Products

Scisense Inc. specializes in the direct measurement of fluid pressures, volumes and ECG for medical research. Common applications include:

• blood pressure (ventricular and arterial)
• ventricular volume and pressure-volume loops
• cardiac electrograms
• bladder and other organ pressure and volume studies
• neurological pressure measurements

Our sensors range in size froman ultra-miniature 1.2 French suitable for working with transgenic mice all the way up to 7 French size for larger animal models. Click here to see all the available catheters specifications.

The key advantage of the Scisense product line lies in our ability to include a high fidelity, solid state, pressure sensor on the same catheter probe as volume and/or ECG sensors. All catheters can be inserted minimally invasively through carotid or femoral arteries, avoiding risky and time consuming open surgery.

Direct vs. Indirect Pressure Measurement

According to the December 2004 American Heart Scientific Statement "methods for directly measuring BP are generally preferred because of their ability to monitor the highly dynamic nature of BP in a comprehensive fashion". Indirect methods, such as tail cuffs and other non-invasive approaches, typically provide data that is "sporadic" and cannot detect diastolic pressure accurately.

Optimal Size

Further, our ultra miniature 1.2 F pressure and pressure-volume catheters are carefully designed for an optimal balance between durability and invasiveness. Woldbaek et al reported (Am J Physiol Heart Circ Physiol 285: H2233–H2239, 2003.) that a 1.2 French size sensor inserted "from the right carotid artery into the left ventricle in six mice caused no drop in mean aortic pressure, whereas introduction of a 1.4-Fr Millar catheter (OD = 0.47 mm; n = 6) caused a pressure drop from 91.6 +/- 9.2 to 65.1 +/- 6.2 mmHg; P < 0.05". Woldbaek et al concluded that "the introduction of the 1.4-Fr Millar catheter to the same positions caused a significant drop in mean aortic blood pressure, indicating
that this catheter affects central hemodynamics".

Based on this research, the 1.2 F ultra miniature catheter size offered by Scisense is the ideal phyiological size to evaluate transgenic and gene-targeted manipulations of the murine genome. Smaller sizes can lead to increased fragility and decreased lifespan of the probes, and therefore should be avoided wherever possible.

Solid State vs. Fluid Filled Sensors

The Scisense solid state sensors measure pressure precisely and accurately at the source. Conventional fluid filled sensors use an extension tube to transmit pressure changes from the tip back to a remotely mounted pressure sensor.

When data is compared across the frequency spectrum from a Scisense catheter and a conventional fluid filled catheter it can been seen that the signal becomes grossly distorted at 5hz (approximately 300 bpm). Given the typical heart of a mouse as 600 bpm it is clear that the solid state pressure sensor from Scisense provides much more accurate detection of pressure changes at high hearts and harmonic frequencies.

In addition to measuring precise and noise free signals, the Scisense pressure transducer can accurately measure dP/dt, one of the most fundemental indicies of cardiac function.

Pressure Only vs. Pressure-Volume Loops

While accurate detection of blood pressure is perhaps the most crucial parameter in any study of cardiac function, only the simultaneous measure of both pressure and volume (the PV loop) properly evaluates the performance of the heart as a pump.

Over the past 30 years the PV loop has steadily become the "gold standard" as a means to study myocardial contractility, compliance, muscle energetics and other important quantitative measure of function in vivo. Scisense PV catheters start at the 1.2 F size for mice and are also offered in larger, multi-segment versions.

Complete Hardware/Software Solutions

Our high precision blood pressure, pressure-volume and ECG catheters allow for complete characterization of the cardiovascular functional phenotype and are compatible with all commercial data acquisition systems. However, for convenience, we offer a complete bundled solution of catheters as well as data acquisition hardware and analysis software through our partnership with Data Sciences International (DSI). DSI offers the world class Ponemah software and ACQ 16 data acquisition unit through Scisense.

Isolated Working Heart Systems

Finally, through an alliance with Radnoti Glass Technology, we also provide complete integrated systems for isolated working heart apparatus. While Scisense pressure, pressure-volume and ECG catheters can work with all commercial equipment, the glassware from Radnotti is the gold standard for researchers worldwide. Scisense equipment is also fully compatible with the variety of perfusion fluids used in working heart systems.