PubMed Health⌕ Search

Biomedical subjects

T H Sweetser

Publications and source records attributed to T H Sweetser.

6 recordsLinked to original sources

Designing planetary protection into the Mars Observer mission.

Planetary protection has been an important consideration during the process of designing the Mars Observer mission. It affected trajectory design of both the interplanetary transfer and the orbits at Mars; these in turn affected the observation strategies developed for the mission. The Project relied mainly on the strategy of collision avoidance to prevent contamination of Mars. Conservative estimates of spacecraft reliability and Martian atmosphere density were used to evaluate decisions concerning the interplanetary trajectory, the orbit insertion phase at Mars, and operations in orbit at Mars and afterwards. Changes in the trajectory design, especially in the orbit insertion phase, required a refinement of those estimates.

Earth, Planet↗

Exstrophy of the bladder: long-term results of bilateral posterior iliac osteotomies and two-stage anatomic repair.

One hundred cases of exstrophy of the bladder treated with bilateral posterior iliac osteotomies to facilitate anterior closure of the pelvis and soft tissues were reviewed. Sixty-nine cases followed 5 to 18 years were evaluated in terms of: success of anterior closure (95%); degree of urinary continence (45% with near normal continence); incidence of chronic urinary tract infection, dilation of upper urinary tract and need for ileal diversion (30%); the effect of bony reconstruction on hip and pelvic development. Modifications of the technique of pelvic stabilization anteriorly and a previously unreported complication of asymmetrical pelvic closure are presented. Closure of the bony pelvis appears to increase the success of repair of both in terms of soft-tissue closure and attainment of urinary continence. Follow-up examinations of the patients throughtout the growing years with special attention to possible development of pelvic obliquity or scoliosis are important.

Bladder Exstrophy↗