OxyHbMeter-a novel bedside medical device for monitoring cell-free hemoglobin in the cerebrospinal fluid-proof of principle.

Delayed cerebral ischemia (DCI) occurs in up to one third of patients suffering from aneurysmal subarachnoid hemorrhage (aSAH). Untreated, it leads to secondary cerebral infarctions and is frequently associated with death or severe disability. After aneurysm rupture, erythrocytes in the subarachnoid space lyse and liberate free hemoglobin (Hb), a key driver for the development of DCI.

Toward the "Perfect" Shunt: Historical Vignette, Current Efforts, and Future Directions.

As a concept, drainage of excess fluid volume in the cranium has been around for more than 1000 years. Starting with the original decompression-trepanation of Abulcasis to modern programmable shunt systems, to other nonshunt-based treatments such as endoscopic third ventriculostomy and choroid plexus cauterization, we have come far as a field. However, there are still fundamental limitations that shunts have yet to overcome: namely posture-induced over- and underdrainage, the continual need for valve opening pressure especially in pediatric cases, and the failure to reinstall physiologic intracranial pressure dynamics.

Performance and Reliable Operation of Physiological Controllers Under Various Cardiovascular Models: In Silico and In Vitro Study.

The evaluation of control schemes for left ventricular assist devices (LVADs) requires the utilization of an appropriate model of the human cardiovascular system. Given that different patients and experimental data yield varying performance of the cardiovascular models (CVMs) and their respective parameters, it becomes crucial to assess the reliable operation of controllers. This study aims to assess the performance and reliability of various LVAD controllers using two state-of-the-art CVMs, with a specific focus on the impact of interpatient variability.

ZTBus: A Large Dataset of Time-Resolved City Bus Driving Missions.

This paper presents the Zurich Transit Bus (ZTBus) dataset, which consists of data recorded during driving missions of electric city buses in Zurich, Switzerland. The data was collected over several years on two trolley buses as part of multiple research projects. It involves more than a thousand missions across all seasons, each mission usually covering a full day of operation.

A Comparison of Proximal and Tracheal Airway Pressures During Pressure Controlled Ventilation.

Background: Airway pressure is usually measured by sensors placed in the ventilator or on the ventilator side of the endotracheal tube (ETT), at the Y-piece. These remote measurements serve as a surrogate for the tracheal or alveolar pressure. Tracheal pressure can only be predicted correctly by using a model that incorporates the pressure at the remote location, the flow through the ETT, and the resistance of the ETT if the latter is a predictable function of Y-piece flow.

Continuous Monitoring of Blood Pressure and Vascular Hemodynamic Properties With Miniature Extravascular Hall-Based Magnetic Sensor.

Continuous measurement of vascular and hemodynamic parameters could improve monitoring of disease progression and enable timely clinical decision making and therapy surveillance in patients suffering from cardiovascular diseases. However, no reliable extravascular implantable sensor technology is currently available. Here, we report the design, characterization, and validation of an extravascular, magnetic flux sensing device capable of capturing the waveforms of the arterial wall diameter, arterial circumferential strain, and arterial pressure without restricting the arterial wall.

The Introduction of an MR-Conditional Prototype for Cardiopulmonary Bypass Support: Technical Aspects and System Requirements.

Introduction: The use of cardiopulmonary bypass (CBP; also known as a heart-lung machine) in newborns with complex congenital heart defects may result in brain damage. Magnetic resonance imaging (MRI) assessments cannot be performed safely because the metal components used to construct CBP devices may elicit adverse effects on patients when they are placed in a magnetic field. Thus, this project aimed to develop a prototype MR-conditional circulatory support system that could be used to perform cerebral perfusion studies in animal models.

Effect of antisiphon devices on ventriculoperitoneal shunt drainage dynamics in growing children.

Objective: Infants and small children face changing boundary conditions when treated with a ventriculoperitoneal shunt (VPS) for hydrocephalus. There are no systematic data describing shunt drainage behavior and changes over time in a growing child. Using a child-adapted patient simulator, the authors investigated the drainage behaviors of fixed differential pressure (DP) valves and adjustable valves with devices for preventing overdrainage in children of different ages.

Bacterial chemotaxis to saccharides is governed by a trade-off between sensing and uptake.

To swim up gradients of nutrients, E. coli senses nutrient concentrations within its periplasm. For small nutrient molecules, periplasmic concentrations typically match extracellular concentrations.

Sim-to-Real for High-Resolution Optical Tactile Sensing: From Images to Three-Dimensional Contact Force Distributions.

The images captured by vision-based tactile sensors carry information about high-resolution tactile fields, such as the distribution of the contact forces applied to their soft sensing surface. However, extracting the information encoded in the images is challenging and often addressed with learning-based approaches, which generally require a large amount of training data. This article proposes a strategy to generate tactile images in simulation for a vision-based tactile sensor based on an internal camera that tracks the motion of spherical particles within a soft material.

Data-Driven Investigation of Gait Patterns in Individuals Affected by Normal Pressure Hydrocephalus.

Normal pressure hydrocephalus (NPH) is a chronic and progressive disease that affects predominantly elderly subjects. The most prevalent symptoms are gait disorders, generally determined by visual observation or measurements taken in complex laboratory environments. However, controlled testing environments can have a significant influence on the way subjects walk and hinder the identification of natural walking characteristics.

A Vision-Based Sensing Approach for a Spherical Soft Robotic Arm.

Sensory feedback is essential for the control of soft robotic systems and to enable deployment in a variety of different tasks. Proprioception refers to sensing the robot's own state and is of crucial importance in order to deploy soft robotic systems outside of laboratory environments, i.e.

A Multi-Static Radar Network with Ultra-Wideband Radio-Equipped Devices.

A growing number of devices, from car key fobs to mobile phones to WiFi-routers, are equipped with ultra-wideband radios. In the network formed by these devices, communicating modules often estimate the channel impulse response to employ a matched filter to decode transmitted data or to accurately time stamp incoming messages when estimating the time-of-flight for localization. This paper investigates how such measurements of the channel impulse response can be utilized to augment existing ultra-wideband communication and localization networks to a multi-static radar network.

An integrated perfusion machine preserves injured human livers for 1 week.

The ability to preserve metabolically active livers ex vivo for 1 week or more could allow repair of poor-quality livers that would otherwise be declined for transplantation. Current approaches for normothermic perfusion can preserve human livers for only 24 h. Here we report a liver perfusion machine that integrates multiple core physiological functions, including automated management of glucose levels and oxygenation, waste-product removal and hematocrit control.

Performance comparison of prediction filters for respiratory motion tracking in radiotherapy.

Purpose: In precision radiotherapy, the intrafractional motion causes substantial uncertainty. Traditionally, the target volume is expanded to cover the tumor in all positions. Alternative approaches are gating and adaptive tracking, which require a time delay as small as possible between the actual tumor motion and the reaction to effectively compensate the motion.

Ultra-Wideband Angle of Arrival Estimation Based on Angle-Dependent Antenna Transfer Function.

Ultra-wideband radio signals are used in communication, indoor localization and radar systems, due to the high data rates, the high resilience to fading and the fine temporal resolution that can be achieved with a large bandwidth. This paper introduces a new method to estimate the angle of arrival of ultra-wideband radio signals with which existing time-of-flight based localization and radar systems can be augmented at no additional hardware cost. The method does not require multiple transmitter or receiver antennas, or relative motion between transmitter and receiver.

The ideal couch tracking system-Requirements and evaluation of current systems.

Introduction: Intrafractional motion can cause substantial uncertainty in precision radiotherapy. Traditionally, the target volume is defined to be sufficiently large to cover the tumor in every position. With the robotic treatment couch, a real-time motion compensation can improve tumor coverage and organ at risk sparing.

Design, Motivation and Evaluation of a Full-Resolution Optical Tactile Sensor.

Human skin is capable of sensing various types of forces with high resolution and accuracy. The development of an artificial sense of touch needs to address these properties, while retaining scalability to large surfaces with arbitrary shapes. The vision-based tactile sensor proposed in this article exploits the extremely high resolution of modern image sensors to reconstruct the normal force distribution applied to a soft material, whose deformation is observed on the camera images.

Perfusion settings and additives in liver normothermic machine perfusion with red blood cells as oxygen carrier. A systematic review of human and porcine perfusion protocols.

Liver machine perfusion (MP) at normothermic temperature (NMP) is a promising way to preserve and evaluate extended criteria donor livers. Currently, no consensus exists in methodology and perfusion protocols. Here, the authors performed a systematic literature search to identify human and porcine studies reporting on liver NMP with red blood cells.

Unconscious physiological response of healthy volunteers to dynamic respiration-synchronized couch motion.

Background: Intrafractional motion can be a substantial uncertainty in precision radiotherapy. Conventionally, the target volume is expanded to account for the motion. Couch-tracking is an alternative, where the patient is moved to compensate for the tumor motion.

Comparison of anti-siphon devices-how do they affect CSF dynamics in supine and upright posture?

Background: Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in upright posture best without leading to CSF accumulation.

Left Ventricular Assist Devices: Challenges Toward Sustaining Long-Term Patient Care.

Over the last few decades, the left ventricular assist device (LVAD) technology has been tremendously improved transitioning from large and noisy paracorporeal volume displacement pumps to small implantable turbodynamic devices with only a single transcutaneous element, the driveline. Nevertheless, there remains a great demand for further improvements to meet the challenge of having a robust and safe device for long-term therapy. Here, we review the state of the art and highlight four key areas of needed improvement targeting long-term, sustainable LVAD function: (1) LVADs available today still have a high risk of thromboembolic and bleeding events that could be addressed by the rational fabrication of novel surface structures and endothelialization approaches aiming at improving the device hemocompatibility.

A Novel Mean-Value Model of the Cardiovascular System Including a Left Ventricular Assist Device.

Time-varying elastance models (TVEMs) are often used for simulation studies of the cardiovascular system with a left ventricular assist device (LVAD). Because these models are computationally expensive, they cannot be used for long-term simulation studies. In addition, their equilibria are periodic solutions, which prevent the extraction of a linear time-invariant model that could be used e.

Is posture-related craniospinal compliance shift caused by jugular vein collapse? A theoretical analysis.

Background: Postural changes are related to changes in cerebrospinal fluid (CSF) dynamics. While sitting up leads to a decrease in cranial CSF pressure, it also causes shifts in the craniospinal CSF volume and compliance distribution. We hypothesized that jugular vein collapse in upright posture is a major contributor to these shifts in CSF volume and compliance.