I’ve been wanting to test the gastric sensor by Alimetry for a while now. This is a unique product, I’ve never seen anything similar before, and – if it lives up to its promises – it offers valuable data in a health segment where data is scarce.
There is a huge demand for a better understanding of the workings of our gastric systems, and so far nobody has been able to meaningfully collect digital health data about it. Although the stomach is controlled by an electrical conduction system regulating its contractions, the signals are weak, a hundred times weaker than those of the heart.
The technical challenge so far was to find a way to capture these mild signals in a clinically reliable way. A reliable solution that could either be used by patients at home or at the point of care would be a hit. This is a niche segment, but one with significant demand.
Properly diagnosing gastric dysfunctions is notoriously tricky: most of the data comes from observations. Patients eat something and they and their practitioners try to figure out what happens and what is the reason if something happens. It involved lots and lots of guesswork, and too often multiple rounds of incorrect theories on the causes of various symptoms.
Thus I was intrigued to lay my hands on a set of gastric sensors and observe it in action. Let’s see what I learned. As our test involved one willing team member of The Medical Futurist, the review will also include the patient’s point of view in the later sections.
What is in the ‘Body Surface Gastric Mapping System’ package?
The delivered package included the following parts:
- A charger dock – with 4 different adapters for all kinds of global outlets, making the device universally usable. The dock needs to be plugged in to charge the reader
- A reader with Bluetooth connectivity and wireless charging capability, you only need to place it on the dock, no wires are needed here. One confusing thing: once you paired your reader with the tablet, it stops showing battery charging levels, even if you disconnect them. The tricky part is that the app also keeps showing the battery charge level it had when it was paired, so you need to unpair and pair them again if you want to see the actual figure while charging
- Two packages of disposable arrays and array templates, each pair separately sealed
- An iPad mini preinstalled with the Alimetry app – and locked to its exclusive use
- A user manual booklet with very detailed information on the device, its parts, the setup and the whole process
Ease of use
As a first-time user, I need to offer kudos to the user-experience team. Although the whole process seems fairly complex, it was very straightforward. I started by reading the full user manual before charging and turning on the other devices, but to be honest, all would be equally obvious just by launching the app and following its step-by-step setup instructions.
The app breaks down the test into small steps, not allowing the practitioner to move forward until everything is in line with the requirements. For example, it is not possible to start setting up the test unless the reader is sufficiently charged to safely last for the entire 4.5 hours of a full cycle.
The only reason you should not rely on the app alone is that the user’s manual includes crucial information on how the patient should prepare for the test, and these are not included in the app.
The 4.5-hour test cycle
Active participation from the physician is mainly required at the setup phase of the Gastric Alimetry process.
You need to complete the following steps in advance:
- Charge the reader to at least 83%
- Set up the iPad by connecting it to a stable Wi-Fi network, setting up a passcode and enabling guided mode and setting up a passcode for that one as well. Guided mode is required so the iPad will not turn off during the test, nor can patients accidentally quit the app
- Charge the tablet to at least 60%
Just before the test:
- Patient measurements prior to the test: to allow proper positioning of the array, you need to measure Xiphoid-Umbilicus and Xiphoid-ASIS distances as well as waist circumference, these values will need to be entered in the app during the preparation phase
- Prepare the skin with a prep gel
- Mark the proper array position on the skin using the array template – you will be guided based on the previous measurements by the app
And at the start of the test:
- Connect the disposable array to the reader and secure it by closing the reader lids
- Remove the adhesive covers from the array and position the reader and array on the patient’s body
- Measure the distance between the bottom of the array and the Umbilicus and enter this value into the app (negative values for small frames, when the array ends below the belly button)
- Let the app check signal strength
- Enter guided mode and hand the tablet to the patient, so they can record any symptoms in the following hours. At this stage, I needed to force-restart the tablet to launch guided mode (and thus enter all the data again), which, as I researched, is a well-known problem of iPad minis
- And finally, make sure that the patient will remain in a comfortable reclining position for the next 4.5 hours – comfort brakes are allowed if necessary
During the test:
- After the first 30 minutes the patient needs to consume a “standard meal”, which is detailed in the manual, so it also needs to be on hand. The recommended “standard meal” is included in the user manual: a nutritional drink and a cereal bar; all nutritional values are provided, so you can match them if the specific brands are not easily available in your area
After the test:
- Make sure the test results are uploaded to the Alimetry server. It happens automatically and will also be shown in the app
What will the test deliver?
The test aims to detect the causes of overlapping gastric symptoms with distinct underlying phenotypes. In this study, researchers tested 43 patients with indistinguishable symptoms and were able to identify two distinct subgroups.
The Gastric Alimetry platform is currently being used in clinical practice to differentiate between chronic nausea and vomiting syndromes (NVSs) that originate in the gut and those that arise through a centrally mediated pathway—a phenotype often tied to anxiety and depression.
The 64-channel reading of the Alimetry devices focuses on the fact that gastric dysfunctions are associated with abnormalities in the gastric bioelectrical slow waves. As shown in this study, the device was efficient in differentiating between patients having gastric neuromuscular disease or dysregulation of the brain-gut interaction.
At the moment it seems Alimetry is a good tool to detect the underlying causes of chronic NVS, and the company works on how to apply it to other gastrointestinal conditions, including functional dyspepsia and gastroparesis.
The patient perspective from our editor-in-chief
I was excited to be the subject of this gastric sensor test. I am an average person, with a normal BMI, and no major gastric problems apart from a mild case of acidic reflux, which is easily managed by dietary choices.
I don’t have noticeable symptoms in my everyday life, but this is the result of avoiding certain foods and beverages in excessive amounts and/or in the evening. Thus I was intrigued by what I will learn from the test.
Test preparation:
- I was told not to eat or drink anything for 6 hours preceding the test. This was scary. I don’t mind not eating, but I normally drink at least a few cups of water/tea during any 6-hours of my waking periods, so I tried drinking plenty of water just before the 6 hours started
- Nevertheless, by the time I was ready to go, I was very thirsty. Going for a 10+ kilometers walk during the 6-hour fasting period was maybe a dumb idea
Test process:
- I am short, and the array placement was surely out of the average, it ended way below my belly button. It was also noted in the final report. Nevertheless, the results were valid.
- The test process was a breeze, after the initial measurements were taken, I took a comfortable – reclining – position, connected my laptop to the big screen in front of me and started binge-watching.
- I was told not to move a lot, not to talk a lot and not to laugh – if possible. Watching Taskmaster was slightly jeopardising the latter, I don’t recommend this show for gastric alimetry.
- The first 30 minutes were the baseline readings, still with an empty stomach. Then I had 10 minutes to consume a test meal: a small drink and a large cereal bar.
- Following the meal came 4 hours of the actual test. It was nothing demanding, the app chimed every time when it was time to update my symptoms and warned me when I was making “excessive movements”.
- I’m not sure if that was the result of not drinking anything – apart from the 200 ml nutritional drink – for 10 hours and 40 minutes, but I experienced the worst reflux episode I had for years during the test. The symptoms almost immediately ceased after I downed a litre of water at the completion. However, I figured that provoking symptoms during the test was probably the whole point.
- I found one thing confusing though. You need to evaluate your symptoms on a scale between 0 (non-existent) and 10 (most severe imaginable) during the test in several areas like upper gut pain, nausea, heartburn or stomach burn and some more. I was not sure how to score my discomfort. I have a vivid imagination, so I would not dare to rate the worst contractions I had during labor as 10. There can be easily more pain in the world, I just never experienced it. Thus I never rated my symptoms above 3. But this might be all right as well, as I was in no big pain.
- The results were comforting, my report came back normal, noting that my symptoms don’t seem to correlate with the meal and fall within a sub-clinical range. This reinforced my previous guess that they were simply the result of not drinking anything for an extended period.
Conclusion
The Gastric Alimetry device is a first-of-a-kind solution, fully fitting all principles of digital health. It is making patients the point of care and it targets a niche area with massive demand. I am eager to see where Body Surface Gastric Mapping develops in the coming years.
The total time requirement of such a test is significant, patients need to dedicate a total of 10.5 hours to it. The discomfort of the prolonged process is tolerable, many gastric diagnostic methods are much more demanding. If you have chronic NVS and would like to find a way to detect its causes, it is well worth the effort.
The post What’s Happening In Your Stomach? – Gastric Alimetry Review appeared first on The Medical Futurist.
