Table 2.

Overview of active devices for ostomy patients.

Author(s) of the Invention (URLs) (Year)	Target Public (Patients)	Main Characteristics	Limitations	Validation
J. A. Hansen et al. [40] (2019) *	The packaging states that it can be used on stomas.	The device controls three concentric zones in the leakage of fluids to the skin through the stoma, sending alarms to the system via communications (it does not specify the type). It talks about memories, processors, a first interface, and a second interface, among other things, without specifying.	They are unknown	They are unknown
M. Seres et al., [41] (according to the authors, the device is already on sale to the public) (2019) *	It does not specify whether it is intended for ileostomy or colostomy patients.	A multisensory device also controls the leakage zones near the stoma by concentric zones.	They are unknown	They are unknown
P. N. Michael et al. [42] (2020) *	It does not specify whether it is intended for ileostomy or colostomy patients.	It detects flooding in the stoma area, using soluble conductive ink that dissolves when exposed to moisture in the areas concentric to the stoma, sending closed/open information to the transponder antenna. It uses radio frequency identification (RFID) technology to communicate between the detection and processing zones. The circuit is closed when there is no flooding and opens when the ink dissolves in that or other areas.	They are unknown	They are unknown
S. Knoedler [43] (2020)*	It does not specify whether it is intended for ileostomy patients or colostomy patients.	A multisensory device that also monitors leakage zones near the stoma by concentric zones detects moisture near the adhesive that supports the device in the stoma area, anticipating possible failure of the adhesive plate and the consequent collapse of the device.	They are unknown	They are unknown
M. E. Kralovec et al. [44] (although this work is outside the search window, it shows yet another technique used) (2015) *	Colostomy patients.	The patent states that it has the particularity of eliminating the sound produced by flatulence. It is referred to as a device for colostomy patients and consists of a loudspeaker, a microphone, and the electronics of the cancellation circuit.	They are unknown	They are unknown
R. Fearn et al. [45] (2020)	Ileostomy patients.	The user can use a flexible piezoelectric sensor to determine how much liquid is in the bag. With this device, the user is aware, via Bluetooth Low Energy, of the amount of fecal product to be eliminated, so they can decide what to do with the information received, whether they need to dehydrate or not.	This device was considered acceptable and usable but did not provide an accurate and consistent reading due to connectivity problems and a high noise/signal ratio in a dynamic environment	Ileostomy volunteers
M. Seres et al. [46] (2018)	Ileostomy patients.	A device in which sets of resistive/capacitive sensors are mounted, capable of calculating the number of stools in the bag, with thermal sensors indicating the risk of dehydration. It can also record skin conditions such as irritation.	It is not known	Several studies have been carried out with ileostomy volunteers
D. Rouholiman et al. [47] (2018)	Colostomy patients, Ileostomy patients, Urostomy patients.	A portable biosensor has been built and connected via Bluetooth, making measuring the flow rate/amount of fluid in the ostomy pouch easier.	According to the authors, the Ostom-i alert sensor can improve users’ quality of life by giving them the freedom and confidence to participate in daily activities, knowing that they can check if their ostomy bag is full discreetly and privately	Twenty volunteers with ostomies were recruited, and the test was run for one month. Volunteers who had had ostomies for less than six months before the test date were excluded
* patent