Magnetic induction tomography (MIT) is an imaging technique that uses eddy current effects to map the conductivity of low conductive objects. It has a wide range of applications and offers numerous possibilities in various fields. One task of this imaging method involves resolving the ill-posed and nonlinear inverse problem. But existing methods have weaknesses. Through a hybrid approach that integrates theoretical algorithms with machine learning methods, an innovative solution to the challenges of MIT reconstruction is presented.

Volumetric ultrasound imaging requires either mechanical motion of 1D arrays or 2D matrix arrays. With 2D arrays, respecting the lambda/2 criterion easily leads to thousands of elements per transducer, with the corresponding challenges with respect to transducer manufacturing, cabling and electronics. In clinical systems, channel reduction schemes such as multiplexing or the use of sub-beamformer ASICs are mostly implemented to find viable solutions for volumetric ultrasound imaging. The use of sparse arrays, where the element distribution deviates from a regular cartesian grid, is another approach to perform 3D ultrasound imaging. In our work, we investigated the potential of a 2D spiral array for volumetric imaging and focused on beamforming approaches adapted to this particular geometry.

Chronic back pain is a major health project in western countries leading to significant societal costs. Physiotherapy, in particular segmental stabilization exercise (SSE) is a typical therapy to enhance core stability. Unfortunately, such an exercise requires the selective contraction of deep abdominal and back muscles, which is challenging. We therefore aimed at using ultrasound as biofeedback where an image of deep muscles allows assessing if exercises are executed correctly. Biofeedback systems have shown that they can support in performing physiotherapy training correctly and accordingly lead to faster and better therapy results. However, no such tools dedicated for optimizing SSE are available up to now.

Introduction: The apnea test (AT) is a crucial procedure in determining brain death. It involves temporarily disconnecting the patient from the ventilator to induce hypercapnia. Pulsatile Electrical Impedance Tomography (EIT) is a potential tool for monitoring physiological changes during AT, but its applicability remains underexplored.

Methods: This study aimed to investigate the feasibility of pulsatile EIT monitoring during AT in patients suspected of brain death. Ten patients underwent AT, with concurrent pulsatile EIT measurements conducted. EIT signals were segmented into intervals aligned with arterial blood gas (ABG) sampling, and analysis was performed to discern patterns of EIT signal changes.

Results: Three distinct patterns of pulsatile EIT signal changes were observed during AT: increasing, fluctuating, and decreasing. These patterns reflected variations in cardio-pulmonary dynamics.

Conclusion: Our findings show the potential of pulsatile EIT monitoring to provide valuable insights into cardio-pulmonary interactions during AT for brain death determination. Further research is necessary to validate these findings and to investigate the clinical application of pulsatile EIT in assessing physiological changes during AT.

In Magnetic particle imaging (MPI), the spatial encoding of the particle response is achieved by a magnetic gradient field called selection field. In this work a selection field generator based on two pairs of nested and freely rotatable Halbach cylinders in dipole configuration generating a gradient field in form of a linear field free region (FFR) is proposed. Through adequate rotation of the Halbach dipoles the FFR can be moved continuously along the cylinder axis. To understand and evaluate the movement of the FFR for different sequences of dipole rotations a simulation study is conducted.

The simulation is based on the approximation of a permanent magnet's field as a magnetic dipole field, so that the Halbach cylinder field results from the superposition of circularly arranged magnetic dipole moments. By the summation of four Halbach dipole fields the selection field can be calculated.

It has turned out that the opposite rotation and the matching field strengths of the dipoles of a pair are prerequisites for the movement of the FFR. With regard to the gradient field strengths and the movement speed of the FFR within a potential imaging area, a phase-shifted rotation of two pairs seems promising for the use in MPI.

Cardiovascular disease is a global health burden.To develop novel treatment options complex in vitro model systems are needed that resemble the pathophysiological situation ex vivo. Nevertheless, current pre-clinical in vitro models for pharmacological research are limited in complexity. Basic cell culture models lack cardiac tissue architecture and intercellular communication, limiting their translational capability. Force measurement methods on ex vivo cultured living myocardial slices (LMS) have been described for contraction analysis studies after compound treatment. Here, we combined LMS with a microphysiological system (MPS) to develop MPSlms as heart-on-chip approach that enables advanced nutrition circulation and integrates electrical pacing (MPSpacer) of the ex vivo cardiac tissue. To optimize the LMS technique, we designed a novel isometric tissue holder (ITH) and miniaturized the LMS format, allowing for extended condition testing and thus refinement of animal experiments. The contractile performance of cardiomyocytes was quantified by applying optical mapping of movement detection, which revealed precise and local variations in contraction within one LMS.