ABSTRACT
Capacitive microfabricated ultrasonic transducers (cMUTs) are the newest and potentially the most promising devices to convert electrical into acoustic signals and vice-versa. These devices are based on the capacitance modulation of a microcondenser which is obtained by microfabrication onto a silicon substrate. The aim of this paper is to describe a PSpice model of the cMUT, based on an analytical distributed model previously reported (IEEE Trans. UFFC 49 (2) (2002) 159-168), which can be used to simulate the performances of a general ultrasound system, either in frequency or time domain. The PSpice model consists of a capacitor with a parallel resistor, which represent the static capacitance and the loss and bias resistances of the transducer, respectively, plus two quadrupoles (GLAPLACE) modeling the mechanical impedance of the membranes and the radiation impedance of the medium. The usefulness of a PSpice model is the possibility to simulate and optimize the cMUT transducers in transmission and reception, along with driving and receiving electronics, in a general ultrasound system. Experimental measurements on a 5 MHz cMUT operating in pulse-echo are in good agreement with model predictions.
ABSTRACT
OBJECTIVE: To assess the experience of public service users in a time-limited psychotherapeutic group dynamic intervention. METHODS: Eleven patients were randomly selected from a group of 52 who had participated in an efficacy study and were interviewed in-depth. Their account was submitted to content analysis, according to the Grounded Theory methodology. RESULTS: In general, patients accepted well and positively evaluated the psychotherapy intervention. The main findings were the importance of patient's interaction with the group participants, and their therapeutic course after the intervention, when most of them carried on with psychotherapy. CONCLUSIONS: The psychotherapeutic intervention was well accepted among the patients, had a favorable outcome and stimulated them to proceed with psychotherapy.
Subject(s)
Patient Satisfaction , Psychotherapy, Group , Adult , Brazil , Female , Follow-Up Studies , Humans , Interview, Psychological , Male , Middle Aged , Outcome and Process Assessment, Health Care , Public SectorABSTRACT
BACKGROUND: The combined modalities of surgery, chemotherapy, and radiation therapy have greatly improved the survival rate in childhood paratesticular rhabdomyosarcoma, but the incidence of complications and late side effects is a cause for concern. METHODS: We reviewed the records of 18 patients treated for paratesticular rhabdomyosarcoma at St. Jude Children's Research Hospital between 1962 and 1989. Patients with Group I disease were treated with orchiectomy, retroperitoneal lymph node dissection, and multi-agent chemotherapy; more advanced cases also received radiation therapy with concurrent chemotherapy. RESULTS: Sequelae included esophageal and common bile duct stricture, inguinal nerve entrapment syndrome, and small bowel obstruction. Short stature was found in all children whose spines were irradiated via para-aortic fields (34-37 Gy) prior to puberty. Two of 18 patients died from treatment complications and one from progressive disease. CONCLUSIONS: Multimodality treatment offers an excellent prognosis in paratesticular rhabdomyosarcoma, but is associated with significant morbidity and mortality rates. A discussion of therapy components and their application to disease stages suggests possible approaches to optimizing treatment for this therapy-sensitive malignancy.
