Smart Pills

S Chelliah, Senior Professor - IT & ITeS, Loyola Institute of Business Administration Located in Chennai, Loyola Institute of Business Administration is a premier B-School established by the Society of Jesus. It offers a two-year full-time PGDM course, along with Part-time PGDM (AICTE approved), Ph.D.(affiliated to the University of Madras) and one-year executive diploma program.

The use of implanted devices like pacemakers and wearable devices like Smartwatches, that record, regulate and report physiological parameters, energy expended, calories burnt etc. is fairly common. Now, consider the following facts/situations: In the U.S.,studies have shown that about 50 percent of the patients frequently forget the medication or dosage and skip it. This will worsen his/her medical condition especially for those needing chronic medication, and the increase in healthcare cost is upwards of $200 billion per year.

For a patient suffering from gastroparesis (a condition where stomach cannot empty the food in a normal manner), the motility within the gastrointestinal(GI)tract must be measured. For these cases, imagine a sensor that is packaged as part of a tablet or capsule, is ingested. It measures the parameters of interest periodically and transmits it in real time to a patch worn on the thigh. How nice would it be!! That is the 'Smart Pill'. So, in addition to chewable, implantable and wearable, here comes the ingestible.

How Does It Work?
The pill consists of an advanced sensor to collect data, a source of energy to power the sensor, and capability to send data to an external agency. The sensor is an integrated circuit, of the size of a grain of sand. It has a few micrometers thick magnesium as the substrate. It has a top layer of gold deposited on the integrated circuit and a layer of cuprous chloride on the gold. With the gastric fluids inside the stomach acting as the electrolyte, the cuprous chloride acting as cathode and magnesium as the anode, a biogalvanic battery is created that powers the sensor. The generated current is modulated by the sensor and it creates an electric field that propagates through the body tissue to the skin surface where it is detected, decoded, and recorded with time-stamp by the patch (receiver)on the torso.

This process is similar to how bioelectric signals of the heart reach the electrodes of electrocardiograph or the signals from the brain reach the electrodes of electroencephalograph, both placed on the surface of the body. Each sensor can identify the medication. Also, each sensor will have a unique and private ID which will be tagged on to the transmitted signals. Hence a single patch can collect
The sensor by virtue of proximity ensures privacy. The transmitter on the patch can send it via a Bluetooth (encrypted) to a base station or
signals from multiple sensors placed within the body and record different physiological parameters.

a smartphone about 2-3 metres away and from there, after strong encryption, via the Internet to the doctors, caregivers, and hospitals. The sensor apart from the type of medication chosen, can also record vital signs such as heart rate, temperature, gastric pH, pressure, heart and lung sounds etc. The patient will not feel any unease or discomfort, both while swallowing the pill and while it traverses through the GI tract. The sensor stays in the stomach for less than four hours, in the small intestine for about six hours and in the large intestine for about sixty hours. Then it is automatically excreted. The patch must be worn at all times. Where needed, other physiologic parameters that are recorded using peripheral devices such as glucometers, blood pressure cuffs etc. can be combined with this smart pill’s data to create a profile of the patient that links the medication, wellness, and response to therapy.

Where needed, other physiologic parameters that are recorded using peripheral devices can be combined with smart pill's data to create a profile of the patient

There are challenges in both manufacturing and using the Smart Pill:
1. In the body, the composition of acids, electrolytes, enzymes, and surfactants change from stomach to small intestine and even in the same organ with time due to digestion, gastric emptying and medication. Thus as the sensor moves along GI system, its impedance and output current will change. Yet, it should function unaffected by these variations.

2. The frequencies for data transmission must not interfere with common medical instruments, electronic devices and with electro physiological signals of the body which are usually in the range of 10-100 Hz. Also, these frequencies should not stimulate any cells or tissue. Considering these, the sensor operates using 10-30 Hz.

3. The sensor should be bioresorbable, safe and should not produce any contraindications or adverse side effects.

The above challenges have been addressed and several clinical trials have been conducted with both healthy people as well as patients with hypertension, heart failure, diabetes, bipolar disorder,schizophrenia. It has been found to be safe and effective. It has been approved by FDA in USA and has received CE Mark certificate in Europe.

Other Applications
An ingestible stethoscope has a sensor to collect heart and lung sounds. The background noise produced by the digestive tract and other organs are filtered and the acoustic signal is converted into heart beats and breathing rates. Sophisticated sensors can measure even specific molecular aspects for particular diseases to assist in location specific and gene-specific treatments. Gastrointestinal imaging can be done to identify internal haemorrhage, crohon’s disease, celiac disease, cancer and polyps. As the signals must pass through the torso to reach the patch on the surface, properties such as hydration and fat content can also possibly be measured.

The smart Pill holds lot of promise. It can be used for very specialized drug release, to target specific locations and to respond to specific local sensing events. It can usher a reliable, efficient, continuous, automated, way of monitoring patients under medication. It has been predicted the ingestible sensor market will grow to about U.S. $700 million in 2022, a compounded growth rate of about 20 percent. In the future, various sensors can be fabricated to record many parameters as the patient goes about pursuing his/her routine life. However, the 'Smart Pill' will not be available at the local drug store in the near future.