Progress on development of the Nimbus-University of Pittsburgh axial flow left ventricular assist system.

Nimbus Inc. (Rancho Cordova, CA) and the University of Pittsburgh have completed the second year of development of a totally implanted axial flow blood pump under the National Institutes of Health Innovative Ventricular Assist System Program. The focus this year has been on completing pump hydraulic development and addressing the development of the other key system components. Having demonstrated satisfactory pump hydraulic and biocompatibility performance, pump development has focused on design features that improve pump manufacturability. A controller featuring full redundancy has been designed and is in the breadboard test phase. Initial printed circuit layout of this circuit has shown it to be appropriately sized at 5 x 6 cm to be compatible with implantation. A completely implantable system requires the use of a transcutaneous energy transformer system (TETS) and a diagnostic telemetry system. The TETS power circuitry has been redesigned incorporating an improved, more reliable operating topography. A telemetry circuit is undergoing characterization testing. Closed loop speed control algorithms are being tested in vitro and in vivo with good success. Eleven in vivo tests were conducted with durations from 1 to 195 days. Endurance pumps have passed the 6 month interval with minimal bearing wear. All aspects of the program continue to function under formal quality assurance.

[Meningococcal disease in the Faroe Islands during the period 1978-1985]. / Meningokoksygdom på Faerøerne 1978-1985.

On the Faroe Islands (45,000 inhabitants), a total of 203 cases of meningococcal disease (MD) were recorded during the period 1978-1985. The peak incidence was 95/100,000 in 1981. MD mainly attacked children, 30% were below two years and 75% were below 11 years of age. The lethality rate was 5.4% (11 deaths). In 1981, rifampicin was introduced as a prophylactic treatment against secondary cases and at the same time, a decrease in incidence occurred. The decrease was more pronounced in the part of the country where the number of prescribed prophylactic doses per case of MD was greatest. These observations indicate that the introduction of rifampicin may have modified the course of the epidemic. None of the MD-patients had received prophylactic treatment with rifampicin. Of 132 examined, one patient with complement deficiency was identified, indicating that complement deficiencies were not a major risk factor in the epidemic of MD on the Faroe Islands.