DS3

The Digitimer DS3 Isolated Current Stimulator is a precision-engineered, battery-powered stimulator designed for use in electrophysiological research, offering accurate and controlled stimulus delivery with low-noise operation. This device is built for high-precision applications such as in vitro and low-noise in vivo studies, providing researchers with a reliable tool for generating constant current pulses.

The DS3 offers highly flexible and adjustable parameters, enabling precise control over pulse duration and amplitude. The device uses a six-position switch and multiplier to select pulse durations ranging from 20 microseconds to 2 seconds. Additionally, the output amplitude can be continuously adjusted using a three-turn dial, with a vernier scale that allows for precise settings between 0.2 and 3.2, across four ranges: x10μA, x100μA, x1mA, and x10mA, providing currents from 2μA to 32mA.

One key feature of the DS3 is its optically isolated output, which ensures very low capacitive coupling between the stimulator and the trigger source, reducing artifacts that might otherwise affect experimental results. The output pulse is indicated by an LED, and the DS3’s self-contained battery system operates only when a pulse is delivered, which greatly extends the life of the batteries. Without the use of a DC-DC converter, the stimulator runs quietly, preventing high-frequency noise from interfering with recordings.

To further enhance the precision of stimuli in challenging conditions, the DS3 offers an output discharge circuit that can be enabled via an internal jumper. This feature is particularly useful when stimulating high-impedance or high-capacitance cells, where electrode charging could potentially lead to lost stimulation. The discharge circuit discharges the electrode after each pulse, ensuring that the stimulator operates reliably even under such conditions.

For external control, the DS3 can be triggered by external devices like the DG2A Train/Delay Generator, and it can also be mounted in a 19" rack frame (D121-11), which can hold up to two DS3 stimulators.

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Key Features

• Constant Current Output: Provides a precise constant current stimulus with a compliance voltage up to 32mA.
• Pulse Duration Control: Selectable pulse durations from 20μs to 2s using a six-position switch and multiplier, with external gating capability.
• Ample Range of Currents: Continuous amplitude control between 0.2 and 3.2, with four selectable ranges (x10μA, x100μA, x1mA, x10mA).
• Low-Noise Operation: Battery-powered with no DC-DC converter, ensuring quiet operation without introducing high-frequency noise.
• Optically Isolated Output: Reduces capacitive coupling between trigger source and stimulator, minimizing artifacts.
• LED Output Indicator: Provides a clear visual indication when an output pulse is active.
• Battery Efficiency: Battery current is drawn only when a stimulus pulse is delivered, extending battery life.
• Output Discharge Circuit: Optional feature to discharge high-impedance, high-capacitance cells after stimulation to prevent charge accumulation.
• External Triggering: Can be triggered by external devices, such as the DG2A Train/Delay Generator.
• 19” Rack Mountable: Can be fitted into a 19" rack frame (D121-11) holding up to two DS3 stimulators.

Applications

The Digitimer DS3 Isolated Current Stimulator is designed for a wide range of applications within the field of neurophysiology and life sciences, where precise and controlled electrical stimulation is required. Its versatility and ability to deliver accurate, low-noise stimuli make it an ideal choice for both basic and advanced research in the following areas:

• Electrophysiological Research: The DS3 is commonly used in electrophysiology laboratories to study the electrical properties of excitable tissues such as neurons, muscles, and sensory cells. Its ability to provide constant current stimulation across a wide range of amplitudes and pulse durations makes it suitable for stimulating various types of tissues while maintaining the integrity of the experimental setup.
• In Vitro Studies: With its precise pulse duration and current control, the DS3 is particularly useful for in vitro experiments where the stimulation of cell cultures, isolated tissues, or neurons is required. The optically isolated output minimizes artifacts and ensures the highest-quality data acquisition during these delicate experiments.
• Neuromuscular Stimulation: The DS3 can be used for neuromuscular stimulation, both in research and clinical environments. It is ideal for experiments studying muscle response to electrical stimulation, whether for understanding neuromuscular control, fatigue, or investigating neuromuscular diseases.
• Stimulation of High-Impedance Tissues: The output discharge circuit can be enabled for experiments that involve high-impedance or high-capacitance cells, preventing charge accumulation at the electrode tip and ensuring that stimulation is reliably delivered even in challenging conditions, such as in the stimulation of high-resistance neural tissues.
• Sensory and Motor Pathway Studies: The DS3 is well-suited for sensory and motor pathway studies in both animal models and human research. Its precise current control allows for accurate motor-evoked potential (MEP) or sensory-evoked potential (SEP) measurements, making it a valuable tool in research into spinal cord injuries, neuromuscular diseases, and motor control.

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