Frequently Asked Questions

What are the advantages of Millar Mikro-Tip® catheters over conventional fluid-filled systems?

Higher Frequency Response

Fluid-filled systems typically have a useful frequency range of less than 20 Hz because they have a very low resonant frequency. The frequency response of Millar Mikro-Tip catheters is flat to 10 kHz.

Position Independence

In conventional fluid-filled systems a long column of fluid (water) separates the source of the pressure within the body from a sensing element outside the body. Due to this configuration, any change or disturbance in the position of the sensing element relative to the water column will cause an inaccurate pressure reading. By measuring pressure through a sensor placed directly at the source, Mikro-Tip catheters are not affected by such external factors.

Motion Artifact

Mikro-Tip catheters virtually eliminate motion artifact. Because Mikro-Tip catheters measure pressure directly at the source, they minimize artifact (unwanted noise) caused by the beating of the heart (catheter whip), patient movement, motion of the catheter inside the body, or inadvertent generation of pressure at any point along the entire catheter.

Ease of Use

In addition to providing superior signal quality, Mikro-Tip catheters offer freedom from the time-consuming set-up procedures of debubbling fluid lines and adjustment of transducer height , as well as the regular flushing required by fluid-filled systems. With Mikro-Tip catheters a simple three-stage process of monitor zeroing, monitor gain adjustment, and transducer balancing is all that is required.

Do I need a control unit for Mikro-Tip catheters and if so, which one?

Yes. For most applications a Pressure Control Unit is necessary.

The TC-510 control unit is the primary interface to most clinical monitors with transducer excitation. This unit provides an electronic calibration of 0 and 100 mmHg and a transducer balance control.

The PCU-2000 is a two-channel amplifier/interface unit which has as electronic calibration and transducer balance control.

Please see the Pressure Control Units page in the Products Section for specifications.

Will Mikro-Tip catheters work with all medical monitors?

Yes, provided there is a strain gauge pressure transducer to interface with our TC-510 control unit or a D.C. amplifier to interface with our PCU-2000 control unit.

Input cables are necessary to interface your monitor or system with a Millar control unit. A Customer Service Representative will gladly help you determine which control unit is best suited for you.

How do I calibrate Mikro-Tip catheters?

To minimize drift, presoak the pressure sensor in sterile water or saline for 30 minutes prior to use.

How do I clean my Mikro-Tip catheter?

Specific cleaning instructions are provided with every catheter and vary somewhat depending on the type of catheter, the type of application and other factors. However, one constant is true for all Mikro-Tip catheters; all catheters should be cleaned immediately after use to prevent development of deposits or film on the pressure sensor. Deposits or film on the sensor may cause the pressure signal to drift and require extended soaking in order to soften and thoroughly remove them. If you are unable to clean the catheter immediately after use, it is vital to soak the catheter in water (and flush the lumen where present) until you are ready to fully clean the catheter. You should clean the catheter with a Millar approved cleaner, being certain to gently wipe the pressure sensor clean with equivalent of a soft gauze pad or Q-tip. Dirt buildup on the sensor is the most common problem, causing drift and possible need for future refurbishing.

Are Mikro-Tip catheters waterproof?

No. The working length of the catheter body is fully submersible. However, the electrical connector and wye connector extension junction must not be exposed to excessive moisture or submerged in fluid.

Can I break the pressure sensor?

Yes. However, Mikro-Tip catheters should not be considered "fragile". Mikro-Tip catheters are designed to be durable when handled and cleaned properly. You should never pick up the catheter by the sensor area. The pressure sensor should be wiped during cleaning but never stabbed with a sharp object. If the Instructions for Use are carefully followed regarding cleaning, storage and use, catheters will provide many uses and may last for years.

How many uses can I expect from my Mikro-Tip® Cardiology Catheter?

The number of uses depends on the model of catheter.

• "Disposable" models are intended for one use.
• "Multi-segment pressure-volume" catheters are intended for 5 uses.
• "Reusable" catheters can be used many times and are not limited to a specific number of uses.

Are Millar products CE marked?

Yes. All Millar catheters, interface cables, and the TC-510 bear the CE mark. In addition Millar Instruments is an ISO 13485:2003 certified company.