FAQ

Frequently asked questions about products from Samba Sensors.

1.             GENERAL MATTERS

1.1.       Can I use both high and low pressure transducers with my Samba system?

Yes. The Samba 201/202 Control Unit uses both low and high pressure Samba transducers. e.g. the Samba Preclin 420 LP and Samba Preclin 360 HP pressure transducers.

1.2.       Can I use my old Samba pressure transducers made for the previous Samba 3200 or 3000 control unit with the new Samba 200 system?

No, due to technical reasons you cannot use previous Samba catheters with your new Samba 201 and 202 control unit. They are unfortunately not compatible.

1.3.       Do I have to install the Samba 200 Software Package?

No, you can connect the Samba system to a separate external data acquisition system (DAS), like the BIOPAC MP-150 system, instead of to a Windows computer. To be able to utilise all the benefits of the Samba 200 system you should however install it as the Samba 200 Software package includes several useful modules. For more information about the package content, please see Samba 200 Software Package >>.

1.4.       What is the recommended cleaning procedure when reusing a Samba Preclin transducer?

We strongly recommend you to use an enzyme cleaner to make sure that all organic depositions are removed from the sensor after in vivo use of the transducer. Our recommendation is to use Tergazyme from Alconox (http://www.alconox.com/downloads/pdf/techbull_tergazyme.pdf).

Always mix the cleaning solution in advance before starting your measurement in order to allow the cleaning agent to dissolve properly before use. Applying magnetic stirring to improve the dissolving process is highly recommended.

For more information please read the "Samba 201 and 202 User Manual" or download our "General cleaning note" from Downloads >>.

1.5.       How much data can be stored in the internal memory of my Samba 200 unit?

The size of the internal memory will allow:

- 33 minutes recording at 625 Hz, or

- 8 hours and 45 minutes recording at 40 Hz, or

- 350 hours recording at 1 Hz

 

2.             APPLICATION ISSUES

2.1.       How do I insert the Samba catheter to measure blood pressure in a mouse or rat?

Samba Sensors has produced an instruction movie that describes in detail the insertion procedure. The Samba instruction film is free of charge, available on CD and can be received upon request.

Please contact your local Samba distributor or send us your request by filling in the Email Contact Form under Contact >>. Choose the headline "Request for instruction CD for micro-surgeons" in the drop-down menu of the Email Form.

2.2.       How do I apply the Samba transducer if I want to measure pressure directly in the tissue, for example in tumour tissue, brain tissue or muscle tissue?

MEASUREMENTS IN NON-DENSE TISSUE

1. Insert a needle/cannula (with 0.5 - 0.6 mm inner diameter) into the non-dense tissue.

2. Introduce the Samba catheter through the needle/cannula until the sensor is at the needle/cannula tip.

3. Remove the needle/cannula.

4. If needed, pull back the Samba catheter slightly while looking at the pressure signal on your screen. When you have a clear and stable signal, without spikes, the measurement is all right.

MEASUREMENTS IN DENSE TISSUE

1. Insert a needle/cannula (0.5 - 0.6 mm inner diameter) with a Luer-Lok fitting and lock at its proximal end (use for example the Qosina part #11058:http://www.qosina.com/catalog/part.asp?partno=11058) into the dense tissue.

2. Introduce the Samba catheter through the Luer-Lok and needle/cannula until the sensor is at the needle/cannula tip.

3. Check that the pressure signal is clear and stable. If not, try to move the Samba catheter slightly until you get a good signal.

4. Allow the needle/cannula, with the Samba catheter inside, to remain in place in the tissue and delicately tighten/seal the Luer-Lok around the Samba fiber (to prevent pressure leakage through the needle/cannula).

2.3.       When positioning the sensor of a Samba Preclin transducer in a glass of water just below the water surface the pressure reading is 3-5 mmHg relative to the atmospheric pressure. Why?

It is the surface tension in the border zone between liquid and gas that is causing this effect. If the water is replaced with a liquid with lower surface tension, like alcohol, the pressure reading will be different but these are physical effects that are hard to measure exactly. It is recommended to stay away from surface areas if the exact hydrostatic pressure is to be measured. The actual pressure (excluding the surface tension component) at the surface is the same as in the air/gas pressure above it according our universal laws of physics.


 

3.             ERROR MESSAGES

3.1.       The message "Bad Connection" is displayed on my Samba control unit. What is the cause and how do I solve the problem?

The "Bad connection" error occurs when light is not passing freely from the control unit further into the transducer through the optical connectors. It is caused either by A) dust/dirt on either connector or in between the fibre ends, or B) a small crack in the optical fibre or C) that the connectors are not correctly positioned or sufficiently pushing against each other. In any of these cases you will get a light "leakage", hence the error.

USING THE HUXCLEANER

The simplest way to correct the error and clean both the male and female optical connectors is to use the HUXCleaner-2.5. For more information and an instruction video ("How to clean") please visit http://www.thefibers.com/products_01_04.html.
The HUXCleaner data sheet can be downloaded from Downloads >>.

SECOND MANUAL METHOD

For a second method to correct the error please follow the procedure below:

1. Start by removing the protective cap from the male connector on the transducer and gently wipe the fiber end with a lint-free tissue (e.g. Kimcare®, Kimwipes® or similar) moistened with Isopropyl alcohol. Before the connector dries, use a lint-free dry tissue to remove the remaining alcohol.

2. Then proceed to carefully cleaning the female optical connector on the Samba 200 control unit with Isopropyl alcohol and a Fiber Optic Cleaning Swab. Allow the connectors to dry completely before reconnecting the transducer.

NOTE:   To minimise the risk of getting "Bad Connection" always check that the transducer connector is clean before connecting it to the control unit. To keep the connectors clean always use the protective caps on both the transducers and the control unit when they are not being used.

 

3.2.       After the installation of the Samba 201/202 unit my mouse stopped functioning. How do I solve this problem?

When connecting the Samba 201/202 unit the first time to a PC through the USB port Microsoft Windows will sometimes install the driver incorrectly. For some reason the MS Plug'n'Play driver installation procedure incorrectly identifies the Samba unit as a Microsoft mouse. The mouse then stops working and the pointer may behave erratically; it jumps at random locations on the screen, even without moving the mouse, and often ends up in the top right corner.

To solve this problem, please download the document "USB driver issue" from Downloads >> under the category "Warranty & service" and follow the instructions carefully.

 

 

4.             COMMUNICATION WITH SAMBA 3200 CONTROL UNIT

4.1.       I'm using a Samba 3200 system but I don't have a RS-232 serial port (COM-port) on my computer. How can I connect my computer to the Samba 3200 Control Unit?

You can use a USB to serial adapter (Keyspan 4-port adapter USA-49W and Aten 1-port UC-232A have both been tested by Samba Sensors). Many other brands may also work.

4.2.       I’m having communication problems when using my laptop, what is wrong?

Sometimes the COM-ports on laptops are shared. You might correct the error by deactivation the IR-port and the modem-port on your PC. Also make sure that there isn't any synchronisation software installed, for example for a PDA, that uses the serial COM-port.

4.3.       I have communication problems with my Keyspan adapter, what do I do?

Use the Keyspan Serial Assistant to identify the correct serial COM-ports and change the buffer size from 16 bytes (default) to 56 bytes. And don't forget to update the settings.


 

5.          SAMBA 200 SOFTWARE PACKAGE

5.1.       Why doesn't the green "Data lost" indicator (lower left corner) light up in the Samba 200 Software /Data Collection module, when the Samba 200 unit is set to a sampling frequency higher than 625Hz?

The Samba 200 units never send data faster than 800Hz on the USB port. At 1250Hz and above only part of the data is being sent to the USB port. All data is however sent via the Analog port.

The "Data lost" indicator only lights up when data is being lost in the computer's serial buffer. This will only happen if the computer is too slow or is too busy running another program.

 



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