Heka Data Acquisition
With PATCHMASTER, experimental design, performance, and analysis are more flexible allowing a high degree of automation and providing access to experimental protocols that are otherwise unattainable.
- Operates on Windows and Macintosh platforms
- Full software control of HEKA patch clamp amplifiers
- Calibrates and tests the patch clamp amplifiers of the EPC 9 and EPC 10 Series
- Features adaptive feedback control and global variables
- Suitable for research and industry
Multi-channel data acquisition software
PATCHMASTER offers features meeting the highest standards of modern electrophysiology. This software, running on PC-based and Macintosh computers, harbors all the comfortable functions of PULSE, but offers a variety of novel procedures aimed to make electrophysiological research even more versatile and efficient.
With PATCHMASTER, experimental design, performance, and analysis become much more flexible, giving rise to a high degree of automation and providing access to experimental protocols that were thus far unattainable with commercial software.
Major innovations of the PATCHMASTER program
PATCHMASTER provides up to 8(16) A/D input channels and 4(8) D/A stimulation channels that can be sampled at high speed. In addition, the number of channels is no longer limited to the number of available AD/DA channels.
Acquired data traces can be processed online by mathe-matical functions to compile additional derived data traces.
Extended trigger possibilities Up to 16 trigger outputs can be defined like a stimulation channel.
Individual timing for different channels
Channels can have completely independent timing and pulse patterns. This allows easy setup of complex stimulation patterns for multiple channels.
For all channels, individual data compression factors can be specified to reduce the amount of stored data.
Global parameters for sequence editing
For definition of a pulse generator sequence, global parameters can be used, e.g. to define the duration of a segment or the amplitude of a stimulation. If these parameters are used in multiple segments or sequences, all locations can be edited by changing a single global parameter.
Multiple Telegraphing Amplifiers
More than one telegraphing amplifier can be supported by using multiple lookup tables.
Simultaneous capacitance measurements on multiple headstages of a patch clamp amplifier (EPC 10 Double, Triple, and Quadro) and On-Cell capacitance measurements at high sine wave frequencies are now possible.
Extended Online Analysis
An arbitrary number of online functions and methods can be defined and saved. Even complex calculations are now possible. Online analysis methods can be directly linked to acquisition sequences.
Two Online Analysis Windows
Up to 12 graphs can be displayed in two different Online Analysis windows. For example, one window can be used to display series derived analyses such as IVs, and the other for display of time lapse data.
Multi-wavelength stimulation for multiple fluorescence excitation systems and analysis for multiple fluorescence signals is now supported.
Protocol Editor for automation
A complete experiment can be automated and standardized, including incorporation of feedback from online analysis or external devices.
PATCHMASTER - a program for patch clamp, 2-electrode voltage clamp experiments, and general data acquisition
Full support of HEKA's patch clamp amplifiers EPC 7, EPC 8, EPC 9, and the EPC 10. The novel program design of PATCHMASTER is perfectly suited for the operation of multi-channel stimulation as used for patch clamp amplifiers with multiple headstages (e.g. EPC 9 Double / Triple, EPC 10 Double / Triple / Quadro).
Additionally, PATCHMASTER can be run with any other patch clamp amplifier, electrophysiological current clamp or voltage clamp devices (e.g. two-electrode voltage clamps used for research on Xenopus oocytes) or a standalone data acquisition interface for general stimulation/data acquisition purposes.
A powerful software for acquisition and analysis of electrophysiological data
The virtual front panel of EPC 10 patch clamp amplifier
Flexible Pulse Generator configures stimulation and acquisition
PATCHMASTER Protocol Editor
The protocol editor is a completely new feature of PATCHMASTER. With this editor, complex experimental procedures can be designed, stored, and executed. This tool greatly increases the versatility of PATCHMASTER and provides means for automatic experiment performance.
The principal idea of the protocol editor is to generate a list of events or tasks, which then are executed automatically. Various functions such as REPEAT LOOPs, input queries, or conditional statements allow for the generation of complex interactive processes.
Online Analysis - Powerful on- and offline data processing
An arbitrary number of analyses can be performed on newly acquired or replayed data. Directly analyzed data or derivative data, obtained by application of mathematical functions on the analysis results, are then displayed in a versatile manner in several graphs placed in two independent windows. This allows for separation of different data types, for example, current-voltage plots are shown separately from time-based data (e.g. chart recording).
Analysis templates can be predefined and stored. Thus, several analysis procedures are available such that various incoming data types can be analyzed without extra editing just by switching between analysis procedures. A direct link between Pulse Generator sequences and analysis procedures provides definition of data acquisition and analysis prior to the experiment
Implemented Lock In modes
In 1982 Neher and Marty introduced the Lock In amplifier into the patch clamp field for Cm measurements using a single sine wave frequency. For determining the appropriate phase setting, they used dithering or the compensation network while changing the phase for obtaining a maximum signal for Cm. This method is appropriate under stationary conditions for measurements of changes in Cm. We refer to this method as the "piecewise-linear" method. Since the piecewise-linear method is prone to errors (see Gillis in B.Sakmann & E.Neher Eds. Single Channel Recording 2nd Edition, Plenum Press) Lindau and Neher introduced in 1988 a method using the real and imaginary part of the admittance plus the DC-conductance to determine the absolute values of Cm, membrane conductance, and access resistance. We refer to this method as the "Sine+DC" method.
The best resolution of small changes in Cm are achieved in the cell-attached patch clamp configuration. Since a different equivalent circuit applies in this recording mode, a third method, referred to as the "On-Cell" method, has been implemented.
Different modes of calibration
Digital control of the filter settings, gain and compensation networks that are featured with the EPC 9 and EPC 10 patch clamp amplifiers directly benefit the calculated calibration mode. Phase shifts introduced by the measuring system can be calculated and the corrected phase of the Lock In amplifier, which is dependent upon the recording conditions, can be set automatically.
A measured calibration method allows the phase and attenuation of the recording system to be determined by analysis of the admittance of a pure resistor at the amplifiers input.
In case other procedures for determination of the phase and attenuation of the measuring system are used, a Manual calibration mode allows the phase and attenuation of the software Lock In to be directly set by the user.
Lowest noise recordings
In the Sine+DC mode, automatic CSlow compensation cancels the bulk of the membrane capacitance and thus allows to be operated the patch clamp amplifier in the high gain (low noise) range during Lock In measurements. In the On-Cell mode signal to noise ratios can be increased by using a higher sine wave frequency (typically 20 kHz) to resolve small changes in Cm (< 100 aF) due to fusion of single vesicles.
Simultaneous measurements from multiple patch clamp amplifiers
In combination with EPC 9 or EPC 10 Multi-Patch amplifiers, simultaneous Cm measurements on multiple amplifiers are supported by our software Lock In. Online equivalent circuit parameter calculation Software Lock In provides online calculation of equivalent circuit parameters and offline recalculation. Customer specific calculations can be done online by using the virtual trace feature of the pulse generator in PatchMaster.
16-bit Multi-Channel Data Acquisition System
The LIH 8+8 is a high resolution, low-noise scientific data acquisition system that utilizes the latest USB 2.0 and high speed processing technologies. The LIH 8+8 provides expandability and versatility that will satisfy both current and future needs. With its USB 2.0 interface, the LIH 8+8 can easily be connected to a laptop computer without the need for a peripheral PCI card. The analog input and output channels are isolated from the digital lines that communicate with the computer. Each analog channel has it's own separate ground patch and the digital section has a completely different ground. The result is complete isolation of the acquisition side from the computer side with full 16 bit capability and low noise.
The LIH 8+8 system is comprised of a USB 2.0 computer interface and one or multiple analog rack units interconnected by CAT5 cables. The USB 2.0 provides superb performance, while the CAT5 cables allow multiple racks to be synchronised during data acquisition. A single external trigger is capable of starting multiple racks simultaneously.
The number of racks supported by one computer is only limited by the number of USB connectors available in that computer. Multiple racks installed in the same computer or in separate computers can be synchronised.
Input and Output Channels
The LIH 8+8 provides eight analog differential inputs, four analog differential outputs via BNC connectors at the front panel. Sixteen digital inputs and sixteen digital outputs are provided on one connector at the rear panel. In parallel, 4 digital outputs and 4 digital inputs are provided via BNC connectors on the front panel. All channels are sampled synchronously.
The LIH 8+8 has a sound generator built-in. A sound connector at the rear panel allows connection of an active speaker or a headset.
The LIH 8+8 features cophasic acquisition of the two most relevant signals; ex. the current and voltage trace of the amplifier. The acquisition board samples these two AD-converters in parallel with no time delay. In the schematic below the two AD channels exhibiting cophasic acquisition are AD-0 and AD-1.
The eight analog differential input channels are separated into two banks of four. One bank is comprised of AD channels 0,2,4 and 6 and the other bank is comprised of AD channels 1,3,5 and 7. Each bank is multiplexed into one 16-bit 200 kHz A/D converter. Both A/D converters sample simultaneously and synchronously at the maximum conversion rate resulting in a total throughput of 400 kHz. This unique arrangement allows pairs of channels to be digitized without phase-shift (ex; AD-0 & AD-1). In other words, there is no time delay between two DA-channels firing and the time of acquisition of two cophasic AD-channels. If the bandwidth of the experiment calls for lower sampling rates, the interface adjusts the rate accordingly.
The LIH 8+8 can be controlled with PATCHMASTER, POTMASTER or CHARTMASTER* software on either a Windows (2000/XP and VISTA) or Mac platform. TIDA software can also be used to control the LIH 8+8 on a Windows (2000/XP) platform. In situations where the LIH 8+8 is being integrated in a self-written data acquisition software on Windows, HEKA provides an EPC DLL (dynamic link library).
* CHARTMASTER is identical to PATCHMASTER but does not control the HEKA Patch clamp amplifier.
LIH 8+8 Specifications
- Eight 16-bit analog inputs
- Two A/D converters, each multiplexed into 4 inputs
- 400 kHz aggregate, max. 200 kHz per A/D converter
- Input type: differential
- Input Range: ±10.24 V
- Differential non-linearity: ±0.002% of FSR
- Drift: ±2 ppm/°C
- Input impedance: 1 MΩ
- Signal to noise ratio: 86 dB, DC-160 kHz, <1mV PP
- Sixteen rear digital inputs
- 4 of the 16 digital inputs can be accessed on the front panel via BNC
- 3.3 and 5V logic compatible
- One isolated hardware trigger input (on either positive or negative edge transition)
- 3.3 and 5V logic compatible
- Single BNC on rear panel
- One 3.5 mm output receptacle on rear panel
- Frequency range of 0.2-4.0 kHz
- Digital I/O connector for EPC 8 or TIB 14S
- Two CAT5 connectors for slave/master operation of multiple LIH 8+8
- 47.5 x 4.4 x 31.1 cm
- Weight: 3.6 kg
- Mounts in 19" rack, mounting hardware included
- Operates on 90-250 VAC, 50/60 Hz
- USB 2.0 cable
- USB 2.0
- All 'clamp' amplifiers are supported. Amplifier windows for all EPC 9 and EPC 10 amplifier types and telegraphing amplifiers are available.
- Automatic test and calibration routines for all HEKA EPC 9 and EPC 10 amplifiers are provided.
- Up to 16 input channels
- Pulsed and continuous acquisition mode
- Automatic data compression (different sample rates for different channels)
- Virtual trace for mathematical online processing of acquired channels
- For each acquisition channel a break criteria can be defined. An Automatic Break will stop the acquisition whenever one of break criteria becomes true.
- Variable data format for storage (INTEGER, REAL, LONGREAL)
- Leak pulses (p/n correction) supported for all output channels (important for multi-headstage clamps)
- Various leak pulse storage modes: none, average, all (important for offline leak correction)
- Up to 4(8) stimulation channels
- Stimulation with an arbitrary number of pulse segments
- Segment types: constant, ramp, sine, square, non-stored
- Various increment modes for segment amplitude and duration
- Segment parameters assignable by global variables (pgf-parameters)
- Display of up to 20 different traces
- Individual display scaling and visual appearance for all traces
- Individual digital filter settings for all traces
- Various different labeling modes (e.g. Grids+Labels, Grids+Values, Labels only)
- Dimmed overlay
- Absolute and relative measure-ments with mouse click
- Read individual data points with scan function
- Arbitrary number of user defined online methods
- More than 40 predefined analysis functions
- Mathematical standard operations allow setup of user defined analysis functions
- Trace operation functions
- Two online windows with up to 12 graphs for graphical representation of analysis results.
- Link of analysis methods to different acquisition sequences
- Four independent trace buffers are available for basic arithmetic operations on the level of a trace (add, subtract, accumulate, deaccumulate)
- Buffer traces can be shown as a reference trace in the oscilloscope window.
- Direct access to set digital outputs, analog outputs, input parameters and to send serial commands.
- Monitoring of digital inputs, analog inputs and input parameter values.
Standardization and Automation
- Macros: A series of user defined actions can be recorded and stored as a macro.
- Protocol Editor: The Protocol Editor allows standardization and automation of complete experimental procedures. Within the procedure, the system can get feedback from external inputs, amplifier controls, online analysis results or user inputs and experimental parameters can be adjusted. A protocol can be started/called from another protocol.
- Batch Control: The complete PATCHMASTER acquisition system can be controlled from another application. The user can write their own application with a custom tailored user interface but still benefit from the advanced features of the HEKA system.
- Acquired data are organized and stored in a data tree. Multiple data packages are usually stored in one data file and organized in levels of Groups/Experiments/Series/ Sweeps and Traces to allow easy review, selection and analysis of all data in that data file.
- Due to the complete software control, a complete set of parameters describing the state of the amplifier and other recording conditions is stored with the data. This allows detailed reconstruction of the experiment for exact analysis at later times.
- Export and printout of raw data traces or online analysis results
- Supported formats: ASCII, IGOR PRO, MathLab and WMF
- High level layout features of IGOR PRO supported.
PATCHMASTER features a software Lock-In amplifier for time resolved measurements of membrane capacitance.
- Sine+DC, Piecewise-linear and ON-CELL capacitance measurements modes
- Calculated calibration mode allows automatic correction for phase lag introduced by the EPC 9 or EPC 10 patch clamp system
- Measured and Manual calibration modes for highest accuracy in challenging recording modes
- Lock In measurements on multiple amplifiers are supported (EPC 9 and EPC 10 multi patch amplifiers required)
- Support of fluorescence excitation light sources TILL Polychrome, PTI DeltaRAM, SUTTER DG4/DG5, Lambda-10
- Multi-excitation and multi-emission protocols
- Simultaneous high-speed fluorescence and patch clamp measurements
- Runs on Windows 98, NT 4.0, 2000, XP, 7, 8, 10. Requires a parallel printer port.
- Runs on Mac OS 9 and Mac OS X. Requires a USB port.
- PatchMaster can read data recorded with PULSE or generated with PULSETOOLS or PULSESIM.
- Data acquisition: EPC 9 or EPC 10 type patch clamp amplifier or ITC-16, ITC-18, LIH 1600, or LIH 8+8 data acquisition interface in combination with any other clamp amplifier.
- Computer: see data sheet "Recommended Configurations".