COVID-19
© Brooke Clarke 2020 Description
DIY
Bag Valve Mask
Snorkel Face Mask
Army Emergency Respirator
Pulse Oximetry
Is COVID-19 a Blood Disorder Rather then a Respiratory Disorder?
SantaMedical SM-110
Masimo 2007 SET Radical V4
Masimo 2004 SET Radical V4
Sensors
Masimo 1863 K2N2A Reuseable Finger Tip Sensor
Masimo 14-Pin Plug to F-Tap Socket & F-Tap tongue to Fingertip Sensor
Chinese Equivalent Single Cable Sensor
History of Ventilators
Ventilator Patents
Photos
Patents
Ventilator Surge Production
Electrocardiograph
Water Filter
Sleep Apnea
Related
References
Links
Background
This is to keep notes related to COVID-19.
Sars-CoV-2 is the virus. COVID-19 is the disease.
There are ethics questions, for example see: Pandemic Justice by Karen Lebacqz 2007
The first ventilator (Wiki) was the Iron Lung (Wiki) which was mainly used for Polio (Wiki) patients.
AARC: 1950s - 1970s Ventilators, 1980 - 1999 Ventilators,
ARDS (Wiki): Acute Respiratory Distress Syndrome - Causes may include sepsis, pancreatitis, trauma, pneumonia, and aspiration. May not be COVID-19, see box below.
Pandemic: While the Wiki page for Pandemic mentions people being killed by disease, it does not clearly make that a part of the definition. But if you read closely it has the elements of: Infectious, contagious, kills many people, and is widespread.
Description
DIY
Bag Valve Mask Ventilator
These bag based ventilators are typically carried in ambulances. It's a complete working ventilator, but requires constant labor to pump the bag. If sensors and a mechanical way to squeeze the bag are added it can be made into a minimal ventilator. There are a number of patents for doing just this.
eBay title: Medical PVC 100% Latex-Free Bag Valve Mask CPR Manual Resuscitator for Adult Use (about $35)
Item Detail:Type: First-aid devicesModel:PVC ResuscitatorSuitable for: AdultsMaterial: CE PVC with 100% latex-Free.Ballon Size: 1650mlReservoir bag: 2000mlPop-off: 60cmH₂OMask: Air cushion mask 20115Oxygen tube:Non latex,CE Mark 0434Color: BlueAccessories:Oxygen tube(1pc), reservoir bag(1pc), mask(1pc)
Fig 1 Kit as received.
Fig 2 Major parts: Bag, Mask, 2L bag reservoir, Tube & intubation supplies.
Fig 3 Mask with 6.5mm (?) O2 inlet port
Red fingers are to hold straps (not supplied) that hold
mask on patient face. Port has the feel of Schrader Valve.
O2 Tube fits this port.
Fig 4 Patient outlet end w/22mm ISO tapered connection
Pop-Off valve protects bladder from over pressure.
Fig 5 Inlet End w/mixing chamber.
Mix Chamber inlets aprox 22mm, 7mm port and two valves.
Over pressure valve and inlet safety valve.
Main pump valve is at bottom of mixing chamber.
O2 Tube fits this port.
Fig 6 Pump Outlet (Duck's beak) Valve
Fig 7 Pop-Off Valve protects main bladder from over pressure
Fig 8 Reservoir Bag is filled by O2
and when full is a visual indicator
that the O2 is present. The port for
the bag can only be used for the bag,
i.e. it is not a standard 22mm ISO port.
3046978 Manually operated resuscitator, Lawrence N Lea, App: 1960-06-22, 128/205.13; 128/205.24; 417/478; 92/92; 128/207.16 - Cited by,
Snorkel Full Face Mask
Note that Full Face Mask Snorkeling (Wiki) is different from the classical plain snorkeling (Wiki) with a tube held in the mouth. The idea is to remove the snorkel tube and float ball valve and replace it with an adapter to hold an air filter. The result is both an excellent inlet air filtration system and a face mask that protects the full face. A modification is possible for a Surgeons where the exhaust air is also filtered and directed away from the patient providing a “sterile-field”.
This project is mainly aimed at PPE (Wiki) rather than use as a ventilator. But in light of the newest idea (still not tested) that COVID-19 is a blood problem rather than ARDS, this mask with the addition of some O2 may work to relieve breathing.
Fig 1 Box
Fig 2 Carry bag
Fig 3 Assembled + GoPro mount
+ GoPro screw + spare flap valve
References
Stat: With diving gear and plumbing supplies, California labs fashion Covid-19 masks and ventilators, April 9, 2020 - Manu Prakash at Stanford, who developed the FoldScope (paper microscope), came up with this on 21 March 2020 in a Tweet.
Google Docs: Pneumask: Reusable Full-Face Snorkel Mask PPE Project - Very good information. Air circuit diagrams for General and Surgeon's versions.
The link to ISO 5356-1:2015 Anaesthetic and respiratory equipment - Conical connectors - part 1: Cones and Sockets is broken.
Inter Surgical has a Chart.pdf of air circuit couplings. and a wall poster. The tubes seem to come in 15mm and 22mm sizes (30mm & 19mm less common). Ports in sizes: 7.6mm, Luer & MDI.
Snorkel Patents
2569451 Diving suit, Browne Jack, Diving Equipment and Supply, App: 1946-02-28, - Face mask covers eyes, nose and mount with one compartment.
4126131 Facemask and goggle combination for excluding smoke or noxious gases from the goggles, Donald G. Davis, John Wippler, David L. Heitman, Scott Technologies Inc (Sierra Eng), App: 1977-03-18, - manual valve to use clean air from the nose + mount mask to flush out the goggles (not the better system of feeding clean air to the eyes first, like in 4676236).
4676236 Helmet airflow system, Gary J. Piorkowski, William P. Giacomini, Gentex Corp, compartments: first for eyes, then for mount and nose (circuit diagram).
Army Emergency Respirator
Class 128/205.24 is closley related to respirators. Also see Sprinkler Control Valves which were early applications of fludics.
Fludics (Wiki) was discovered by Billy M. Horton, Dr. R. E. Bowles and Ray Warren at the Harry Diamond Labs in the late 1950s. This same lab, then called the Army Research Labs, invented the Breathing valve assembly.
ARL: Redditors revive interest in 1960s Army emergency ventilator invention -
3419029 Breathing valve assembly, Henrik H Straub, Army, App: 1967-01-27, 128/205.24; 137/835; 137/102 -
3586021 Fluidic breathing assistor, James P Mcguinness, Bowles Fluidics Corp, App: 1968-11-2, 128/204.24; 137/835 -
Pulse Oximetry (Wiki)
Whenever someone has problems related to breathing a test of the dissolved oxygen in their blood is an indicator of what's going on. Whether it's pneumonia (Wiki) or COVID-19 (Wiki). This test works by measuring the transparency of an ear lobe or finger at two different wavelengths, such as red and near infrared. At the same time the pulse rate can be detected.
Perfusion (Wiki)
3796213 Perfusion monitor, F Stephens, 1974-03-12 -
4109643 Perfusion meter, Albert K. Bond, Edwin B. Merrick, Larry L. Nielsen, HP Inc, 1978-08-29 - single 650nm LED & CdS photocell (Wiki)
Is COVID-19 a Blood Disorder Rather then a Respiratory Disorder?
2020 May 21: WaPo: More evidence emerges on why covid-19 is so much worse than the flu - "Doctors have described widespread damage to blood vessels and the presence of blood clots that would not be expected in a respiratory disease."
2020 May 21: NEJM: Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19 -
2020 April 22: A mysterious blood-clotting complication is killing coronavirus patients -
2020 April 21: New analysis recommends less reliance on ventilators to treat coronavirus patients -
2020 April 10: COVID-19 May be a Blood disorder rather than a Respiratory disorder
2020 April 9: ChemRxiv: COVID-19:Attacks the 1-Beta Chain of Hemoglobin and Captures the Porphyrin to Inhibit Human Heme Metabolism, - "The attack will cause less and less hemoglobin that can carry oxygen and carbon dioxide." Even though the article starts off saying "...COVID-19) is an infectious acute respiratory infection.." the problem is really related to blood hemoglobin (Wiki).
2020 April 9: Stat: With ventilators running out, doctors say the machines are overused for Covid-19, - "Many patients have blood oxygen levels so low they should be dead. But they’re not gasping for air, their hearts aren’t racing, and their brains show no signs of blinking off from lack of oxygen."
2020 April 6: Medscape: Do COVID-19 Vent Protocols Need a Second Look?, April 6, 2020 - "In the past, we haven't seen patients who are talking in full sentences and not complaining of overt shortness of breath, with saturations in the high 70s. It's just not something we typically see when we're intubating some of these patients. That is to say, when we're putting a breathing tube in, they tend to drop their saturations very quickly; we see saturations going down to 20 to 30. Typically, one would expect some kind of reflexive response from the heart rate, which is to say that usually we see tachycardia, and if patients go too low, then we see bradycardia. These are things that we just weren't seeing. I've seen literally a saturation of zero on a monitor, which is not something we ever want and something we actively try to avoid. And yet we saw it, and many of my colleagues have similarly seen saturations of 10 and 20. We try to put breathing tubes in to avoid this very situation. Now, these patients tend to desaturate extremely quickly, so these situations have occurred. Still, what we're seeing—that there was no change in the heart rate—is just unusual. It's just something that we are not used to seeing."
2020 April 5: Medium (by way of archive.org): Covid-19 had us all fooled, but now we might have finally found its secret. - written for non doctors
2020 March 30: ATS Journals: Covid-19 Does Not Lead to a “Typical” Acute Respiratory Distress Syndrome, Luciano Gattinoni, - "... the lowest possible PEEP and gentle ventilation..." The first paper suggesting that classical ARDS (high PEEP) ventilation is a mistake and pointing to blood hematology as the problem.
-------------------------------
If this is the case then a low Pulse Oximetry reading may be an indicator of COVID-19 if other symptoms of something like pneumonia (Wiki) are not present? Note somewhere in the above I read that pneumonia typically shows up a more in one lung than the other. I had pneumonia pretty much all of January 2020 and it was in only one lung. This is very different than COVID-19 in that both lungs are equally grainy in CT images (Wiki).
SantaMedical SM-110
After getting a reading where the pulsing bar graph is beside the SpO2% reading if you press the On/Off button the display will invert. Note since the SpO2% reading is always near the On/Off button the readings flip top to bottom. The included document says the LED wavelengths are 660 & 905 nm. Runs on a pair of AAA cells (two included). Because the display is LED based and LEDs are used as part of the sensing system battery drain will result in shorter battery life than an instrument that used a LCD display. But LEDs are easy to read in dim light and easier to interface so maybe a good design choice.
Reading %
Description
>=95%
Normal
92%
potential hypoxemia (Wiki)
<=89%
Unhealthy
Photos
Fig 1
Fig 2 Pulse rate (BPM) over SpO2%
Fig 3 SpO2% over Pulse Rate (BPM)
also see Photelometer in References.Masimo 2007 SET Radical 4 Pulse Oximetry
"SET" is a Maximo registered trademark acronym for Signal Extraction Technology. It was a game changer compared to conventional pulse oximeters in that it not only greatly reduced the effect of motion it also allowed more precise measurements by separating arterial from venous blood. Many, if not all Pulse Oximeters made by Masimo are branded "SET". But that does not mean they all use the same sensors. Which sensors go with which meters is something I'm trying to understand.
The RDS-1 Remote Docking Station has all the possible features except an internal battery (which is in the RDS-1b). The RDS-2 and RDS-3 have fewer features.
Sensors
Masimo 1863 K2N2A Reuseable Finger Tip Sensor
The cable that connects the 1863 9-pin Male to the Radical V4 might be this one on eBay:
The eBay listings seem to say this was one of the correct sensors to go with the Radical V4, but there's a connector mismatch. The sensor has what amounts to a push-on DB-9m connector (see Fig 8 above). The connector on the Radical V4 appears to have a total of 14 terminals in two rows of 7.
Masimo SET 1814 LNC-10 SpO2 Patient Ext. Cable LNCS 9 Pin to LNC 14 Pin - 10FT
aka: LNC-10 LNCS Series Patient Cable, Ref: 1814
QR code: (01) 00843997000512, (11) 180501, (10) 18E57 (lot number)
Tag on cable: Do Not Discard, 1814-08HAE
Masimo 1863 Pin Out
See Fig 2 above for pin numbering. Black: -, Red +
Looks like app pins are open?
Ohms
1
2
3
4
5
6
7
8
9
1
*
OL
OL OL OL OL OL OL OL 2
OL * OL OL OL OL OL OL OL 3
OL OL * OL OL OL OL OL OL 4
OL OL OL *
OL OL
OL 5
OL OL OL OL *
OL OL OL OL 6
OL OL OL OL OL *
OL OL OL 7
OL OL OL
OL OL *
OL 8
OL OL OL
OL OL
*
OL 9
OL OL OL OL OL OL OL OL *
OL: Over Load (Open)
Diode
1
2
3
4
5
6
7
8
9
1
*
2
*
3
*
4
*
5
*
6
*
7
*
8
*
9
*
Masimo 2004 SET Radical V4
Got this second set containing:
Docking Station RDS-1 (no label)
Radical V4
Line Cord
Two cables including one that mates to the Radical V4. Note the sensor cable is NOT the 1863 shown above but instead one that has the "tongue".
The "tongue" connector is stamped 15BJF. Don't know if that's a model or lot number?
The adapter cable tongue socket is marked 9 JO01, again don't know if model or serial number.
Masimo 14-Pin Plug to F-Tap Socket & F-Tap tongue to Fingertip Sensor
Fig 21 Two Cables
Fig 22 Tongue connection
PC Series patient Cable
Ref: 1173
14-pin connector to Radical V4 - Socket for F-Tap sensor cable.
barcode: (01) 108439997001806, (10) 11JPF (lot number)
Patents:
6280213 Patient cable connector, David R. Tobler, Thomas J. Gerhardt, Eugene E. Mason, Mike A. Mills, Masimo Corp, 2001-08-28, 439/160; 439/729; 439/838; 439/909 - makes use of locking hole (108) in F-tab.
6152754
5934925
5645440
D393830 Patient cable connector, David R. Tobler, Thomas J. Gerhardt, Eugene E. Mason, Mike A. Mills, Masimo Corp, 1998-04-28
Fig 24 Finger sensor to LNOP F-Tab
Genuinie MASIMO 1269 SPO2 Adult Hard Shell Finger Sensor LNOP F-Tab 3' Cable
Fig 25 Display (Second Unit)
Notice that below the LCD this Second unit has a sticker
with English names for the 3 buttons.
In Fig 1 above there are no labels on the 3 buttons.
Display Comments:
Left: %SpO2 is changing between 94 and 95
no upper alarm limit and 83% lower alarm limit
Center top: Alarm silence has been pressed and will remain silent doe another 45 seconds.
Center bottom: The Perfusion Index (Wiki, Photoplethysmogram) varies between 0.02% & 20%. Higher for stronger pulse. This is reflected in the sound for each pulse.
Right top: Pulse rate: Alarm 150 Beats Per Minute max, 50 BPM min.
Alarm type: APOD shown (Adaptive Probe Off Detection white paper)
Bottom Right: date and time.
Fig 26
This shows the one hour trend instead of the pulsing PI.
Fig 25 & Fig 26 are for a 2004 SET ver4.1.0.0
Fig 27
Fig 27 is for a 2007 SET ver 4/3/2/0
Note lack of English language sticker on 3 buttons at bottom.
If APOD was selected it would appear just to the left of the battery icon. So "normal" probe off detection here.
Philips VueLink is a type of data output in a format to match Philips patient monitors. A special cable is required.
Chinese Equivalent Single Cable SpO2 Sensor
eBay listing "14-Pin 3-M Reusable SpO2 Sensor Cable Adult Finger Clip Fit For Masimo Oximax CE". Single cable design. Under $20 including shipping From Rowland Heights, Calif.
But the 14-pin connector does not latch to the Radical V4 so not usable. The slightest movement of the cable causes it to unplug.
Fig 1
Fig 2 Top is Masimo brand, bottom is Chinese copy.
Two possible problems:
1. the fingers on the Chinese version have been bent 180 deg instead of9080 deg,
2. The gap between the fingers is too small.
Click photo for a magnified view.
In Fig 3 the fingers have been bent, not quite to 90 degrees.
By being a little less than 90 deg, say 80 deg, when you
push in the connector the fingers cam back without squeezing
the release levers and snap into place.
Fig 3 Top is Masimo brand, bottom is Chinese copy.
Masimo Radical Patents (from Fig 4)
Masimo/Patents - lists many patents grouped by product.
Drawing
Patent Date
Description &Etc
RE38492
Signal processing apparatus and method (was: 6036642)
RE38476
Signal processing apparatus (was: 6081815)
6699194
1997-04-14
Signal processing apparatus and method
6684090
Pulse oximetry data confidence indicator
6658276
Pulse oximeter user interface - Radical (Ver 4)
6654624
Pulse oximeter probe-off detector
6650917
Signal processing apparatus
6643530
Method and apparatus for demodulating signals in a pulse oximetry system
6606511
Pulse oximetry pulse indicator - output depends on quality of data, not always the same
6584336
Universal/upgrading pulse oximeter - The Remote Docking Station has output to other manufacturers to upgrade SpO2
6501975
Signal processing apparatus and method
6463311
Plethysmograph (Wiki) pulse recognition processor (e.g., pulse rate and amplitude)
6430525
Variable mode averager
6360114
Pulse oximeter probe-off detector
6263222
Signal processing apparatus
6236872
Signal processing apparatus
6229856
Method and apparatus for demodulating signals in a pulse oximetry system
6206830
Signal processing apparatus and method
6157850
Signal processing apparatus
6081815
Method for processing a hyperlink formatted message to make it compatible with an alphanumeric messaging device (see RE38476)
6067462
Signal processing apparatus and method
6036642
See RE38492
6011986
Manual and automatic probe calibration - adjust drive current to tweak wavelength.
6002952
Signal processing apparatus and method
5919134
Method and apparatus for demodulating signals in a pulse oximetry system
5823950
Manual and automatic probe calibration
5769785
Signal processing apparatus and method
5758644
Manual and automatic probe calibration
5685299
Signal processing apparatus
5632272
Signal processing apparatus - Monitor 3 of 3
5490505
Signal processing apparatus - Monitor 2 of 3
5482036
Signal processing apparatus and method - Monitor 1 of 3
Masimo Finger Probes
Drawing
Patent
Date
Description &Etc Radical up to 1997-04-14
EP0576560
1991-03-21
Low noise optical probe
5337744
1993-07-14
Low noise finger cot probe
5452717
1993-07-14
Finger-cot probe
5743262
1995-06-07
Blood glucose monitoring system - spectrum 850 to 1350 nm, wedge wheel filter
5638816
1995-06-07
Active pulse blood constituent monitoring - cuff adds active additional pulse
5645440
1995-10-16
Patient cable connector - 6 pin PCB - "attach both disposable and durable sensors"
6088607
1991-03-21
Low noise optical probe - Optics
5934925
1995-10-16
Patient cable connector - very similar to 5645440 Generation after Radical 1997-04-14
5995855
1998-02-11
Pulse oximetry sensor adapter - complex
6525386
1998-03-10
Non-protruding optoelectronic lens - custom LED plastic package, not TO-5 package (Wiki)
6256523
1998-06-09
Low-noise optical probes - Optics, 6-terminal flex circuit
6278522
1999-05-26
Optical filter for spectroscopic measurement and method of producing the optical filter - "chemical analysis, blood glucose monitoring, and the like"
6377829
1999-12-09
Resposable pulse oximetry sensor - flex circuit, ID element (405) is printed resistor (real reason $) on tape
EP2319398
1999-05-27
Stereo pulse oximeter - Fick principle (Wiki), CO = Cardiac Output See: 5218962
6580086
1999-10-19
Shielded optical probe and method - reuseable, cable, through or reflected
6165005
1999-12-07
Patient cable sensor switch - 6-terminal PCB
Radius PPG Sensors
Drawing
Patent
Date
Description &Etc
7764982 2006-03-01
Multiple wavelength sensor emitters 4x4 array
9295421 2014-10-13
Non-invasive physiological sensor cover
10194848
10327337
10335033
10478107
RD (not Rainbow) Sensors
Drawing
Patent
Date
Description &Etc
6388240
Shielded optical probe and method having a longevity indication
6515273
6861639
6979812
7096054
7186966
7272425
7280858
7729733
7761127
7764982
7791155
7880626
8050728
8255026
8355766
8399822
8634889
8781544
8886271
8922382
9072474
9107626
9241662
9295421
9560998
9949676
10039482
10194848
10201298
10205291
10342470
10327337
10478107
LNOP Sensors
Red Patient LNOP Cable
Drawing
Patent
Date
Description &Etc
6152754 1999-12-21
Circuit board based cable connector - 6-terminals PCB
7919713 2008-04-16
Low noise oximetry cable including conductive cords
8255026 2007-10-12
Patient monitor capable of monitoring the quality of attached probes and accessories - resistor ID
8921699 2011-04-04
Low noise oximetry cable including conductive cords
8922382 2011-01-27
System and method for monitoring the life of a physiological sensor - Fig 1 Radical (prior art); add: temp & Memory related to: 6388240 & 6515273. (worn out or $)
9107626 2014-12-17
System and method for monitoring the life of a physiological sensor - Fig 1 Radical (prior art); "
9241662 2013-12-11
Configurable physiological measurement system - memory in cables and sensors ($)
9949676 2012-08-27
Patient monitor capable of monitoring the quality of attached probes and accessories " ($)
10039482 2016-12-22
System and method for monitoring the life of a physiological sensor
Rainbow Cables
Drawing
Patent
Date
Description &Etc
7919713
above
8050728 2006-03-01
Multiple wavelength sensor drivers -4 x 4 array of LED (not just 2)
630, 620, 610, -, 700, 730, 660, 805, -, -, -, 905, -, -, -, -
8118620 2008-10-09
Connector assembly with reduced unshielded area
8255026 2007-10-12
Patient monitor capable of monitoring the quality of attached probes and accessories ($)
8529301
8921699
8922382
9107626
9241662
9949676
10039482
Low Noise Cabled Sensors (LNCS)
Digital Clip sensors (DCI, DCI-P) [P = Pediatric]
RD SET Trauma: 4011
LNCS Trauma: 2411
LNC Patient Cables - and adapter cables to different monitors
Oximetry Patents
Note the Photelometer patents predate all of these. But . . . the measurement was made on a blood sample outside someone's body.
2358992 Oxygen meter, Glenn A Millikan, App: 1941-06-28, 356/41; 250/221; 250/239; 250/226 - "It has long been recognized that the hemoglobin of the blood changes color from red toward blue as the oxygen content diminishes." Using red and green filters.
2414747 Method and apparatus for controlling the oxygen content of the blood of living animals, Harry M Kirschbaum, 1947-01-21, 128/204.23; 137/624.15; 250/226; 137/2; 250/215; 356/41-
2706927 Apparatus for determining percentage oxygen-saturation of blood, Wood Earl Howard, Research Corp, App: 1949-08-04, 600/344; 250/226; 356/41 - dual wavelengths of light instead of filters
2754819 Apparatus for automatically administering anesthetics, Harry M Kirschbaum, 1956-07-17, 128/204.23 - based on O2 saturation
2790438 Earpieces for oximeters, Taplin Ronald Harold, Paul William, 1957-04-30, 600/344 - O2 saturation in blood based on 650 & 800 nm filters
3152587 Medical photometric apparatus, Ullrich Georg Josef, Mager Theo, Fritz Hillige & Co, 1964-10-13
3647299 Oximeter, Robert G Lavallee, American Optical Corp, App: 1970-04-20, - 600, 805 & 910 nm wavelength LED sources.
3704706 Heart rate and respiratory monitor, Bonita Falkner Herczfeld, Peter R Herczfeld, Richard D Klafter, Drexel U, App: 1969-10-23, Pub: 1972-12-05 - 670nm GaAs laser source Monsanto MV10A + Motorola MRD210 Si photodetector: reflective mode. Single wavelength.
3769974 Blood pulse measuring employing reflected red light, R Smart, K Swonger, Martin Marietta, 1973-11-06, - 6 to 9 angstrom IR LEDs reflect off blood - just for pulse
4621643 Calibrated optical oximeter probe, William New, Jr., James E. Corenman, Nellcor Inc, App: 1982-09-02, 600/331; 250/252.1; 356/41; 600/479 - simple two LEDs (660 & 940 nm).
4653498 Pulse oximeter monitor, William New, Jr., James E. Corenman, Nellcor Puritan Bennett, Priority: 1982-09-13, Pub: 1989-04-18, - 8085 uC,
EP0930045A2 Signal processing apparatus and method for an oximeter, Mohammed K. Diab, Esmaiel Kiani-Azarbayjany, Masimo Corp, Priority: 1991-03-07, -
5337744 Low noise finger cot probe, Brendan Branigan, Masimo Corp, Priority: 1993-07-14, -
5490505 Signal processing apparatus, Mohamed K. Diab, Esmaiel Kiani-Azarbayjany, Walter M. Weber, Masimo Corp, Priority: 1991-03-07, -
5919134 Method and apparatus for demodulating signals in a pulse oximetry system, Mohamed K. Diab, Masimo Corp, Priority: 1997-04-14, - similar to 6229856
6229856 Method and apparatus for demodulating signals in a pulse oximetry system, Mohamed K. Diab, Walter M. Weber, Ammar Al-Ali, Masimo Corp, Priority: 1997-04-14, - polarity reversal for Red/IR selection, includes both off. Makes use of sampling Red, IR, OFF then analog filtering on those 3 signals.
8571619 Hemoglobin display and patient treatment, Ammar Al-AliMassi, Joe E. Kiani, Michael O'Reilly, Masimo Corp, Priority: 2009-05-20, - Masimo "Radical".
9037207 Hemoglobin display and patient treatment, Ammar Al-AliMassi, Joe E. Kiani, Michael O'Reilly, Masimo Corp, Priority: 2009-05-20, - Masimo "Radical".
9795739 Hemoglobin display and patient treatment, Ammar Al-Ali, Massi Joe E. Kiani, Michael O'Reilly, Masimo Corp, Priority: 2009-05-20, - Masimo "Radical".
History of Ventilators
The story of ventilators starts with Forrest Bird (Wiki).
ventilators
Trying to understand Ventilators (Wiki). These are used to breathe for a patient either wearing a mask or an intubated (Wiki) patient such as one in a coma (Wiki)
There are a number of DIY (Wiki) ventilator plans on the internet, most of which may meet the minimum requirements, but would not at all be suitable to use on a real patient. I say that because when I was writing computer software for microwave testing less than 10% of the time and effort was needed to meet the stated design goals and 90% of the time was spent preventing problems caused by operators who were untrained, tired, distracted or otherwise not knowledgeable about what they were supposed to do. The specifications on the UK web page say that someone needs to be able to operate a machine with 30 minutes or less training and that all controls and connections need to be clearly marked. The instructions for use need to be printed directly on the machine. There are a number of safety features than need to be present in case of malfunctions and there may or may not be a requirement that the unit work during a power failure or the movement of the patient to another room. Also is should survive a drop onto a concrete floor, &Etc.
Photos (missing until I buy a
Ventilator)
Fig 1
Fig 2
Fig 3
Patents
Patent numbers appearing on a Bird Mark 7 ventilator: 3191596, 3353536, 3739776, 3068856, 3485243, 3454000, 3172406, 3688794. These are not all ventilator patents, but also include related accessory equipment.
Forrest M Bird
3068856 Fluid control device, Forrest M Bird, Henry L Pohndorf, App: 1958-02-14, Pub: 1962-12-18, 128/203.12; 128/204.19 - An outstanding feature of the present invention is that the patient can switch the respirator on with a very minimum of effort - 0.001 centimeter of water or less. The first Bird Respirator.
Patent Citations (11)Cited By (27)
3172406 Nebulizer, Forrest M Bird, Henry L Pohndorf, 1965-03-09, 128/200.21; D24/110; 128/200.18; 239/338 -
3191596 Respirator, Forrest M Bird, Henry L Pohndorf, App: 1960-09-19, Pub: 1965-06-29, 128/204.19; 128/204.25; 128/204.26 - Improved Bird Respirator. One very important problem has been how to compensate for leakage. Patent Citations (7)Cited By (68)
3331368 Pressure and volume limiting ventilating apparatus, Forrest M Bird, Henry L Pohndorf, App: 1965-03-24, Pub: 1967-07-18, 128/205.24 - Fixes a problem in the above two patents:
"For example, the accelerator cartridge assembly acted as a dam for gas molecules constantly coming from a metering valve assembly during the expiratory phase when the main control valve was in the off position. The effect of this dam was to create a reservoir of gas molecules under pressure in the spaces between the dam and the metering valve assembly. It has been found that the number of gas molecules accumulating in the reservoir during the expiratory phase and during the duration of the pause before initiating the inspiratory or inhalation phase for opening of the main control valve varied considerably because of large variations in the expiratory phase and the duration of the pause from breath to breath of the patient. In fact, this reser voir of gas molecules acted as a preload which was de pendent on a variable time and also dependent upon Vari able pressures upstream from the metering valve assembly. Certain difficulties were also encountered with the accelerator-interruptor cartridge.
3347228 Volume Limiting Ventilation Apparatus, Forrest M Bird, Henry L Pohndorf, Oct 17, 1967, 128/204.26; 128/204.19; 600/534; 600/538 - volume limiting ventilating apparatus in which thoracic volume is sensed.
3454000 Apparatus for the mechanical ventilation of a patient, Forrest M Bird, Henry L Pohndorf, 1969-07-08, 601/41 -
3485243 Respirator with improved exhalation valve and control means, Forrest M Bird, Henry L Pohndorf, App:1965-08-02, 128/204.25; 137/114; 128/205.24 -
3353536 Nebulizer, Forrest M Bird, Henry L Pohndorf, 1967-11-21, 128/200.18; 128/200.21; 261/DIG.65; 239/338; 422/266 -
3688794 Exhalation valve for respirator, Forrest M Bird, Henry L Pohndorf, 1972-09-05, 137/529; 128/205.24; 137/542; 251/82 -
3739776 Fail-safe breathing circuit and valve assembly for use therewith, F Bird, H Pohndorf, 1973-06-19, 128/204.25 -
Ventec Life Systems
10245406B2 Ventilator with integrated oxygen production, Douglas F. DeVries, David M. Good, Shan E. Gaw, Joseph Cipollone, Richard Branson, Ventec Life Systems Inc, App: 2015-03-24, Pub: 2019-04-02, Patent citations (436) -
10576237B2 Active exhalation valve, Douglas F. DeVries, Shan E. Gaw, Ventec Life Systems, Priority: 2015-03-24, Pub: 2020-03-03, - Cough Assist
Thermo Electron Corp
A number of patents for a Spirometer. Did not find any ventilator patents.
Ventilator Surge Production
There are a number of parings of companies to make ventilators in high volume quickly.
GM & Ventec
This was the first announced partnership.
2020 March 27 -Ventec Life Systems and GM Partner to Mass Produce Critical Care Ventilators in Response to COVID-19 Pandemic - The VOCSN (Wiki) may be the most capable unit on the market. VOCSN combines: Ventilator (Wiki), Oxygen concentrator (Wiki), Cough Assist (Wiki), Suction Unit (Wiki) and Nebulizer (Wiki).
The VOCSN is a very capable unit, but it's complex so that will slow down the production. Maybe parts can be left out? For example make the oxygen generator optional so that for hospitals that have plumbed in O2 they can get units faster.
Note that GM is going to assemble the ventilators in a clean facility used to manufacture automotive electronics, not a dirty car plant. They mainly will bring a strong supply chain that can support monthly volumes in the range of 2 to 20 thousand per month.
The GM version will include neither Suctioin, Nebulizer nor Oxygen. So instead of VOCSN is will be VC only. That lowers the price ($420 Million (plus some more for tooling) for 30 Thousand units = $14k each instead of $17k each).
Ford & GE
FORD WORKS WITH 3M, GE, UAW TO SPEED PRODUCTION OF RESPIRATORS FOR HEALTHCARE WORKERS, VENTILATORS FOR CORONAVIRUS PATIENTSThe above is talking about two very different things.
The Ford & 3M partnership is to make a PAPR. This is just a gas mask with an electrical blower, see the Scott C420 PAPR. I expect these can be made in high volume quickly as PPE for caregivers.
The Ford & GE partnership is to make a ventilator. It will be a simplified version of the GE Carescape R860. The user interface may be the GE units strong suit, so how it will be simplified is not clear.
Tesla & Medtronic
Medtronic claims to have released PB560 ventilator manufacturing documents (PB560 User Manual), but as of 31 March 2020 they have not. (see:
eevBLAB #72 - BUSTED! Medtronics Open Ventilator FAIL). They have published specifications, like would be used in a contract to buy them, and service documents that have some design information, but nothing that would allow anyone to build a part that would go into one. They say as of 31 March 2020: More documents and source code files pertaining to the PB560 ventilator system will be available soon.
But much more is needed for someone to even start to do planning to build this. They could easily give those documents to Tesla which would allow them to make some of the parts.
1 April 2020: After signing a limited license the manufacturing info is now available. But that license expires 1 Oct 2024 or sooner if WHO says the pandemic is over. This is good for someone like Tesla, but bad for any new open source development.
Bloom Energy & Stanford Health Care
Normally works with green electric power, but is now also repairing Ventilators. Stanford will test the repaired ventilators prior to shipment to hospitals.
YouTube: Bloom Energy:Adapting Manufacturing Operations to Support COVID-19 Response Efforts -
MiCo BioMed
A South Korea company that makes the VERI-Q PCR 316 diagnostic tester. It uses an optical setup that's very similar to a fluorescence microscope (Wiki). Producing test results in less than one hour
See: Edmund Optics: Diagnosing the Novel Coronavirus with Optics - based on PCR (Wiki).
Vyaire Medical LTV 1200
One of the models stocked by FEMA. Has internal low capacity battery. The unit runs on a "12 Volt" source, it has no AC mains input. Internal battery needs to be changed if unit stored for any length of time. The manual only says that a service technician needs to replace the battery using a Vyaire p/n so the model of the replacement battery is not known.
Electrocardiograph
Just parking this topic here for now.
HP 43200MC
1882402 Electrocardiograph, R.H. Kruse, Cambridge Instrument Co, 1932-10-11, 600/523 - "string-galvanometer electrocardiograph" Major parts: string galvanometer, a lamp, a time-mark er motor, and a camera motor. AC line powered to get away from the multiple problems of storage battery operation. There's a need to separate the sensitive circuits from the power circuits. No electronics
1958696 String galvanometer, J.D. Digby, Cambridge Instrument Co, 1934-05-15, 324/97; 74/501.5R - no electronics
2124208 Method and apparatus for amplifying and recording electrical currents, Frank G Paully, Hellige Inc, 1938-07-19, 600/523; 346/33ME; 330/129 - vacuum tubes. "...amplifying and recording feeble electrical Cur rents produced by living organisms, as in making electrocardiograms..." Problems with film and pen & ink recording.
2439640 Electrocardiograph, Traugott Paul, Electro Physical Lab, App: 1944-05-24, Pub: 1948-04-13, 600/523; 600/522; 346/33ME - Tubes, pen on roll paper, batteries, wood box
Patent Citations (5)
Cited By (4)
2655425 Electrocardiograph, Harvey W Wood, Cambridge Instrument, 1953-10-13, 346/23; 324/113; 200/19.01; 324/130; 346/33ME; 346/71 - balanced tube amp, paper strip chart output. Includes a galvanic standard cell.
Cites:2739030 Electrocardiograph, Ralph H Kruse, Cambridge Instrument, 1956-03-20, 346/76.1; 346/33ME; 346/139R; 346/112 - true rectangular coordinate recorder
2124208 (see above)
2170515 Sensitometer, John C Dionne, Henry W Keevil, 1939-08-22, - for testing the sensitivity of relays, like used in railroad signaling systems.
2436720 Measuring and controlling apparatus, Harry S Jones, Brown Instruments Co, 1948-02-24, 236/78R; 236/78B; 346/33R; 346/62; 318/639; 346/46; 374/168 - sensitive modular amplifier.
2439640 (see above)
2516520 Vacuum Tube Voltmeter (VTVM), Lamport Harold, Marvin G Schorr, 1950-07-25, 324/123R; 324/130 - "... portable milli voltmeter for the measurement of bioelectric potentials. "
2571223 Electrocardiograph, Murray W Edinburg, 1951-10-16, 600/508; 330/120; 330/123; 346/33R; 128/902; 330/122; 346/33ME - balanced tubes using VR75 & VR90 voltage regulation tubes, driving a dual coil electromagnet pen recorder.
Cites:
2409033 Electroencephalograph (Wiki) device, Garceau Lovett, 1946-10-08, 600/544; 330/65; 330/120; 600/386; 346/33ME - suitcase unit, paper strip chart output. Balanced tube circuit.
Cites:3147063 Stylus apparatus, Miller Arthur, HP, 1964-09-01, 346/139R; 346/117A -
1071192 Recording measuring instrument
1782519 Electric Meter
1901921 Electrical meter
2003913 Position controlling device
2412639 Electrocardiograph, Paul Traugott, Electro-Physical Labs, 1946-12-17, - includes stylus parking
2606093 Recording apparatus
3506813 Signal-to-noise ratio enhancement methods and means, Charles R Trimble, HP, 1970-04-14, - a form of averaging, not summing
3829826 Cable fastener for electrocardiograph electrodes, D Brown, R Dennison, HP, 1974-08-13, 439/835; 24/667; 600/372 -
4109643 Perfusion meter, Albert K. Bond, Edwin B. Merrick, Larry L. Nielsen, HP, 1978-08-29, 600/479; 356/41 - uses HP 14385A Optical Plethysmograph (single 650 nm LED and photoresistor (Wiki).
4170992 Fiducial point location, Richard F. Dillman, HP, 1979-10-16, - applied to ECG
4692273 Novel gel compositions, processes for making same and uses in transmitting and measuring electrical impulses, Katherine Lawrence, HP, 1987-09-08, -
Water Filter
Started this paragraph after watching the YouTube:
Virology and Forgotten History - @8:06 the Charles Chamberland microbe (Wiki) Filter is mentioned. It filtered bacteria, not a virus (Wiki). Koch's postulates (Wiki) caused a two decade delay in the advancement of virology (Wiki) because they only applied to bacteria that are much larger than a virus. Koch's postulates replaced the prior Miasma theory (Wiki). Also see my Faradic web page for Quack ideas.
Many of the basic filter materials for water are the same as used in Gas Masks. Some from of carbon being most common.
336089 Filter, C.E. Chambrland, Feb 16, 1886, - a can holds a half dozen cylindrical filters plumbed in parallel.
336385 Filtering Compound, Charles Edouard Chamberland (France), Feb. 16, 1886, - 20% to 40% clay & 60% to 80% porcelain-earth. Baked at 1850 to 2400 degrees F.
336386 Filtering Compound, Charles Edouard Chamberland (France), Feb. 16, 1886, - 60% to 80% earthenware-clay, diluted in water, mixed with 20% to 40% of biscuit of the said clay and fired as above.
388162 Filter, F.K. Way, Pasteur Chamberland Filter Co, Aug 21, 1888 - can containing a number of cylindrical filters.
507770 Air-Valve, Frank K. Way, Frank M. Waters, Pasteur Chamberland Filter Co, 1893-10-31, - allows air to escape but not water. For use with “Système Pasteur”.
519664 Filter, C.E. Chamberland, May 8, 1894, - can containing a number of cylindrical filters.
602304 Filter, C.E. Chamberland, Apr 12, 1898, - filter feeds water cooler with spigot.
615941 Combined Filter and Cooler, Walter G Wuichet, Pasteur Chamberland Filter Co, Dec 13, 1898, -
648043 Portable Filter, J.S. Miles, Pasteur Chamberland Filter Co, Apr 24, 1900 - tripod mounted can of cartridges with hand lever pump.
654775 Filter, W.G. Wuichet, Pasteur Chamberland Filter Co, Jul 31, 1900, - single cylindrical unit on stand. gravity feed to spigot. like office water cooler.
662668 Novelty for advertising or similar purposes, Claude R Crandall, Pasteur Chamberland Filter Co, 1900-11-27, - two water wheels that can be in a store window display. One or more of the wheels turn in a direction opposite to what is expected.
664803 Combined faucet and overflow, Walter G Wuichet, Pasteur Chamberland Filter Co,1900-12-25, - crock pot with bottom spigot
684031 Lever-jack, Walter G Wuichet, Pasteur Chamberland Filter Co, 1901-10-08, - Similar to the Farm Jack. Assigned to PCFC because he worked there?
695375 Filter, Charles Edouard Chamberland, 1902-03-11, - can containing a number of cylindrical filters.
713197 Combined filter and cooler, Joseph E Bimm, Pasteur Chamberland Filter Co, 1902-11-11, -
885125 Cooler, Walter G Wuichet, Pasteur Chamberland Filter Co, 1908-04-21, -
Surgical Pump
12753 Elastic-tube pump, Porter & Bradley, 1855-04-17, 417/476 -
249285 Instrument for transfusion of blood, E.E. Allen, 1881-11-08, 417/477.14 -
487136 Surgical pump, C.H. Traux, 1892-11-29, 417/477.8 604/185 604/153 - Wiki: Peristaltic pump -
5222880 Self-regulating blood pump, Jean P. Montoya, Scott I. Merz, Robert H. Bartlett, UoM, 417/477.13; 138/119; 138/128
Sleep Apnea
Sleep Heart Health Study - 6.6.2.7 Scoring respiratory events - There are many different kinds of events, not mentioned are missed events caused by hardware not being perfice. The Perfusion Index as part of high end Pulse Oximetey equipment gives an indication of the limits of the equipment. If the PI is low then it's easy for the equipment to miss a pulse beat, but that's less likely to happen with a high PI value. Note that the Chinese finger-tip sensors that have a single cable gave higher PI values than the factory two-piece cable sensors.
Philips: Alice NightOne -
Measures:
Nasal Cannula for air flow. This is done using
Thoracic Effort Belt for chest motion related to breathing
SpO2 Sensor (Finger Clip) for Pulse Oximetry
I have the feeling that the proprietary software maximizes the "event count per hour" in order to make more money for everyone in the medical food chain. When asked for details I was not able to get any. "Trust us" is how this is handled.
There is also some funny business associated with the machines. I was prescribed a machine that included data logging. Later the equipment company asked me to trade it for a lesser machine. There was no doctor involved, so suspect it's a way for the equipment vendor to make some extra money.
Related
Gas Masks & N95
Scott C420 Powered Air-Purifying Respirator (PAPR)
Photelometer & American Optical Hb-Meter
References
2020 March 27 -Ventec Life Systems and GM Partner to Mass Produce Critical Care Ventilators in Response to COVID-19 Pandemic - The VOCSN (Wiki) may be the most capable unit on the market. VOCSN combines: Ventilator (Wiki), Oxygen concentrator (Wiki), Cough Assist (Wiki), Suction Unit (Wiki) and Nebulizer (Wiki).
Frank's Hospital Workshop - background, instruction manuals, service manuals, testing of a broad selection of hospital equipment.
YouTube: Steve Mold:
The bizarre flashing lights on a smartwatch, 13:28 - pulse rate, pulse oximetry, lung size?
Links
PRC68, Alphanumeric Index of Web pages, Contact, Products for Sale
Page Created 25 March 2020