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Posts Tagged ‘sensors’


Salt sensor for self-monitor sodium intake

Reporter: Danut Dragoi, PhD

Introduction

On Wednesday, February 17, 2016, the New York City Economic Development Corporation (NYCEDC), in partnership with Health 2.0 and Blueprint Health, announced the winners of the latest round of pilot funding from Digital Health Marketplace (formerly Pilot Health Tech NYC), a groundbreaking competition to support healthcare technology entrepreneurship in NYC by matching start-up companies who have an innovative technology with an institutional host who will help support it, see link in here

This year, one of the winning teams on the pilot funding from Digital Health Marketplace (formerly Pilot Health Tech NYC), a groundbreaking competition to support healthcare technology entrepreneurship in NYC, is Weill Cornell graduate student Fon Powell and the Weill Cornell Clinical and Translational Science Center (CTSC). As the innovator, Ms. Powell and her company Sodium Analyte Level Test LLC (S.A.L.T.) have developed a portable, smart phone-based home urinary analysis test that will allow users to conveniently self-monitor sodium intake, while providing physicians and researchers a mechanism to gather data on salt levels. As her host, the CTSC will support Ms. Powell in gathering pilot and proof-of-concept data in human participants that will help her expand the business and meet regulatory requirements, see link in here.

Figure below shows the analytical instrument that can connect to an iPhone and display the results of salt measurements.

Salt on iPhone

Image SOURCE: http://www.saltcounts.com/

How is it working?

As we know Na+ in our body can be eliminated through urine, in which Sodium is in ionic state. Urine basically is about 95% water and urea, CH4N2O, and other constituents. A complete composition of urine can be found here, which is an aqueous solution of greater than 95% water, with the remaining constituents, in order of decreasing concentration urea 9.3 g/L, chloride 1.87 g/L, sodium 1.17 g/L, potassium 0.750 g/L, creatinine 0.670 g/L and other dissolved ions, inorganic and organic compounds (proteins, hormones, metabolites). If we assume 1 L volume of our body fluids is 1 kg of our body weight, than 1.17g/L x 80L gives 93.6 g Salt. Now using data from the Figure above we get the reading of 1500 mg  salt/day which is less 62.4 times. I mention this calculation in order to have an idea how salt is metabolized in our body with no simple formula. In fact the algorithm of the calculations is a protected IP and reflects the complexity of the problem.

According with the information here, the device is working as follows: 2 disposable urine strips measure 2 urine analytes, one from dietary salt and one, a metabolic constant. After a picture is taken of each test strip, vision processing software decodes the strip. The patented SALT algorithm, developed by researchers at Cornell, gives salt levels.

Spare parts, test strips, and manufacturing

The device utilizes two basic strips see link in here and other materials shown below.

  • Creatinine test paper by Teco Diagnostics
  • Creatinine strips by PortaScience
  • Chloride strips by Hach Inc.

PortaScience, see link in here , will package strips together as a kit, with proper bottle and labeling. Total cost of manufacturing is $24.97/bottle, with a proVit of $15.02/bottle.

Source

http://www.saltcounts.com/

https://www.google.com/#q=chemical+formula+urea

https://www.google.com/search?q=patent+SALT+algorithm,+developed+by+researchers+at+Cornell&biw=1366&bih=623&source=lnms&sa=X&ved=0ahUKEwjT29nIvZ3LAhUNwGMKHVTYAWAQ_AUIBigA&dpr=1#q=chemical+composition+of+urine

http://elabnyc.com/wp-content/uploads/SALT_Executive_Summary.pdf

http://www.portascience.com/

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brain implants without wires

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

Powering brain implants without wires with thin-film wireless power transmission system

Avoids risk of infections through skull opening and leakage of cerebrospinal fluid, and allows for free-moving subjects and more flexible uses of brain-computer interfaces
February 8, 2016

http://www.kurzweilai.net/powering-brain-implants-without-wires-with-thin-film-wireless-power-transmission-system

 

Schematic of proposed architecture of an implantable wireless-powered neural interface system that can provide power to implanted devices. Adding a transmitter chip could allow for neural signals to be transmitted via the antenna for external processing. (credit: Toyohashi University Of Technology)

 

A research team at Toyohashi University of Technology in Japan has fabricated an implanted wireless power transmission (WPT) device to deliver power to an implanted neural interface system, such as a brain-computer interface (BCI) device.

Described in an open-access paper in Sensors journal, the system avoids having to connect an implanted device to an external power source via wires through a hole in the skull, which can cause infections through the opening and risk of infection and leakage of the cerebrospinal fluid during long-term measurement. The system also allows for free-moving subjects, allowing for more natural behavior in experiments.

 

Photographs of fabricated flexible antenna and bonded CMOS rectifier chip with RF transformer (credit: Kenji Okabe et al./Sensors)

 

The researchers used a wafer-level packaging technique to integrate a silicon large-scale integration (LSI) chip in a thin (5 micrometers), flexible parylene film, using flip-chip (face-down) bonding to the film. The system includes a thin-film antenna and a rectifier to convert a radio-frequency signal to DC voltage (similar to how an RFID chip works). The entire system measures 27 mm × 5 mm, and the flexible film can conform to the surface of the brain.

 

http://www.kurzweilai.net/images/Warwick-turns-on-light.jpg

Coventry University prof. Kevin Warwick turns on a light with a double-click of his finger, which triggers an implant in his arm (wired to a computer connected to the light). Adding an RF transmitter chip (and associated processing) to the Toyohashi system could similarly allow for controlling devices, but without wires. (credit: Kevin Warwick/element14)

 

The researchers plan to integrate additional functions, including amplifiers, analog-to-digital converters, signal processors, and  a radio frequency circuit for transmitting (and receiving) data.

Tethered Braingate brain-computer interface for paralyzed patients (credit: Brown University)

 

Such a system could perform some of the functions of the Braingate system, which allows paralyzed patients to communicate (see “People with paralysis control robotic arms using brain-computer interface“).

This work is partially supported by Grants-in-Aid for Scientific Research, Young Scientists, and the Japan Society for the Promotion of Science.

https://youtu.be/LW6tcuBJ6-w

element14 | Kevin Warwick’s BrainGate Implant

 

Abstract of Co-Design Method and Wafer-Level Packaging Technique of Thin-Film Flexible Antenna and Silicon CMOS Rectifier Chips for Wireless-Powered Neural Interface Systems

In this paper, a co-design method and a wafer-level packaging technique of a flexible antenna and a CMOS rectifier chip for use in a small-sized implantable system on the brain surface are proposed. The proposed co-design method optimizes the system architecture, and can help avoid the use of external matching components, resulting in the realization of a small-size system. In addition, the technique employed to assemble a silicon large-scale integration (LSI) chip on the very thin parylene film (5 μm) enables the integration of the rectifier circuits and the flexible antenna (rectenna). In the demonstration of wireless power transmission (WPT), the fabricated flexible rectenna achieved a maximum efficiency of 0.497% with a distance of 3 cm between antennas. In addition, WPT with radio waves allows a misalignment of 185% against antenna size, implying that the misalignment has a less effect on the WPT characteristics compared with electromagnetic induction.

 

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Diagnosing Lung Cancer in Exhaled Breath using Gold Nanoparticles

Reporter-curator: Tilda Barliya PhD

 

Authors: Gang Peng, Ulrike Tisch, Orna Adams1, Meggie Hakim, Nisrean Shehada, Yoav Y. Broza, Salem Billan, Roxolyana Abdah-Bortnyak, Abraham Kuten & Hossam Haick. (NATURE NANOTECHNOLOGY | VOL 4 | OCTOBER 2009 |)

 

Abstract:

Conventional diagnostic methods for lung cancer1,2 are unsuitable for widespread screening, because they are expensive and occasionally miss tumours. Gas chromatography/mass spectrometry studies have shown that several volatile organic compounds, which normally appear at levels of 1–20 ppb in healthy human breath, are elevated to levels between 10 and 100 ppb in lung cancer patients. Here we show that an array of sensors based on gold nanoparticles can rapidly distinguish the breath of lung cancer patients from the breath of healthy individuals in an atmosphere of high humidity. In combination with solidphase microextraction, gas chromatography/mass spectrometry was used to identify 42 volatile organic compounds that represent lung cancer biomarkers. Four of these were used to train and optimize the sensors, demonstrating good agreement between patient and simulated breath samples. Our results show that sensors based on gold nanoparticles could form the basis of an inexpensive and non-invasive diagnostic tool for lung cancer. (http://www.nature.com/nnano/journal/v4/n10/abs/nnano.2009.235.html) (lnbd.technion.ac.il/NanoChemistry/SendFile.asp?DBID=1…1…) Nanosensors Detect Cancer Breath

Introduction:

Lung cancer accounts for 28% of cancer-related deaths. Approximately 1.3 million people die worldwide every year. Breath testing is a fast, non-invasive diagnostic method that links specific volatile organic compounds (VOCs) in exhaled breath to medical conditions. Gas chromatography/mass spectrometry (GC-MS), ion flow tube mass spectrometry10, laser absorption spectrometry,infrared spectroscopy, polymer-coated surface acoustic wave sensors and coated quartz crystal microbalance sensors have been used for this purpose. However, these techniques are expensive, slow, require complex instruments and, furthermore, require pre-concentration of the biomarkers (that is, treating the biomarkers by a process to increase the relative concentration of the biomarkers to a level that can be detected by the specific technique) to improve detection.

Here, we report a simple, inexpensive, portable sensing technology to distinguish the breath of lung cancer patients from healthy subjects without the need to pre-treat the exhaled breath in any way (see also refs 14–16 for the diagnosis of lung cancer by sensing technology that is based on arrays of polymer/carbon black sensors). Our study consisted of four phases and included volunteers aged 28–60 years. Samples were collected from 56 healthy controls and 40 lung cancer patients after clinical diagnosis using conventional methods and before chemotherapy or other treatment.

In the first phase, we collected exhaled alveolar breath of lung cancer patients and healthy subjects using an ‘offline’ method. This method was designed to avoid potential errors arising from the failure to distinguish endogenous compounds from exogenous ones in the breath and to exclude nasal entrainment of the gas. Exogenous VOCs can be either directly absorbed through the lung via the inhaled breath or indirectly through the blood or skin. Endogenous VOCs are generated by cellular biochemical processes in the body and may provide insight into the body’s function

In the second phase, we identified the VOCs that can serve as biomarkers for lung cancer in the breath samples and determined their relative compositions, using GC-MS in combination with solidphase microextraction (SPME). GC-MS analysis identified over 300–400 different VOCs per breath sample, with .87% reproducibility for a specific volunteer examined multiple times over a period of six months. Forward stepwise discriminant analysis identified 33 common VOCs that appear in at least 83% of the patients but in fewer than 83% of the healthy subjects

The compounds that were observed in both healthy breath and lung cancer breath were presented not only at different concentrations but also in distinctively different mixture compositions.

Further forward stepwise discriminant analysis revealed nine uncommon VOCs that appear in at least 83% of the patients but not in the majority (83%) of healthy subjects. This additional class of VOCs has not been recognized in earlier GC-MS studies.

In spite of these advances in the GC-MS analysis, these data certainly do not account for all the VOCs present in the exhaled breath samples, because the pre-concentration technique can be thought of as a solid phase that extracts only part of the analytes present in the examined phase and, subsequently, releases only part of the extracted analytes.

So, it is likely that the actual mixture of VOCs to which, for example, an array of gold nanoparticle sensors would be responding  is different from that obtained by GC-MS.

In the third phase of this study we designed an array of nine crossreactive chemiresistors, in which each sensor was widely responsive to a variety of odorants for the detection of lung cancer by means of breath testing. We used chemiresistors based on assemblies of 5-nm gold nanoparticles  with different organic functionalities (dodecanethiol, decanethiol, 1-butanethiol, 2-ethylhexanethiol, hexanethiol, tert-dodecanethiol, 4-methoxy-toluenethiol, 2-mercaptobenzoxazole and 11-mercapto-1-undecanol).Diagnosing lung cancer in exhaled breath

Chemiresistors based on functionalized gold nanoparticles combine the advantages of organic specificity with the robustness and processability of inorganic materials.

The response of the nine-sensor array to both healthy and lung cancer breath samples was analysed using principal component analysis . It can be seen that there is no overlap of the lung cancer and healthy patterns.

The PCA of the healthy control group revealed that the set of gold nanoparticles sensors was not influenced by characteristics such as gender, age or smoking habits, thus strengthening the ability of the sensors to discriminate between healthy and cancerous breath. Experiments with a wider population of volunteers to thoroughly probe the influence of diet, alcohol consumption,metabolic state and genetics are under way and will be published elsewhere.

Summary:

To summarize, we have demonstrated that an array of chemiresistors based on functionalized gold nanoparticles in combination with pattern recognition methods can distinguish between the breath of lung cancer patients and healthy controls, without the need for dehumidification or pre-concentration of the lung cancer biomarkers. Our results show great promise for fast, easy and cost-effective diagnosis and screening of lung cancer. The developed devices are expected to be relatively inexpensive, portable and amenable to use in widespread screening, making them potentially valuable in saving millions of lives every year. Given the impact of the rising incidence of cancer on health budgets worldwide, the proposed technology will be a significant saving for both private and public health expenditures. The potential exists for using the proposed technology to diagnose other conditions and diseases, which could mean additional cost reductions and enhanced opportunities to save lives.

Ref:

1. Gang Peng, Ulrike Tisch, Orna Adams, Meggie Hakim, Nisrean Shehada, Yoav Y. Broza, Salem Billan, Roxolyana Abdah-Bortnyak, Abraham Kuten& Hossam Haick. Diagnosing lung cancer in exhaled breath using gold nanoparticles. Nature Nanotechnology 4, 669 – 673 (2009) http://www.nature.com/nnano/journal/v4/n10/abs/nnano.2009.235.html

2. http://lungcancer.about.com/od/diagnosisoflungcancer/a/diagnosislungca.htm

3. http://metabolomx.com/2011/12/15/metabolomx-test-detects-lung-cancer-from-breath/

4. http://www.chestnet.org/accp/pccsu/medical-applications-exhaled-breath-analysis-and-testing?page=0,3

 

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