A digital pill (also known as smart pill, ingestible sensor) is a

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and ...

dosage form Dosage forms (also called unit doses) are pharmaceutical drug products in the form in which they are marketed for use, with a specific mixture of active ingredients and inactive components ( excipients), in a particular configuration (such as a c ...

that contains an ingestible sensor inside of a

pill Pill or The Pill may refer to: Drugs * Pill (pharmacy), referring to anything small for a specific dose of medicine * "The Pill", a general nickname for the combined oral contraceptive pill Film and television * ''The Pill'' (film), a 2011 fil ...

. The sensor begins transmitting medical data after it is consumed. The technology that makes up the pill, as well as the data transmitted by the pill's sensor, are considered to be part of

digital medicine Digital medicine refers to the application of advanced digital technologies, such as artificial intelligence, machine learning, and big data analytics, to improve patient outcomes and healthcare delivery. It involves the integration of technology an ...

. The purpose of the sensor is to determine whether the person is taking their medication or not (called "

compliance Compliance can mean: Healthcare * Compliance (medicine), a patient's (or doctor's) adherence to a recommended course of treatment * Compliance (physiology), the tendency of a hollow organ to resist recoil toward its original dimensions (this is a ...

"). There are privacy concerns with respect to who receives the data and what is done with it.

Overview

The first emergence of a swallowable electronic device was in 1957, this device used radio frequency to transmit temperature and pressure readings. The field lay stagnant until technology caught up with invention in the 1990s. The first digital pill to be approved by the United States

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

(FDA), a version of

aripiprazole Aripiprazole, sold under the brand names Abilify and Aristada among others, is an atypical antipsychotic. It is primarily used in the treatment of schizophrenia and bipolar disorder. Other uses include as an add-on treatment in major depress ...

(Abilify) manufactured by

Otsuka Pharmaceutical (), abbreviated OPC, is a pharmaceutical company headquartered in Tokyo, Osaka and Naruto, Japan. The company was established August 10, 1964. History OPC's parent company Otsuka Holdings Co. Ltd. joined the Tokyo Stock Exchange through an in ...

, was approved in November 2017. This digital pill's sensor, developed by Proteus Digital Health, is activated by acid in the stomach, and generates an electrical signal that is picked up by a patch worn on the ribcage; the patch in turn forwards information to a

smartphone app A mobile application or app is a computer program or software application designed to run on a mobile device such as a phone, tablet, or watch. Mobile applications often stand in contrast to desktop applications which are designed to run on de ...

. The drug is taken by people with

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social wi ...

. People with the condition tend to have problems with adherence, and the digital pill could help with that; however some people with schizophrenia have

paranoia Paranoia is an instinct or thought process that is believed to be heavily influenced by anxiety or fear, often to the point of delusion and irrationality. Paranoid thinking typically includes persecutory beliefs, or beliefs of conspiracy conce ...

which the digital pill could make worse. A video from the

Wall Street Journal ''The Wall Street Journal'' is an American business-focused, international daily newspaper based in New York City, with international editions also available in Chinese and Japanese. The ''Journal'', along with its Asian editions, is published ...

that shows an overview of how digital pills work can be found here: https://www.wsj.com/video/what-is-a-digital-pill/6A4444D6-DBAD-421A-8B53-C51E23A20268.html

Types of Digital Pills

The most common types of ingestible sensors are used for imaging, sensing different types of gasses, to monitor medication compliance or absorption of medication, and electrochemical signal sensing.

Imaging Capsules

Images and video require the highest bandwidth for data delivery. Ingestible capsules containing video cameras are used for generating images of the macroscopic structures of hollow organs, such as the stomach and small bowel. These devices are powered by batteries, can transmit video at up to 2.7 Mbit/s, and are less invasive than other traditional endoscopic imaging devices.

Gas Sensing Capsules

Gas Sensing Capsules utilize a gas-permeable membrane surrounding an

electrochemical gas sensor Electrochemical gas sensors are gas detectors that measure the concentration of a target gas by oxidizing or reducing the target gas at an electrode and measuring the resulting current. History Beginning his research in 1962, Mr. Naoyoshi Tagu ...

and are primarily used to detect the partial-pressures of different gasses produced as the byproduct of metabolic reactions by bacteria in the intestines. The presence of gasses like carbon dioxide and methane in the gut provides useful data for analysis of metabolic and digestional health. This internal measurement of a body's organs provides a superior analysis in terms of accuracy and reliability as compared to the traditional technique of breath-test analysis.

Medication Monitoring Capsules

Ingestible sensors that are specific for the monitoring of the absorption of medication or compliance will also signal the user that medication needs to be taken. These are activated in the stomach by pH differences and will transmit via Bluetooth.

Electrochemical Sensing Capsules

Voltammetry can be used in vitro on stool liquid as a Gi tract diagnostic tool. The device would be able to perform cyclic, square wave, and differential pulse voltammetries.McCaffrey, C.; Twomey, K.; Ogurtsov, V. I. Development of a Wireless Swallowable Capsule with Potentiostatic Electrochemical Sensor for Gastrointestinal Track Investigation Sens. Actuators, B 2015, 218, 8– 15 DOI: 10.1016/j.snb.2015.04.063

Sensing Targets

Due to the nature of ingestible sensors, they are optimized for passage through hollow organs. This makes them ideal for data collection throughout the digestive tract, which includes multiple organs between the mouth and anus.

Oral Cavity

The most common clinical targets for the ingestible sensor in the oral cavity would aid in the determination of: electrolyte imbalances, body metabolism based on chemical makeup of saliva, hormonal imbalances, infectious conditions, i.e. HIV and viral hepatitis, allergy disorders and cancer.

Esophagus

Digital pills that have imaging capabilities are used in

endoscopy An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are inse ...

to look for inflammation and lacerations in the esophagus. The mucosa contained in the

esophagus The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...

can also be tested to look for issues such as eosinophilic esophagitis.{{Cite journal, last1=Kalantar-zadeh, first1=Kourosh, last2=Ha, first2=Nam, last3=Zhen Ou, first3=Jian, last4=Berean, first4=Kyle J., date=March 1, 2017, title=Ingestible Sensors, url=https://pubs.acs.org/doi/pdf/10.1021/acssensors.7b00045, journal=ACS Sensors, volume=2, issue=4, pages=468–483, doi=10.1021/acssensors.7b00045, pmid=28723186, doi-access=free

Stomach

The

pH value In chemistry, pH (), historically denoting "potential of hydrogen" (or "power of hydrogen"), is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions (solutions with higher concentrations of ions) are m ...

of the

stomach The stomach is a muscular, hollow organ in the gastrointestinal tract of humans and many other animals, including several invertebrates. The stomach has a dilated structure and functions as a vital organ in the digestive system. The stomach i ...

is important for proper digestion and is something that can be detected by certain types of digital pills. Stomach enzymes and electrolyte production are also able to be detected by a digital pill. These pills can also search for specific bacteria in various areas of the body. For example, digital pills can be programmed to search for

helicobacter pylori ''Helicobacter pylori'', previously known as ''Campylobacter pylori'', is a gram-negative, microaerophilic, spiral (helical) bacterium usually found in the stomach. Its helical shape (from which the genus name, helicobacter, derives) is th ...

in the stomach, which is known to be a cause of

ulcers An ulcer is a discontinuity or break in a bodily membrane that impedes normal function of the affected organ. According to Robbins's pathology, "ulcer is the breach of the continuity of skin, epithelium or mucous membrane caused by sloughing o ...

Colon

The potential targets would be to monitor stool (colonic content) for medical diagnosis of infection (parasite, viral, or bacterial sources), poor nutrient absorption, or colon cancer. Also, the ingestible sensor could do an internal colonoscopy that would be less invasive than traditional.

Powering the Digital Pill

Most digital pills use silver-oxide batteries. Lithium ion batteries are dangerous to the human bodies digestive system and therefore cannot be used.

Passive and Active Digital Pill Locomotion

Most digital pills rely on passive locomotion, or allowing the body's digestive system to do all the work moving the pill, however some pills do utilise active locomotion. One active locomotion method is to include a small magnet in the digital pill that can then be activated by an external magnetic field, which can then move the pill from outside the body.

Device Safety

It is possible that the digital pill and pacemakers may interfere with each other, however, this has not been verified.

References

Medical devices Telemedicine