DIY Chemistry Points The Way To Open Source Blood Glucose Testing

January 4, 2024 by Dan Maloney 16 Comments

Every diabetic knows that one of the major burdens of the disease is managing supplies. From insulin to alcohol wipes, diabetes is a resource-intensive disease, and running out of anything has the potential for disaster. This is especially true for glucose test trips, the little electrochemical dongles that plug into a meter and read the amount of glucose in a single drop of blood.

As you might expect, glucose test strips are highly proprietary, tightly regulated, and very expensive. But the chemistry that makes them work is pretty simple, which led [Markus Bindhammer] to these experiments with open source glucose testing. It’s all part of a larger effort at developing an open Arduino glucometer, a project that has been going on since 2016 but stalled in part thanks to supply chain difficulties on the chemistry side, mainly in procuring glucose oxidase, an enzyme that oxidizes glucose. The reaction creates hydrogen peroxide, which can be measured to determine the amount of glucose present.

With glucose oxidase once again readily available — from bakery and wine-making suppliers — [Markus] started playing with the chemistry. The first reaction in the video below demonstrates how iodine and starch can be used as a reagent to detect peroxide. A tiny drop of glucose solution turns the iodine-starch suspension a deep blue color in the presence of glucose oxidase.

While lovely, colorimetric reactions such as these aren’t optimal for analyzing blood, so reaction number two uses electrochemistry to detect glucose. Platinum electrodes are bathed in a solution of glucose oxidase and connected to a multimeter. When glucose is added to the solution, the peroxide produced lowers the resistance across the electrodes. This is essentially what’s going on in commercial glucose test strips, as well as in continuous glucose monitors.

Hats off to [Markus] for working so diligently on this project. We’re keenly interested in this project, and we’ll be following developments closely. Continue reading “DIY Chemistry Points The Way To Open Source Blood Glucose Testing” →

British Hospital Blasts Through Waiting Lists By Slashing Surgeon Downtime

January 4, 2024 by Lewin Day 66 Comments

It feels like it doesn’t matter where you go, health systems are struggling. In the US, just about any procedure is super expensive. In the UK and Australia, waiting lists extend far into the future and patients are left sitting in ambulances as hospitals lack capacity. In France, staff shortages rage furiously, frustrating operations.

It might seem like hope is fruitless and there is little that can be done. But amidst this horrid backdrop, one London hospital is finding some serious gains with some neat optimizations to the way it handles surgery, as The Times reports.

Continue reading “British Hospital Blasts Through Waiting Lists By Slashing Surgeon Downtime” →

An Insulin Injection That Lasts For Days: A New Hope For Diabetics

December 27, 2023 by Maya Posch 12 Comments

A major challenge for people who have a form of diabetes is the need to regulate the glucose levels in their body. Normally this is where the body’s insulin-producing cells would respond to glucose with a matching amount of insulin, but in absence of this response it is up to the patient to manually inject insulin. Yet recent research offers the hope that these daily injections might be replaced with weekly injections, using insulin-binding substances that provide a glucose-response rather like the natural one. One such approach was tested by Juan Zhang and colleagues, with the results detailed in Nature Biomedical Engineering.

In this study, the researchers injected a group of diabetic (type 1) mice and minipigs with the formulation, consisting out of gluconic acid-modified recombinant human insulin bound to a glucose-responsive phenylboronic acid-diol complex. The phenylboronic acid element binds more easily to glucose, which results in the insulin being released, with no significant hypoglycemia observed in this small non-human test group. A major advantage of this mechanism is that it is fully self-regulating through the amount of glucose present in the blood.

This study is similar to work by Sijie Xian and colleagues published in Advanced Materials (ChemRxiv preprint) where a similar complex of glucose-sensitive, bound insulin complex was studied, albeit in vitro. With non-human animal testing showing good results for this method, human trials may not be far off, which could mean the end to daily glucose and insulin management for millions in the US alone.

(Top image: Chemical structures of the insulin-DiPBA complex and its functioning. Credit: Sijie Xian et al., 2023)

Mobile Phones And The Question Of Declining Sperm Quality

November 28, 2023 by Lewin Day 105 Comments

In a world increasingly reliant on technology, a pressing question arises: can our dependence on gadgets, particularly mobile phones, be affecting our health in unexpected ways? A growing body of research is now pointing towards a startling trend – declining sperm quality in the human population – with mobile phones emerging as a potential culprit.

Recent studies have been sounding the alarm over a noticeable decline in sperm counts and quality across the globe. This decline isn’t just about quantity; it’s about the vitality, motility, and overall health of sperm cells. The implications of this trend are profound, affecting fertility rates and possibly even the long-term viability of populations. The situation is murky and complicated, but new studies suggest that cellular phones could have a role to play.

Continue reading “Mobile Phones And The Question Of Declining Sperm Quality” →

In New Doctor’s Office, Stethoscope Wears You

November 26, 2023 by Al Williams 28 Comments

The medical professional wearing a stethoscope is a familiar image, but Northwestern University wants to change that. Instead of someone hanging an ancient device around their neck to listen inside of you, they want to put sticky sensors on patients to continuously monitor sounds from hearts, lungs, and the GI tract.

The tiny devices stick to your skin and wirelessly beam audio to clinicians for analysis. They’ve tested the devices on people ranging from people with chronic lung disease to premature babies. In fact, you can hear breath sounds (and crying) from a microphone attached to a baby in the video below. The device uses noise suppression to remove the crying sounds effectively.

Continue reading “In New Doctor’s Office, Stethoscope Wears You” →

3D printed ring with 4-integrated electrodes for measuring bioimpedance for measuring blood pressure from the finger

Smart Ring Measures Blood Pressure

November 6, 2023 by Orlando Hoilett 17 Comments

Continuous blood pressure monitoring has always been a major challenge for the biohacking community. Those giant arm cuffs aren’t exactly the kind of thing you want to wear all day and the wrist monitors aren’t super great either. So, [Kaan] and his research team set out to create a better continuous blood pressure monitor. This time as a ring.

When your heart beats, the volume of blood in the blood vessels increases ever so slightly. This increase in volume results in a decrease in electrical impedance because blood is fairly conductive. We’ve seen a similar volume measurement using light for detecting heart rate, but [Kaan] says with impedance, you won’t need to worry about the effect of skin tone on the accuracy of the measurement.

As far as the hardware is concerned, they inject a small, constant 10 kHz sinusoidal current into the finger through 2 current-injecting electrodes, and then measure the resulting voltage drop across the finger with two sensing electrodes, a standard 4-probe Kelvin approach. Their results seem pretty good. They are within 5.27 millimeters of mercury (mmHg) of the gold standard for systolic blood pressure and 3.87 mmHg for diastolic blood pressure across 10 subjects, which they say are within the American Association for the Advancement of Medical Instrumentation’s (AAMI) guidelines. That’s definitely something to catch your attention.

We’ve seen several attempts to measure blood pressure using the analogous photoplethysmography technique, but those generally don’t seem to work out. Will the impedance plethysmography approach overcome the optical technique’s shortcomings? Only time will tell.

Open Source Ear Monitoring Platform Listens To Your Ears

October 17, 2023 by Richard Baguley 17 Comments

All sorts of exciting things happen in your ears, and now there is a good open source way to monitor them. Open Earable is a new project from a group of researchers and companies that monitors and records what is going on in your ear.

The project is designed as an easy-to-build, cheap way for audiologists and others to capture data about what is happening inside and around the ear. It’s a clip-on device that looks like a small hearing aid but has a six-degree Inertial Measurement Unit (IMU) and several other sensors to measure things around your ear and inside the ear canal. A pressure and temperature sensor measures the air pressure and temperature just inside the ear canal, and a small speaker can squirt sound right in there.

A button on the outside allows the user to control the device, and it can play back or record sound to the internal SD card memory. These are all controlled by an Arduino that includes Bluetooth Low Energy. The existing design only allows you to play a stored WAV file, not streaming audio. That’s a solvable problem, though, so it could also be turned into a set of hacker headphones.

Joking aside, this looks like an exciting research project and a useful tool for researchers. The GitHub repository for version 1.3 of the project lays it all out, including a full BoM and code, and the STL files for the case and PCB designs are in the Resources section of the site.

[Updated 18/10/2023 to correct IMU to Measurement, not Management. Intertial management needs a different set of devices]