Experimental devices for measurement of biomedical signals

The MediSIG team mainly designs and constructs experimental devices for the measuring and data processing of biological signals. We concentrate on devices which are not available or do not yet have the desired parameters on the commercial market.

Examples of devices:


  • The Detector of Vagus Nerve Stimulation. The device for detection of activity of vagus nerve stimulation is intended for independent monitoring of implanted vagus nerve stimulation. It measures the electrical potential from the patient's neck, processes it and detects activity of the stimulator.
  • RECO – device for respiration control. LEDs bargraph for pacing of breathing. It is used for controlled excitation of the cardiovascular system. It enables setting of pacing frequency 1–39 min-1, various modulations – ramp and sinus with depth of 25–100%.
  • The Strain Gauge Plethysmograph. The strain gauge plethysmograph, which can be used for several measurement techniques in medicine, essentially measures the changes in human limb volume directly. However, it can be also used in indirect measurement for evaluating limb blood flow, blood pressure, digital volume pulses, for measuring circumferential changes of exposed arteries and breathing. Our device can measure up to 10 channels simultaneously.
  • Experimental Syringe Mixing Pump For Ultrasound Contrast Agents. The pump enables continual infusion and bolus while mixing the contents of the syringe. The control of the pump is ensured by microcontrollers and is fully programmable by the user. The device is battery operated and has a robust mechanical construction. Technical parameters: syringe 10 ml and 20 ml type, infusion flow rate 0.3..4.0 ml/min, bolus flow rate 0 .3..4.0 ml/min, bolus time max. 60 seconds, mixing rate 30 cycles/min ±180º, minimum continuous working time 4.5 hours per one full battery charge.
  • Multi-Channel Impedance Cardiography. Impedance cardiography is a method based on measuring changes of thorax electrical impedance. From the changes of thorax electrical impedance it is possible to calculate important parameters of the cardiovascular system, like stroke volume or cardiac output. The monitor makes it possible to measure small changes of impedance on separate parts of the human body and to evaluate blood flow, particularly the propagation of pulse waves in the whole body. It also makes it possible to analyze vessel compliance. Commercial devices are equipped with one or two channels and the simultaneous survey of blood flow in many parts of the body is not possible. The main advantages of the monitor are the high quality of the impedance signal, coherent impedance detection in all channels, measurement of impedance phase changes and the option of stand-alone measurement without computer and supply voltage.
    • The multi-channel device consists of two-channel units. Each unit is comprised of two current generators and two voltage detectors. The device makes it possible to interconnect up to 9 units with clock and synchronization signals and to build an 18-channel device. The unit stores the impedance signal on a SD/SDHC memory card, transfers it in real-time to the PC through the USB port, and possibly represents it on analogue output.
    • The parameters of the unit are:
      • measurement frequency 30 to 70 kHz or 1 kHz to 1 MHz (optional)
      • measurement current 1 mA, adjustable
      • clock frequency of direct digital synthesis, AD converter and synchronous detector 60 MHz
      • overall dynamic range of 127 dBc/√Hz
      • phase resolution better than 0.001 degree
      • output data format 16-bit complex envelope at 10 kHz sampling
      • operating time 3 hours
  • Device for microneurography. The dedicated preamplifier and amplifier with signal filtering and detection are used for monitoring the electrical activity in the nerves. The amplifies and processed signals obtained by means of microelectrodes (special insulated needle with conductive tip) directly from the desired part of nerves.
  • ECG 12. Experimental 12 lead electrocardiograph amplifier with broad pass band up to 500 Hz. This device is intended to be used for special ECG measurements that cannot be performed with a standard commercial device. The amplifier is battery operated and is equipped with the 12 analog outputs, 1 monitor output and USB data acquisition unit. Figure PowerPoint 6


MediSIG has also designed and constructed a wide range of various devices for measuring biological signals like electrical amplifiers and filters, pressure measurement devices for the monitoring of breathing, pressure monitoring in lungs and esophagus, devices for phonocardiography – special microphones with dedicated amplifiers, spirometers, etc. The majority of these devices are battery operated to enable use during measurements of weak biological signals, where using AC mains operated devices cause unacceptable artifacts in the measured signal.