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HIC-2500 Product Information  


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Front View of the HIC-2500 Bioelectric Impedance Cardiograph System


The HIC model 2500 is a noninvasive instrument for detecting and monitoring bioelectric impedance cardiography signals from human subjects. The HIC series instruments produced by Bio-Impedance Technology, Inc. use modern state-of-the-art electronic materials and techniques. The signal and operational specifications are similar to the "older generation" Minnesota Impedance Cardiograph (Model 304B) instrument, except that the subject excitation current has been significantly reduced ( 500A rms) and the Zo output signal is 0.42v/10 ohms. The reduced Zo output voltage results from the instrument's circuitry operating at a greatly reduced voltage of +/- 5 volts. However, the Zo signal output level is more that adequate for any type of external computer signal processing or strip chart application. The output signals and connectors are completely compatible with the COP-WIN cardiac output acquisition and analysis software system also available from Bio-Impedance Technology, Inc.    In all HIC models the electronics are housed in a rugged, but attractive, compact steel enclosure with easy-to-use pushbutton controls and embedded computer-driven display. The color of the instrument is light blue with almond- colored front and rear panels. The HIC's embedded computer monitors and controls the various functions and operational modes of the instrument. The user can adjust the instrument's sensitivity for the ECG  in order to accommodate the differences in these signals between subjects.

The instrument comes with a 10 ft. 4-lead shielded impedance cable assembly terminated with 4 alligator clips at one end (for use with band electrodes) and a 9-pin connector on the other end which mates with the HIC:

HIC-2500(with power supply and  impedance cable)

An optional separate external ECG cable with three plug-in leads can also be ordered for use with the HIC in order to achieve greater ECG electrode placement flexibility (see accessories section). The ECG cable consists of a single cable with a 5-pin circular connector on one end, and a receptacle, on the other end, which accepts the three ECG electrode lead wires with clips for use with disposable electrodes.

ECG Cable
Optional ECG Cable Assembly

All signal input and control circuitry which handles the electrode signals is optically and/or transformer isolated from the rest of the electronic circuitry powered by the system's power supply for subject/patient safety. There is no direct connection of the subject electrodes to either the enclosure or the power supply of the instrument.


Sample HIC Waveform
Example of digitized ECG and dZ/dt waveforms from the HIC


  • Modern electronic circuitry housed in a rugged compact well-shielded steel enclosure.
  • External table-top medical-grade UL and CSA approved power supply for reduced 60 Hz noise in the impedance signals.
  • Low-power and low-voltage (+/- 5 volts) operation.
  • Embedded microcomputer that monitors impedance signals, controls instrument operation, and displays status information. Bright blue-green gas-discharge display indicating mode of operation and impedance signal values.
  • Complete electrical isolation of all electrode signals by employing optical and transformer isolation for subject/patient safety.
  • Manually-adjustable sensitivity ECG gain control, located on the front-panel.
  • Push-button operation for power on/off, internal/external ECG electrode selection, and modes of operation selection. Easy pushbutton selection of all operational modes.
  • Now includes HIC-FLT3-5P Post Filter Module for use in electrically noisy environments!



All of the instrument's controls are located on the front panel of the HIC-2500. A latching pushbutton switchs is use for power on/off control and selection of either internal or external ECG electrodes respectively. The internal ECG signal position uses the impedance electrodes to detect the ECG signal, while the external position connects an optional external ECG electrode cable assembly to the HIC's isolated ECG circuitry.

Additionally, there is a row of four momentary pushbutton switches that permit the user to select the different modes of operation in the HIC-2500. These pushbuttons are monitored by the embedded computer, and when pressed by the operator, cause the computer to setup the instrument's circuitry for the desired operation and functions. 


All the HIC impedance cardiographs have  input connectors located on the front panel, one for the impedance electrode cable assembly, one for an external ECG electrode cable connection. The impedance electrode connector is a 9-pin (DB-9) female connector with jack-screw receptacles for securing the mating impedance electrode cable connector. Four of the nine pins are used for the connections of the four impedance electrodes (2 current and 2 voltage). The remaining five pins are used for electrode shield-drive connections.The ECG front-panel connector is a circular 5-pin connector that is used when a separate external ECG electrode cable (optional accessory) is employed. 

The HIC-2500 impedance cardiograph rear panel contain 3 BNC female connectors corresponding to each of the 3 output signals (ECG, Zo, and dZ/dt) produced by the instrument. There is also a 5-pin DIN female power connector located on the lower right corner of the rear panel for connection of the instrument's external medical-grade international power supply.  


The HIC-2500 impedance cardiograph is primarily intended for impedance cardiography applications involving the assessment of stroke volume and cardiac output and associated cardiac performance parameters. It is designed for use with human subjects where the total thoracic bioelectric impedance at 100 KHz falls within the range or 5 ohms to 100 ohms. The instrument can also be used for other monitoring applications involving the use of impedance cardiograph methodology, such as the monitoring of pulmonary congestion, pulmonary edema, pleural effusion, and numerous indices related to cardiac dynamics.


    Instrument Dimensions 9.25"W x 4.0"H x 7.5"D
    LCD  Display Area 70.8 mm x 11.5 mm
    Circuitry Operating Voltage +/- 5 Volts
    A.C. Power Requirements for Power Supply 120 VAC 60 Hz @ 0.23 A Standard USA 3-prong outlet
    (international versions available)
    Power Consumption  less than 23.0 W.
    Constant Current Waveform Sine Wave
    Constant Current Oscillator Frequency 100 Khz
    Isolated Subject Excitation Current 500A rms
    Subject Isolation Voltage 3 KV
    Imped. Detector Amplifier diff. input impedance 1 Meg. 
    Zo Signal Linear Range 1 to 100 ohms
    Zo Signal Output Voltage Resolution0.4 V/10 ohms (.04v/Ohm)
    dZ/dt Signal Output Resolution0.4 v/ohm/sec.
    ECG Sensitivity 500 uV for Full Scale Out
    ECG Maximum Output 5.0 Volts peak
    Output Impedance (all BNC outputs)100 ohms


The HIC-2500 Bioelectric Impedance Cardiograph is warranted by Bio-Impedance Technology, Inc. (BIT) for a period of one year from the date of delivery for both parts and labor. The customer must first contact BIT regarding any problems or service needs, and to arrange for an RMA number if return is required. The customer must pay the shipping to BIT for repair during the warranty period. BIT will pay the cost of return shipping during the warranty period. Following the warranty period, the customer must pay for both the parts and labor and the shipping in both directions.

The HIC-2500 employs high-quality electronic components and rugged materials, and are designed to give long, reliable service.

    Separate External 3-Electrode ECG Cable Assembly (see photo above): Part No. HIC2000ECG3

    Extra 10 ft. 4-Lead Impedance Electrode Cable Assembly: Part No. HIC2000ZC10

    Set of 3, 6 ft. BNC to BNC output cables: Part No. HIC2500BNC6

For pricing and ordering information contact:
    Bio-Impedance Technology, Inc.
    88 VilCom Circle/ Suite 165
    Chapel Hill, NC  27514
    Phone: (919) 960-7799

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0-2010  Bio-Impedance Technology   Last Update September 2, 2010
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