Jack McCubbin

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In order to obtain adequate signal to noise ratio (SNR), stimulus-evoked brain signals are averaged over a large number of trials. However, in certain applications, e.g. fetal magnetoencephalography (MEG), this approach fails due to underlying conditions (inherently small signals, non-stationary/poorly characterized signals, or limited number of trials).(More)
Sixty-seven cases of eclampsia were managed from 1977 to 1980, for an incidence of 1 in 310 deliveries. Eighty-four percent of patients were nulliparous and 82% had received some prenatal care. Prior to convulsion, 14 patients (21%) had a diastolic blood pressure below 90 mmHg, 39% had no edema, and 21% had no proteinuria. Thirty-seven patients (55%) had(More)
Thirty-four pregnant women with acute appendicitis presented at Parkland Memorial Hospital during a 15-year period. Abdominal pain, usually accompanied by nausea with or without vomiting, was the most common presenting symptom. Anorexia was less constant, and its occurrence decreased with advancing gestation. Physical findings usually included direct(More)
Fetal magnetoencephalogram (fMEG) is measured in the presence of a large interference from maternal and fetal magnetocardiograms (mMCG and fMCG). This cardiac interference can be successfully removed by orthogonal projection of the corresponding spatial vectors. However, orthogonal projection redistributes the fMEG signal among channels. Such redistribution(More)
Development of the CTF MEG system has been advanced with the introduction of a computer processing cluster between the data acquisition electronics and the host computer. The advent of fast processors, memory, and network interfaces has made this innovation feasible for large data streams at high sampling rates. We have implemented tasks including(More)
Fetal brain signals produce weak magnetic fields at the maternal abdominal surface. In the presence of much stronger interference these weak fetal fields are often nearly indistinguishable from noise. Our initial objective was to validate these weak fetal brain fields by demonstrating that they agree with the electromagnetic model of the fetal brain. The(More)
Flash-evoked responses can be recorded from the fetus in utero. However, a standard analysis approach based on orthogonal projection (OP) to attenuate maternal and fetal cardiac signals leads to a spatial redistribution of the signal. This effect prevents the correlation of source location with a known fetal head location in some cases and the(More)
Sixty-seven cases of eclampsia were managed between August 1977 and July 1980. Routinely acquired laboratory tests of these cases have been analyzed. In addition, the group of patients with eclampsia was compared with a group of 24 healthy pregnant women. There was no significant difference in platelet count, serum fibrinogen, and bilirubin values. The(More)
The fetal magnetoencephalogram (fMEG) is measured in the presence of large interference from the maternal and fetal magnetocardiograms. This interference can be efficiently attenuated by orthogonal projection of the corresponding spatial vectors. However, the projection operators redistribute the fMEG signal among sensors. Although redistribution can be(More)
A prospective study comparing continuous intravenous magnesium sulfate to intramuscular magnesium sulfate was performed in 32 preeclamptic patients. Eighteen patients received the intramuscular regimen for mild and severe preeclampsia as recommended by Pritchard. The remaining 14 patients received an intravenous regimen consisting of a 4 gm loading dose(More)