You are here:   Products
  |  Login

Categories

Minimize

All Products

Enquiry List

Minimize

Your Enquiry List is empty

Products

Minimize

Scisense ADVantage Admittance PV (Pressure Volume) Systems

Scisense is the first company to manufacture a revolutionary PV loop system ADVantageTM which derives volume based on measuring complex admittance.
Code
ADVantage Admittance

Scisense ADVantage Admittance PV (Pressure Volume) Systems

   

ADVantage Admittance PV (Pressure Volume) Systems

Since the mid-1970's the PV loop has steadily become the gold standard as a means to study myocardial contractility, compliance, muscle energetics and other important quantitative measures of function. Approaches such as ultrasonic crystals, magnetic resonance imagine (MRI) and echocardiography have been used to measure instantaneous volume with varying degrees of success. However, these technologies all have severe limitations, particularly during the generation of load independent indices of contractility. Pressure Volume catheter technology has emerged as the most reliable method to generate real-time ventricular PV loops in the intact heart, particularly now as a result of recent advancements in the field through the use of "admittance" instead of the older "conductance" technology.

Scisense offers two PV Loop system product lines to fit a variety of budgets and protocols:

  • Pressure-Volume Systems - Absolute Volume (ADVantage™ with Admittance Technology)
  • Pressure-Volume Systems - Relative Volume Measurements (Conductance Technology)

These PV loop systems can be configured to work for all sizes of animals, as well as isolated working heart systems. Some of the key differences between the two volume measurement technologies are:

Admittance vs.Conductance PV Loop Systems


Admittance-PV Systems
(the Scisense ADVantage™)
Conductance PV Systems
(Traditional Technology)
Absolute Volume (ml/µl) Yes No
Relative Volume (rvu's) Optional No
Real Time Yes No
Saline Bolus Required No Yes
Cuvette Required No Yes
Self-Calibrating Yes No
Catheter Position Feeback Yes No
Inter-Animal Comparison Yes No
"Pre & Post" Studies Yes No
MI Studies Yes No
Enlarged Hearts Yes Optional
Isolated Working Hearts Yes Optional
Catheter Type Admittance (FTE) Conductance (FTS)

Overall, the Admittance technology contained exclusively in the Scisense ADVantage product line represents a great technology leap forward in pressure volume measurement studies. Now available for all sizes of animals from mice to pigs, sheep, etc., the technology brings a number of new important benefits to cardiovascular assessment:

  • Increased accuracy of results
  • Repeatable results with lower standard deviations
  • Fewer animals required
  • Reduced project times

Scisense is the first company to manufacture a revolutionary PV loop system ADVantageTM which derives volume based on measuring complex admittance.

Admittance vs. Conductance Techniques

Conductance Technique

Traditional PV systems use conductance to estimate LV volume using a tetra-polar catheter positioned along the long axis of the LV (see below). 


This has a number of drawbacks:

The relationship between blood conductance and volume is non linear, due to non linear shape of stimulating electric field.

Conductance measurement extends into blood pool AND into surrounding tissue (muscle)

  • This implies that the measurement will artificially increase the volume because the catheter will see further than only the blood pool
  • The correction for the parallel conductance G|| is a calculated constant in the above equation, but the parallel conductance is known to be non-constant

The accepted methods for parallel conductance measurement are outdated

  • Hypertonic saline bolus injection is commonly used to measure G||
  • This measured value is a constant, and is not time dependent
  • Need a better technique to separate the blood and muscle components of the signal

Conductance approach is modeled after an inaccurate circuit model for blood and myocardium

  • Traditional approach models both blood (Gblood) and cardiac muscle (Gmuscle) as real or resistive components only, ignoring the imaginary or capacitive properties of cardiac muscle
  • Hence, separating blood and muscle is difficult and often done incorrectly in the traditional approach


Admittance technique

  • Admittance technique measures both conductive and capacitive properties of blood and muscle
  • The basis of measuring admittance instead of conductance is that at frequency ranges of about 20 kHz, blood is purely resistive and has no measurable capacitance, but muscle has both capacitance and resistance properties
  • This allows separation of the admittance of the muscle from the admittance of blood, using electric field theory
  • New proposed circuit model which models the blood as resistive, the cardiac muscle as both resistive and capacitive .

Improved PV Measurement through Admittance Technology

The Admittance technique is an improvement over the Conductance technique for the real-time removal of muscle conductance. Blood and muscle respond very differently to alternating (AC) electrical currents. The fixed charges in muscle cells create a significant reactance that causes a phase shift (time delay) in the measured signal, relative to the excitation signal. Admittance technology uses this phase shift to determine the instantaneous muscle conductance and remove it from the total measured conductance.

BENEFITS

  1. Accurate, reproducible PV data - users experience tighter confidence intervals for admittance derived volume compared to data calculated by the 'classical' approach.
  2. Study subtle changes in heart function - inter-animal comparisons, drug therapy evaluation, degrees of heart failure, etc.
  3. Fewer animals required per study -improved data collection methods and accuracy checks mean each data set is valuable.
  4. Return on Investment - collect, interpret, and publish more cardiac function data faster!

Automatic calibration of the Volume Signal Eliminates Hypertonic Saline Injection AND Cuvette Calibrations:


Real time calculations are made by the ADVantage system to ensure that measured volume does not include contributions from the myocardial wall. The ADVantage system measures the phase shift of the electrical field as it passes through both the blood and muscle.

Varying myocardial wall thicknesses through ED and ES (and therefore parallel conductance) are accounted for in real time.

Catheter calibration is performed by the system, eliminating the need to place the catheter in the middle of cuvette wells (at 37°C) of different sizes, each of which affect the electrical field in a different way.


Catheter Positioning Feedback Facilitates Surgery:

Due to the position of the aortic valve a catheter in the LV is naturally offset from the centerline. Phase shift measurements indicate this proximity and allow the user to ideally position the catheter.


Absolute Volume in Real-Time

Mathematically derived algorithms (Wei’s Equation) compensate for both the varying wall thickness throughout the heart cycle as well as the changing proximity to the myocardial wall. These calculations are performed by the ADVantage control unit allowing absolute volume to be output in real time as an analog signal to any acquisition system.


PV Loops for All Sizes of Hearts:

New Scisense technology called “variable segment length” (VSL) allows the same catheter to be used in both large and small hearts of the same animal type, reducing experimental costs and uncertainty over which electrode ring spacing is appropriate. Users simply select the spacing that ‘best fits’ the heart they are studying, ensuring the utmost accurate measurements.


Tactile-Button Operation and System Menus increase Ease of Use:

All of the controls and calibrations are accessible using the wide LCD flash screen with an easy to use menu. Navigation through the menu is designed to step the researcher through the study.


ADVantage Specifications

Pressure-Volume Control Unit - ADVantageTM

The Scisense ADVantage™ pressure-volume control unit is a state-of-the-art admittance-based volume measurement system. It is the first technology to output true volumes in real-time.

The ADVantage PV Loop system has been designed with a variable gain system to work with all sizes of hearts. A powerful onboard microprocessor manages the real time pressure and volume signals and outputs them as analog signals through standard BNC connectors, assuring compatibility with all commercial data acquisition systems.

   Admittance based Pressure-Volume Control Units
   
   
Specifications:  
Number of Inputs: 1 (9 pin Redel)
Pressure Output: 2.3 Volt/100 mmHg
Power Supply Out: +5VDC, +/- 12 VDC
Power Supply In: 100-250 Vac, 50-60 Hz
   
Dimensions: H : 6.9 cm (2.7”)
  W : 22.6 cm (8.9")
  L : 16.8 cm (6.6")
   
Calibration Controls: Pressure: 0 mmHg (-2.86V) and 100 mmHg (-0.57V)
   
Volume (Span 0V to +5V): 0 uL - 150 uL,
  0 uL - 1000 uL
  0 uL - 2000 uL
  0 mL - 200 mL
   
Phase: 0° to 20° (Span 0V to +5V)  
Magnitude (Span 0V to +5V): 0 uS - 5000 uS
  0 uS - 5000 uS
  0 uS - 15000 uS
  0 mS - 50 mS
   
Catheter Cable: 122 cm (48"/ 4 feet) cable for small animal
  366 cm (144"/ 12 feet) cable for large animal
   
Output Connector: BNC
Signal Gain: 1143 (Pressure)

ADVantage Compatible PV Catheters



Part Number Name Description Recommended Long Axis Length
FTE-1212B-3518 1.2F Pressure-Volume Catheter (small mouse) The ideal catheter for small mouse pressure-volume studies: the catheter has a 3.5mm electrode distance to best fit the long axis of the left ventricle. 5.25 mm to
5.75 mm
FTE-1212B-4018 1.2F Pressure-Volume Catheter Our standard mouse pressure-volume with a 4.0 mm recording electrodes spacing for use with average sized mice. 5.75 mm to
6.25 mm
FTE-1212B-4518 1.2F Pressure-Volume Catheter (standard) Our standard mouse pressure-volume with a 4.5 mm recording electrodes spacing for use with average sized mice. 6.25 mm to
6.75 mm
FTE-1214B-4518-A25 1.2F Dual Pressure-Volume Catheter (standard) A specialty 1.2F PV catheter with two pressure sensors: the first sensor (P1) is located at the tip of the catheter (2.5 mm distal to E1) for measuring aortic pressure, while the second is located between E2 and E3 for ventricular pressure measurement. This particular spacing is best for combination left ventricular pressure and aortic blood pressure in the mouse. The distance between the two sensors can be adjusted, please ask for additional information. 6.00 mm to
6.50 mm
FTE-1218B-E418 1.2F Mouse VSL Pressure-Volume Catheter A unique 1.2F Pressure-Volume catheter that offers four different volume electrode spacings: 5 mm, 6mm, 7mm, and 8 mm. This is the ideal PV catheter for studies with mouse where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 7.75 mm to
10.25 mm
Part Number Name Description Recommended Long Axis Length
FTE-1912B-6018 1.9F Pressure-Volume Catheter Our rat pressure-volume catheter with an 6 mm ring spacing for use with small sized rats. 7.75 mm to
8.25
FTE-1912B-8018 1.9F Pressure-Volume Catheter (Polyimide) Our standard rat pressure-volume catheter with an 8 mm ring spacing for use with average sized rats. 9.75 mm to
10.75
FTE-1914B-8018-A50 1.9F Dual Pressure-Volume Catheter Our standard rat pressure-volume catheter with an 8 mm ring spacing for use with average sized rats. 9.50 mm to
10.00
FTE1-1912B-8018 1.9F Pressure-Volume Catheter (Pebax) A more flexible and softer version of our standard rat pressure-volume catheter with an 8 mm ring spacing for use with average sized rats. 9.75 mm to
10.25
FTE-1912B-10018 1.9F Pressure-Volume Catheter (Polyimide) Our standard rat pressure-volume catheter with an 10 mm ring spacing for use with average sized rats. 11.75 mm to
12.25
FTE-1914B-8018-A50 1.9F Dual Pressure-Volume Catheter A specialty 1.9F PV catheter with two pressure sensors: the first sensor (P1) is located at the tip of the catheter (5.0 mm distal to E1) for measuring aortic pressure, while the second is located between E2 and E3 for ventricular pressure measurement. This particular spacing is best for combination left ventricular pressure and aortic blood pressure in the rat. The distance between the two sensors can be adjusted, please ask for additional information. 9.50 mm to
10.00
FTE-1918B-E118 1.9F Small Rat VSL Pressure-Volume Catheter A unique 1.9F Pressure-Volume catheter that offers four different volume electrode spacings: 6 mm, 8mm, 10mm, and 12 mm. This is the ideal PV catheter for studies with smaller rats where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 10.75 mm to
15.25 mm
FTE-1918B-E218 1.9F Medium Rat VSL Pressure-Volume Catheter A unique 1.9F Pressure-Volume catheter that offers four different volume electrode spacings: 8mm, 10mm, 12mm, and 14 mm. This is the ideal PV catheter for studies with medium rats where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 12.75 mm to
17.25 mm
FTE-1918B-E318 1.9F Large Rat VSL Pressure-Volume Catheter A unique 1.9F Pressure-Volume catheter that offers four different volume electrode spacings: 8mm, 11mm, 14mm, and 17 mm. This is the ideal PV catheter for studies with large rats where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 14.75 mm to
21.25 mm


Part Number Name Description Recommended Long Axis Length
FTE-3518B-E124 3.5F Small Rabbit VSL Pressure-Volume Catheter A unique 3.5F Pressure-Volume catheter that offers four different volume electrode spacings: 5mm, 8mm, 11mm, and 14mm. This is the ideal VSL PV catheter for studies with smaller rabbits where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 13.0 mm to
22.0 mm
FTE-3518B-E224 3.5F Medium Rabbit VSL Pressure-Volume Catheter A unique 3.5F Pressure-Volume catheter that offers four different volume electrode spacings: 8mm, 11mm, 14mm, and 17mm. This is the ideal VSL PV catheter for studies with standard sized rabbits where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes. 16.0 mm to
25.0 mm
FTE-3518B-E324 3.5F Large Rabbit VSL Pressure-Volume Catheter A unique 3.5F Pressure-Volume catheter that offers four different volume electrode spacings: 11mm, 14mm, 17mm, and 20mm. This is the ideal VSL PV catheter for studies with larger rabbits where there is an expectation that the ventricular long axis length space may increase or decrease, thus still supporting a "best fit" for the volume electrodes.

Accessorize your purchase with these related items

Pressure Catheter Controllers
Pressure Catheter Controllers
$0.00