Term

Definition
E=I*R
or
V=I*R
E= electromotive force or voltage (V) (volts)
I=electric current or flow of electrons (Amperes)
R=resistance (Ohms)



Term

Definition
provide the energy to operate the circuit
may take the form of a battery or a time varying constant voltage or a constant current source 


Term

Definition
travels down the voltage gradient from + to  


Term

Definition
from the source of electrons to the deficit from  to + 


Term
direct current (DC) source
(time invariant) 

Definition
no changes in voltage with time
ex: output of a battery 


Term

Definition
delivers the specified current irrespective of whatever voltage it takes to produce the current 


Term

Definition
produces the specified voltage regardless of the current that must flow 


Term
Alternating current (AC) sources 

Definition
produce voltages or currents that are time varying
V(t)=A*sin(ωt+Φ)
V=voltage
A=peak amplitude (V_{p})
ω=radian frequency (frequency in Hz f=ω/(2*π) or
ω=2*π*f)
t=time (seconds)
Φ= phase delay (radians) usually 0 


Term

Definition
I(t)=A*sin(ωt+Φ)
the source driving the circuit is a current rather than a voltage
useful when modeling the cardiovascular system if you need the CO to remain constant 


Term

Definition
combinations of alternating current (time varying) and direct current (time invariant)
the mean goes from 0 to the value of the time invariant signal
ex: V(t)=10*sin(12.566*t)+8 the mean is 8 volts 


Term

Definition
measurement is one of voltage (electrical potential) vs. time
mean contains no clinical info. 


Term

Definition
signal generated by the mechanical action of the myocardium squeezing blood into the hydraulic impedance of the vasculature
example of a mixed (AC+DC) signal source 


Term

Definition
useful when the maximum stress on the blood vessel wasll is an important consideration, as in patients with aneurysms, intracranial hypertension 


Term
mean blood pressure
(systolic/diastolic) 

Definition
useful determinant of organ perfusion especially when considered as perfusion pressure (mean arterial pressure minus venous pressure) 


Term

Definition
important when considering perfusion of the left ventricle (majority of the left ventricular blood flow occurs during diastole) 


Term

Definition


Term

Definition
measurement of the change in volume of the pulsatile blood vessels as detected by light passing through the tissue of interest
most useful info derived is the amplitude of the volume signal 


Term

Definition
mean values of blood pressure and mean values of CO
used to calc. systemic vascular resistance
SVR=(MAPMCVP)/(mean CO) 


Term

Definition
diastolic and systolic pressure 


Term

Definition
has signal amplitude on the Y axis which is the ratio of output signal amplitude to the amplitude of the input signal and frequency on the X axis 


Term

Definition
has an amplitude ratio of 1: output and input amplitudes are the same=perfect reproduction 


Term
curve above ideal response 

Definition
output signal is greater than input signal and at that frequency the input signal is artifically amplified and the output signal is distorted from the input signal 


Term
curve lower than ideal response 

Definition
the amplitude of the output signal at that frequency is artifically attenuated or less than the amplitude of the input signal. indicates that the output signal is a distorted form of the input signal 


Term
a frequency of 0 corresponds to... 

Definition
the mean or DC component, which is reproduced exactly because the amplitude of the system response at zero frequency is 1 


Term

Definition
a method for describing complex waveforms in terms of more manageable sine an cosine waves
sine waves can be added together in order to produce a more complex waveform
as higher and higher order odd harmonics are added to the fundamental, the waveform becomes a better approximation to the goal of producing a perfect square wave 


Term

Definition
the basic period of the waveform 


Term

Definition
an integer number times the fundamental frequency 


Term
1st term of the Fourier series 

Definition
represents the mean of the waveform and it is a term that has no frequency associated with it
by definition the mean is a constant, independent of frequency
even a system with inadequate frequency response is still capable of accurately measuring the mean of the waveform 


Term

Definition
electronic methods for removing unwanted frequencies from signals 


Term

Definition
frequencies below the cutoff are allowed to pass through but frequencies above the cutoff are removed 


Term

Definition
high frequencies are permitted to move through the filter and low frequencies are removed 


Term

Definition
small region where only certain frequencies can pass through
there is a low pass cutoff frequency at f_{1} and a high pass cutoff frequency at f_{2} with a center frequency for the pass band 


Term

Definition
passes all low and high frequency signals but rejects the frequencies that are above the lower cutoff f_{1} and below the upper cutoff f_{2}
used in ECG monitoring to eliminate the 60 Hz interference 


Term
standard ECG frequency response 

Definition

