Our webinar reveals how device developers will need to maneuver through conservative, highly regulated, monopolistic yet fragmented healthcare systems that often provide contradictory incentives.

Chiplets: the path to IoT diversity

Following the presentation, our audience had the opportunity to ask a variety of questions. Here’s what our experts had to say in reply.

Arun Venkat, Director, Global Head of Smart Implants
John Genova, Senior Vice President, Global Medical Technology

 

Question: What are your thoughts and experience about the role of human factors engineering in gaining acceptability from implant users?

 

 

Arun: Human factors is embedded into our medical device development process and the whole mapping of the market is from a human-centric design perspective. I know this word is thrown around quite a bit, but if you look at the implant space it is still very tech heavy. It is still extremely focused on the clinical application but healthcare is getting increasingly patient centric.

There is a significant consumer aspect to development therefore human factors become very relevant, especially during the very early in the device design process. How does the patient interact with the device? What do they gain from it? Do they want to continue interacting with it? How is that patient engagement leading to improvement in therapy delivery?

John: It’s true not only will the patient or consumer want to know about their implant and work with it but also, we mentioned earlier about younger people and children. Where parents and care givers will be involved in the care continuum, human factors extend to consider how do they interact with the patient – this is so important and the whole area must be understood to make sure better delivery of healthcare is achieved.

 

Question: In general, implantable devices are geared towards an older generation. How do we deliver a product that can stand up to us living longer and perhaps also help younger people? How can we guarantee the reliability we need to ensure the device functions for the rest of their life?

 

Arun: That’s an interesting and relevant question, I think there will be a breed of implant devices for all ages. If you review the hearing aid market for instance, it’s already here today with hearing aids for children – young children in some cases in the form of cochlear implants.

I have also noticed some clients come to us for interesting applications of implants that are not medical, a few years ago we had a company come to us for an implant to replace security cards for their employees, as a product development company we expect more innovative requests in the future.

 

Question: How could the use of a digital twin enable smart, connected implants?

Arun: This is interesting, we have done a lot of work in this space during the last 10 years, even before the name “digital twin” had been defined. We’ve been working closely with several companies in this space, all of them have body models and as part of these collaborations are doing our own scalable body models. Our models are based on the Ansys HFSS tool, and we have custom scripts that link solid works to space claim. We used digital twins not just for electromagnetics work, we’ve used them for thermal work, we’ve used that in conjunction with fluent for flow work on multiple medical and non-medical devices.

We’ve not yet explored the potential of using digital twin to reduce clinical trials and trying to exercise the entire device in a digital phantom. We still use them as tools as part of the design cycle and not in the V&V stage of the medical device development process.

 

Question: In the case of life supporting devices such as pacemakers, will energy harvesting be stable enough for soft capsule devices?

 

Arun: No, not today, there’s still a lot of work to be done, that’s why I identified it as a vision that we want to get to, but today it’s all about external power delivery. There are many power delivery modalities available but it’s still with an external device, there is no self-sustaining energy harvesting device with continuous power available when needed. You can trickle charge in instances when you get a boost of power but then nothing can give you power like either an external device or a battery at least today.

 

Question: What are your thoughts about where wireless power transfer in the future?

 

Arun: Wireless power transfer are popular modalities that have been around for a long time, inductive systems have been around for over 20-30 years then more recently the mid-field wireless system and more recently far-field wireless systems. There are many companies exploring different modalities, but it all comes down to how much power do you need, what is the size of your device and how deep is your device in the body? Is your patient okay with wearing an external during the charging procedure or sitting in a spot while the charging procedure happens or do, they want to freely move about?

One of the hot topics in the industry right now is how can we design chargers where the patient can freely move about not restricted to a certain space while charging. We are exploring some technology allowing free moving charging solutions but of course at the end of the day physics will have its limitations – it’s a very hot topic and a lot of people both in industry and the research community are interested in addressing these challenges.

John: As complexity increases and we seek smaller, battery-less and wireless solutions with potential to move around in the body this is an area that is getting a lot of attention and rightfully so – because devices can’t get smaller if we can’t charge them - it’s very difficult and something that is being looked at by a number of people.

 

Question: Focusing on the neuro-stim area, I’m interested in your opinion about Elon Musk neural company and its cognitive enhancement implant that are being developed.

Arun: Neuralink, is one of a number of companies designing brain machine interfaces, there is interesting brain machine interface (BMI) work being developed out of MIT who are also exploring non-invasive methods for BMI.

These are all very interesting areas and I definitely think they will bring about a certain bridging the gap between the physical and the digital world, we can expect a lot more data that’s relevant and that can feed into the same metric, that I discussed about during the webinar, creating actionable insights that are useful to the patient.

 

Question: What other current limitations do you see on neuro implants and neurostimulation?

Arun: The tissue interface is key, we can make the implant smaller, we can transfer power to it, but the reality is you need a certain size to harvest enough power from an external field and then enough power to create enough current on the nerve to be able to cause the right action potentials.

I think from that perspective the soft implants which we are exploring today are going to be a significant step forward especially in terms of improving the electrodynamics and I use that word carefully because you think of devices in the market today. It puts out two to five milliamps of current and can address up to one kilo ohms of electrode impedance. Now that’s high, but there is potential to get significantly lower impedances and the entire device a lot smaller and simpler if you could have better tissue interfaces.

 

Question: Do you think better standards are required to address the issue of power absorption into the body?

 

Arun: This is an interesting one, there are a few different standards. Look at charging, I think Medtronic pioneered the popular CEM43 standard, but I think there is an important gap that researchers are starting to see and that we saw in our work four or five years ago. If you look at a radiator that’s inside your body, absorption is only one of the electromagnetic mechanisms that cause loss of energy.

Absorption to heat is an important one, but the trapping of electromagnetic energy due to total internal reflection makes a bigger contribution. If you try to calculate and separate out the different loss mechanisms in tissue what you’ll find is that almost 70% to 80%, although of course it is frequency dependent and tissue dependent, is going to be due to total internal reflection. 

I would pose the question differently - instead of energy being lost as heat can you actually design better radiators or better systems that can leak out of the body? This is something we have invested in and created intellectual property in as we have found traditional radiator designs don’t comes close in pre-clinical testing to the RF performance. I think the body electromagnetics should be looked at with a keener eye as there is still a lot of unexplored areas.

 

Question: Can you provide us a brief overview of the latest trends in completely passive sensing?

Arun: We all familiar with CardioMEMS type devices which are essentially LC resonators, a ceramic with a printed coil and a glass capacitor that flexes a diaphragm to change the capacitance and in turn change the resonant frequency. That’s a completely passive, chip-less solution.

There are new variants coming from the RFID space. RFID has been exploring chip-less RFIDs for a long time and we have been expanding that to chip-less sensors, we have some IP that looks at near-field sensing using passive resonant structures where the resonant frequency changes with the measurable (similar to LC resonators) but it also changes other attributes of the electromagnetic wave and the electromagnetic relation which can be measured to provide greater resolution. These result in some very accurate and very low-cost sensors.

Recently I’ve seen interest growing in injectable electrodes, injectable sensing, which is very exciting. In 2014 we did some work on using Galinstan (gallium indium alloy) working with Michael Dickey’s lab looking at designing liquid metal antennas that go in implants. So, there’s all sorts of such work that is being done today that I think will realize the kind of vision we have for soft body long term bio-compatibility implants.

Author
Arun Venkat
Director, Global Head of Smart Implants