Design of a hybrid left ventricular assist device with a new wireless charging system.

BACKGROUND: The objective of this study was to design a new wireless left ventricular assist device (LVAD) that can be charged without using a conventional transcutaneous energy transfer system (TETS). METHODS: Our new wireless LVAD was a hybrid pump operating in two different modes: magnetic and electric modes. The pump was driven wirelessly by extracorporeal rotating magnets in magnetic mode, whereas it was driven by electricity provided by an intracorporeal battery in electric mode. A magnetic torque transmission system was introduced to wirelessly transmit torque to the pump impeller. The intracorporeal battery was charged in magnetic mode making use of electromagnetic coils as a generator, whereas the coils were used as a motor in electric mode. To demonstrate the feasibility of our system, we conducted a bench-top durability test for 1 week. RESULTS: Our hybrid pump had shown sufficient pump performance as a LVAD, with a head pressure of approximately 80 mm Hg and a flow volume of 5.0 L/min, for 1 week. The intracorporeal battery was wirelessly charged enough to power electric mode for 2.5 h a day throughout the 1-week durability test. CONCLUSIONS: Our hybrid wireless LVAD system demonstrated the possibility of a wireless LVAD and has the potential to reduce medical complications of LVAD therapy.

Design of an Innovative Wireless Left Ventricular Assist Device Driven by either Extracorporeal Magnets or an Intracorporeal Battery Pack.

This study aimed to design a new wireless left ventricular assist device (LVAD) that solved the driveline problem of current LVADs and the heat problem of the transcutaneous energy transfer system (TETS). Our new wireless LVAD consisted of two blood pumps capable of driving using extracorporeal magnets and an intracorporeal battery pack. When one pump was driven, the other pump was stopped. The battery pack was wirelessly and slowly charged using TETS with low-power transmission, whereas the magnetic pump was driven wirelessly by extracorporeal magnets. We demonstrated the feasibility of our system in a bench-top durability test for 7 days. The distance between the extracorporeal magnets and the magnetic pump was 27.5 mm. Our LVAD system had steadily provided sufficient pressure and flow volume (approximately 108 mmHg and 5.0 L/min, respectively) to the test loop for 7 days. Although loss of synchronism occurred once during the test, it recovered within a few minutes. The results demonstrate the feasibility of the proposed wireless LVAD system. Further technical improvements are required in our system, such as downsizing the electric devices inside the body, to conduct an in vivo test for the next step.

Isolation of ESBL-producing Bacteria from Sputum in Community-acquired Pneumonia or Healthcare-associated Pneumonia Does Not Indicate the Need for Antibiotics with Activity against This Class.

Objective In the past decade, extended-spectrum ß-lactamase (ESBL)-producing bacteria have increasingly frequently been isolated from various kinds of clinical specimens. However, the appropriate treatment of pneumonia in which ESBL-producing bacteria are isolated from sputum culture is poorly understood. To investigate whether or not ESBL-producing bacteria isolated from sputum in pneumonia cases should be treated as the causative bacteria. Methods and Patients In this retrospective study, we screened for patients, admitted between January 2009 and December 2015 in whom pneumonia was suspected and for whom sputum cultures yielded Escherichia coli or Klebsiella spp. isolates. We identified patients with community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP) from whom ESBL-producing bacteria had been isolated from sputum culture and to whom antibiotic treatment had been given with a diagnosis of pneumonia. We analyzed the patients' backgrounds and the effect of the antibiotic treatment for the initial 3-5 days. Results From 400 patients initially screened, 27 with ESBL-producing bacteria were secondarily screened. In this subset of patients, 15 were diagnosed with pneumonia, including 7 with CAP (5 E. coli and 2 K. pneumoniae) and 8 with HCAP (8 E. coli). These patients exhibited an average age of 84.1 years old, and 9 of 15 were men. No patients were initially treated with antimicrobials that are effective against isolated ESBL-producing bacteria. However, 13 of 15 patients showed improvement of pneumonia following the initial antibiotic treatment. Conclusion ESBL-producing bacteria isolated from sputum are not likely to be the actual causative organisms of pneumonia.