Hatteras Instruments MC4000 Blood Pressure Analysis System Technical Synopsis

Transcription

1 Model MC4000 Hatteras Instruments MC4000 Blood Pressure Analysis System Technical Synopsis Introduction The MC4000 Blood Pressure Analysis System combines the latest in blood pressure analysis technology with the efficiency of multi-channel operation. Measurement results include Pulse Rate, Systolic, Diastolic, and MAP. The system is expandable by easily adding a second specimen platform for use with either mice or rats. All measurement results correlate precisely with intra-arterial methods and the data is automatically saved in a database. The data can also be exported to any common spreadsheet application. The MC4000 is accurate, efficient and time saving. System Features The MC4000 incorporates custom algorithms for measuring diastolic blood pressure independently of systolic pressure. Other systems calculate the diastolic pressure based on the systolic measurement. The parameter settings for determining diastolic and systolic BP are adjustable by the user. This feature allows the user to make adjustments to the system settings for correlation with simultaneous intra-arterial measurements. Measurement waveform data collected by the MC4000 is automatically saved and can be retrieved by the user at any time for additional analysis. Measurement results are also automatically saved and in addition to being incorporated into the database they can be exported to any common spreadsheet software program. Another function of the software supplied with the system allows the user to retrieve a stored measurement and extract the waveform data in.csv format with the time and voltage levels reported as text values. This feature can be particularly valuable for researchers interested in conducting further signal analysis to determine cardiovascular function. The following MC4000 parameters are user adjustable: Researcher ID Specimen ID Experiment ID Preliminary Cycles Measurement Cycles Minimum Pulse Amplitude Number of Consecutive Peaks Ignore Peaks Smaller Than Maximum Pressure Pulse Timeout Measurement Timeout Time between Measurements Systolic Threshold Diastolic Threshold Systolic Signal Criterion Diastolic Signal Criterion Group Measurements Measurement Groups Time Between Groups Calibrate System Pressure Test Platform Temperature. The MC4000 can be expanded for dual platform operation by adding another specimen platform. The platforms are connected to the power unit through a molded DB15 cable. Connection of the platform to a portable or desktop computer is through a standard RS232 serial port with a null-modem cable. 1

2 Highlights of System Features Custom Algorithms designed specifically for non-invasive measurements. Fast and Accurate measurements for pulse, diastolic, systolic and MAP. Precise Correlation with intra-arterial measurements. Waveform Data Conversion for determining cardiovascular function. MC4000 Analysis Software for total automation of the system. Adjustable System Parameters for customizing experiments. Dual Specimen Platform Operation for increased capability. MC4000 Components The MC4000 Blood Pressure Analysis System includes: Custom Blood Pressure Analysis Software Power/Utility Unit Multi-channel Specimen Platform with specimen holders Airline, power cables, interconnect cables Accessory Kit (contains tail-cuff balloons, tool for making end caps, etc.) Operators Manual The following is optional equipment: Additional specimen platform Training Platform Power/Utility Unit: The MC4000 Power/Utility unit supplies the specimen platforms with control power and air. The power unit can supply control power to two specimen platforms simultaneously and air to the platforms in alternating fashion. Control solenoids located in the power unit divert air flow to the appropriate air outlet depending on which specimen platform is active. The unit has an on/off switch built into the socket for accepting the power cable. A front panel mounted LED indicating light alerts the user to a power on condition. An externally accessible fuse provides fault protection for the equipment. Power and control signals between the specimen platform and power/utility unit are supplied through a molded DB15 style cable. Specimen Platform: The specimen platform is available for either mice or rats. Included with the platform are animal holders for containing the specimen during measurements. The main components of the specimen platform are the sensor assembly, LED assembly, tail-cuff, and electronics. The sensor assembly houses a very sensitive photodiode integrated circuit for sensing the blood flow through the animals tail. This is an important feature of the MC4000. Other systems use old technology photocells that are noisy and prone to failure. The LED assembly contains a bright red LED for illuminating the animals tail so that the blood pulse may be detected. The tail-cuff is constructed of brass with PTFE resin end caps for securing the tail-cuff bladder. The bladder is a common latex balloon. The specimen platform electronics incorporates a 12 bit A/d converter that gives signal resolution of +/- 2,048 values for each sample. Most other systems use 8 bit A/D conversion allowing only +/-128 values which results in reduced accuracy. The signal sample rate is 200 samples per second. The analog to digital conversion takes place at the signal source. 2

3 This eliminates the possibility of additional noise problems that can occur when transferring the signal over lengthy cables before being digitized. The pressure measurement is also made at the source as a pressure transducer is built into the specimen platform electronics. Each channel has it s own electronics and it s own pressure transducer. This feature eliminates the problems with pressure gradients that can occur when only one pressure transducer is used through a common pressure header for determining all pressure readings. The specimen platform incorporates a flexible strip heater attached to the underside of the top of the platform at each channel location for maintaining a comfortable environment for the animal. The temperature is user settable and precisely maintained by the internal microprocessor by using a precision temperature sensor for feedback control. Other systems use only a variable transformer with a dial setting that is inaccurate and potentially harmful to the animals by allowing the platform to overheat. Heating the animal is not necessary with the MC4000. The ability to keep the platform from being cold thus ensuring the comfort of the animal is the only reason that the heater is used. Computer control of the specimen platform is maintained by the analysis software through a standard RS232 serial port on any standard portable or desktop computer. Highlights of System Components Power/Utility Unit for handling power and air for dual specimen platforms. RS232 Serial Port for communications with a portable or desktop computer. Specimen Platform for mice or rats. 12 Bit A/D Conversion for superior signal resolution. Photodiode Integrated Circuitry for sensing pulse. Temperature Regulation through microprocessor control. Specially Designed Holders for containing untrained animals. Special V Grooved Sensor Assembly to help prevent movement of tail. Fast Setup of system by connecting power cable, serial cable, and airline. MC4000 System Operation Operation of the MC4000 Blood Pressure Analysis System is completely automatic. Once the animals are placed on the specimen platform, clicking on the Go button on the analysis system toolbar initiates the measurement process. The system automatically detects a pulse, inflates the tail-cuff and measures the diastolic and systolic pressure and calculates the mean arterial pressure (MAP). Each measurement is part of a measurement set. When the measurement set is complete, the system calculates the mean and standard deviation for the pulse, diastolic, systolic and MAP. A measurement set can consist of up to 50 measurements. In addition, the user has the option of making groups of measurements during a measurement session. Up to 25 measurement sets can be obtained during a group session and the time between measurement sets can be adjusted from 1 to 30 minutes. This feature is particularly useful for determining the effects of dosing over an extended period of time. Once the measurement process is complete, the measurement results are automatically displayed. While viewing the results, the data can be polled to see the individual measurements that were obtained to make the results report. Current measurement results can be displayed at any time by the software until another analysis is conducted. 3

4 MC4000 Analysis Software for Windows The MC4000 Analysis Software is especially designed to make blood pressure measurements on rodents easy and efficient. All system functions are easily accessible through the standard Windows point and click format. Setup Initialization parameters for each experiment can be customized and saved through the Analysis Parameters window so that experiments can be easily repeated. The system default values for the analysis parameters can be restored at any time by clicking on the Reset button. The platform temperature setting can be displayed as either Fahrenheit or Centigrade. Getting Started An experiment begins by registering the specimens in the Specimen Registration window. When a specimen is entered, it is automatically stored in the database. An existing specimen can be selected from the database through the drop down menu for each specimen location. Once all specimens are entered, the analysis is begun by clicking on the Go button. Once the analysis is complete, all experiment data, including the signal waveform, is saved under the experiment ID. The data is also stamped with the date and time that the analysis was conducted. 4

5 Specimen ID s can also be entered into the database through the Specimen Log. When entering data in the specimen log, the user establishes the relationships of the specimen to the experiment, the investigator and the specimen type. The Specimen Log is also useful for viewing the overall statistics for a particular specimen. By clicking the Show Data button, on the Specimen Log all accumulated data for a specimen can be viewed in the Specimen Data Summary window. 5

6 Exporting Results Exporting results to a common spread sheet is easy. From the Specimen Data Summary window, all measurement data for a specimen can be exported in a comma separated value format (*.csv) for use in any standard spreadsheet software. To export the data for a specimen, Select File and then select Export CSV. The measurement data is automatically converted and can be easily viewed as a spreadsheet. Maintaining Experiments Any number of experiments can be maintained by the MC4000 analysis software. New experiments can be entered in the Experiment Log. When establishing a new experiment, the experiment type is identified, as well as, the research models that are applicable to the experiment. Experiments can be created at any time in the database, however, an experiment cannot be removed unless all stored measurement data associated with the experiment is deleted in a separate process. 6

7 Every time an analysis is conducted for a particular experiment, the software creates an analysis session that is saved in the Session Log. All measurement results and individual data can be retrieved by highlighting a particular session from the session log and clicking Open Session. When the session is opened, the Analysis Results for that particular session are displayed. Highlighting the results of an individual specimen and clicking on the Details button allows the user to retrieve all measurement data associated with that specimen for the selected measurement set. When the Specimen Data table is open, individual measurements that are obviously erroneous can be rejected by selecting the measurement and then clicking on the Reject button. The results are then recalculated for the mean and standard deviation for that measurement set. The data for that measurement is maintained in the database and can be reinstated at any time. 7

8 Viewing Waveforms While obtaining measurements, the signal waveform is displayed in real-time. The data is scrolled on the display screen rather than repeatedly redrawn as is standard with other systems. When the waveform data is viewed after saving, the amplitude and time axis can be scaled for an up close view of any portion of the waveform. In addition, the waveform graph can be copied and pasted into common software such as Word for Windows, PowerPoint or many others. This feature allows a researcher to produce efficient and professional looking reports. Closing Comments As a researcher your time is very valuable. Efficient use of your time is important and so are the results of your work. The Hatteras Instruments MC4000 Blood Pressure Analysis System can ensure that your time is well spent and that the quality of your work is exceptional. Blood pressure measurements are completed in record time and with extremely accurate results that correlate precisely with intra-arterial values. With the MC4000: Large populations of animals can be easily evaluated. Analysis time in the lab is greatly reduced while accuracy is improved. Record keeping and reporting is simplified by the database software. Your time cannot be better spent and neither can your money. The MC4000 is the fastest, most accurate and most economical system available. Give us a call and get started on your way to BP measurement success. After all, with the MC4000 Blood Pressure Analysis System for use with rodents..it s as easy as it gets! Hatteras Instruments, Incorporated 105 Southbank Drive Cary, North Carolina PH: FX: