Difference between revisions of "Digital Pills"

Revision as of 18:59, 11 February 2022

Digital pills, also known as smart pills or ingestible sensors, are a category of small devices that can safely travel throughout the body while communicating with an external device.^[1] Currently, the application of digital pills can enable physicians to image internal structures, measure critical values, and monitor patient activity without invasive procedures.^[2] The use of digital pills also raises important ethical considerations that affect patients, physicians, and society as a whole.^[2]

Background

One of the earliest inventions for ingestible sensors comes in 1957 from the work of Jacobson and Mackay who wanted to use radio frequency transmission to get real-time reports of different vital measurements from patients.^[2] Jacobson and Mackay called their device endoradiosonde and it was able to measure pH, temperature, and pressure in the gastrointestinal tract.^[3] The next major breakthrough came in the 2000s when SmartPill, a wireless motility capsule (WMC), was developed, approved, and sold across the United States to measure pH, pressure, and temperature all at once for a more accurate diagnosis of gastric emptying.^[3] In 2001, a video capsule endoscope (VCE) was also approved by the Food and Drug Administration for widespread commercial use.^[3] Most recently, the FDA approved another digital pill, Abilify MyCite, which can be used to monitor patient adherence to their medication.^[4] The 2000s introduced the miniaturization of electronic circuits and batteries, advancements in biomaterials, and innovation in drug developments which together have paved the way for digital medicine to progress.^[3] Currently, digital pills exist or are being tested for a wide range of applications including temperature sensing^[5], pH monitoring^[6], motility sensing^[7], capsule endoscopy^[3], biopsy^[3], gas sensing^[3], inflammation detection^[3], drug delivery^[3], and adherence monitoring^[3]. Almost all digital pills require three components for their utilization: 1) the capsule with a sensor; 2) receiver usually worn by the patient; and 3) a computer or mobile application with compatible software that can be used to store and analyze the data^[2].

Types of Smart Pills

Imaging Capsules

These smart pills are a type of diagnostic instrument that enables doctors to collect visual data about the structural integrity and condition of organ lining inside the different organs of the gastrointestinal (digestive) tract.^[2] A major advantage of imaging capsules is that they provide an alternative to traditional imaging techniques that use tube endoscopes which are more invasive.^[2] Endoscopy instruments also tend to be large and rigid which limits access to many areas of the gastrointestinal tract and brings greater discomfort to patients.^[2] A Typical wireless imaging capsule systems have 3 components: 1) capsule endoscope; 2) sensing system such as a pad/patch or belt attached to the patient; and 3) some sort of computer or application on a mobile device with the right software to receive the information.^[8] Over the years, imaging capsules have made great progress with improved algorithms for detecting hemorrhage and lesions and enhanced video quality.^[2] Due to the uniqueness of each organ within the gastrointestinal tract, different capsules with specific features were developed for each organ.^[2]

Current Products

PillCam SB by Given Imaging Inc: This is the first swallowable camera capsule released by Given Imaging inc. and it is used to analyze the small intestine (also called small bowel, this is where SB comes from).^[2] Since the initial release in 2000, newer versions have been released with greater battery power and imaging resolution.^[2] The capsule consists of a video camera, light source, batteries, radio transmitter, and an antenna.^[9] The capsule is able to take 50,000 pictures over the course of 8 hours which averages to about two pictures every second.^[9] The images taken by the capsule are transmitted to a belt worn by the patient which can relay the information to a workstation or other electronic device with the appropriate software.^[9] To prepare for the capsule, patients are required to fast for 10 hours and then are given the pill with water to swallow; once the capsule has entered the gastrointestinal tract it will capture images for about eight hours and the patient can resume normal daily activities right after consumption.^[9]

PillCam ESO by Given Imaging Inc: This capsule is used to take images of the esophagus and there are two cameras, one at each end, to get more information in less time.^[2] The pill travels down the esophagus very quickly and as a result, the pill is designed to have a short battery life but a high frame rate.^[2], ^[8] Patients are asked to fast two hours before their examination and when they come in they are fitted with 3 thoracic sensors that are connected to a data recorder on some type of workstation with the appropriate software.^[8] The patient is given 100mL of water while standing and then they ingest the activated capsule with another 10mL of water that they drink while laying down on their back.^[8] There is a 5 minute ingestion period which consists of 2 minutes with the patients laying down on their back (supine position), 2 minutes with the patient raised to 30 degrees, and then an additional minute of the patient raised to 60 degrees.^[8] Lastly, the patient remains seated in an upright manner for 15 minutes to maximize the time for the capsule to capture images as it travels through the esophagus.^[8]

There are many other ingestible sensors available on the market such as PillCam Colon, Endo Capsule, OMOM capsule, and MiroCam capsule that are specific to other organs of the gastrointestinal tract for optimized imaging.^[2]

Temperature Sensing Capsules

Temperature sensing smart pills are a diagnostic tool that can be used to make sure body temperature remains within the homeostatic range and they can also be used to measure heat stress in patients ^[2]. There is a growing trend of the inclusion of temperature sensing capabilities in other pills that have a different primary function ^[2].

Current Products

CorTemp by VitalSense. The capsule consists of a thermistor-based temperature sensor and is usually used for core body temperature measurements ^[2].

pH Monitoring Capsules

pH monitoring capsules serve as a diagnostic measure that can help physicians track pH fluxes in patients. pH is an important characteristic that measures the level of acidity in a given environment. This characteristic becomes especially important when working with the gastrointestinal tract as different organs maintain different pHs. Imbalances in pH can lead to many diseases such as ______ and monitoring for these changes can be life-saving. These capsules are designed with a battery life of several days and this feature allows doctors to use pH capsules to assess the passage time of a patient’s gastrointestinal tract as a whole or of specific organs based on pH changes ^[2].

Current Products

Bravo pH monitoring system

Medication Monitoring Pills

The medication monitoring pills can be used by patients and doctors to make sure that the patients are taking their pills according to their prescription and that they are not skipping any of their medications. Medication non-adherence is a growing problem that is preventable and the monitoring pills provide a viable option ^[4].

Current Products

Abilify MyCite

Capsules in Development

Research into the field of smart pills continues to grow as new illnesses are discovered and new therapeutics are needed. Currently, research on gas sensing capsules, visible and infrared wavelength spectrometry capsules, Raman Spectroscopy, Confocal Microscopy and Optical Coherence Tomography, and Electrochemical sensing capsules is being done ^[2]. Some of these pills are further in clinical trials with human patients, others are still in animal trials, and some are still just ideas ^[2].

Ethical Concerns

Patient-Related

Autonomy and Informed Consent

Typical medical procedures, from simple tasks such as measuring a patient’s blood pressure to more invasive tasks such as drawing blood all require informed consent from the patient. The addition of technology brings in an additional stipulation, the user agreement ^[10]. These forms tend to be extensively long and written by lawyers to describe in detail how the software and hardware of the product can be used ^[10]. This can lead to issues in informed consent as the patients may not always fully understand the user agreement. Traditional informed consent gives the patients the convenience of a face-to-face conversation with their doctor to address all their concerns and obtain a proper understanding of the situation. User agreements do not offer such services and many times patients do not fully realize what they are agreeing to due to comprehension difficulties of the form ^[10]. User Agreement forms can also be updated at any time without notice and are non-negotiable which may infringe on patient autonomy ^[10]. Many user agreement forms require the patients to allow the company to collect data so that they can continue to improve their product. If a patient is uncomfortable, their alternative is to find a completely new treatment, an option that may not be feasible for all patients. This can potentially put the patient in an uncomfortable situation where they feel as if they do not have complete control over their choices.

See Also

References

1. ↑ Farr, C. (2017, December 18). The first 'Digital Pill' has just been approved - here's how it could revolutionize health care. CNBC. Retrieved February 11, 2022, from https://www.cnbc.com/2017/11/14/what-is-a-digital-pill.html.
2. ↑ ^{2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18 2.19} Kalantar-zadeh, K., Ha, N., Ou, J. Z., & Berean, K. J. (2017). Ingestible sensors. ACS Sensors, 2(4), 468–483. https://doi.org/10.1021/acssensors.7b00045.
3. ↑ ^{3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9} Mau, M. M., Sarker, S., & Terry, B. S. (2021). Ingestible devices for long-term gastrointestinal residency: A Review. Progress in Biomedical Engineering, 3(4), 042001. https://doi.org/10.1088/2516-1091/ac1731.
4. ↑ ^{4.0 4.1} impacX Team. (2021, May 10). Smart pills: The era of Edible Digital Pills has arrived! impacX. Retrieved January 28, 2022, from https://impacx.io/blog/smart-pills-what-are-these-edible-digital-pills/.
5. ↑ Cortemp. HQ, Inc. (2022, January 24). Retrieved February 11, 2022, from https://www.hqinc.net/cortemp/#:~:text=Our%20CorTemp%C2%AE%20Ingestible%20Core,the%20outside%20of%20the%20body.
6. ↑ Mayo Foundation for Medical Education and Research. (2020, May 22). Gastroesophageal reflux disease (GERD). Mayo Clinic. Retrieved February 11, 2022, from https://www.mayoclinic.org/diseases-conditions/gerd/symptoms-causes/syc-20361940.
7. ↑ Farrar, J. T., Zworykin, V. K., & Baum, J. (1957). Pressure-sensitive telemetering capsule for study of gastrointestinal motility. Science, 126(3280), 975–976. https://doi.org/10.1126/science.126.3280.975.
8. ↑ ^{8.0 8.1 8.2 8.3 8.4 8.5} Wang, A., Banerjee, S., Barth, B. A., Bhat, Y. M., Chauhan, S., Gottlieb, K. T., Konda, V., Maple, J. T., Murad, F., Pfau, P. R., Pleskow, D. K., Siddiqui, U. D., Tokar, J. L., & Rodriguez, S. A. (2013). Wireless capsule endoscopy. Gastrointestinal Endoscopy, 78(6), 805–815. https://doi.org/10.1016/j.gie.2013.06.026
9. ↑ ^{9.0 9.1 9.2 9.3} John Hopkins Medicine. (n.d.). PILLCAM™ SB FREQUENTLY ASKED QUESTIONS (FAQ). John Hopkins Bayview Medical Center. Retrieved February 11, 2022, from https://www.hopkinsmedicine.org/johns_hopkins_bayview/_docs/medical_services/gastroenterology/pill_cam_sb_faqs.pdf.
10. ↑ ^{10.0 10.1 10.2 10.3} Klugman, C. M., Dunn, L. B., Schwartz, J., & Cohen, I. G. (2018). The Ethics of Smart Pills and self-acting devices: Autonomy, truth-telling, and trust at the dawn of Digital Medicine. The American Journal of Bioethics, 18(9), 38–47. https://doi.org/10.1080/15265161.2018.1498933.