Bodiflo LLC has developed a non-invasive research device, which measures dynamic fluid circulation or ‘impedance’ of the brain. The measurement is made using specialized hardware and software, which captures real time data and visualizes it effectively in near real time for the medical specialist.
Bodiflo LLC Hardware
The hardware for the Bodiflo LLC system consists of:
- Multi-Frequency REG
- Dual Hemisphere Doppler Box and Probes
- Respiratory Sensor
- PowerLab 16 Track A/D Convertor
- 2 Laptops
The Bodiflo LLC impedance measurement system utilizes a Multi-Frequency REG (MF-REG), which determines the capacitance and resistance for different brain tissue structures. The capacitance and resistance are measured through the use of a small electrical current (0.5 millivolts) which travels through the brain measuring the intracellular and extracellular volumes.
The MF-REG has three different frequency currents at 16 kHz, 100 kHz and 200 kHz, which measure the brain fluid dynamics in different ways. These currents are measured using three electrodes, which are attached externally to the skull at different positions on a headband worn by the patient.
The 16 kHz current primarily measures the extra-cellular fluid (Cerebral Spinal Fluid).
The 100 kHz current measures a mix of extra-cellular fluid with some small component of intra-cellular fluid (blood).
The 200 kHz current measures the entire intra-cranial environment including intra-cellular fluid, interstitial (membrane), extra-cellular fluid and the cellular structures.
Diagram 1.0 MF-REG Box
Dual Hemisphere Doppler Box and Probes
The Bodiflo LLC system also consists of the doppler box that features dual external probes fitted to a “rack” system enabling constant monitoring whilst the subject is engaged in a series of tests.
The probes on each hemisphere are aligned to access the “temporal windows” in the cranium and capture the “medial artery” in each brain hemisphere.
The electrode headband is worn underneath the dual hemisphere doppler probe headset.
Diagram 2.0 MF-REG headband and doppler
The Bodiflo LLC system also contains a respiratory sensor, which is a piezo electric strain gauge that is designed to be “wrapped” around the subject’s chest just below the ribcage.
The respiratory sensor measures the subject/patient’s breathing rate.
Diagram 3.0 Respiratory Band
Power Lab” 16 Track Analogue / Digital Converter
The AD Instruments Power Lab converts the analogue signals from the MF-REG and dual hemisphere doppler to digital data to be read in and interpreted for analysis using Bodiflo LLC’s “Impedance Automation Software (IAS)” and “Lab Chart” software.
Diagram 4.0 AD Instruments Power Lab
Bodiflo LLC Software
There are three software suites which the Bodiflo LLC system utilises:
- Impedance Automation Software (IAS).
- The AD Instruments “Lab Chart” software allows the MF-REG signal input to be monitored Doppler box software.
- Impedance Automation Software (IAS).
Bodiflo LLC has developed sophisticated software with a completely unique method of combining output data signals from the Dual Hemisphere Doppler (TCD) and output signals from the Multiple Frequency REG (Rheoencephalograph). This is supported by an ECG and Respiratory band monitor.
The combined data arrays gathered by the hardware are transformed in the IAS software to form a new wave.
The MF – REG was designed to register other values on a non-pulsing (steady state) level. These values are:
- R1: The resistance of the skull and it’s covering – muscles and skin.
- R2: The resistance of the intracranial contents.
- C: The capacitance or ability of the intra cranial contents to hold a charge, which is a constant at any given moment but which changes as the structure of the brain changes e.g. Ageing.
he MF-REG has the capacity to record steady state resistance on each frequency as well as the pulsing wave on 3 frequencies. The steady state resistance values are received at a frequency of 100 times per cardiac cycle. The IAS software performs the necessary calculations on this data and computes values for R1, R2 and C from this data. IAS also plots the changes during any single selected cardiac cycle; this is displayed in near real time.
The IAS software presents sophisticated visualizations of brain fluid dynamics based on the data calculations performed.
Diagram 6.0 Animation of Cranial Fluid Movements
ICP is displayed as a graduated ring (Blue) around each hemisphere. As the pressure increases the ring becomes more pronounced using contrast enhancement and colour change.
Arterial Blood flow Pulse
Arterial Blood flow Pulse is presented as an ascending pulse through the central area increasing in contrast and evidence then decreasing back after their peak. Each hemisphere operates independently.
The CSF is displayed as a pulse derived from the spectrum analysis.
The Venous outflow is derived from the Functional test or monitoring sequences of the standard test –(CSFm – Slow Fluctuation)
Monitoring of trends in a subject can be seen as a “Revue” of the subject’s data over a previous time interval (selectable).
In the event that a subject’s data driven display exceeds a “Trend Channel” an alarm is sounded or flashed on screen.
Comparative Analysis of Subject
Comparative Analysis of subject’s physiological data parameters can be weighted against their own results from a prior baseline or against a “Normative” database average.
Diagram 7.0 Scatter Graph
The IAS software accepts the data columns directly from Lab Chart and carries out all the above functions as well as calculating the Angle of CCe and CSFm (CSFm is the range of variation between MIN and MAX data points) in Systolic and CSFm Diastolic rendered in a graphed array.
Diagram 8.0 IAS Calculation Screen
The IAS software provides a number of meaningful templates for loading test data. Custom tests can also be created with a variety of customizable variables.
Lab Chart data can also be copied and pasted directly into IAS.
Doppler Box and Lab Chart Software
The Doppler Box Software allows for adjustment of the Doppler Probes’ signal Depth, Gain, Sample Volume and Power.
Once the Arteries have been aligned correctly the signal will resemble the figure below.
Diagram 9.0: Doppler Software
When the signals are strong and consistent the data is saved into the subject’s file and the signal is “piped” to the AD Instruments “Power Lab” 16 Track Analogue / Digital Converter.
The AD Instruments “Lab Chart” software allows the Doppler signal input to be monitored. Lab Chart is useful for setting biomarkers which indicate a subject at rest versus a subject engaged in an activity. The diagram below shows a patient at ‘rest’ on IsoTechnology’s ‘IsoPUMP’.
Diagram 10.0 Patient on the IsoPUMP creating rest baseline with Bodiflo LLC System attached
Diagram 11.0 Lab Chart software display of ‘rest’ baseline for subject