Resistive Pulse Sensing
Resistive Pulse Sensing - Related Videos
12:01
Quantification and Size-profiling of Extracellular Vesicles Using Tunable Resistive Pulse Sensing
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Cited by 99 •
2014
Extracellular vesicles play important roles in physiological and pathological processes, including coagulation, immune responses, and cancer or as potential therapeutic agents in drug delivery or regenerative medicine. This protocol presents methods for the quantification and size characterization of isolated and non-isolated extracellular vesicles in various fluids using tunable resistive pulse sensing.
04:17
Approximate Number Sense Test
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2023
Source: Laboratory of Jonathan Flombaum—Johns Hopkins University A common carnival game is to ask people to guess the number of jellybeans packed into a jar. The chances that anyone will get the exact number right are low. But what about the chances that someone will guess 17 or 147,000? Probably even less than the chances of guessing the correct answer; 17 and 147,000 just seem irrational. Why? After all, if the beans cannot be taken out and counted one-at-a-time, how can someone tell that an...
16:40
A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
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Cited by 5 •
2012
Dual-chamber implantable cardioverter-defibrillators (ICDs) may improve detection of atrial fibrillation as well as differentiation of tachycardias. However, this advantage is undermined by complications associated with the second electrode, which is required in conventional dual chamber devices. Therefore, BIOTRONIK has developed a new electrode called the LinoxSMART S DX that, when used in conjunction with the Lumax DX ICD, offers dual-chamber detection without the risks associated with the...
05:15
The Rouge Test: Searching for a Sense of Self
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2023
Source: Laboratories of Nicholaus Noles and Judith Danovitch—University of Louisville Humans are different from other animals in many ways, but one of the abilities that sets humans apart is their advanced ability to understand other people and simulate their thoughts and feelings, even when the thoughts and feelings do not align with their own. In scientific terms, these abilities are referred to as theory of mind, and this understanding is necessary for activities like giving compliments,...
01:16
Pulse
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2024
When the heart pumps blood out, arterial elastic fibers play a crucial role in sustaining a high-pressure gradient. They expand to accommodate the received blood and then recoil - a process known as the pulse that can be either manually palpated or electronically quantified. Despite a reduction in its effect with increased distance from the heart, elements of the pulse's systolic and diastolic components persist, observable even at the arteriole level. The pulse serves as a clinical indicator...
FAQs
Pulse amplitude primarily reflects the extent to which a passing object changes the electrical pathway, making it useful for estimating particle dimensions. Pulse duration provides information about how long the object occupies the sensing region and therefore relates to transit behavior. Considering both signals together can improve characterization beyond counting events alone, particularly for biological particles with differing sizes or passage dynamics.
The aperture defines the confined region through which particles pass, so its scale affects how strongly an object displaces the conducting electrolyte. The electrolyte provides the baseline electrical pathway against which each transient change is detected. Together, these features determine whether individual passages produce measurable resistance or impedance changes and influence the quality of size and number estimates.
Size and transit behavior contribute different information to the electrical signal. A particle's dimensions influence pulse amplitude, whereas its movement through the aperture influences pulse duration. Examining these features separately helps identify whether signal variation reflects differences in particle dimensions or in passage timing. This distinction is useful when characterizing heterogeneous biological samples or engineered microparticles.
Individual pulses can support estimates of particle number, dimensions, and, in some cases, physical properties. The distribution of amplitudes and durations can therefore reveal variation within a sample rather than only its total concentration. In bioengineering, that added resolution supports characterization of bacteria, extracellular vesicles, synthetic microparticles, and other particle populations.
The method is useful when researchers need to count and characterize discrete biological or engineered particles. Applications described for bioengineering include analyzing bacteria, extracellular vesicles, synthetic microparticles, and biomaterials. Its ability to connect electrical pulse features with particle dimensions and transit behavior can support quality control, diagnostics, and the development of engineered particle systems.
Microfluidic implementations enable analysis with small sample volumes while maintaining high throughput. This combination is valuable when samples are limited or when many individual particles must be assessed efficiently. In bioengineering workflows, such formats can support repeated characterization of cells, bacteria, extracellular vesicles, and synthetic microparticles, while generating particle-level information relevant to diagnostics and quality control.