmonary drug particles in microscale. To speculate human responses from rat studies, scale-up factors are widely used to extrapolate particle lung deposition from rat to human. However, available scale- up methods are highly simplified and not accurate, because they directly use the rat-to-human ratios of body weight (BW) or lung surface area as the scale-up factor. To find a precise scale-up strategy, an experimentally validated Computational Fluid-Particle Dynamics (CFPD) was employed to simulate the transport and deposition of microparticles in both human and rate respiratory systems, which encompasses the pulmonary routes from mouth/nose to airways up to Generation 17 (G17) for human and G23 for the rat. Microparticles with the same range of Stk/Fr were injected into both models with the airflow at resting conditions. Numerical results indicate that particles (with the size ranging from 1 to 13 µm for humans and 0.6 to 6 µm for rat) have similar deposition pattern (DP) and deposition fraction (DF) in both models, which are resulted from both inertial impaction and gravitational sedimentation effects. A novel correlation is proposed to predict DFs in both human and rat respiratory systems as a function of the ratio of Stokes number to Froude number (Stk/Fr). Using the correlation as the novel scale-up tool, inter-species extrapolations can be precisely done on predicting particle depositions in human respiratory systems based on the deposition data in rats obtained from animal studies.


Track 7 - Computer Modeling & Simulation

"Development of an Open-Access Library of Pediatric Congenital Heart Diseases and Treatments: A Tutorial on the Atlas of Human Cardiac Anatomy" DMD2020-9064
Amanda Tenhoff, University of Minnesota

Abstract: The major aim of this project is to construct a growing database of information regarding specific manifestations of congenital heart diseases (CHDs), subsequent treatments, clinical cases, and patient outcomes. This will include 3D models generated from clinical imaging of individual patient hearts and respective de-identified clinical case information - all of which will be incorporated onto the free-access Atlas of Human Cardiac Anatomy website (http://www.vhlab.umn.edu/atlas/), where anyone can learn more about these diseases and their complexities [1]. Generated models can also be used for 3D printing, such as for pre-surgical planning, as well as for incorporation into virtual reality in order to expand outreach and education efforts [2]. Future work will incorporate computational modeling to enhance insights relative to treatment strategies and surgical planning. By studying a broad range of these unique individual cases, it will be possible for patients, clinicians, and medical device designers alike to better understand the clinical presentations of congenital heart diseases and develop more effective treatment strategies.


Track 7 - Computer Modeling & Simulation

"Using Computational Modeling Derived From Micro Ct Scanning for the Post-Implant Analyses of Various Cardiac Devices" DMD2020-9071
Thomas Valenzuela, Jorge Zhingre Sanchez, Mikayle Holm, Tinen Iles and Paul Iaizzo, University of Minnesota

Abstract: There are few medical devices currently utilized that have not had, at the very least, a second iteration. Medical device companies continually strive to improve their product and hopefully the best on the market. Medical devices are often optimized by defining the size of the device, making it more efficient and/or improving the device to tissue interface. Using the capabilities of the Visible Heart® Laboratories various cardiac devices can be implanted in reanimated swine and human hearts for the assessment of the various aforementioned parameters. After the implantation of these devices and assessment in functional anatomies, specimens were perfusion- fixed and then a micro-CT scanner was utilized to take high- resolution scans of the resultant device and tissue interfaces. These scans are used to generate high-resolution (~20 microns) 3D models of the numerous implanted devices, measurement analyses, device simulations, and the creation of virtual reality scenes. All can then be used for detailed visual analyses. These abilities to render high-resolution models will allow medical device designers to closely evaluate their designs, in order to optimize their next iterations.


Track 7 - Computer Modeling & Simulation

"On the Modal Analysis of Blood Flows in Brain Aneurysms" DMD2020-9100
Trung Le and Lahcen Akerkouch, North Dakota State University

Abstract: Complex, unstable inflow jet has been linked to aneurysm growth and rupture. However, methodologies to characterize this inflow jet has not been well established. Our previous works (Le et al., J. Biomech. Engr., 2010 and Le et al., An- nals Biomedical Eng., 2013) have shown a possible transition from the stable mode (cavity) to the unstable mode (vortex ring) of this jet. We have proposed the use of a non-dimensional index called Aneurysm Number to characterize this transition (Le et al., 2013). However, the quantification of such a transition is lacking. Currently, there has no efforts in quantifying unstable flows in intracranial aneurysms, which is essential in stratifying rupture risks. In this work, the aneurysmal geometries from three patients at Sanford Health, North Dakota are reconstructed from Magnetic Resonance Angiogram and Digital Subtraction Angiogram data. Using our in-house CFD code (Virtual Flow Simulator), high-resolution flow data is obtained via numerical simulation. We perform modal analysis of blood flow dynamics for these cases using Proper Orthogonal Decomposition. Our results show that there are up to five dominant modes in the flow arising from the interaction of the incoming jet and the aneurysm dome. The spatial distribution of these modes reflect the characteristics of the inflow jet and can be used to quantified flow unsteadiness. Future works will be needed to apply the same procedure for a larger population of patients to examine its relevance in clinical practice.


Track 8 - Human Factors

"Stakeholder Engagement With Prototypes During Front-End Medical Device Design: Who Is Engaged With What Prototype?" DMD2020-9020
Marianna Coulentianos, Ilka Rodriguez-Calero, Shanna Daly and Kathleen Sienko, University of Michigan

Abstract: Stakeholder engagement with prototypes during the front- end phases of medical device design can support the processes associated with problem identification and definition. This study examined what prototypes are leveraged to engage specific types of stakeholders during front-end design. Semi-structured interviews with 22 design practitioners in the medical device industry were performed. Transcript analysis revealed patterns: designers engaged users with physical 3D prototypes, financial decision-makers with physical 3D and CAD prototypes, government, regulatory stakeholders with 2D prototypes, and expert advisors with CAD prototypes. The rationale provided by practitioners revealed the intentional selection and alignment of prototypes for stakeholder engagements based on stakeholder type.


Track 8 - Human Factors

"Visualizing Telemetry Metrics From Upper-Airway Stimulation to Enhance Sleep Therapy Management" DMD2020-9035
Matheus Araujo, University of Minnesota; Kent Lee and Quan Ni, Inspire Medical Systems; Jaideeep Srivastava, University of Minnesota

Abstract: Upper-Airway Stimulation (UAS) therapy is an innovative alternative to Continuous Positive Airway Pressure (CPAP) treatment for patients with obstructive sleep apnea (OSA) and CPAP intolerance. Patients who have implanted a UAS device are responsible for activating and managing the therapy at home before sleep. Consistent nightly use is required for a reduced OSA burden, measured by the apnea-hypopnea index. Thus, understanding patient behavior and possible challenges to nightly use are crucial to therapy success. In this work, we present two novel visualizations to monitor telemetry data recorded by the UAS sleep remote. They provide doctors and sleep clinicians with detailed information to easily classify therapy use and sleep patterns. We also present how to show daily metrics such as hours of average usage, therapy intensity, and duration of therapy pauses, to identify optimal therapy settings and measure the long-term effectiveness of interventions.


Track 8 - Human Factors

"Single Versus Multiple Prototypes: Medical Device Design Practitioners' Rationale for Varying Prototype Quantities to Engage Stakeholders During Front-End Design" DMD2020-9046
Ilka Rodríguez-Calero, Marianna Coulentianos, Shanna Daly and Kathleen Sienko, University of Michigan

Abstract: Engaging stakeholders during medical device design processes, especially during front-end design activities, is a critical consideration for successful product design, which includes the safety and effectiveness of devices. The use of prototypes with stakeholders is encouraged by proponents of human-centered design, but guidelines for front-end stakeholder engagement with detailed descriptions of prototyping practices are lacking. One foundational question about prototyping uses is, how many prototypes should be used during stakeholder engagement? This study investigated why design practitioners chose to use multiple prototypes or a single prototype to engage stakeholders during the design front-end. Participants described using multiple prototypes, for example, to elicit priorities, invite participation, and support feedback. Participants also described using a single prototype, for instance, to probe responses and to refine a specific concept. These results have the potential to inform design decisions and pedagogical approaches to prototyping use.


Track 9 - Wearables

"A Framework for Mapping and Controlling Exoskeleton Gait Patterns in Both Simulation and Real-World" DMD2020-9009
Lowell Rose, Michael Bazzocchi, Connal de Souza, Julie Vaughan-Graham, Kara Patterson, University of Toronto; and Goldie Nejat, University of Toronto and Toronto Rehabilitation Institute

Abstract: Stroke is a leading cause of disability, and robotic lower body exoskeletons have been developed to aid in gait rehabilitation. The simulation modeling and testing processes are often developed and deployed separately. This introduces additional steps which can hinder on-the-fly customization of gait patterns required for individualized gait rehabilitation. In this paper, we present a centralized control architecture which integrates both the simulated model and the exoskeleton hardware for lower body exoskeletons. The architecture allows for ease of simulating, adapting, and deploying gait patterns on an exoskeleton for use in gait rehabilitation, and allows for the on-the-fly customization and verification of gait patterns by physiotherapists during rehabilitation. Experiments validate the use of our overall control architecture to both model and control a physical exoskeleton, while following desired gait patterns.


Track 9 - Wearables

"Development of a Pressure Measuring Garment to Understand How to Quantify Compression" DMD2020-9024
Michael Weber and Abigail Clarke-Sather, University of Minnesota Duluth; Tara Bergeron, Anisa Janko, Alicia Jensen, Brittany Malvick and Steven Cope, College of St. Scholastica

Abstract: Encouraging research shows reductions in the number of disruptive behaviors for children diagnosed with Autism Spectrum Disorder (ASD) when wearing compression shirts. However, current studies do not consider the amount of pressure compression shirts apply to the body and how different amounts of pressure applied to the body may lead to different outcomes for children diagnosed with ASD. The purpose of this proof of concept research project was to develop a method for measuring the pressure applied by a compression shirt at a specific location on the body. This study used conductive thread as the principle element to measure the compression applied by a garment onto the body, specifically the arm. It was found that for the specific stitch and thread tested, the relationship between the displacement the sensor exhibits and the change in resistance was 25.95 Ω/m. With this relation, the pressure applied by a compression garment to a mannequin arm and the arms of four participants was found. A general trend that the measured pressure applied by a garment onto the body directly correlated with increasing individual arm circumference was found.


Track 9 - Wearables

"Flexible Circuit Board Package Embedded With Multi-Stack Dies" DMD2020-9032
Nobuki Ueta, Shunsuke Sato, Masakazu Sato, Yoshio Nakao and Osamu Nakao, Fujikura Ltd.; Joshua Magnuson and Rocky Ishizuka, Fujikura America, Inc.

Abstract: Miniaturization of electronics modules is always required for various medical applications including wearable technology, such as hearing aids, and implantable devices. Many types of high-density packaging technologies, such as package-on-package, bare-die stack, flex folded package and Through Si Via (TSV) technologies, have been proposed and used to fulfill the request. Among them, embedded die technology is one of the promising technologies to realize miniaturization and high-density packaging. We have developed WABETM (wafer and board level device embedded) technology for embedding dies into multilayer flexible printed circuit (FPC) boards. The WABE package is comprised of thin dies (85 µm thickness), multi-layer polyimide, adhesive films and conductive paste. The dies are sandwiched by polyimide films with Cu circuits (FPCs). The conductive paste provides electrical connections between the layers as well as the layer and embedded die. First, each FPC layer is fabricated individually, and via holes are filled with conductive paste, and the dies are mounted on certain layers. Then, all layers undergo a one-step co-lamination process, and they are pressed to cure the adhesive material and conductive paste at the same time. This WABE technology has enabled multiple dies to be embedded by the one-step lamination process. Even if multiple dies are embedded, the footprint of a package can be reduced drastically by embedding multiple dies vertically in stacks. This paper describes the details of the results of fabricating a test vehicle with six embedded dies (three-dies in two stacks side-by-side). The fabricated test vehicle had 14 copper layers with less than 0.9 mm thickness. This paper also reports the results of various reliability testing on the package. These results were obtained by electrical measurements of daisy chain patterns formed between some of the layers. The fabricated test vehicle showed high reliability based on the results of a moisture and heat test and heat-shock test. These results show that the WABE technology to embed multiple dies vertically in polyimide film is one of the most promising packaging technologies to significantly miniaturize electronic circuits such as medical electronics.


Track 9 - Wearables

"Assessing Induced Emotions in Employees in a Workplace Setting Using Wearable Devices" DMD2020-9062
Emma Fortune, Yaqoub Yusuf, Sarah Zornes, Jorge Loyo Lopez and Renaldo Blocker, Mayo Clinic

Abstract: A working environment which elicits positive emotions in employees is vital for employee retention, engagement and productivity. Wearable sensors provide the means to objectively measure the emotional responses of employees in the workplace in real-time. The study aim was to perform a preliminary investigation into the validity of using wearable electroencephalography (EEG) and galvanic skin response (GSR) devices in combination with video-based facial expression analysis to classify employee's emotional responses to video stimuli as positive, neutral or negative. Five office employees each watched three short video clips at three time points during their regular work shifts while wearing EEG sensors on the forehead and GSR sensors on the middle and index fingers of their non-dominant hand with their face in view of a webcam. The combinations of both EEG and GSR with video-based facial expression analysis (FEA) were able to accurately detect positive emotions elicited from video stimuli 80% of the time. The majority (60%) of the negative stimuli were misclassified as neutral. The GSR sensor alone was able to detect a response to either positive or negative stimuli 80% of the time. The results suggest that these devices may be capable of detecting both arousal and positive emotions in real- time in the workplace.


Track 9 - Wearables

"Real-Time Voice Activity Detection Using Neck-Mounted Accelerometers for Controlling a Wearable Vibration Device to Treat Speech Impairment" DMD2020-9081
Saurav Dubey, Arash Mahnan and Jürgen Konczak, University of Minnesota

Abstract: Speech analysis using microphones can be problematic for Voice Activity Detection (VAD) in the presence of background noise. This study explored the use of wearable accelerometers instead of microphones. We assessed if accelerometers placed on the neck can be part of a VAD system embedded in a wearable collar-like device that delivers vibro-tactile stimulation (VTS) to laryngeal muscles during speech as a therapy for patients with the voice disorder spasmodic dysphonia. Specifically, we aimed to a) find the ideal location for placing accelerometers to the neck, and b) develop a VAD algorithm that reliably detects the onset and offset of speech. Six healthy adult participants (M/F = 3/3, 26 ± SD = 5.1 years) vocalized 20 sample sentences with and without VTS at three neck locations: 1) thyroid cartilage, 2) sternocleidomastoid, and 3) posterior neck above C7. Based on time-synchronized acceleration and audio signals the number of onsets of speech and total time voiced were identified by the VAD algorithm. The thyroid cartilage attachment location had over 90% accuracy detecting speech in both measures. The average accuracy of the sternocleidomastoid and C7 locations were below 75% and 15% respectively. VAD accuracy decreased in VTS trials at all locations. We conclude that accelerometer signals due to tissue motion at thyroid cartilage are most suitable for real-time VAD. The algorithm can be improved in robustness to noise caused by vibration through use of advanced processing methods such as adaptive filtering.


Track 9 - Wearables

"Design of a Wearable Health Monitoring System for In-Home and Emergency Use" DMD2020-9091
Michael Bertsch and Stephen Gent, South Dakota State University

Abstract: Recent advancements in wearable medical technologies have streamlined health monitoring with simple, non-invasive measurements. These devices, however, often cost the user hundreds to thousands of dollars and are rarely capable of monitoring multiple parameters. The objective of this project is to develop an affordable, user-friendly wearable device capable of monitoring multiple parameters: body temperature, blood pressure, heart rate, blood oxygen, and body positioning. By combining wearable sensors with Inter-Integrated Circuit (I2C) technology, the data from many sensors can be transmitted while maintaining a compact size. In parallel with this device, a mobile application was designed as an interface to receive real-time comprehensive measurements. This device has the potential to combat shortfalls of the medical industry by reducing monitor application time in emergency medical settings and monitoring patients in rural communities who are often hours away from the nearest medical centers.


Track 9 - Wearables

"An Untethered Electro-Pneumatic Exosuit for Gait Assistance of People With Foot Drop" DMD2020-9099
Lizzette Salmeron, Gladys Juca, Satesh Mahadeo, Jiechao Ma, Shuangyue Yu and Hao Su, City College

Abstract: Individuals with foot drop caused by stroke or cerebral palsy (CP) have a particular need for robotic ankle exoskeleton. This paper proposes an untethered soft robot using an origami actuator to lift the toes of the wearer. The weight, connections, and complex control of the system are reduced through mechanical design. A compact and portable pneumatic system is designed to perform suction and compression with a single pump. The load test of the actuator shows the capability of 300N in 30 kPa. An untethered, simple and affordable robotic ankle exoskeleton is developed with the pneumatic actuator. The wearer can finish its simple 3-step donning procedure within 1 min.


Track 10 - Special Devices

"Point-of-Care Viscosity Surrogate Measurement Through Utilization of Smartphone Sensors and Custom 3d Printed Design" DMD2020-9004
Awaiz Khan, Virginia Tech Carilion School of Medicine; Bradley Icard, Cone Health Medical Group; Edmundo Rubio, Virginia Tech Carilion School of Medicine

Abstract: This project sought to develop a method to provide a clinically meaningful, surrogate measure for viscosity that will help analyze complex biofluids. Goals for this project included precise measurements that differentiate a wide variety of standard viscosities, table-top level of size, and ease-of-use. The design utilized a custom 3D-printed analog of a cone and plate viscometer with an attachment for a smartphone to provide gyroscopic data. The device is currently in the stages of final validation and will ultimately be tested in a 40-patient clinical trial intended to assess efficacy of mucolytic therapy in mechanically ventilated patients.


Track 10 - Special Devices

"A Realistic Phantom for Ultrasound-Guided Central Venous Cannulation" DMD2020-9007
Si Yen Ng and Chi-Lun Lin, National Cheng Kung University

Abstract: Ultrasound-guided central venous cannulation (CVC) has become standard to care. Ultrasound imaging allows the CVC procedure to be completed much safer than a standard blind landmark approach. To enhance medical personnel's skill in performing challenging ultrasound-guided CVC, an adult size CVC phantom that simulated the human head to the chest, with a detachable CVC operational part, was proposed in this study to provide medical personnel with realistic needle insertion haptic feedback and ultrasound imaging. The detachable CVC operational part could be customized to simulate different patient conditions, such as adult patient (with normal standard size of vascular), the elderly (with collapsed vascular), children (with smaller diameter of vascular), vascular fibrosis patient (with hardening of vascular) and obese patient (with thick fat tissue). In the current stage of prototype development, a CVC operational part with simulated blood vessels and clavicle embedded inside the fat- and muscle-mimicking tissue was produced. Both the fat- and muscle-mimicking tissue pose mechanical and acoustic properties similar to real tissues. The target vein for CVC procedure could be recognized from the ultrasound imaging of the CVC operational part.


Track 10 - Special Devices

"Design and Implementation of a Balloon Catheter Pressure Testing System" DMD2020-9017
Aaron Tucker, Breanne Retherford, Paul Rothweiler, Ahmed Selim and Art Erdman, University of Minnesota

Abstract: Medical device companies that aim to sell catheters with pressure sensing elements need a way to test their systems before packaging their product. An example of one of these products is an Intra-aortic Balloon Pump (IABP) which provides mechanical pumping assistance to a patient experiencing cardiogenic shock. To test these devices, companies will place the assembly in controlled pressure chamber to test the response to pressure changes. However commercially available systems are cost prohibitive. The Earl E. Bakken Medical Devices Center needs a way to test custom designed balloon catheters. As a result, a low-cost, pneumatic catheter test chamber was designed and built to provide a benchtop platform for testing. In order to control the chamber pressure, the system utilizes feedback control with an Arduino control module. Since pneumatic systems exhibit nonlinear behavior, a novel control method was used to implement feedback control and simulate the pressure profile experienced in the human body.


Track 10 - Special Devices

"Design of a Portable Venomanometer System for Episcleral Venous Pressure Measurement" DMD2020-9021
Tze Yeen Yap, Carl Nelson, University of Nebraska - Lincoln; Deepta Ghate, Vikas Gulati, Shan Fan, Sachin Kedar and Meghal Gagrani, University of Nebraska Medical Center; Adam Hahn, Blaine Minden, Luke Moorhous, Zachary Fowler and Deepak Khazanchi, University of Nebraska at Omaha

Abstract: Traumatic brain injury (TBI) has been considered a precarious health issue especially within the military population. Research has shown that early treatment of TBI could reduce possible neurocognitive injury. However, the nature of military triage has created challenges for early TBI detection. Intracranial pressure (ICP), which is used as a biomarker of outcomes in TBI, is not only expensive to measure but is also invasive and requires specialized surgical and procedural skills. Episcleral venous pressure (EVP) was proven to be a good alternative biomarker to ICP. However, the current technology in measuring EVP is not portable, and requires a skilled operator with a slit-lamp for testing. Moreover, the measurement is highly subjective and depends on the operator's skill and technique. Therefore, there is a critical need for alternative technology for non-clinical TBI diagnosis. In this paper, we present an improved venomanometer design for measuring EVP in the field.


Track 10 - Special Devices

"Adherence of Upper Airway Stimulation in Us and German Medical Centers: A Multicenter Meta-Analysis on Adhere Registry" DMD2020-9026
Jingxin Lei, University of Minnesota; Kent Lee, Inspire Medical Systems, Inc.

Abstract: Upper airway stimulation (UAS) is shown to be effective with high adherence for patients with moderate to severe obstructive sleep apnea. However, the consistency of adherence among medical sites remains to be verified. This study examines the adherence to UAS among medical sites in an international multicenter registry. A statistically significant adherence decrease between 6-month and 12-month visit was found in the study cohort as well as in most sites. No significant heterogeneity was found among sites with either all patients or only patients who had adherence at both visits recorded. In addition, there is no enough evidence that region and experience of sites influences the adherence. This study indicates that UAS therapy adherence is consistent among sites, regardless of region and experience of sites.


Track 10 - Special Devices

"Train of Four Monitoring Device" DMD2020-9038
Anastasia Karapanagou, Nicholas Bergstrom, Christopher Beauregard, Kyler Dillon, Jeanine Skorinko and Ahmet Can Sabuncu, Worcester Polytechnic Institute; Eric Rosero, University of Texas Southwestern Medical Center

Abstract: Assessment of neuromuscular blockade during anesthesia is achieved using the Train of Four (TOF) monitoring technique. However, current devices are limited to conditions in which the hand can move freely during operation. The goal of this project was to design, prototype, and test a device which extends the TOF technique to conditions where movement is restricted. Interviews were conducted with stakeholders to better understand the need for this device and to get feedback on preliminary designs. The resulting device consists of a thumb-mounted balloon, which converts the force due to thumb twitches into pressure, which then acts as the physical analog to muscle response. This pressure is transduced and analyzed to produce a TOF count and TOF ratio. A prototype was constructed and tested on human subjects with different hand geometries.


Track 10 - Special Devices

"Mitigating Complications Caused by Intravenous Therapy: The Iv Patency Monitoring Device" DMD2020-9041
Daniel Portillo, Grant Copeland, Bao Huy Vu, Omar Navarro, Gabriela Pineda, Sepehr Seifi, Lyle Hood and Sukhwinder Kaur, The University of Texas at San Antonio; Nitin Das, Daniel DeArmond and John H. Calhoon, The University of Texas Health Science Center

Abstract: Although intravenous therapy (IV) is one of the most frequently utilized approaches for fluid delivery in modern healthcare, it is associated with some form of complication up to 40% of the time. While many complications are minor, occlusion and extravasation can prevent the delivery of a needed fluid-based intervention or cause delivery into the subdermal space, based intervention or cause delivery into the subdermal space, which can lead to distributed tissue damage and necrosis. To address this need, this group developed the IV patency monitoring device (IVP) to generate and analyze a small pulse wave within the IV fluid. The study hypothesis was that changes in the IV's communication with the blood stream could be detected as an alteration in this signal. This study investigated wave characteristics generated by the IVP in a benchtop tissue phantom. Results demonstrated that wave characteristics change detectably between simulated patent communication with a simulated blood stream and states of extravasation or occlusion. Future work will focus on improved detection methods and integrating a real-time alert system, which will better prepare the IVP for clinical translation and impact.


Track 10 - Special Devices

"Task-Specific Assistive Device (Tad): An Accessible Technological Solution for Upper Limb Disability" DMD2020-9047
Veena Jayasree-Krishnan and Shramana Ghosh; NYU Tandon School of Engineering; Preeti Raghavan, John Hopkins University; Jack Spiegler, Purdue University; Vikram Kapila, NYU Tandon School of Engineering

Abstract: The task-specific assistive device (TAD) is a compact, and portable assistive device consisting of an actuated six-bar linkage designed to facilitate the activity of drinking from a cup without using the hands. In this paper, we examine the effectiveness of the device in supporting patients with conditions of incomplete tetraplegia and hemiplegia by simulating disability in 17 healthy subjects. The average percentage reduction in bending angle of torso with the use of TAD was found to be 40.31% for subjects with simulated incomplete tetraplegia and 37.14% for subjects with simulated hemiplegia. Users also completed the system usability scale (SUS), indicating that the device was easy to use. The users' workload, measured using the NASA task load index (NASA-TLX) was found to be minimal and the device was found to be robust through user experience tests. The results of this work indicate that TAD is a promising solution for facilitating independence in a basic activity of daily living such as drinking from a cup without using the hands.


Track 10 - Special Devices

"Novel Method and Device for Delivery and Retention of Intrauterine Devices in the Immediate Postpartum Period: Pilot Baboon Feasibility Study" DMD2020-9049
Etse-Oghena Campbell and Christopher Rylander, University of Texas at Austin; Lauren Thaxton and Yvette Williams-Brown, Dell Medical School

Abstract: The immediate post-partum period offers a convenient time to have an intrauterine device placed because of the co-location of a non-pregnant patient, clinician and device; however, this practice is associated with increased expulsion rates of up to 30%, compared with a 3% expulsion rate for interval insertions, and is consequently not recommended by clinicians. This paper presents a device and method to improve intrauterine device retention in immediate postpartum patients. We present the results of an initial feasibility study that illustrate it is possible to temporarily tether a commercially available intrauterine device in an immediately postpartum baboon uterus through the puerperal period. The results indicate this device and method could lead to improved intrauterine device access.


Track 10 - Special Devices

"Solid Fiber Inside Capillary and Modified Fusion-Spliced Fiber Optic Microneedle Devices" DMD2020-9050
Jason Mehta and Christopher Rylander, The University of Texas at Austin

Abstract: Clinical treatment of Glioblastoma Multiforme (GBM) is generally ineffective in increasing patient survival. Convection- enhanced delivery (CED) is an alternative, investigative therapy in which a small caliber catheter is placed directly into the brain parenchyma. However, standard CED drug delivery techniques are unable to reach the entirety of the brain tumor, attributing to the failure of Phase III clinical trials. Fiber optic microneedle devices (FMDs), capable of simultaneous fluid and laser energy delivery have shown potential to increase the drug dispersal volume when compared to fluid only devices. Previously described FMDs have had low laser transmission efficiency. In this work, we present two FMD manufacturing methods, a solid fiber inside capillary (SFIC) FMD and a modified fusion spliced (FS) FMD. Transmission efficiency of the two proposed FMDs were measured using a 1064 nm laser and an integrating sphere detector with air, deionized water, and black ink inside of the bore of the FMDs. The transmission efficiency of the FS FMD was between 45 and 127% larger than that of historically reported FS FMDs. Additionally, the transmission efficiency of the SFIC was significantly higher than the FS FMD (p ≤ 0.04 for all groups). However, the SFIC FMDs suffered catastrophic fracture failure at bend radii larger than the manufacture specification, likely due to scribing of the capillary during the FMD fabrication process. Modifying FS FMDs appears to be the preferred fabrication method providing improved light transmission efficiency and mechanical strength on par with the capillary manufacturer's specifications.


Track 10 - Special Devices

"Electrical Inhibitor for Tocolysis" DMD2020-9075
Ashwin RajKumar, NYU Tandon School of Engineering; Jeffrey Karsdon and Frederick Naftolin, NYU Langone School of Medicine

Abstract: PTB is one of the leading causes of neonatal morbidities and mortalities. Limited methods are available to physicians for mitigating PTB, thus posing an urgent need to develop effective methods for its prevention. In prior research, a benchtop EUCD was developed for tocolysis through injection of current pulses. However, the benchtop version is wall tethered and constrains patients to hospitals, i.e., it is unsuitable for deployment in out- patient or home settings. This paper focuses on the development of a mechatronics-based, low-cost, battery-powered, portable, and reproducible EUCD, which is suitable for in-home and clinical environments. The developed mechatronic version is validated for electrical performance with resistive load-tests, which indicate that the mechatronic device can generate current pulses similar to the existing benchtop EUCD. Furthermore, the signals generated from the device are evaluated for repeatability using CV analysis and the results indicate that the mechatronic version can produce repeatable frequency (1-100Hz), amplitude (1-17mA), and pulse width (1-120ms) modulated current signals. An IoMT methodology is proposed to enable seamless transition of the developed device from a clinical environment to a home- based environment for use by the patients.


Track 10 - Special Devices

"Introducing a Cost-Effective Radiopaque Scale Design for Intra-Operative Use" DMD2020-9076
Roopam Dey, University of Cape Town; Giancarlo Beukes and Gokul Nair, Impulse Biomedical (Pty) Ltd; Sudesh Sivarasu, University of Cape Town

Abstract: Radiopaque scales are generally costly and can not be developed using off-the shelf materials. They have numerous uses in the field of surgery, especially orthopaedic surgery. They can be used to guide surgeons by taking intra-operative measurements, pin point insertion points on bones and detect locations of deformations and tumors inside the body. This paper details the method of creating low-cost radiopaque scale using materials such as barium and iodine. Barium was found to be a better contrast agent than iodine and is recommended for use.


Track 10 - Special Devices

"Design and Fabrication of Patient-Specific Pediatric Laryngoscopes at the Point-of-Care" DMD2020-9077
Madelene Habib, Robert Sims, Matthew Boutelle, James Inziello, Fluvio Lobo and Jack Stubbs, University of Central Florida

Abstract: Pediatric laryngoscope blades do not vary, in size and shape, as patients' airways do. Difficult airway intubations may require physicians to try different blade sizes and even improvise. In addition to physical trauma and complications, difficult intubations may result in longer OR times. As advanced three-dimensional (3D) imaging, modeling, and printing technologies become more ubiquitous at the point-of-care, so will the development of patient-specific solutions. Here we introduce a method for the design and fabrication of patient-specific, single- use pediatric laryngoscope blades. The process seeks to optimize procedures and mitigate complications by providing physicians with the right tool at the right time.


Track 10 - Special Devices

"A New System to Objectively Measure Ankle Proprioception" DMD2020-9094
Arash Mahnan, Jessica Holst-Wolf andd Jürgen Konczak, University of Minnesota

Abstract: Proprioceptive afferents from the ankle joint are essential feedback for maintaining balance. However, there is no widely accepted test or measurement system available for ankle proprioceptive acuity. Here, we present a novel hardware system and apply an accepted psychometric testing protocol appropriate for measuring ankle proprioceptive acuity. Twelve healthy adult participants completed the assessment to establish the system validity. Here, we show exemplar data of the ankle JND threshold and results for all twelve participants. This assessment has the potential to become a tool for clinicians to identify proprioceptive impairment at the ankle and measure the efficacy of sensorimotor interventions for balance.


 


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