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 more versatile and efficient.

With PATCHMASTER, experimental design, performance, and analysis are more flexible, giving rise to a high degree of automation and providing access to experimental protocols that are unattainable with commercial software.

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 mathematical functions to compile additional derived data traces.

Up to 16 trigger outputs can be defined as a stimulation channel.

Channels can have completely independent timing and pulse patterns. This allows for 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.

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.

More than one telegraphing amplifier can be supported by using multiple lookup tables.

Simultaneous capacitance measurements on multiple headstages of a patch clamp amplifier (EPC10 Double, Triple, and Quadro) and on-cell capacitance measurements at high sine wave frequencies are now possible.

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.

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.

A complete experiment can be automated and standardized, including incorporation of feedback from online analysis or external devices.

Full support of HEKA's patch clamp amplifiers EPC7, EPC8, EPC9, and the EPC10. 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. EPC9 Double/Triple, EPC10 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.

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.

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

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. This method is appropriate under stationary conditions for measurements of changes in Cm and we refer to this method as the "piecewise-linear" method.

Since the piecewise-linear method is prone to errors (Gillis in B.Sakmann & E.Neher Eds. Single Channel Recording 2nd Edition, Plenum Press), in 1988 Lindau and Neher introduced 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.

Digital control of the filter settings, gain and compensation networks that are featured with the EPC9 and EPC10 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.

In the Sine+DC mode, automatic Cslow compensation cancels the bulk of the membrane capacitance and thus permits the patch clamp amplifier to be operated in the high gain (low noise) range during lock-in measurements. In the on-cell mode, the signal to noise ratio can be increased by using a higher sine wave frequency (typically 20 kHz) to resolve small changes in Cm (< 100 aF), commonly seen in fusion of single vesicles.

In combination with EPC9 or EPC10 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.

FITMASTER features analysis and fitting routines for electrophysiological data. Analysis can be performed on the levels of Sweeps/Traces and Series. Besides standard fit functions such as Polynomials, Exponentials, Gaussians, and Boltzmanns, tailored functions to fit e.g. whole-cell current traces according to Hodgkin&Huxley gating formalism, current-voltage relationships and dose-response curves allow publication-proof analysis of your data.

The experienced patch clamp investigator will be fascinated by the versatility of the program and logical structure of the functions. All of the features of PATCHMASTER's Online Analysis are also present in FITMASTER. In principle, FITMASTER extends these capabilities by adding more specific analysis features and the generation of an analysis tree. The way FITMASTER works is tightly linked to the tree structure of data generated by PATCHAMSTER up to the level of a Series. Hence, FITMASTER has equivalent hierarchical levels of analysis corresponding to the tree levels featured in the Replay data tree. The analysis is organized in a structured way, relating to Sweeps and Series. The lowest level is the analysis of a raw data trace, a Trace. The TraceFit dialog provides tools for selecting a section of the trace for analysis and specifications of the type of analysis to be performed. The values determined by this sweep analysis can be further processed in SeriesFit. But in contrast to PULSEFIT, FITMASTER allows pooling of data on the level of the Series by introducing the new waves buffer concept. Several results of the TraceFit can be compiled in the waves buffer and then displayed in the SeriesFit graph. Several fit functions can be used to describe this ensemble of data points.

FITMASTER now features Action Potential analysis ...

... and Single Channel detection.

The CHARTMASTER software was designed with the main objective to streamline data collection, presentation and analysis during and after an experiment.

CHARTMASTER provides all of the necessary software tools that make experimental design and analysis more flexible.

With CHARTMASTER's high degree of automation, experimental protocols are now possible that were unattainable with other commercial software products.

CHARTMASTER's versatile design allows it to be used for any general purpose data acquisition need. In addition, CHARTMASTER can be used in conjunction with PATCHMASTER to provide even greater capabilities for elaborate electrophysiological recordings.

The heart of the CHARTMASTER software is the Pulse Generator. The Pulse Generator defines all of the parameters for data acquisition, waveform generation and external device control. A Pulse Generator file is comprised of any number of predefined sequences.

The CHARTMASTER protocol editor is a powerful feature in which complex experimental procedures can be designed, stored, and executed. This tool greatly increases the versatility of CHARTMASTER that will be appreciated by researchers asking for complex, precisely timed experimental protocols.
The principal idea of the protocol editor is to generate a list of events or tasks which can be executed automatically. Various functions such as REPEAT Loops, input queries, or conditional statements allow the generation of complex interactive processes. In addition, the high degree of automation possibilities increases efficiency, minimizes experimental errors and is thus highly suited for both industrial and research applications.

The CHARTMASTER software provides an arbitrary number of analyses that can be performed on newly acquired or stored data. Directly analyzed or derivative data obtained by application of mathematical functions on the analysis results can be displayed as several graphs placed in two independent analysis windows.
This allows separation of different data types, for example, current-voltage plots can be shown separately from time lapse data (e.g. chart recording).

The I/O Control window allows direct access to the hardware interface. The status of digital and analog input channels is monitored. Digital and analog output signals can be set. In addition, defined input parameters are also displayed.
Analysis templates can be predefined and stored. Thus, several analysis procedures can easily be switched between and applied to incoming data types without extra editing. A direct link between Pulse Generator sequences and analysis procedures provides definition of data acquisition and analysis prior to the experiment.

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 synchronized 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.

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 co-phasic 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 co-phasic 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 co-phasic 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 or CHARTMASTER software, on either a Windows or Mac platform. TIDA software can also be used to control the LIH 8+8 on an older 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).