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The award-winning Phase Change Matters blog tracks the latest news and research on phase change materials and thermal energy storage. E-mail tips and comments to Ben Welter, communications director at Entropy Solutions. Follow the blog on Twitter at @PureTemp. Subscribe to the weekly PCM newsletter. Or join the discussion on LinkedIn.

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Patent application: Mobile lab for rapid detection and analysis of biological targets

Ben Welter - Friday, March 15, 2019

U.S. patent application 20190076844 (applicant MRIGlobal, Kansas City, Missouri):

"A mobile field-deployable laboratory to more conveniently enable the detecting, sequencing and analyzing of biological agents at the point-of-need. This device enables field operators to go from sample to actionable information in the field without the need for an internet connection or grid-based power. ... [The] cooling system includes a phase-change cooling system capable of holding a predetermined selected temperature constant for a predetermined time period."

http://www.freepatentsonline.com/20190076844.pdf

Patent application: Self-heating personal covering

Ben Welter - Friday, March 01, 2019

U.S. patent application 20190059619 (applicant Aspen Surgical Products Inc., Caledonia, Mich.):

"Disclosed is a self-heating personal covering that includes a first layer and a second layer that is parallel to and opposite of the first layer, and at least a portion of the second layer is fastened to at least a portion of the first layer. The self-heating personal covering also includes at least one heat source positioned between the first layer and the second layer. The at least one heat source is held in a prescribed position by the first layer and the second layer, and includes a material that undergoes an exothermic reaction upon exposure to oxygen. ... [At] least one heat distributing structure is a layer of phase change material. The layer of phase change material may be positioned between the at least one heat source and the second layer."

http://www.freepatentsonline.com/20190059619.pdf

Patent application: Contact lens with metered liquid system

Ben Welter - Monday, January 28, 2019

U.S. patent application 20190025610 (applicants California Institute of Technology, Pasadena, Calif., and University of Southern California, Los Angeles):

Contact lens patent drawing"A contact lens fluid delivery device having a liquid reservoir connected to a channel with a flow regulator is described. Other eye hydration and variable dioptric power contact lenses are described herein. Also described are implantable liquid delivery apparatuses having a liquid storage reservoir connected to a channel with a flow regulator. These devices and apparatuses are useful for specific, targeted delivery of therapeutic liquids within a subject. In some embodiments, the devices incorporate actuation chambers which provide a driving force releasing the fluid into the targeted area e.g., the eye. The actuation chambers described herein can contain phase change materials or osmotic chambers or a combination thereof to drive the release of fluid."

http://www.freepatentsonline.com/20190025610.pdf

PCM-equipped infant warming mat set for large-scale trial in Rwanda

Ben Welter - Monday, January 07, 2019

Dr. Anne HansenAn infant warming mat developed at Lawrence Berkeley National Laboratory in California is undergoing approval for a six-month trial at 10 hospitals in Rwanda beginning next fall. The DREAM infant warmer uses biobased phase change material to keep newborns warm in places where electricity is unavailable or unreliable. Dr. Anne Hansen, medical director of the neonatal intensive care unit at Boston Children's Hospital, helped develop the mat and is directing the trial. In an interview, she provided background on the device and explained how it works.

Q: Tell me about the need for this device. What problem does it solve?

A: In low- and middle-income countries, hypothermia is a contributing cause in about one million infant deaths per year. Newborn babies, especially babies who are low birth weight or preterm or both, tend to cool to the temperature of their environment. Therefore even in warm climates like that of sub-Saharan Africa, newborns can become dangerously cold. It's rare for hypothermia to be the primary cause of death, but hypothermia in newborns can contribute to respiratory problems, glucose regulation, immune system function, and most importantly growth, including brain growth, and therefore neuro-developmental outcome. This can perpetuate the cycle of poverty.

Q: Why is this a particular problem for babies born in lower-income countries?

A: Babies born in a rich country receive a heat chain that protects them all the way from the delivery room until they go home from the hospital. This includes electric warming tables and incubators. In poor countries, this heat chain is more difficult to ensure. The supply of electricity can be inconsistent at best, the expensive warmers and incubators may be unaffordable. If they can be acquired, the nurses may not have the training to work these complex medical devices, causing hypo- and hyperthermia, as well as raising infection control concerns given how hard they can be to clean between uses. Finally, unless the facility has advanced biomedical engineers to provide the maintenance and repairs, the warmers do not last long. Because of all these problems, ensuring that newborns in resource-limited settings have access to a consistent heat chain requires a lot of workarounds. 

The World Health Organization recommends skin-to-skin care, where you put a newborn directly on the mother's chest and she provides the external heat source. Skin-to-skin is great; we are total fans of skin-to-skin. The problem is that there are times where it's not very feasible, when the mother is sick or the mother dies in childbirth or if she has twins or triplets. If the baby is sick and requires medical assessment and treatments, the skin-to-skin positioning may not be feasible. Also, importantly, it's hard to be a human incubator for weeks to even months while a preterm baby gets old enough and mature enough to not need this external heat source. So providing heat by continuous skin-to-skin all day, all night for a long time, mothers just can't do that. They need to bathe, they may need to cook over a fire, or take care of their other children. So they have to stop; they put the baby down on a regular bed and then the baby gets cold. Finally, for the smallest babies, skin-to-skin may not provide enough heat; they're only getting heat from the part of their skin that is in direct contact with the mother's chest, but they aren't getting any heat from their backs.

We set out to design a warmer both to complement to skin-to-skin care when a mother wants to put her baby down, that could also be additive to skin-to-skin care when it is not providing enough heat. It needed to be electricity-free, inexpensive, intuitive to use, requiring minimal training, easily washed and reused with a goal of a thousand cycles.

Q: What was your role in the development of the device?

A: I've been working with Partners In Health (called Inshuti Mi Buzima in Rwanda) for almost 10 years. They work in very close collaboration with the Rwanda Ministry of Health. When I first went there in 2010, we helped them to develop and implement their national standards for newborn medicine. One of the problems that really stood out for me was that the options for thermoregulation were not working. When I came home, I partnered with Lawrence Berkeley National Lab to think about some other alternatives. We looked at a lot of ideas and ultimately settled on this phase change approach because it's so simple and straightforward.

DREAM warming mat thermosThe engineers did the actual design work, but we worked closely with them over many years to fine-tune it, figuring out how long it needed to be, how heavy it could be, how much people were willing to pay for it. From the outset we worked hand in glove with both Rwandan clinicians and the Ministry of Health. For example, the warmer is heated in thermos that holds boiling water to melt the PCM. The Ministry of Health was insistent that the thermos be wide-based and stable so that it wouldn't tip over when it was being filled with the boiling water and present any risk of burns.

We have completed two clinical studies of the warmer in Rwanda and it has performed extremely well. We are just gearing up to do what I hope will be a definitive large study with 10 hospitals in Rwanda this year. The Rwanda Ministry of Health has been amazing through all of this, supporting and facilitating all of our studies. We' want to have the warmer approved by the Rwandan Standards Bureau, which is like their FDA. They have also expressed interest in sponsoring the warmer for an international approval process, but we are going to wait on this until after we have the results from our large trial that we will be conducting later this year.

Q: Describe how the device functions.

DREAM warming mat packsA: We use your phase change material, PureTemp 37, configured as a set of 12 candles, each in its own plastic sleeve. The mat measures about 45.7 cm, by 25.4 cm, by 1.91 cm thick and contains about 1.2 kilograms of PCM. This arrangement allows the mat to be rolled up for charging or storage. Boiling water is used to charge the mat. All human civilizations know how to heat water, whether it is using a tea kettle with electricity or coal without. You heat 1.7 liters of water to boiling temperature, which provides the exact amount of energy needed to melt all the wax. The mat has a little temperature indicator that shows when it is cool enough to be safe to use. Once it has cooled, you dry it off and slip it in a little insulating pad. Then you put the baby, ideally naked, on the pad. This tends to be a population that does not have diapers, so a critical piece of the design was to avoid any fabric, Velcro or anything else that couldn't easily be cleaned with standard hospital cleanser. Ideally you give the baby a hat, and socks if you've got them, and then you wrap the baby and the warmer up in a blanket. The warmer stays hot for up to six hours, exactly at skin temperature.

Q: What's the projected price for a single unit?

A: Our goal is to keep it well under $100.

Q: Tell me about the upcoming study.

A: We're going to start this study in September of 2019 and it will run for six months. It's a complex study design called a step wedge study, specifically chosen to avoid the ethical conflict of having control patients such that one cold baby gets the warmer and another in the next bed does not. Instead, we will collect pre-data prior to introducing the warmer and this will serve as our control data. Then we will introduce the warmer, and use our post-data as our treatment data. Our hope is that we will find a reduction in hypothermia, hospital length of stay, and mortality, with improvement in growth. If so, then we we'll move to full-scale production, first for distribution across the rest of Rwanda and then in other appropriate countries in the sub-Saharan Africa.

Q: Where does the mat stand as far as approval processes in Africa?

A: We are still really at the prototype phase. We met this summer with a representative of the Rwandan Standards Bureau in Kigali. He said that, based on the results of our two preliminary pilot studies with 204 uses, it would be appropriate to for us to submit the paperwork for approval. We have not done that yet because they want to approve the absolutely final design, and we are still doing a bit more work, finding a more robust plastic and temperature indicator. Once we have our final design, we will submit the paperwork to the Rwandan Standards Bureau, sponsored by the Ministry of Health. Based on our feedback from this summer's meeting I am optimistic that they will approve it.

Rwandan twins on warming mat

Q: What's been the most satisfying part of this project for you?

A: That is the easiest question. It is absolutely 100 percent the mothers. I will never forget the very first patients that we enrolled, a pair of twins. When we walked into the hospital that very first day, we had just explained to the nurses how to prepare the warmer, we were ready to enroll our first patients, and there was this mother with these twins. She looked so tired, not smiling or really interacting. Through a translator I asked her if she would like to have her babies enrolled in this study. She learned what it was, and signed the consent form.

One of the babies was so cold that we did the combination of the skin-to-skin and warmer across the back, and the other baby went straight on the warmer. She looked at the babies and she saw them getting warm. She just had this unbelievable look of relief - she was so happy. She said, "This is the first time that I've seen my babies look comfortable since they were born."

Patent application: Surgical instrument with phase change cooling

Ben Welter - Wednesday, January 02, 2019

Covidien patent drawing

U.S. patent application 20180375402 (applicant Covidien LP, Mansfield, Mass.):

"Systems and methods are discussed herein for cooling a surgical handset using a phase-change material. A container filled with a phase-change material may be telescoped over a heat-generating mechanism of a surgical handset, such as a battery and/or a motor. When the surgical handset is activated, the heat generated by the heat-generating mechanism is absorbed by the phase-change material in the container, which transitions from a first phase to a second phase."

http://www.freepatentsonline.com/20180375402.pdf

Incubator uses PCM to keep lab samples at optimum temperatures

Ben Welter - Saturday, December 22, 2018

Intellectual Ventures’ Global Good fund has signed a licensing agreement with JP Selecta of Spain to manufacture and distribute a microbiological incubator for laboratories in areas with unreliable electrical power.

Incudigit SV 30LThe body of the Incudigit-SV 30L is lined with phase change material, enabling the device to maintain a user-adjustable temperature setpoint of 35° C, 36° C or 37° C for at least eight hours without power. 

“This incubator will help frontline health workers perform important culture-based microbiological tests in places where power is unreliable – a critical step in managing diseases like tuberculosis, sepsis, enteric and diarrheal diseases, and sexually-transmitted bacterial infections,” said Maurizio Vecchione, executive vice president of Global Good.

Three members of the Intellectual Ventures team that developed the incubator (Michael Friend, principal investigator; Simon Ghionea, senior researcher and electrical engineer; and Andy Miller, senior researcher and mechanical engineer) fielded questions about the device.

Q: What was your role in the development of the Incudigit-SV 30L?

A: The team came up with the initial concept, analyzed and designed the first-generation prototype, tested in the lab and the field and then transitioned the device to JP Selecta for the product development cycle. After the first product units were developed, the team then verified the performance of the units.

Q: What was the biggest challenge in developing the device?

Drawing of Incudigit SV 30 prototypeA: The device has to be able to support power blackouts which could occur with ambient conditions above and below the temperature setpoints (of which there are three), so developing a method to properly assess the state of the PCM was a challenge. Additionally, while the initial PCM chosen for the device had great performance at first, it was discovered that after repeated deep cycling that the enthalpy was depleting. This PCM could be recharged using an overheat procedure; however this imposed an unacceptable impact on the use case. We wound up having to change to a more stable PCM with slightly less performance than the original.

Q: Describe the typical user of the device.

A: The typical user is a medical technician/microbiologist in a laboratory which does not have reliable power. In most countries in the developing world this may be all the labs with the exception of the national reference laboratory.

Q: When will manufacturing/distribution begin?

A: With product launch this week, manufacturing/distribution is just beginning. The first units will be delivered to Doctors Without Borders for pilot tests in South Sudan and Niger in January as well as the African Medical and Research Foundation and the Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit. As this is allowing microbial culture to take place in labs where it previously could not occur, it will be difficult to estimate quantities.

Q: Describe how the device functions, especially how PCM is used. Does the device include a battery to provide active cooling and power the electronics when external power is not available?

A: The device uses PCM as a “thermal storage battery” in order to control the temperature (see reference paper http://medicaldevices.asmedigitalcollection.asme.org/article.aspx?articleid=2718461). A key feature is to maintain the PCM in a state such that it can maintain incubation setpoint temperatures at 35, 36, and 37 C during power blackouts with ambient conditions that can be above or below the setpoints. No active heating or cooling is used, only a small battery to maintain the electronics to perform temperature and power monitoring. [see YouTube video]

Q: What are the specs on the phase change material?

A: It's a paraffin with a peak melt point of 37 C and a thermal storage capacity of 160 joules per gram.

Q: How much PCM is used in each device?

A: 19 liters.

Patent application: Implantable thermal therapy devices

Ben Welter - Friday, December 21, 2018

U.S. patent application 20180360652 (applicant Medicool Technologies Inc., Rochester, Minn.):

"Implantable thermal therapy devices, systems, and methods are provided for the treatment of pathological conditions including arrhythmias and trauma. The implantable thermal therapy devices and systems are specifically structured to deliver transient cooling to a target tissue, and to gradually dissipate the heat energy transferred from the target tissue to other body masses in a controlled and delicate manner. In some examples, a phase change material can be used to accomplish such a gradual dissipation of the heat."

http://www.freepatentsonline.com/20180360652.pdf

Patent application: Apparatus for controlling environmental conditions of substances

Ben Welter - Thursday, November 29, 2018

U.S. patent application 20180333330 (inventor Ron Nagar, Tel Aviv, Israel):

"An apparatus, comprising an environmental control element configured to control at least one environmental condition of a substance contained within a chamber, the environmental control element includes a thermal insulator configured to provide a thermal shield to the substance and a phase change material (PCM) configured to thermally regulate at least one environmental condition. The environmental control element is configured to control the environmental condition without use of an external power source, thereby allowing the apparatus to be thermally self-recharging."

http://www.freepatentsonline.com/20180333330.pdf

Patent application: Personal cooling device with PCM

Ben Welter - Friday, October 12, 2018

U.S. patent application 20180289531 (applicant Relief Technologies Inc., San Francisco, Calif.):

Relief Technologies patent drawing"A cooling device includes a package substrate, a plurality of cooling units, and device electronics. The plurality of cooling units are configured to cool a user's body. Each cooling unit includes a plurality of semiconductor cooling elements sandwiched between a first cooling unit substrate and a second cooling unit substrate. Each of the cooling units is connected to the package substrate. The device electronics are coupled to the cooling units. The device electronics are configured to store a first cooling device profile that includes data indicating an amount of power to deliver to each of the cooling units over a period of time. The device electronics are configured to deliver power to the cooling units according to the first cooling device profile, wirelessly receive a second cooling device profile from an external computing device, and deliver power to the cooling units according to the second cooling device profile."

http://www.freepatentsonline.com/20180289531.pdf

PCM briefing: Students raise money to send Arktek containers to Zimbabwe; nominations open for Young Scientist Research Award

Ben Welter - Monday, August 20, 2018

• Four middle school students in Beijing have raised enough money to send three Arktek vaccine containers to Zimbabwe. The PCM-equipped containers, which cost about $5,800 each, keep diphtheria, pertussis, tetanus and other vaccines at a safe temperature for weeks without refrigeration. The girls presented the fundraiser as an entry in the Public Benefit International Challenge for Youth 2018. They also visited the factories in Shandong province to see how the containers are manufactured. Although they didn't win the competition, the girls continue to raise money to send more Arktek containers to African nations. 

• New from Transparency Market Research: "Cooling Fabrics Market - Global Industry Analysis, Size, Share, Growth, Trends, and Forecast 2017 - 2025"

India and Indonesia have signed a memo of understanding that recognizes, for the first time, the Indonesian Sustainable Palm Oil and the Indian Palm Oil Sustainability frameworks as legitimate sustainability efforts. The Solvent Extractors Association of India, the Indonesian Palm Oil Board and supply chain development organization Solidaridad signed the agreement July 16.

• Nominations are being accepted for the Young Scientist Research Award, which recognizes substantial research contributions in one of the areas represented by a division of the American Oil Chemists' Society. The award, sponsored by the International Food Science Centre A/S, recognizes young researchers whose work "has significantly effected an advance within their discipline, or holds substantial promise for such an effect in the near future." Nominations are due by Oct. 1.