the LE 5001 is a microprocessor-based instrument, specifically designed to take non-invasive blood pressure readings on experimental animals (mice, rats or dogs).

Blood pressure measurements made with the LE5001 system is based on the sphygmomanometric technique.  The unit uses a pressure cuff that occludes the passage of blood in the animal's tail combined with a transducer which monitors the heart rate of the animal.  Typically this cuff and transducer are placed over the animal's tail to record from the caudal artery.

The LE 5001 detects teh systolic or maximum pressure (SP) values, diastolic or minimum pressure (DP) values and the mean.  The mean is calculated as:

MP=DP + 0.33(SP + DP)¹

Additionally, heart rate (HR) is also picked up by the transducer. Its value is displayed continuously, and then stored along with the corresponding systolic, diastolic and mean pressure values.  When using Sedacom software (separate purchase), all measurement data can be sent to a PC using the RS-232 communication.

Equipment Description

• Cuff: Pneumatic connection for the tail cuff.
• Transducer: DIN 6 connector used to connect pulse transducer.
• Beat: Red colored LED that flashes at the same frequency that the heart beats when transducer is placed on the animal’s tail.
• Gain: Potentiometer used to adjust the signal coming from the transducer.
• Display: 4 ROW, 20 column display. It is used to display the result of measurements, and several messages depending on the mode the instrument is in.
• Start: Button used to start the measurement when the signal is appropriate. If there is no signal or the signal or the signal level is lower than the necessary level (INSUFFICIENT LEVEL), or if there is too much signal (PULSE LEVEL HIGH) the start button will not begin a run. If the pulse level is correct (PULSE LEVEL READY) the start button will initiate a run.
• Stop: Button used to cancel a currently-running measurement.

• Remote:35mm mono jack plug for foot switch. It has the same function as the START button on the front panel.
• Cuff Pressure: BNC connector for the analog output of the pressure waveform. The conversion factor is 0V = 0mmHg, 500mV=350mmHg so you can connect it to your desired data acquisition system.
• Pulse Wave: BNC connector for analog output of the heart rate. It goes from + There is not a conversion factor because the GAIN control on the front panel change the level of the signal. It can be connected to a data recorder system.
• Up/Down: Selectro of mode of systolic pressure detection. Results obtain in both modes are different.
  • Up: Systolic pressure is detected when pump inflates. This mode is for DOG.
  • Down: Systolic pressure is detected when pump deflates through the exhaust valve. This mode is for RAT and MOUSE.
• DOG/RAT/MOUSE: 3-position filter. It selects the window of frequencies that the instrument will detect for different animals.
  • DOG: From 48BPM to 840BPM
  • RAT: From 270BPM to 960BPM
  • MOUSE: From 360BPM to 1020BPM
• RS-232: DB9 femal connector used to connect LE5001 to computer serial port. It is used with the Sedacom software.
• Power: Power switch and fuse holder.

Operating Principle

Waveforms of Figure 12 have been obtained by connecting CUFF PRESSURE and PULSE WAVE analog outputs to a data logger.

1. As soon as the “START” button is pressed the air pump starts and pressure in the sleeve starts to increase (see Figure 12). At a certain pressure value, the amplitude of the pulse wave starts to fall and will eventually reach zero (point 1 on Figure 12). There is a brief pressure increase and the sleeve pressure will deflate. Point 1 is the systolic pressure taken in UP mode.
2. The pressure value in the sleeve at the time when the blood pulses reappear (point 2) is equivalent to the systolic pressure in DOWN mode.
3. The pressure in the sleeve falls until it reaches the diastolic pressure, which is the pressure value corresponding to the instant when the pulse wave recovers its initial value (point 3). The air in the sleeve is immediately release until the pressure is 0. And in point 4 the instrument is ready to take another pressure measurement.

For additional information please see attached user's manual.

You may also be interested in setting up communication with a computer.  Please check out the Sedacom user's manual and article here.