IEEE transactions on bio-medical engineering
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IEEE Trans Biomed Eng · Feb 1990
System for mechanical measurements during cardiopulmonary resuscitation in humans.
Effective study of CPR requires measurement of the mechanical properties of the human chest and the resultant vascular pressures. A computer-based mobile data acquisition system was designed and built for this purpose. During manual CPR a short cylindrical module was placed between the rescuer's hands and the patient's chest. ⋯ An audible signal was produced as an aid in maintaining desired compression rate and duration. The system's mobility permitted rapid implementation at any hospital location. In conclusion, this system was capable of measuring, recording, and displaying multiple physical quantities during manual CPR in humans.
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IEEE Trans Biomed Eng · Feb 1990
Identification of dynamic mechanical parameters of the human chest during manual cardiopulmonary resuscitation.
Survival from cardiac arrest is dependent on timely cardiopulmonary resuscitation (CPR). Since CPR is often unsuccessful, the outcome may be improved by a better understanding of the relationship between force applied to the sternum and the resulting hemodynamic effects. The first step in this complex chain of interactions is the mechanical response of the chest wall to cyclical compression. ⋯ A considerable amount of damping was found, with no significant difference between compression and release. The equivalent mass was too small to be determined accurately. This method can be used to obtain the dynamic mechanical parameters of the human chest and may lead to a better understanding of CPR.
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This paper describes the scaling limitations of multichannel recording probes fabricated for use in neurophysiology using silicon integrated circuit technologies. Scaled silicon probe substrates 8 microns thick and 16 microns wide can be fabricated using boron etch-stop techniques. Theoretical expressions for calculating the thickness and width of silicon substrates have been derived and agree closely with experimental results. ⋯ The probe shank dimensions can be designed to vary the strength and stiffness for different applications. The scaled silicon substrates have a fracture stress of about 2 x 10(10) dyn/cm2, which is about six times that of bulk silicon, and are strong and very flexible. Scaling the feature sizes of recording electrode arrays down to 1 micron is possible with less than 1 percent electrical crosstalk between channels.
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An advanced multiple channel cochlear implant hearing prosthesis is described. Stimulation is presented through an array of 20 electrodes located in the scala tympani. Any two electrodes can be configured as a bipolar pair to conduct a symmetrical, biphasic, constant-current pulsatile stimulus. ⋯ The device also incorporates a telemetry system that enables electrode voltage waveforms to be monitored externally in real time. The electronics of the implant are contained almost entirely on a custom designed integrated circuit. Preliminary results obtained with the first patient to receive the advanced implant are included.
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IEEE Trans Biomed Eng · Jul 1989
Batch-fabricated thin-film electrodes for stimulation of the central auditory system.
Silicon micromachining and thin-film technology have been employed to fabricate iridium stimulating arrays which can be used to excite discrete volumes of the central nervous system. Silicon multichannel probes with thicknesses ranging from 1 to 40 microns and arbitrary two-dimensional shapes can be fabricated using a high-yield, circuit-compatible process. ⋯ In vivo tests have been performed in the central auditory pathways to demonstrate neural activation using the devices. These tests show a selective activation both as a function of site separation and site size.