A Low-Power Injection-Locked VCO for an Implantable MICS Band Transmitter with Wireless Frequency Reference and Tune-while-Lock Channel Calibration.

This paper presents the design of an 800 MHz VCO for both free-running and injection locked operation in a novel low power transmitter with wireless frequency reference, operating in the MICS band (402-405 MHz). The transmitter employs simultaneous tuning and locking, to set the desired channel with a minimal injected power. The VCO is designed and fabricated in a 0.13 $\mu \mathrm{m}$ SiGe BiCMOS process and has a core area of 0.5 $\mathrm{m}\mathrm{m}^{2}$. The measurement of the free-running VCO shows -107 dBc/Hz phase noise at 300 kHz frequency offset. If locked to an external frequency reference the VCO shows 118 dBc/Hz phase noise at 300 KHz offset, while consuming 3 mA from a 1.2 V supply (3.6 mW). When the VCO is tuned during the locking, 20 dBm of reference power is required to enable operation in the whole MICS band. The measured phase noise of the free-running VCO ensures reliable calibration of the proposed transmitter and the locked VCO satisfies all requirements of an implantable device using MICS band data transmission. Therefore, this VCO presents a key building block of an injection locked, frequency agile, implantable transmitter for the MICS band.

Contactless Investigation of Dielectric Samples with a High-Q Millimeter-Wave Sensor.

Experiments using an on-chip sensor in silicon technology for dielectric measurements at 120 GHz are presented. The passive sensor element, a coplanar strip line (CPS) bandpass filter, consists of a combination of short-ended T-stubs placed inside a CPS, yielding a resonant transmission behavior of the sensor. The high quality factor of this bandpass filter is achieved by both: using edge-coupled lines and removing the substrate beneath the transducer by silicon back-side etching. Measurements showed that the unloaded transducer exhibits a quality factor of 11. The sensor is applied to characterize the cultivation progress of yeast in a glucose medium. Sparameter measurements using RF probes show a recorded S21 center frequency that shifts from 124GHz to 125GHz within 22 hours of cultivation. The typical dynamic behavior and cultivation phases of yeast are confirmed by millimeter-wave monitoring the cell culture. Experiments prove that detection and characterization of dielectric samples in small volumes can be performed without contact to the sample and label-free.

A wideband scalar network analyzer for biomedical dehydration measurements.

This paper presents a wideband microwave approach towards biomedical dehydration monitoring. The introduced concept is verified via invasive measurements on several blood samples. A microwave measurement circuit, based of a two-port scalar vector network analyzer is presented. The circuit operates between 5GHz and 20GHz using a planar permittivity sensor. Measurements of all subcomponents are shown together with measurements of a Water-NaCl-Glycerol solution.

Temporary arterial shunts to maintain limb perfusion after arterial injury: an animal study.

BACKGROUND: Temporary shunt placement can quickly restore perfusion after extremity arterial injury. This study examined the adequacy of limb blood flow with shunt use, non-heparin-bonded shunt patency over prolonged periods, and the safety of this technique. METHODS: Common iliac arteries were divided and 4.0-mm Silastic Sundt shunts placed in 16 anesthetized pigs. Eight (group I) had shunts placed immediately; eight others (group II) were shunted after an hour of limb ischemia and hemorrhagic shock. Physiologic parameters and femoral artery blood flow in both hindlimbs were continuously monitored. Limb lactic acid generation, oxygen utilization, and hematologic and metabolic effects were serially evaluated for 24 hours. RESULTS: Shunts remained patent in 13 of 16 pigs. Shunts thrombosed in two group I animals because of technical errors, but functioned well after thrombectomy and repositioning. Patency could not be maintained in one animal that died from shock. Flow in group I shunted limbs was 57 (+/-11 SD) % of control. For group II animals in shock, shunted limb flow initially averaged 46 +/- 15% of control, but 4 hours after shunt placement, the mean limb blood flow was the same as in group I. Increased oxygen extraction compensated for the lower flow. Lactic acid production was not increased in comparison to control limbs. CONCLUSION: Shunts provided adequate flow in this model of extremity trauma. Correctly placed shunts stayed patent for 24 hours, without anticoagulation, if shunt placement followed resuscitation.

Evaluation of diagnostic peritoneal lavage in stable patients with gunshot wounds to the abdomen.

BACKGROUND: Diagnostic peritoneal lavage (DPL) is used to diagnose intra-abdominal injury in patients with stab wounds and blunt trauma. Because exploratory celiotomy is routinely performed on patients with gunshot wounds to the abdomen, DPL is rarely employed. However, several studies have questioned routine exploration and have drawn attention to the associated morbidity of negative celiotomy. Diagnostic peritoneal lavage is an easily performed and inexpensive test that may be useful in this situation. OBJECTIVE: To evaluate the performance of DPL in the diagnosis of intra-abdominal injury in hemodynamically stable patients with gunshot wounds to the abdomen. DESIGN: A prospective clinical trial. SETTING: Two urban trauma centers. PATIENTS: Patients with gunshot wounds to the abdomen and a systolic blood pressure of at least 90 mm Hg. INTERVENTIONS: Clinical predication of intra-abdominal injury in the emergency department and DPL performed in the operating room before the initiation of celiotomy. Injuries found during the celiotomy were recorded. MAIN OUTCOME MEASURES: The results of the clinical evaluation and DPL were compared with the findings of the celiotomy. RESULTS: Forty-four patients were enrolled into the study. Intra-abdominal injury was present in 32 (73%) of these patients. The senior surgery resident correctly predicted the presence of intra-abdominal injury in 36 (82%) of the patients (sensitivity = 90.0%, specificity = 58.3%, positive predictive value = 85.3%, negative predictive value = 63.6%, phi = 0.52, P < .01) in the emergency department before DPL and celiotomy were performed. Diagnostic peritoneal lavage correctly identified the presence or absence of intra-abdominal injury in 40 (91%) of the patients (positive predictive value = 96.7%, negative predictive value = 78.6%, phi = 0.79, P < .01). CONCLUSIONS: Clinical judgment is highly accurate in separating patients with tangential gunshot wounds to the abdomen from those with intra-abdominal injury but may miss patients with intra-abdominal hemorrhage. Diagnostic peritoneal lavage is highly predictive of the presence of intra-abdominal injury. The return of gross blood on aspiration or a lavage red blood cell count greater than 10 x 10(9)/L should prompt an urgent celiotomy. Missed injuries are rare and most likely to be bowel perforations. Diagnostic peritoneal lavage is an objective test that may augment clinical judgment in selecting hemodynamically stable patients with potential tangential gunshot wounds for observation and is especially useful in identifying intra-abdominal hemorrhage.

Bomb-related injuries.

Between 1980 and 1990 there were 12,216 bombing incidents in the United States, the majority involving pipe-bomb type devices. Victims of such devices may suffer a combination of blast, penetrating, and thermal injuries requiring special surgical approaches. A series of cases is presented which illustrates the management dilemmas faced in such situations. Given the nationwide incidence of bombings, both local emergency medical systems and trauma surgeons should be prepared to deal with blast injuries, be aware of their regional incidence of bombings, and have a planned response that is coordinated with law enforcement agencies.

Effects of traditional coronary risk factors on rates of incident coronary events in a low-risk population. The Adventist Health Study.

BACKGROUND: California Seventh-Day Adventists have lower mortality rates from coronary heart disease (CHD) than other Californians. Associations between traditional risk factor and CHD events have not been reported previously for Adventists. METHODS AND RESULTS: A cohort study allowed 6 years of follow-up of 27,658 male and female California Seventh-Day Adventists. Data collected included age, sex, physician-diagnosed hypertension and diabetes mellitus, body height, weight, previous and current cigarette smoking habits, and current exercise habits. Incident cases of definite myocardial infarction (MI) and definite fatal CHD were diagnosed according to recognized criteria. Both stratified and proportional hazards analyses demonstrated that in this low-risk population, the above traditional coronary risk factors exhibit their usual associations with risk of CHD events. It was noted that exercise had a strong negative association with fatal CHD events (relative risks [RR], 1.0, 0.66, and 0.50 with increasing exercise) but no association with risk of MI (either nonfatal or all cases). Conversely, obesity was much more clearly associated with MI (RR, 1.0, 1.18, and 1.83 with increasing tertiles of obesity) than with fatal events. The importance of the risk factors was similar in both sexes, except that the effect of cigarette smoking seemed more pronounced in women. CONCLUSIONS: The epidemiology of coronary heart disease in this low-risk California population appears to be at least qualitatively similar to that seen in other groups. There was evidence that the effects of exercise and obesity may differ depending on whether fatal CHD and MI (either all MI or nonfatal alone) is the end point.

Diaspirin cross-linked hemoglobin solution as a resuscitative fluid following severe hemorrhage in the rat.

The effect of diaspirin cross-linked hemoglobin (DCLHb) on mean arterial pressure (MAP) and heart rate (HR) was compared to Ringer's lactate (RL) and shed blood in a 70% lethal model of hemorrhage (35 cc/kg blood loss) in conscious rats. All animals resuscitated with DCLHb regardless of dose (17.5 and 35 cc/kg) and concentration (7% and 10% solution) exhibited complete restoration of MAP and HR which was maintained for at least 5 hrs. Hemodynamic responses in DCLHb-treated animals were not significantly different from 35 cc/kg blood-treated animals. In RL (105 cc/kg) treated animals the MAP was restored to 60-70% of baseline. 24 hr survival in animals resuscitated with fluids ranged between 88-100% and was not significantly different between treatment groups.

Trauma in pregnancy. Predicting pregnancy outcome.

A multicenter study involving three American College of Surgeons Level 1 trauma centers was undertaken to assess parameters that may predict fetal outcome. The records of 93 injured pregnant patients admitted from April 1, 1985, to March 31, 1990, were reviewed. There were three maternal deaths (3%) (mean Injury Severity Score, 43). Fourteen fetal/neonatal deaths (15%) occurred during the acute care admission period. Of these, eight were fetal deaths (two associated with maternal death), four were cases of elective abortions, and two were neonatal deaths. In general, the maternal physiologic and laboratory parameters assessed failed to accurately predict pregnancy outcome, while Injury Severity Score did differ significantly between patients whose pregnancies were viable (Injury Severity Score = 6.2) and those whose pregnancies were nonviable (Injury Severity Score = 21.6). Unique to this study were the findings that the Glasgow Coma Score also differed significantly in patients with viable (Glasgow Coma Score, 14.5) and nonviable (Glasgow Coma Score, 12.0) pregnancies, while fetal heart rate at admission to the emergency department did not. In this study, the incidence of fetal death was increased following direct uteroplacental fetal injury (100% of cases), maternal shock (67%), pelvic fracture (57%), severe head injury (56%), and hypoxia (33%). The adequacy of noninvasive maternal monitoring in assessing fetal well-being is challenged, and a discussion of diagnostic modalities for assessment for the injured gravida is set forth.

[Parent-child relations as a predisposition for psychogenic pain syndrome in adulthood. A controlled, retrospective study in relation to G. L. Engel's "pain-proneness"]. / Eltern-Kind-Beziehung als Prädisposition für ein psychogenes Schmerzsyndrom im Erwachsenenalter. Eine kontrollierte, retrospektive Studie zu G. L. Engels "pain-proneness".

In a retrospective study on 151 chronic pain patients the relevance of childhood factors as described by G. L. Engel ("pain-proneness") are empirically investigated. All patients are studied by a structured interview developed for pain patients. Two groups were clinically differentiated and compared regarding childhood development: A psychogenic pain group (PP) without any somatic pathology (IASP-classification axis 5: 09; n = 75) and a group of chronic pain patients with somatic pathology (OP; n = 35). A "psychosomatic group" (IASP-axis 5: 07, e.g. migraine; n = 41) was excluded from further investigation. There are significant differences between PP and OP regarding the emotional quality of the relationship to both parents, physical abuse by the parents, a higher strain of both parents by the job (often a family enterprise), frequent aggressive conflicts between parents and their separation or divorce. Often a favorite toy or animal replaced the missing object. Pain or complaints with same localisation of significant others are significantly more frequent. No significant differences between the two pain groups are found as to loss of parent by death and the number of hospitalisation during childhood.

A hypothesis on the etiological role of diet on age of menarche.

Body size and body composition have been suggested as the best explanation for the temporal trend toward early menarche over the last 100 years. There is evidence from human and animal studies that indicates that body size is not the primary factor in influencing the occurrence of menarche. The data actually show that diet may be a primary environmental control mechanism of menarche especially since it alters hormone levels. We see diet as an etiological factor in both the long term and immediate control of menarche. In the long term it influences body size and development leading to menarche. In the short term it acts at a critical state to precipitate the onset of menarche and related physiological changes. This hypothesis does not exclude other less important factors associated with menarche. Our data shows that the present trend toward early menarche can be reversed when a balanced vegetarian diet is selected in place of the ordinary American diet.

Patterns of alcohol and cigarette use in pregnancy.

Maternal smoking and drinking have been implicated as factors in the adverse outcome of pregnancies. This California study of over 12,000 women demonstrates that a large proportion of them smoke or drink during pregnancy. Drinking habits appear to be associated with age, ethnicity, martial status, income, education, church attendance, and prenatal care, but not with gestational age, breast-feeding, or self-reported health. Smoking shows associations with income and education. Drinking and smoking are closely interrelated, showing strikingly parallel associations with such factors as use of caffeine or illicit drugs. Subgroups of pregnant women who exhibit difference drinking habits were found not comparable on certain other characteristics which potentially influence the health of neonates. The importance is reemphasized of utilizing large populations, adjusting for confounding variables, and paying particular attention to smoking habits. Forthcoming multivariate analyses of the data set should disentangle effects of the confounding variables.