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This paper reports on the evaluation of recurrent and convolutional neural networks as real-time grasp phase classifiers for future control of neuroprostheses for people with high spinal cord injury. A field-programmable gate array has been chosen as an implementation platform due to its form factor and ability to perform parallel computations, which are specific for the selected neural networks. Three different phases of two grasp patterns and the additional open hand pattern were predicted by means of surface Electromyography (EMG) signals (i.e. Seven classes in total). Across seven healthy subjects, CNN (Convolutional Neural Networks) and RNN (Recurrent Neural Networks) had a mean accuracy of 85.23% with a standard deviation of 4.77% and 112 µs per prediction and 83.30% with a standard deviation of 4.36% and 40 µs per prediction, respectively.

We present the first results of work towards a foil-based epiretinal prosthesis that can stimulate retinal cells. The prosthesis receives trigger signals and energy in the form of high intensity infrared radiation. Array-like silicon photodiodes with attached thin film electrodes convert the received infrared light into electrical stimulation signals, which are intended to stimulate ganglion cells. The photodiodes are arranged like stones in a mosaic on an only 10 µm thin and thus flexible polymer foil. Like this, the prosthesis can adapt to the curved shape of the eye and will have close contact with the retina.

The motility of the gastrointestinal tract is crucial for digestive activity and dysfunction can lead to severe disease pattern. A method for analysing the motility is needed when treatment approaches shall be evaluated. Therefore markers attached to different locations on the stomach and the bowel of pigs are video tracked in this research study. The markers are designed to provide a high contrast and have an adhesive side for fixation. Above the operation field a video camera has been placed to film the markers during the procedure. To analyse the video data a special algorithm has been implemented. The algorithm requires a registration process at the beginning of each recording which allows the parallel tracking of multiple markers. After the registration the algorithm tracks the position of the marker frame by frame. Each frame is converted into a greyscale picture by adding specified colour values of each pixel. This allows emphasizing certain colours. The centre of the marker is determined by computing the horizontal and vertical centre of the marker starting at the corresponding marker position of the previous frame. After completion the data is stored as coordinates and a video with the marker position displayed for further processing. For advanced analysis the data can be synchronized with electromyography signals, for example. The marked videos show a promising tracking of the markers. However, if the algorithm loses track of a marker during a recording, it is unlikely to relocate it due to the successive processing of the frames. Nevertheless this method provides a simple and easy to use solution for movement detection of the gastrointestinal tract.

Aspects and approaches for the design of systems for simultaneous signal and energy transmission for medical implants are presented. The main focus is on the consideration of the mutual influence on both transmission lines. To minimize the influence of capacitive as well as inductive paths, that affect the transmission, reducing the number of components is discussed. In order to increase the degree of miniaturization and reliability, the realization of certain functionalities is based on the so-called parasitics of electrical components. An implementation example is presented.

This paper presents the design of implantable electronics as a part of a system for prosthetic hand control. Purpose of the implant is the sensing of electrical signals originating from biological tissue and the actuation of the same, therefore closing the loop and allowing for an improved control of the prosthetic hand. The implant contains two integrated circuits for eight channel EMG monitoring and four channel stimulation, respectively. An on-board microcontroller allows for local pre-processing. All intracorporeal to extracorporeal communications are running through and are directed by the main processing platform. The external components of the control system include, in addition to the main processing and control platform, the inductive power transfer circuits and the pressure sensors for the sensory feedback. Different assembly and encapsulation options are taken into account for the implantable electronics and are unified in a single PCB design.

Gastrointestinal (GI) motility disorders are frequent and clinically significant conditions with impairment of patient’s quality of life. Examples range from upper GI symptoms such as dysphagia and gastroparesis to lower GI manifestations, namely chronic-intestinal pseudo obstruction, diarrhea and constipation. Furthermore, postoperative motility disorders are common. Currently, available pharmacological or dietetic treatment options are limited. Since GI motility is based on myoelectric activity, electrical stimulation (ES) is a promising alternative. Numerous studies have demonstrated suitable pacing strategies and parameters in different GI segments. However, results of multilocular ES are rare. We report the first experimental study to evaluate ES of five GI parts in a porcine model. Multi-channel electromyography (EMG) recordings of gastrointestinal baseline and poststimulatory electrical activity were realized together with video-based marker tracking (VBMT). ES provoked visible GI contractions and appeared to modulate frequencies of slow waves and spikes. Further investigations are needed for analysis of locoregional and cross-organ effects of ES on the GI tract.

The usability of flexible electrodes in moving environment is limited due to different mechanical characteristics of their metallic and polymeric components. To achieve structure compatible electrodes, all used materials need to have similar Young’s moduli as the surrounding tissue. This paper describes the characterization of macroscopic as well as miniaturized electrodes entirely made out of modified silicone (PDMS). Electrochemical, mechanical, biological, optical, and applicative methods were used. It could be shown, that PDMS electrodes are capable to be used for recording electrocardiograms with similar form and amplitude as with standard electrodes.

Finite element analysis (FEA) of electric current distribution in the pelvis minor may help to assess the usability of non-invasive surface stimulation for continuous pelvic intraoperative neuromonitoring. FEA requires generation of quality volumetric tetrahedral mesh geometry. This study proposes the generation of a suitable mesh based on MRI data. The resulting volumetric mesh models the autonomous nerve structures at risk during total mesorectal excision. The model also contains the bone, cartilage, fat, skin, muscle tissues of the pelvic region, and a set of electrodes for surface stimulation. The model is ready for finite element analysis of the discrete Maxwell’s equations.

In applied biomedical engineering and medical industry the transfer of established technology towards customers’ needs is essential for successful development and therefore business opportunities. In chronological order, we can show the transfer of scientific results of neurophysiological research into an existing neuromonitoring system and product which can be used by non-experts in medical technology in the operating room environment. All neurophysiology functions were realized in an intuitive graphical user interface. To stimulate the autonomous nerves, a specialized parameter paradigm was used, different from motor nerve stimulation. In the background, a complex signal processing algorithm recorded smooth muscle and bladder manometry data in synchronized time and automatically detected neurophysiological signals. The acquired data was then presented in real-time. With this effort a complex scientific task could be simplified to a Yes/No statement to the end-user. Beside all the reduction of complexity, the scientific challenge was still obtained, as raw-data is still possible to be recorded.

Two dimensional pelvic intraoperative neuromonitoring (pIONM®) is based on electric stimulation of autonomic nerves under observation of electromyography of internal anal sphincter (IAS) and manometry of urinary bladder. The method provides nerve identification and verification of its’ functional integrity. Currently pIONM® is gaining increased attention in times where preservation of function is becoming more and more important. Ongoing technical and methodological developments in experimental and clinical settings require further analysis of the obtained signals. This work describes a postprocessing algorithm for pIONM® signals, developed for automated analysis of huge amount of recorded data. The analysis routine includes a graphical representation of the recorded signals in the time and frequency domain, as well as a quantitative evaluation by means of features calculated from the time and frequency domain. The produced plots are summarized automatically in a PowerPoint presentation. The calculated features are filled into a standardized Excel-sheet, ready for statistical analysis.

Need: Electrical stimulation (ES) is a promising therapy for multisegmental gastrointestinal (GI) motility disorders such as gastroparesis with slow-transit constipation or chronic intestinal pseudo-obstruction. Wireless communicating GI devices for smart sensing and ES-based motility modulation will soon be available. Before placement, a potential benefit for each GI segment must be intraoperatively assessed. Technical Solution: A minimally invasive multisegmental electromyography (EMG) analysis with ES of the GI tract is required. Proof of Concept: Two porcine experiments were performed with a laparoscopic setup. Multiple hook-needle electrodes were subserosally applied in the stomach, duodenum, jejunum, ileum, and colon. EMG signals were acquired for computer-assisted motility analysis. Gastric ES, duodenal ES, jejunal ES, ileal ES, and colonic ES were applied. Next Steps: Further technological and rapid regulatory solutions are desired to initialize a clinical trial of the next generation devices in the near future. Conclusion: We demonstrate a laparoscopic strategy with EMG analysis and ES of multiple GI segments. Thus, GI function may be evaluated before theranostic devices are placed. Extended GI resection or organ transplantation may be delayed or even avoided in affected patients. [ABSTRACT FROM AUTHOR]

In this paper, a new approach aimed at improving the performance of intraneural longitudinal interfaces (tf-LIFEs) with the peripheral nervous system (PNS) is presented. Our goal is to develop a movable interface by embedding microactuators into the flexible tf-LIFEs structure. In this way, the optimal position of the electrical contacts can be searched inside the PNS and lost connections with neural cells could be replaced. For this purpose a thin film of shape memory alloy (tf-SMA) was selected. A multisegmented SMA was realized and embedded between two polyimide thin films in order to simulate the tf-LIFE structure. Thermal evaluation, fabrication procedure, the first characterization and preliminary experimental results of the new movable interface are described in the manuscript. A total controllable stroke of about 10 [micro]m was obtained for the presented prototype. Index Terms--Biorobotics, intraneural interfaces, neuroprostheses, shape memory alloys, tf-LIFE.