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.

Air embolism occurs when an air bubble enters the arterial system through the catheters. This can happen due to different reasons such as lack of attention, connection failure, or inexperience. This situation results in tissue damage in vital organs such as the heart and brain which may lead to death. To our knowledge, there is no technology preventing an air embolus from happening. Doctors try to prevent this complication with their attention and catheter control. In this project, a new air-trap device that prevents air embolus was tested in-vitro in air embolism model. Experimental results with a prototype showed that the new design was successful. Air embolism was blocked at various pressure-speed ranges. Air Trap device can be used to prevent air embolism by cardiologists, interventional radiologists and cardiovascular surgeons that perform a percutaneous intervention.

Recent advancements in deep learning have led to the possibility of increased performance in computer vision tools. A major development has been the usage of Convolutional Neural Networks (CNN) for automatically detecting features within a given image. Architectures such as YOLO 1 have obtained incredibly high performances for the real-time detection of every-day objects within images. However to date, there have been few reports of deep learning applied to detect anatomical features within CT scans; especially those within the cardiovascular space. We propose here an automatic anatomical feature detection pipeline for identifying the features of the left atrium using a CNN. Slices of CT scans were fed into a single neural network which predicted the four bounding box coordinates that encapsulate the left atrium. The network can be optimized end-to-end and generate predictions at great speed, achieving a validation smooth L1 loss of 11.95 when predicting the left atrial bounding boxes.

Bioprinting is a 3D fabrication technology used to accurately dispense cell-laden biomaterials for the fabrication of complex 3D functional living tissues. A syringe-based extrusion (SBE) deposition method comprising of multiple nozzles is integrated into the system. This allows for a wider selection of biomaterials that can be used for the formation of the extracellular matrix (ECM). The 3D bioprinting system presented in this paper aims to facilitate the process of 3D bioprinting through its ability to control the environmental parameters within an enclosed printing chamber. The primary objective of this research is to print viable 3D tissue constructs seeded with cells with high structural integrity and high resolution.

As the medical field continues to increase its effectiveness and scope, computational fluid dynamics (CFD) has become essential to understanding flow mechanics cardiovascular systems. Many simulations and experiments have been conducted to confirm the behavior of blood within veins and arteries, under both Newtonian and non-Newtonian conditions. Traditionally, these simulations have been conducted where blood is represented as a homogeneous fluid. However, blood is a heterogeneous fluid mixture, consisting of fluid plasma and solid components of red blood cells (RBC), white blood cells (WBC), and platelets. The effects of the heterogeneity of blood becomes more influential in blood flows through smaller diameter vessels and high velocity flows, as the addition of particles will create variations in flow speed, shear stress, and fluid displacement due to particle-particle and particle-wall collisions [1].

There currently exist many cardiac assist devices for the clinical treatment of congestive heart failure, which affects nearly 5 million Americans and costs the United States health care system nearly $32 billion annually [1]. The majority of these clinical devices help to improve cardiac perfusion by utilizing a blood pump — either pulsatile or continuous flow — cannulated to the circulatory system to create a parallel bypass for blood flow. These devices are typically very effective in the short term (days to months) but are typically limited by problems associated with chronic use [2]. Some of the most prevalent complications stem from the need for long-term system anticoagulation, invasive implant surgeries, catastrophic wear and tear of mechanical parts or drivelines, and infections at the percutaneous driveline site. Therefore, there is a great medical need to develop new or improve existing technologies to minimize and/or eliminate these adverse events.

In 2017, the American Heart Association reported that one third of deaths in the United States, and 31% of deaths worldwide, are attributed to cardiovascular disease (CVD) [1]. A risk factor pervasive across most types of CVD is chronic high blood pressure, or hypertension [2].

Patients with peripheral arterial disease (PAD) have compromised blood flow to their extremities as a result of arterial narrowing. PAD is often associated with impairment in endothelial function which is exaggerated by injury from processes related to cardiovascular risk factors such as ageing, hypertension, hyperlipidemia, diabetes, smoking, and obesity [1]. Furthermore, patients with diabetes often have calcified arteries making standard non-invasive testing non diagnostic [2]. With increase in diabetes prevalence and concomitant PAD, a new non-invasive assessment method of arterial function that has the potential to reflect both arterial tone and response to ischemia reperfusion may be valuable. We have developed a peripheral arterial tonometry (PAT) system (previously described, [3]) that is capable of measuring pulsatility in peripheral digits. We complemented our system with simultaneous peripheral temperature measurements that could not only add value in understanding PAD, but also aid in clinical diagnoses. In this investigation, we characterized our system on healthy individuals before using it on patients suffering from arterial disease in future investigations.

Peripheral Artery Disease (PAD) is a widespread and often undiagnosed condition associated with increased incidence of serious cardiovascular events. Current diagnostic tests for PAD may not be adequate for screening the large at-risk population. A new skin blood flow measurement technique using RF heating in the millimeter wave band, with simultaneous surface temperature measurement offers a potential method for screening individuals at risk for PAD quickly and easily. The feasibility of a transducer design incorporating a microstrip antenna and one or more infrared temperature sensors was evaluated in vitro , using a phantom skin material and a custom flow chamber. Results demonstrate the ability to heat the unperfused phantom by up to 7°C in less than 60 s, depending on antenna separation distance from the target surface. At a distance of 2 mm, preliminary results indicate the rate of temperature increase is sensitive to flowrate. These results suggest a possible method for noninvasive screening of individuals for PAD that is quick, easy and inexpensive.

Obstructive Sleep Apnea (OSA) is a prevalent disease among adults and children (Macey, Woo, Kumar, Cross, & Harper, 2010). Patients with OSA have recurrent episodes of airflow limitation during sleep, which lead to daytime sleepiness and several comorbidities, including cardiovascular diseases (Durán, Esnaola, Rubio, & Iztueta, 2001). During the episode of OSA, the airway is partially occluded (hypopnoeas) or totally blocked (apneas). Since the velopharynx is the narrowest segment of the pharyngeal airway, the local air velocity increases significantly leading to the large decrease in the intraluminal pressure. The relationship between the distribution of the minimum pressure and the anatomical geometry of the airway is thus very important. Hence, understanding the mechanical interaction between the soft palate and air flow is important in investigating OSA pathology.

Atherosclerosis is a chronic progressive cardiovascular disease that results from plaque formation in the arteries. It is one of the leading causes of death and loss of healthy life in modern world. Atherosclerosis lesions consist of sub-endothelial accumulations of cholesterol and inflammatory cells [1]. However, not all lesions progress to the final stage to cause catastrophic ischemic cardiovascular events [2]. Early identification and treatment of high-risk plaques before they rupture, and precipitate adverse events constitutes a major challenge in cardiology today. Numerous investigations have confirmed that atherosclerosis is an inflammatory disease [3] [4] [5]. This confirmation has opened the treatment of this disease to many novel anti-inflammatory therapeutics. The use of nanoparticle-nanomedicines has gained popularity over recent years. Initially approved as anticancer treatment therapeutics [6], nanomedicine also holds promise for anti-inflammatory treatment, personalized medicine, target-specific treatment, and imaging of atherosclerotic disease [7]. The primary aim of this collaborative work is to develop and validate a novel strategy for catheter-directed local treatment of high-risk plaque using anti-inflammatory nanoparticles. Preselected drugs with the highest anti-inflammatory efficacy will be incorporated into a novel liposome nanocarrier, and delivered in-vivo through a specially designed catheter to high-risk atherosclerotic plaques. The catheter has specially designed perfusion pores that inject drug into the blood stream in such a controlled manner that the streamlines carry the nanoparticles to the stenotic arterial wall. Once the particles make it to the arterial wall, they can be absorbed into the inflamed tissue. In this paper, we discuss the design and development of an atraumatic drug delivery catheter for the administration of lipid nanoparticles.

A quarter of a million people in the United States are affected by spinal cord injury (SCI), which causes loss of sensation and muscle function. Improvements in clinical care have resulted in a lower risk of mortality from initial complications like bedsores or urosepsis, though patients are more susceptible to long term conditions like coronary heart disease [1], which is a leading cause of death for SCI patients [2]. Patients with SCI have sedentary lifestyles, decreased aerobic fitness, and limited levels of oxygen uptake, which contribute to increased rates of cardiovascular complications [2]. To mitigate these factors, SCI patients must perform vigorous aerobic exercise, which can be done through functional electrical stimulation (FES) [3].

Cardiovascular, orthopedic, and interventional radiology procedures using fluoroscopy require healthcare professionals to wear heavy lead garments for radiation protection, sometimes for up to 12 hours per day. Wearing lead garments for prolonged periods of time can lead to musculoskeletal injuries, discomfort, and fatigue. MobiLead is a mobile lead garment frame that was developed to reduce the weight supported by the user in an effort to mitigate these problems. The MobiLead system moves the lower garment load off the user’s body to a structural ground-supported frame and redistributes the upper load from the shoulders to the hips through a torso frame. The system is compact and maximizes the limited space available in operating rooms, while still giving the surgeon adequate mobility for various emergency procedures. Preliminary analysis of device effectiveness was conducted using electromyography and qualitative surgeon user feedback surveys. This paper will discuss the design, fabrication, and testing procedures for this mobile radiation protection system optimizing both support and mobility.

The purpose of this test method is to assist in the determination of the thrombogenic potential of medical materials exposed to human whole blood. By evaluating surface-induced activation, platelet adherence to a material, and platelet and leukocyte depletion from blood, a material’s potential for thrombus formation can be assessed. If a significant decrease in platelets and/or leukocytes is observed in whole blood when compared to a blank control, the tested material has the potential to induce an in-vivo thrombogenic response. The present standard for the testing of platelet and leukocyte response to cardiovascular materials, ASTM F2888-13, Standard Test Method for Platelet Leukocyte Count - An In-Vitro Measure for Hemocompatibility Assessment of Cardiovascular Materials [1], mandates the use of several reference materials in the presence of blood anticoagulated with sodium citrate. This study was designed to address the relevance of the assay method when using a potent anticoagulant, 3.2% sodium citrate, to evaluate the thrombogenic potential of medical devices. Current studies on this question are under investigation at the FDA also with the intent of improving the standard methods for this assay by evaluating blood anticoagulated with 2–3 IU/mL of heparin [2]. For this study, the effects of several biomaterials were evaluated when exposed to blood anticoagulated with sodium citrate and, concurrently, an even lower dose of heparin at 1 IU/mL also used by our laboratory in a new circulating in vitro assay for thrombogenicity [3]. We believe this test method allows for a sensitive assay that can more accurately predict potential thrombogenic outcomes of cardiovascular materials, while maintaining appropriate responses in both positive and negative control materials.

Due to the anatomical and physiological similarities to humans that include similar heart size, flow rate, skin, liver enzymes and bone healing, porcine models as a powerful investigational platform have been widely used in research areas such as diabetes, obesity and islet transplantation [1]. The advantages of relative low cost, ease in handling and comparatively short period of breeding time may make swine provide a promising solution to the shortage of human donors and difficulty in isolating purified islets from adult human in future. Porcine cytokines play a significant role in innate immunity, apoptosis, angiogenesis, cell growth and differentiation. They are involved in cellular responses, maintenance of homeostasis, and disease states such as inflammatory disease, cardiovascular disease, and cancer. Thus, the technologies to analyze the expression of cytokines are developed rapidly and are still hot topics. The traditional approach for cytokine detection and quantification is the use of an enzyme-linked immunosorbent assay (ELISA). However, its inability to do multiplex test calls for more robust detection system. Biochip-based assay for the detection of biological agents using giant magnetoresistive (GMR) sensors and magnetic nanoparticles have emerged recently [2, 3]. It is proved that the nanomagnetic biosensor technology has advantages of low cost, high sensitivity, multiplexity, and real-time signal readout. The integration of GMR biosensor and use of weak magnetic fields allow to eventually realize point-of-care and portability. In addition, interferon gamma (IFNγ) is one of the most important porcine cytokines, and is associated with a number of autoinflammatory and autoimmune diseases. In this work, IFNγ is selected as a model target for the detection of porcine cytokine using nanomagnetic GMR biosensor.

The recent and rapid developments of immersive, interactive 3D environments have been critical in advancing interfaces for entertainment, design, and education. For cardiovascular research, our laboratory and others have been able to use such software tools for the construction of heart models from DICOM files. These models can then be printed in hard or soft plastic from a 3D printer. In general, such models are considered useful for surgical planning and education; these modalities are being applied as critical tools in the field of cardiovascular research. Recently, the development of virtual reality (VR) has introduced a new modality for exploring 3D virtual structures with high resolution, high flexibility, and fast turn-around times. Until recently, the adoption of these technologies has been hindered by the high costs of VR goggles and the complexities in their setup. New developments in phone software and hardware, however, have alleviated some of these difficulties by allowing smartphone screens, graphics units, and gyroscopes to provide the necessary technologies for VR. In this way, phones can be placed inside a headset holder and used freely, without being connected to the computer. Here we explore the utility of using this VR setup in the context of internal heart anatomy visualization.

A valveless shear-driven micro-fluidic pump design (SDMFP) for hemodynamic applications is presented in this work. One of the possible medical and biomedical applications is in-vivo hemodynamic (human blood circulation) support/assist. One or more SDMFPs can be inserted/implanted into vascular lumens in a form of a stent/duct in series and/or in parallel (bypass duct) to support blood circulation in-vivo. A comprehensive review of various micro-pump designs up to about mid 2000’s is given in [1,2]. Many of micropump designs considered are not suitable for in-vivo or even in-vitro medical/biomedical applications. Operating principles, design, and SDMFP features are given in [3]. A particular design used in cardiovascular applications has no moving valves. SDMFP with Gourney-flap type valves to support high-pressure applications are developed for other applications. SDMFP could be fully bi-directional and can control its operation on the run using embedded microcontrollers and sensors. Estimated efficiency is high with low leakage resulting in low power consumption. Proprietary “fish-scale” surface coating ShearQ™ designs are implemented to improve unidirectional flow pumping efficiency. Bi-directional feature may be especially critical when clogging of blood vessels is detected. By automatically and temporarily switching into the reverse-mode operation and retrogressive flow, while inducing suction-head for a short time periods it is hoped that possibly blood conduits can be cleared/unclogged and the normal forward-flow operation resumed. Such may be an important feature if SDMFP is used in-vivo, such as, in coronary arteries which are prone to clogging leading to cardiac-arrest.

Blood pressure is an indicator of a cardiovascular functioning and could provide early symptoms of cardiovascular system impairment. Blood pressure measurement using catheterization technique is considered the gold standard for blood pressure measurement [1]. However, due its invasive nature and complexity, non-invasive techniques of blood pressure estimation such as auscultation, oscillometry, and volume clamping have gained wide popularity [1]. While these non-invasive cuff based methodologies provide a good estimate of blood pressure, they are limited by their inability to provide a continuous estimate of blood pressure [1–2]. Continuous blood pressure estimate is critical for monitoring cardiovascular diseases such as hypertension and heart failure. Pulse transit time (PTT) is a time taken by a pulse wave to travel between a proximal and distal arterial site [3]. The speed at which pulse wave travels in the artery has been found to be proportional to blood pressure [1, 3]. A rise in blood pressure would cause blood vessels to increase in diameter resulting in a stiffer arterial wall and shorter PTT [1–3]. To avail such relationship with blood pressure, PTT has been extensively used as a marker of arterial elasticity and a non-invasive surrogate for arterial blood pressure estimation. Typically, a combination of electrocardiogram (ECG) and photoplethysmogram (PPG) or arterial blood pressure (ABP) signal is used for the purpose of blood pressure estimation [3], where the proximal and distal timing of PTT (also referred as pulse arrival time, PAT) is marked by R peak of ECG and a foot/peak of a PPG, respectively. In the literature, it has been shown that PAT derived using ECG-PPG combination infers an inaccurate estimate of blood pressure due to the inclusion of isovolumetric contraction period [1–3, 4]. Seismocardiogram (SCG) is a recording of chest acceleration due to heart movement, from which the opening and closing of the aortic valve can be obtained [5]. There is a distinct point on the dorso-ventral SCG signal that marks the opening of the aortic valve (annotated as AO). In the literature, AO has been proposed for timing the onset of the proximal pulse of the wave [6–8]. A combination of AO as a proximal pulse and PPG as a distal pulse has been used to derive pulse transit time and is shown to be correlated with blood pressure [7]. Ballistocardiogram (BCG) which is a measure of recoil forces of a human body in response to pumping of blood in blood vessels has also been explored as an alternative to ECG for timing proximal pulse [5, 9]. Use of SCG or BCG for timing the proximal point of a pulse can overcome the limitation of ECG-based PTT computation [6–7, 9]. However, a limitation of current blood pressure estimation systems is the requirement of two morphologically different signals, one for annotating the proximal (ECG, SCG, BCG) and other for annotating the distal (PPG, ABP) timing of a pulse wave. In the current research, we introduce a methodology to derive PTT from seismocardiograms alone. Two accelerometers were used for such purpose, one was placed on the xiphoid process of the sternum (marks proximal timing) and the other one was placed on the external carotid artery (marks distal timing). PTT was derived as a time taken by a pulse wave to travel between AO of both the xiphoidal and carotid SCG.

Cardiovascular diseases including atherosclerosis, thrombosis, aneurysm and arrhythmia remain the major cause of mortality in developed countries, accounting for 34% of deaths each year [1]. Commonly used minimally invasive vascular intervention with using catheters leads to higher success rate than open surgery [2]. Integrating robotic technologies into active control of catheters in teleoperation manner has promised to reduce radiation exposure to surgeons and improve accuracy during electro-physiological (EP) procedures [1]. Common used commercial robotic EP catheter platforms such as Sensei (Hansen Medical Inc., USA) and Niobe (Stereotaxis Inc., USA) are usually composed of a catheter driver (slave side) which can be remotely controlled by a console operator (master side). However, the Sensei catheters are more rigid and bigger than standard catheters because of their two-layer-sheath structure; and Magnetic Niobe systems are huge and expensive. In this paper, we propose a mechanism of remote-driving catheterization platforms in which a commercial tip-steerable ablation catheter (St. Jude Medical Inc., USA) (Fig. 1) is manipulated by a catheter driver in three degree of freedoms (DOF) (insertion/withdrawal, rotation and tip deflection). In addition, we also present the design of the control software based on Object-Oriented Programming (OOP) method which is expected to give the other researchers a guide line during robotic catheter design.

The time required to get a device to market is critical to a successful design, development, and manufacturing process [1]. Achieving status of the first device to market is often a priority for manufacturers and developers. Upon market introduction, it is well known that device performance must meet at least minimum standards in order to provide consumer satisfaction and be a successful product to prevent competitive devices from taking over the market [1]. However, if a design only meets minimum expectations, it may struggle to maintain market control. This demonstrates the tradeoffs of speed-to-market and performance, for which optimization has not been clearly defined [2]. Product performance and usability can be designed in, evaluated and enhanced in order to avoid user errors and achieve optimal profitability. For medical devices, clinical trials are a key step in preparing to take a device to market. Clinical trials can allow for analyses of the effectiveness of the device in the patient care process. For wearable medical devices, patient usability is crucial to patient adherence and safety since the device will be operated by non-medically trained individuals [3,4]. Without adequate usability, adherence and continuity of care are greatly reduced which will reduce the overall effectiveness of the device [5,6]. Human factors principles can best be incorporated in the design process to improve the usability of medical devices and patient safety [5,6,7], specifically for those used in telemedicine [4] and cardiovascular treatment [3]. The objective of this project was to evaluate a telemedicine heart rate monitoring device for patient usability in order to improve the next device’s performance and lead to greater patient adherence for the current version via an improved user manual.