Archive for October 2014
Noninvasive Cardiac Output | Data Acquisition
Noninvasive
Cardiac Output (NICO) measures can be determined by employing electrical
bioimpedance (EBI) measurement techniques. Electrical bioimpedance is the
characteristic impedance of a volume
of tissue and fluid. For Cardiac Output measures, the
relevant tissue includes the heart and the immediate surrounding volume of the
thorax, and the relevant fluid is blood.
The electrical
impedance of the thorax (Zt) can be thought of as composed of two impedance
types:
- The base impedance (Zo) corresponding to non-time varying tissues, such as muscle, bone and fat. Zo is measured when the pulsatile volume is minimal.
- The delta impedance (dZ) corresponding to time-varying fluid volume (blood).
Zt drops with
each pulsatile volume of blood ejected from the heart. dZ/dt is the magnitude
of the largest impedance change during systole.
Noninvasive
cardiac output amplifiers incorporate a precision high-frequency current
source, which injects a very small (400 microamp rms) current through the
measurement tissue volume defined by the placement of a set of current source
electrodes. A separate set of monitoring electrodes measures the voltage
developed across the tissue volume. Because the current is constant, the
voltage measured is proportional to the characteristics of the biological
impedance of the tissue volume.
BIOPAC data
acquisition hardware for recording real-time Noninvasive Cardiac Output
parameters include tethered amplifiers such as the NICO100C (or NICO100C-MRI
for fMRI environments), EBI100C, or SS31L, or the wireless BioNomadix BN-NICO.
Hardware
simultaneously measures impedance magnitude and phase, and may
incorporate an internal derivative function to output dZ/dt simultaneously with
Z; an AcqKnowledge calculation channel can also be used to determine
dZ/dt. The internal derivative function inverts the polarity of the dZ/dt
signal so that it displays a positive-going peak, coincident with negative
slopes indicated in Z, as per academic research convention.
Disposable
Ag/AgCl Paired Electrodes (EL500) are recommended for bioimpedance and cardiac
output studies. Paired electrodes provide fixed spacing between the dual
contacts and are pre-gelled with hypo-allergenic, wet liquid gel electrolyte
(10% chloride salt); the gel cavity is situated between electrode and skin
surfaces and helps reduce motion artifact.
The impact of
movement artifacts on recorded data is a significant methodological concern in
impedance cardiography; Ensemble Averaging tools in AcqKnowledge provide
an automated strategy to remove these artifacts. Watch a demo now!
Data Hardware & Software Platforms
Data
acquisition hardware and software requirements vary widely based on experiment
protocol, classroom setup, field studies, etc. BIOPAC data acquisition hardware
platforms support wired, wireless, and fMRI setups, for human or animal
subjects, with powerful, intuitive data software for research and teaching
applications. Use with a variety of amplifiers, stimulators, triggers,
transducers, gas analysis modules, and/or electrodes to acquire life science
signals, including
ECG, EEG, EOG, EMG, EGG, EDA, Respiration, Pulse, Temperature, Impedance
Cardiography, Force, Accelerometry, Goniometry, Dynamometry, Gyro, and more.
Combine data hardware for multi-subject or multi-parameter
protocols.
Research hardware platforms are fully-integrated with AcqKnowledge® data acquisition software, which provides automated routines for data scoring, measurement, and reporting, and can support multiple hardware units. Teaching platforms include Biopac Student Lab software with media-rich tutorial style guide lessons for specified objectives, plus active learning options for student-designed experiments and advanced analysis.
Wired (tethered) data acquisition hardware platforms include the MP150 and MP36R Research Systems. The MP150 16-channel system with universal amplifier provides high resolution (16 bit), high-speed acquisition (400 kHz aggregate) with16 analog inputs and two analog outputs, digital I/O lines (to automatically control other TTL level equipment), and online calculation channels. The MP36R 4-channel research system with built-in amplifiers provides four analog inputs and one analog output, I/O port for digital devices, calculation channels, trigger port, headphone jack, and electrode impedance checker. The MP36R supports software-controlled amplifiers and calculation channels.
Mobita® 32-channel
wearable wireless systems are
ideal for biopotential applications that demand subject mobility and data
logging. The Mobita EEG System uses water electrodes—no skin prep or gels
required. Record live data into AcqKnowledge or log to an internal
storage card for later upload into AcqKnowledge; modes are easily
switched to suit specific protocols.
B-Alert
X10® Wireless Systems
provide nine channels of high fidelity EEG plus ECG, and data software
for cognitive state metrics software is available. The stand-alone system easily
interfaces with MP150 Research System to synchronize with other physiological
data.
BioHarness® with AcqKnowledge is a lightweight, non-restrictive data logger and telemetry system to monitor, record, and analyze a variety of physiological parameters, including ECG, respiration, posture, and acceleration.
Stellar®
Small Animal Telemetry
Licenses with AcqKnowledge
control wireless data acquisition
from Stellar Implantable Telemetry Systems. The
easy-to-configure Animal Scheduler works for a subset or complete group of
conscious, unrestrained small animals for long term recordings.
Multiple
display modes can be viewed simultaneously, and signal conditioning tools (e.g.,
filtering and artifact removal) can be
applied.
These and other BIOPAC data hardware and software solutions are used in thousands of labs worldwide and cited in thousands of publications. Learn more about research systems and teaching systems.
Research hardware platforms are fully-integrated with AcqKnowledge® data acquisition software, which provides automated routines for data scoring, measurement, and reporting, and can support multiple hardware units. Teaching platforms include Biopac Student Lab software with media-rich tutorial style guide lessons for specified objectives, plus active learning options for student-designed experiments and advanced analysis.
Wired (tethered) data acquisition hardware platforms include the MP150 and MP36R Research Systems. The MP150 16-channel system with universal amplifier provides high resolution (16 bit), high-speed acquisition (400 kHz aggregate) with16 analog inputs and two analog outputs, digital I/O lines (to automatically control other TTL level equipment), and online calculation channels. The MP36R 4-channel research system with built-in amplifiers provides four analog inputs and one analog output, I/O port for digital devices, calculation channels, trigger port, headphone jack, and electrode impedance checker. The MP36R supports software-controlled amplifiers and calculation channels.
Wireless data
hardware includes options for live or logged data:
BioNomadix
wireless, wearable physiology monitoring devices noninvasively record
high-quality, full-bandwidth data while comfortably allowing subjects to move
freely in natural indoor environments. Digital transmission and transducers
placed close to the signal source provide excellent signal quality. Record
up to 16 channels of BioNomadix data with a BIOPAC MP150 System—the system also
works with multiple MP150 systems or third-party data acquisition hardware via
an isolated power supply module.
B-Alert
X10® Wireless Systems
provide nine channels of high fidelity EEG plus ECG, and data software
for cognitive state metrics software is available. The stand-alone system easily
interfaces with MP150 Research System to synchronize with other physiological
data.BioHarness® with AcqKnowledge is a lightweight, non-restrictive data logger and telemetry system to monitor, record, and analyze a variety of physiological parameters, including ECG, respiration, posture, and acceleration.
These and other BIOPAC data hardware and software solutions are used in thousands of labs worldwide and cited in thousands of publications. Learn more about research systems and teaching systems.
Biomechanics Transducers | Data Acquisition
Biomechanics
data can include measures of force and motion of body position, posture, and
joint movement over a wide range of static and dynamic conditions. Biomechanics
measurements are meaningful for a wide variety of research applications, such as
biomedical engineering, exercise physiology, sports training or rehab, and
ergonomics (for characteristics of a specific work activity or environment).
Biomechanics transducers include goniometers, torsiometers, and
accelerometers. Transducers are unobtrusive and lightweight, and can be worn
comfortably and undetected under clothing or attached to external
equipment—leaving the subject to move freely in the normal
environment.
Biomechanics transducers connect directly to the BIOPAC Acquisition Unit as part of an MP or BSL System. For a more complete physiological analysis, additional signals can be recorded (e.g., EMG, respiration, heart rate) and video data can be tightly-synchronized for a clear and detailed view of the biomechanics of a movement with the subject’s physiological data.
Goniometers incorporate gauge elements that measure bending strain along or around a particular axis and transform angular position into a proportional electrical signal. The gauge mechanism allows for accurate measurement of polycentric joints. As the joint moves through a determined angle, the relative linear distance between the two mounting positions will change. A telescopic endblock prevents the measuring element from becoming over-stretched or buckled as the limb moves. The bending strain is proportional to the sum total angular shift along the axis. Because the bending force is extremely small, the output signal is uniquely a proportional function of the angular shift.
Twin-axis goniometers measure rotation about two orthogonal planes
simultaneously to record limb angular movement, such as adequate bending in the
elbows or knees, unsafe rounding in the lower spine, wrist or ankle
flexion/extension, abduction/adduction, radial/ulnar deviations, etc.
Single-axis goniometers measure the angle in one plane only and are used to
record digit joint movement of fingers, thumb or
toes.
Torsiometers measure rotation about a single axis (e.g., forearm pronation/supination) to record angular twisting (as opposed to bending) of the torso, spine or neck.
Tri-Axial Accelerometers are high level output transducers that provide three outputs to measure acceleration along the X-, Y- and Z-axes simultaneously. To reliably record head tilt, place an accelerometer on the head. To measure accelerations when performing slow movements, such as walking and hand tremor, ±5 G accelerometers are optimal; ±50 G are more suitable for quick movements, such as swinging a tennis racket.
For applications where quick or rapid movements are involved, fit a “sock” bandage over the whole sensor and interconnect lead. For accurate results from long recordings, use double-sided adhesive between the endblocks and skin, and place single-sided adhesive tape over the top of the endblocks. No tape should come into contact with the spring. The connection lead should also be taped down near the sensor element.
Biomechanics transducers connect directly to the BIOPAC Acquisition Unit as part of an MP or BSL System. For a more complete physiological analysis, additional signals can be recorded (e.g., EMG, respiration, heart rate) and video data can be tightly-synchronized for a clear and detailed view of the biomechanics of a movement with the subject’s physiological data.
Goniometers incorporate gauge elements that measure bending strain along or around a particular axis and transform angular position into a proportional electrical signal. The gauge mechanism allows for accurate measurement of polycentric joints. As the joint moves through a determined angle, the relative linear distance between the two mounting positions will change. A telescopic endblock prevents the measuring element from becoming over-stretched or buckled as the limb moves. The bending strain is proportional to the sum total angular shift along the axis. Because the bending force is extremely small, the output signal is uniquely a proportional function of the angular shift.
Torsiometers measure rotation about a single axis (e.g., forearm pronation/supination) to record angular twisting (as opposed to bending) of the torso, spine or neck.
Tri-Axial Accelerometers are high level output transducers that provide three outputs to measure acceleration along the X-, Y- and Z-axes simultaneously. To reliably record head tilt, place an accelerometer on the head. To measure accelerations when performing slow movements, such as walking and hand tremor, ±5 G accelerometers are optimal; ±50 G are more suitable for quick movements, such as swinging a tennis racket.
For applications where quick or rapid movements are involved, fit a “sock” bandage over the whole sensor and interconnect lead. For accurate results from long recordings, use double-sided adhesive between the endblocks and skin, and place single-sided adhesive tape over the top of the endblocks. No tape should come into contact with the spring. The connection lead should also be taped down near the sensor element.