Showing posts with label capacitance. Show all posts
Showing posts with label capacitance. Show all posts

Wednesday, October 14, 2020

Oh, patents! WirelessThinklabs One stethoscope (2)

Copyright © Françoise Herrmann

Although the Thinklabs One wireless electronic stethoscopes were released in 2003, seventeen years prior to the COVID 19 pandemic, for all the reasons that make digital auscultation unquestionably superior to conventional auscultation, the devices are now also proven life-saving devices. Life-saving for front-line professionals, working within the context of the hazardous and contagious situations of the COVID 19 pandemic. Situations where professionals are required to wear hazmat suits, or other sorts of personal protection equipment (PPE), such as hoods, face masks and face shields. Indeed, use of a wireless stethoscope, such as the ThinkLabs One, effectively prevents breaking the protection afforded by PPE equipment. Thanks to wireless functionalities, it is also possible to safely auscultate in an isolation room while streaming data to a triage room in real-time, or to auscultate at bedside, while streaming to a professional in another room.  Likewise, it is possible to auscultate in one location, and to stream sounds at a far greater distance within the context of telemedicine.

In fact, ThinkLabs One stethoscopes are marketed as the “smallest and most powerful stethoscopes in the world”, considering the versatility and inclusiveness of their design. Sounds can be amplified 100x, not only to capture and filter heart, lung or blood pressure sounds in unprecedented ways, even through clothes or in chaotic ER environments, but also to enable use for professionals with hearing loss. Auscultatory sounds can even be streamed to programmable Bluetooth-enabled hearing aids. Thinklab One stethoscopes are also powerful enough to be used with disposable protective sleeves for each patient.

Many patents are associated with the Thinklabs One electronic stethoscope. However, the core invention of the Thinklabs One electronic stethoscope —the invention that made it possible to capture, selectively filter, and amplify, body sounds electronically with very little distortion, thereby setting it apart in a class of its own— is the capacitative Electromagnetic Diaphragm (EmD) invention. An invention that directly uses capacitance variation to transduce sounds from the body into electronic signals, without the use of a prior art microphone mounted behind the stethoscope diaphragm, or the use of a prior art piezo-electric crystal sensor connected to the stethoscope diaphragm. This invention is recited in US6498854, titled Transducer for sensing body sounds, a utility patent granted on December 24, 2002.

In the inventor’s own words:  

“I investigated various sensor methods and had many failures, as you'd expect in research. But one method performed beautifully - using capacitive sensing, where the diaphragm acts as one plate of a capacitor. It's really tricky getting such circuits to work well, but I was working in my garage in the middle of winter.” (Clive Leonard Smith, Thinklabs Founder, One designer and inventor)

 The abstract of this invention is included below, together with the patent Figure 8. The patent Figure 8 schematically represents the conductive stethoscope diaphragm 2, in contact with the patient’s body, forming a capacitance with a second plate 3; one or both plates comprising permanently charged material, thus creating an electrical field 80 between them, without relying on DC charging. The diaphragm 2 is mounted to the stethoscope housing, using a mounting clamp 9, made of rubber, to prevent vibrations, from the housing, to reach the surface of the diaphragm 2.

An acoustic-to-electrical transducer for sensing body sounds is disclosed. The transducer comprises a capacitive sensor, whereby a stethoscope diaphragm forms one plate of a capacitor, with the second plate of the capacitor being co-planar to the diaphragm. The capacitance of the two plates varies with the distance between them, said distance being modified by motion of the diaphragm in response to sound pressure. The sensor, circuitry, manufacturing methods and improvements are disclosed. [Abstract US6498854] 

An image of the elegant ThinkLabs One electronic stethoscope is also included above. The Thinklabs One electronic stethoscope looks different from a conventional acoustic stethoscope, with none of the bulky tubing or earpieces. Frequency amplification, corresponding to low pitch heart sounds captured with the bell of a conventional stethoscope, as well as the higher pitch lung sounds captured by the diagram of a conventional stethoscope, is selected using a  dedicated filter button on the perimeter of the Thinklabs One. An Alt (toggle) button enables users to switch filters for the purposes of toggling between their favorite two frequencies. For example, the Alt button is used for toggling between a preferred filter to capture low pitch heart sounds, and a preferred filter to capture high pitch lung sounds. Two additional buttons (plus and minus) on the periphery of the Thinklabs One enable adjustment of the volume. 

Reference

Thinklabs (website)  https://www.thinklabs.com

Wednesday, February 18, 2015

Oh, Google Doodle! February 18, 2015

Copyright © Françoise Herrmann

Check out today's Google Doodle at www.google.com (and click on the Doodle)! Today's Google Doodle celebrates Alessandro Volta's 270th birthday on Feb. 18, 1745, the inventor of the voltaic pile (i.e.;battery)! 


Google Doodles are the delightful and beautifully crafted daily changes to the Google logo posted on the Google.com splash search page. For an archive of the Doodles, search for GoogleDoodles. Perhaps that one day there might be a Google Doodle exhibit to light up MOMAs worldwide! This is charming, whimsical, highly technical and amazingly participatory art!


Google’s Doodle is linked to a Wikipedia article about Alessandro Volta. In the article you will find out that Volta’s invention was reported to The Royal Society in 1880, and then to the Institut de France, two of the oldest learned societies on record, founded respectively in 1660 and 1795, where the invention was granted Letters patent.

In the Wikipedia article, you will also learn that Alessandro Volta’s invention concerned the production of electricity using a chemical reaction at a time when electricity was thought to be produced exclusively by living beings, according to Galvani’s “frog leg” experiments identifying animal electricity. Volta’s pile or battery placed two metals in contact with a liquid electrolyte (sulfuric acid mixed with water, or soaked saltwater brine paper), creating a voltaic cell where electricity flows as result of a series of electrochemical transfers and reactions.

You will also find out that Alessandro Volta is credited with the discovery of methane, and subsequently the study of electrical capacitance where his experiments resulted in Volta’s law of capacitance, and electrical potential became known as the “volt”. This work in experimental physics was carried out at the University of Pavia, in Italy where Alessandro Volta was chair and professor for 40 years.  

 Below, today's animated Google Doodle celebrating Alessandro Volta's sparks of genius 
(Copyright © Google Inc.)

Wikipedia - Letters Patent http://en.wikipedia.org/wiki/Letters_patent
Wikipedia - Alessandro Volta http://en.wikipedia.org/wiki/Alessandro_Volta

Wikipedia - Luigi Galvani http://en.wikipedia.org/wiki/Luigi_Galvani
Wikipedia - Capacitance http://en.wikipedia.org/wiki/Capacitance 
Wikipedia - Voltaic pile http://en.wikipedia.org/wiki/Voltaic_pile 
The Royal Society https://royalsociety.org/
Institut de France http://www.institut-de-france.fr/
Google Doodles http://www.google.com/doodles/

Monday, October 21, 2013

Oh, patents! Apple Touch ID

© Françoise Herrmann
 Apple’s new Iphone 5S comes equipped with new Touch ID technology. This technology, is designed to give you access to your Iphone without “sliding to unlock”, using a finger print sensor under the home button. 
The patent application for Touch ID technology, US20130271422 (A1),was published just a few days ago, on October 17, 2013!
Touch ID technology is called “Capacitive sensing array modulation”, and the scope of the invention extends to other devices, which means that you may find similar capacitive sensors with your next Macbook or Ipad enabling you to login with your finger print instead of typing in your password. And that’s a huge deal… on many counts… chiefly because typing in passwords is very time consuming, and you probably have too many passwords to remember…
Capacitive or “touchscreen” technology, is the touch-driven technology that revolutionized interfacing with computers, tablets and smartphones, once Apple started to build it into the screens of its first Iphone.
How does a capacitive fingerprint sensor work, and what is the technical problem addressed with Apple’s Touch ID tech?
Capacitive sensors produce a fingerprint image by measuring the capacitance, or amount of electric charge, between each sensing element of the sensor, and the fingerprint’s fleshy ridges and valleys, with capacitance inversely proportional to the separation distance. Thus, the capacitance of fingerprint fleshy ridges is higher than the capacitance of the fleshy valleys.
The trick in obtaining a clear finger print image lies partly in the right amount of voltage, or flesh excitability. When the voltage of the sensing elements is too high, the sensing creates an uncomfortable physical sensation for the user (i.e., an electric shock), and when it is too low, the capacitance readings yield a blurry image.
Apple’s invention consists in resolving this issue, with a capacitive array sensing technology that provides high voltage resolution without shocking the user’s finger (!)
So, the Iphone 5S probably started a whole new way of accessing your computers, tablets and smartphones. Bye bye “slide and unlock”, bye-bye passwords…(finally)!
Below is the Touch ID patent application abstract and an Apple Iphone Touch ID set up screen:

 Abstract -US20130271422 (A1)
 Capacitive sensing array modulation
A capacitive fingerprint sensor that may be formed of an array of sensing elements. Each capacitive sensing element of the array may register a voltage that varies with the capacitance of a capacitive coupling. A finger may capacitively couple to the individual capacitive sensing elements of the sensor, such that the sensor may sense a capacitance between each capacitive sensing element and the flesh of the fingerprint. The capacitance signal may be detected by sensing the change in voltage on the capacitive sensing element as the relative voltage between the finger and the sensing chip is changed. Alternately, the capacitance signal may be detected by sensing the change in charge received by the capacitive sensing elements as the relative voltage between the finger and the sensing chip is changed.
Inventors :Jean-Marie Bussat, Steven Hotelling, and Benjamin Lyon
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Source: Only at the USPTO…! Select icon that will display with blog