6mm anatomical cortical resolution. The neuronal arbor is comprised of 5.9 M elementary 1.2μm long dipoles. On a standard server, the computations require about 5min.

Our results indicate that the BEM-FMM approach may be well suited to support numerical multiscale modeling pertinent to modern high-resolution and submillimeter iEEG.

Based on the speed and ease of implementation, this new algorithm represents a method that will greatly facilitate simulations at multi-scale across a variety of applications.

Based on the speed and ease of implementation, this new algorithm represents a method that will greatly facilitate simulations at multi-scale across a variety of applications.Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic conditions. The current assessment of COPD requires a maximal maneuver during a spirometry test to quantify airflow limitations of patients. Other less invasive measurements such as thoracic bioimpedance and myographic signals have been studied as an alternative to classical methods as they provide information about respiration. Particularly, strong correlations have been shown between thoracic bioimpedance and respiratory volume. The main objective of this study is to investigate bioimpedance and its combination with myographic parameters in COPD patients to assess the applicability in respiratory disease monitoring. We measured bioimpedance, surface electromyography and surface mechanomyography in forty-three COPD patients during an incremental inspiratory threshold loading protocol. We introduced two novel features that can be used to assess COPD condition derived from the variation of bioimpedance and the electrical and mechanical activity during each respiratory cycle. These features demonstrate significant differences between mild and severe patients, indicating a lower inspiratory contribution of the inspiratory muscles to global respiratory ventilation in the severest COPD patients. In conclusion, the combination of bioimpedance and myographic signals provides useful indices to noninvasively assess the breathing of COPD patients.

Septic shock is a life-threatening manifestation of infection with a mortality of 20-50% [1]. A catecholamine vasopressor, norepinephrine (NE), is widely used to treat septic shock primarily by increasing blood pressure. For this reason, future blood pressure knowledge is invaluable for properly controlling NE infusion rates in septic patients. However, recent machine learning and data-driven methods often treat the physiological effects of NE as a black box. In this paper, a real-time, physiology-informed human mean arterial blood pressure model for septic shock patients undergoing NE infusion is studied.

Our methods combine learning theory, adaptive filter theory, and physiology. We learn least mean square adaptive filters to predict three physiological parameters (heart rate, pulse pressure, and the product of total arterial compliance and arterial resistance) from previous data and previous NE infusion rate. These predictions are combined according to a physiology model to predict future mean arterial blood pressure.

Our model successfully forecasts mean arterial blood pressure on 30 septic patients from two databases. Specifically, we predict mean arterial blood pressure 3.33 minutes to 20 minutes into the future with a root mean square error from 3.56 mmHg to 6.22 mmHg. Additionally, we compare the computational cost of different models and discover a correlation between learned NE response models and a patient’s SOFA score.

Our approach advances our capability to predict the effects of changing NE infusion rates in septic patients.

More accurately predicted MAP can lessen clinicians’ workload and reduce error in NE titration.

More accurately predicted MAP can lessen clinicians’ workload and reduce error in NE titration.

Most MRI scanners are equipped to receive signals from

H array coils but few support multi-channel reception for other nuclei. Using receive arrays can provide significant SNR benefits, usually exploited to enable accelerated imaging, but the extension of these arrays to non-

H nuclei has received less attention because of the relative lack of broadband array receivers. Non-

H nuclei often have low sensitivity and stand to benefit greatly from the increase in SNR that arrays can provide. This paper presents a cost-effective approach for adapting standard

H multi-channel array receivers for use with other nuclei – in this case,

C.

A frequency translation system has been developed that uses active mixers residing at the magnet bore to convert the received signal from a non-

H array to the

H frequency for reception by the host system receiver.

This system has been demonstrated at 4.7T and 7T while preserving SNR and isolation.

H decoupling, particularly important for

C detection, can be straightforwardly accommodated.

Frequency translation can convert

H-only multi-channel receivers for use with other nuclei while maintaining SNR and channel isolation while still enabling

H decoupling.

This work allows existing multi-channel MRI receivers to be adapted to receive signals from nuclei other than

H, allowing for the use of receive arrays for in vivo multi-nuclear NMR.

This work allows existing multi-channel MRI receivers to be adapted to receive signals from nuclei other than 1H, allowing for the use of receive arrays for in vivo multi-nuclear NMR.

Virtual Reality haptic-based surgical simulators for training purposes have recently been receiving increased traction within the medical field. However, its future adoption is contingent on the accuracy and reliability of the haptic feedback.

This study describes and analyzes the implementation of a set of haptic-tailored experiments to extract the force feedback of a medical probe used in minimally invasive spinal lumbar interbody fusion surgeries.

Experiments to extract linear, lateral and rotational insertion, relaxation and extraction of the tool within the spinal muscles, intervertebral discs and lumbar nerve on two cadaveric torsos were conducted.

Notably, mean force-displacement and torque-angular displacement curves describing the different tool-tissue responses were reported with a maximum force of 6.87 (±1.79) N at 40 mm in the muscle and an initial rupture force through the Annulus Fibrosis of 20.550 (±7.841) N at 6.441 mm in the L

/L

disc.

The analysis showed that increasing the velocity of the probe slightly reduced and delayed depth of the muscle punctures but significantly lowered the force reduction due to relaxation. Decreasing probe depth resulted with a reduction to the force relaxation drop. However, varying the puncturing angle of attack resulted with a significant effect on increasing force intensities. Finally, not resecting the thoracolumbar fascia prior to puncturing the muscle resulted with a significant increase in the force intensities.

These results present a complete characterization of the input required for probe access for spinal surgeries to provide an accurate haptic response in training simulators.

These results present a complete characterization of the input required for probe access for spinal surgeries to provide an accurate haptic response in training simulators.

Surgical graspers must be safe, not to damage tissue, and effective, to establish a stable contact for operation. For conventional rigid graspers, these requirements are conflicting and tissue damage is often induced. We thus proposed novel soft graspers, based on morphing jaws that increase contact area with clutching force.

We introduced two soft jaw concepts DJ and CJ. They were designed (using analytical and numerical models) and prototyped (10mm diameter, 10mm span). Corresponding graspers were obtained by integrating the jaws into a conventional tool used in the dVRK surgical robotics platform. Morphing performance was experimentally characterized. Jaw-tissue interaction was quantitatively assessed through damage indicators obtained from ex vivo tests and histological analysis, also comparing DJ, CJ and dVRK rigid jaws. Soft graspers were demonstrated through ex vivo tests on dVRK. Ex vivo tests and related analysis were devised/performed with medical doctors.

Design goal was achieved for both soft jaws by morphing, contact area exceeded by 20-30% the maximum area allowed by encumbrance specifications to rigid jaws. Experimental characterization was in good agreement with model predictions (error≈4%). Damage indicators showed differences amongst DJ, CJ and dVRK jaws (ANOVA p-value = 0.0005) damage was one order of magnitude lower for soft graspers (each pairwise comparison was statistically significant).

We proposed and demonstrated soft graspers potentially less harmful to tissue than conventional graspers.

Beyond minimally invasive surgery, the proposed concepts and design methodology can foster the development of graspers for soft robotics.

Beyond minimally invasive surgery, the proposed concepts and design methodology can foster the development of graspers for soft robotics.

To investigate the thermal and frequency dependence of dielectric properties of ex vivo liver tissue – relative permittivity and effective conductivity – over the frequency range 500 MHz to 6GHz and temperatures ranging from 20 to 130°C.

We measured the dielectric properties of fresh ex vivo bovine liver tissue using the open-ended coaxial probe method (n = 15 samples). Numerical optimization techniques were utilized to obtain parametric models for characterizing changes in broadband dielectric properties as a function of temperature and thermal isoeffective dose. The effect of heating tissue at rates over the range 6.4-16.9°C/min was studied. The measured dielectric properties were used in simulations of microwave ablation to assess changes in simulated antenna return loss compared to experimental measurements.

Across all frequencies, both relative permittivity and effective conductivity dropped sharply over the temperature range 89 – 107°C. Below 91°C, the slope of the effective conductivity changes from positive values at lower frequencies (0.5-1.64GHz) to negative values at higher frequencies (1.64-6GHz). The maximum achieved correlation values between transient reflection coefficients from measurements and simulations ranged between 0.83 – 0.89 and 0.68 – 0.91, respectively, when using temperature-dependent and thermal-dose dependent dielectric property parameterizations.

We have presented experimental measurements and parametric models for characterizing changes in dielectric properties of bovine liver tissue at ablative temperatures.

The presented dielectric property models will contribute to the development of ablation systems operating at frequencies other than 2.45GHz, as well as broadband techniques for monitoring growth of microwave ablation zones.

The presented dielectric property models will contribute to the development of ablation systems operating at frequencies other than 2.45 GHz, as well as broadband techniques for monitoring growth of microwave ablation zones.

Spiking activity of individual neurons can be separated from the acquired multi-unit activity with spike sorting methods. Processing the recorded high-dimensional neural data can take a large amount of time when performed on general-purpose computers.

In this paper, an FPGA-based real-time spike sorting system is presented which takes into account the spatial correlation between the electrical signals recorded with closely-packed recording sites to cluster multi-channel neural data. The system uses a spatial window-based version of the Online Sorting algorithm, which uses unsupervised template-matching for clustering.

The test results show that the proposed system can reach an average accuracy of 86% using simulated data (16-32 neurons, 4-10dB Signal-to-Noise Ratio), while the single-channel clustering version achieves only 74% average accuracy in the same cases on a 128-channel electrode array. The developed system was also tested on in vivo cortical recordings obtained from an anesthetized rat.

The proposed FPGA-based spike sorting system can process more than 11000 spikes/second, so it can be used during in vivo experiments providing real-time feedback on the location and electrophysiological properties of well-separable single units.