Prediction and prevention system for Severe Acute Respiratory Syndrome CoronaVirus 2 infection by preempting the onset of a cough.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is fast becoming one of the most significant infections worldwide. Of all the causes of SARS-CoV-2 infection, airborne-droplet infection via coughing is the most common. Therefore, if predicting the onset of a cough and preventing infection were possible, it would have a globally positive impact. Here, we describe a new prediction and prevention system for SARS-CoV-2 infection. Usually, air is inhaled prior to coughing, and the cough, which contains droplets of the virus, then occurs during acute exhalation. Therefore, if we can predict the onset of a cough, we can prevent the spread of SARS-CoV-2. At Tohoku University, a diagnosis system for evaluating swallowing motions and peripheral circulation has already been developed, and our prediction system can be integrated into this system. Using three-dimensional human body imaging, we developed a prediction system for preempting the onset of a cough. If we can predict the onset a cough, we can prevent the spread of SARS-CoV-2 infection, by decreasing the shower of virally active airborne droplets. Here, we describe the newly developed prediction and prevention system for SARS-CoV-2 infection that preempts the onset of a cough.Clinical Relevance- If predicting the onset of a cough and preventing infection were possible, it would have a globally positive impact. Here, we describe the newly developed prediction and prevention system for SARS-CoV-2 infection.

In Vitro Modelling for Bulging Sinus Effects of an Expanded Polytetrafluoroethylene Valved Conduit Based on High-Speed 3D Leaflet Evaluation.

The study aimed to develop a pulmonary circulatory system capable of high-speed 3D reconstruction of valve leaflets to elucidate the local hemodynamic characteristics in the valved conduits with bulging sinuses. Then a simultaneous measurement system for leaflet structure and pressure and flow characteristics was designed to obtain valve leaflet dynamic behaviour with different conduit structures. An image preprocessing method was established to obtain the three leaflets behaviour simultaneously for one sequence with two leaflets images from each pair of three high-speed cameras. Firstly, the multi-digital image correlation analyses were performed, and then the valve leaflet structure was measured under the static condition with fixed opening angles in the water-filled visualization chamber and the pulsatile flow tests simulating paediatric pulmonary flow conditions in the different types of conduit structures; with or without bulging sinuses. The results showed the maximum 3D reconstruction error to be around 0.06 mm. In the steady flow test, the evaluation of opening angles under the different flow rates conditions was achieved. In the pulsatile flow test, each leaflet's opening and closing behaviours were successfully reconstructed simultaneously at the high-frequency recording rate of 960fps. Therefore, the system developed in this study confirms the design evaluation method of an ePTFE valved conduit behaviour with leaflet structures interacting with local fluid dynamics in the vicinity of valves. Clinical Relevance- The system reveals the bulging sinus effects on ePTFE valve leaflet motion by the 3D reconstruction using multi-camera high-speed sequential imaging in vitro.

Design of an Artificial Tongue Driven by Shape Memory Alloy Fibers.

Dysphasia is one of the complications which may cause functional disability after the surgical treatment of oral cancer. The loss of the function derived by tongue and other oral tissues impairs the retention and delivery of liquids and food masses as well as the swallowing motion into pharynx. As accumulation of liquids or food masses in the larynx can lead to pneumonia, therefore swallowing support to improve each coordination of the tongue, the epiglottis and the esophagus in the process of swallowing is highly desirable. In this study, we designed a new artificial tongue which was capable of contracting to deliver the bolus masses in the swallowing propulsion phase in the oral cavity. We designed a two-layered artificial tongue simulating the anatomical identical muscle structures with the longitudinal muscle, and the transverse muscle-genioglossus layer. A silicone rubber material was used for the surface layer, and the covalent shape memory alloy fibers (diameter: 150µm) were implemented in the secondary structure beneath of the silicone rubber material of the artificial tongue. Its contraction was driven by with shape memory alloy fibers shortage inside of the artificial tongue unit. The actuation was accurately controlled by the originally designed electrical current input with pulse width modulation. Firstly, we examined a prototype structure of the artificial tongue as well as the changes in unit thickness as it constricted by electric power supply switching. Secondly, we performed a feasibility study of the prototype into the head-neck medical training model with larynx-tracheal structure with esophagus. The results were as follows: a) the artificial tongue model showed a large contraction with a motion to increase upward pressure, b) the tongue unit expressed the capability of reducing shallow space between dorsal tongue surface and palate in the oral cavity model. Therefore, the first artificial tongue design with active contractile motion will be useful orally installable device for improving delivery function of bolus masses through swallowing procedure in dysphasia.Clinical Relevance- The active artificial tongue system designed for the first time exhibited an effective contractile motion to support bolus food masses propulsion in swallowing process in the oral cavity in the patients with dysphasia.

Development of muscle connection components for implantable power generation system.

We have been developing an implantable power generation system that uses muscle contraction following electrical stimulation as a permanent power source for small implantable medical devices. However, if the muscle tissue is overloaded for power generation, the tissue may rupture or blood flow may be impaired. In this study, we developed a new muscle-connecting component that solves these problems. The new connection device has three rods attached to the muscle fibers, and the force exerted on the muscle fibers is converted from horizontal to vertical when the muscle contracts. We conducted simulations with a three-dimensional (3D) model, as well as pulse wave muscle measurements and in vivo tests using the actual muscle. The pulse wave in the connecting part and its downstream were optically measured from the muscle surface, and the blood flow was not obstructed. The 3D model simulations revealed that the distribution of stress was preferable compared with the case in which a rod was stuck vertically in the muscle. In the in vivo muscle tests, the metal rod and resin parts were attached to the muscle, and a load of up to approximately 9 N was applied to the connecting part. Consequently, the connecting part was stable and integrated with the muscle, and there was no damage in the muscle. Although no long-term or histological evaluations were conducted, the device may be useful because of the intramuscular power generation owing to the minimal load applied on the part connected with the muscle.

Development and accuracy evaluation of a degree of occlusion visualization system for roller pumps used in cardiopulmonary bypass.

In roller pumps used for cardiopulmonary bypass (CPB), the degree of blockage within the tube resulting from compression of the tube by the rollers, or the degree of occlusion, is closely related to hemolysis, with both tight occlusive and non-occlusive degrees promoting hemolysis. There are as yet no international standards regarding methods of adjusting occlusiveness, and the amount of mechanical stress exerted upon blood remains unknown. To prevent hemolysis during CPB using roller pumps, there is a need to clarify and quantitatively assess the mechanical stress of the occlusiveness of the roller pump. In this study, we have developed a degree of occlusion quantification system which constructs the flow channel shape within an occluded tube from red optical density images, and we have verified the validity of this system. Utilizing a linear actuator, an acrylic roller and raceway, a solution colored with simulated blood powder, and a 3/8-inch vinyl chloride tube, this system uses a camera to capture red optical density images within an occluded tube and constructs the tube flow channel shape using a formula manipulation system. To verify the accuracy of this system, we compared the thickness of a cross-section of the flow channel constructed with the degree of occlusion quantification system with the thickness of a cross-section of silicone cured under the same occlusion conditions. Our experiments indicated that for areas with a small tube gap, this system can construct highly accurate three-dimensional shapes and obtain quantitative indicators assessing the degree of occlusion.

Implantable power generation system utilizing muscle contractions excited by electrical stimulation.

An implantable power generation system driven by muscle contractions for supplying power to active implantable medical devices, such as pacemakers and neurostimulators, is proposed. In this system, a muscle is intentionally contracted by an electrical stimulation in accordance with the demands of the active implantable medical device for electrical power. The proposed system, which comprises a small electromagnetic induction generator, electrodes with an electrical circuit for stimulation and a transmission device to convert the linear motion of the muscle contractions into rotational motion for the magneto rotor, generates electrical energy. In an ex vivo demonstration using the gastrocnemius muscle of a toad, which was 28 mm in length and weighed 1.3 g, the electrical energy generated by the prototype exceeded the energy consumed for electrical stimulation, with the net power being 111 µW. It was demonstrated that the proposed implantable power generation system has the potential to replace implantable batteries for active implantable medical devices.