Cerebrospinal fluid shunts for the treatment of hydrocephalus fail at a rate of 40% within the first year. The importance of this problem is supported by one institution’s analysis of neurosurgical 30-day readmissions with CSF shunt failure only second to brain tumor readmissions. Hospital shunt related costs have been estimated at $1.4 to $2 billion annually. The majority of these costs are attributable to shunt failures based on the number of revisions out of the total numbers of annual shunt procedures. The technical innovation of this project is a low cost, low risk and easy to implement CSF shunt design change compatible with current protocols. The proposed product is an innovative distal catheter to minimize the need for revision surgery due to obstruction (also referred to as occlusion). This is accomplished with a dual lumen catheter (current distal catheters are single lumen) consisting of a primary lumen and a secondary lumen providing redundant functionality in the event ofprimary lumen occlusion thereby eliminating the need for surgical shunt revision. 40% of shunts fail within the year after implant and distal catheter obstruction accounts for up to 24% of failures. Though less prevalent than proximal catheter occlusion, incidence of distal catheter occlusion is significant and improved reliability would reduce costs and improve patient outcomes by lowering the number of revisions.

BackgroundThis paper presents a first, formative study to explore the usability of a new peritoneal dialysis connector design intended for use by patients. The study was conducted with a user population of both naive users and experienced peritoneal dialysis patients across a range of ages. The goals of the study were to evaluate the usability of the key user interfaces of this connector design by test participants representative of new and experienced peritoneal dialysis patients, as well as to evaluate the use of the connector as it interacts with other components of the peritoneal dialysis system including peritoneal dialysis fluid bags and tubing. Further objectives were to capture any usability issues and obtain participants’ feedback on the design.MethodsA total of 7 patient and non-patient participants received brief training and performed simulated connection and disconnection of peritoneal catheter extension sets for therapy with the new design.ResultsAll 7 participants completed the simulated connection and disconnection tasks successfully, with only one use error (0.22%), 18 close calls (4.0%), 6 use difficulties (1.3%) observed from the total of 449 use steps performed by all participants. Other findings include usability improvement with repeated use, participants feedback and suggestions for the ‘protective enclosure’, a novel feature of the touchless connector design.ConclusionThe studied connector design showed minimal use errors or difficulties and based on participant feedback, the usability can be significantly improved with minimal modifications in future prototypes.

In this paper, we describe the design of a touchless peritoneal dialysis connector system and how we evaluated its potential for preventing peritoneal dialysis-associated peritonitis, in comparison to the standard of care. The unique feature of this system is an enclosure within which patients can connect and disconnect for therapy, protecting their peritoneal catheters from touch or aerosols. We simulated a worst-case contamination scenario by spraying 40mL of a standardized inoculum [1x107 colony-forming units (CFU) per milliliter] of test organisms, Staphylococcus epidermidis ATCC1228 and Pseudomonas aeruginosa ATCC39327, while test participants made mock connections for therapy. We then compared the incidence of fluid path contamination by test organisms in the touchless connector system and the standard of care. 4 participants were recruited to perform a total of 56 tests, divided in a 1:1 ratio between both systems. Peritoneal dialysis fluid sample from each test was collected and maintained at body temperature (37 C) for 16 hours before being plated on Luria Bertani agar, Mannitol Salts Agar and Pseudomonas isolation agar for enumeration. No contamination was observed in the test samples from the touchless connector system, compared to 65%, 75% and 70% incidence contamination for the standard of care on Luria Bertani agar, Mannitol Salts Agar and Pseudomonas isolation agar respectively. In conclusion, the results show that the touchless connector system can prevent fluid path contamination even in heavy bacterial exposures and may help reduce peritoneal dialysis-associated peritonitis risks from inadvertent contamination with further development.