Cardiovascular Health & Nutrition

BIOMARKERS

EQUIPMENT

MINDWARE CARDIO MOBILE

The MindWare Cardio Mobile Ambulatory Impedance Cardiograph has the same features of the MW1000A, but also the following improvements:

– High performance and small form factor
– Collects EKG, GSC, EMG, Z0, dZ/dT and respiratory signals
– Local-mode recording to SD card
– Real time multi-unit synchronized wireless data transmission
– Native 24 hour run time capability
– Built in 3-axis accelerometer
– Simple electrode wire interface
– Built-in subject response buttons for event marking

CNS SYSTEMS CNAP MONITOR 500

The continuous noninvasive blood pressure system employs a double finger cuff that is comfortable for the subject to wear and easy to place on the hand. The system outputs a continuous noninvasive blood pressure waveform that is similar to a direct arterial blood pressure waveform and displays values for systolic, diastolic, mean blood pressure, and heart rate.

BIOPAC MP150

The MP150 system is a complete and expandable data acquisition system that functions like an on-screen chart recorder, oscilloscope and X/Y plotter, allowing you to record, view, save and print data. It includes all the necessary hardware and software required to turn any computer into a powerful data acquisition workstation specifically designed for life science applications.

MINDWARE BIONEX CHASSIS

This product was designed to be the workhorse of most laboratories. It contains 8 user configurable slots providing up to 32 channels of custom signal conditioning. These slots can be configured using any combination of the six available BioNex modules. It also supports high speed data acquisition, simultaneous digital input / output, stimulus generation, and flexible triggering options.

CLINICAL SIGNIFICANCE

HEART RATE VARIABILITY (HRV)

HRV is the physiological phenomenon of variation in the time interval between heart beats (HP). It is measured by the variation in the beat to beat intervals. We call this the Time Domain. A healthy heart rate variability is reflected by lots of variation in the time domain between successive heart beats. This would indicate a very robust autonomic nervous system. Someone with less variation between one heart beat to the next has low heart rate variability and indicates decreased autonomic nervous system regulation. The importance of Heart Rate Variability is that it is controlled by the autonomic nervous system and therefore is a window into its function.

The second component of Heart Rate Variability besides the time domain is the spectral analysis. The ECG is broken down into very specific frequency band widths that correspond to specific functions. Low frequency, for example, has to do with the Sympathetic nervous system and high frequency has to do with Parasympathetic nervous system function.

LF/HF ratio: the relative power of the LF and HF components (the LF/HF ratio) might provide an accurate index of sympathovagal balance.

VLF activity is associated with the thermoregulation of vasomotor tone and with the rennin– angiotensin–aldosterone system.

VHF: the spectral power of VHF of HRV is a reliable evaluation index of cardiovascular diseases, such as chronic heart failure and coronary artery disease.

LF activity is associated with the intrinsic oscillations of the baroreceptor reflex (i.e. blood pressure fluctuations). HRV components in the low-frequency (LF) range are mediated via both sympathetic and parasympathetic systems.

HF activity is associated with heart rate modulation via the influence of respiration. The high-frequency (HF) components of the HRV signal are mediated via the parasympathetic system. (C ardiac vagal modulation)

Respiratory sinus arrhythmia (RSA) is a naturally occurring variation in heart rate that occurs during a breathing cycle. RSA is also a measure of parasympathetic nervous system activity – which denotes “rest and digest” behaviors.

Vagal tone is an internal biological process referring to the activity of the vagus nerve, the tenth cranial nerve located in the medulla oblongata of the brainstem. The vagus nerve serves as the key component of the parasympathetic branch of the autonomic nervous system, regulating the homeostasis (or “resting state”) of the majority of the body’s internal organ systems that operate on a largely subconscious level, such as the heart, lungs, eyes, adrenal glands, and digestive tract. Due to the regulatory nature of the PNS, vagal activity is continuous, chronic, and passive (“tone” in this usage is analogous to “tension”).

BLOOD PRESSURE VARIABILITY (BPV)

An essential part of each health screening is the examination of the cardiovascular system since a major cause of death is due to coronary artery disease. High blood pressure is a major risk factor for heart disease and also for a number of other diseases, such as stroke, kidney failure, etc. Not only adults but also children benefit from blood pressure screenings. Standard blood pressure devices record data only from one single beat, so short term disturbances in hemodynamics cannot be tracked.

The baroreflex or baroreceptor reflex is one of the body’s homeostatic mechanisms for maintaining blood pressure. It provides a negative feedback loop in which an elevated blood pressure reflexively causes heart rate and thus blood pressure to decrease; similarly, decreased blood pressure depresses the baroreflex, causing heart rate and thus blood pressure to rise. The system relies on specialized neurons, known as baroreceptors, in the aortic arch, carotid sinuses, and elsewhere to monitor changes in blood pressure and relay them to the brainstem. Subsequent changes in blood pressure are mediated by the autonomic nervous system. Atrial natriuretic peptide forms a parallel negative feedback loop in an endocrinological contrast to the renin-angiotensin system.