Non-acid reflux is common in premature neonates. Current methods of diagnosing gastroesophageal reflux (GER) such as pH probes, multichannel impedance monitoring, X-rays, or endoscopy are either invasive or unable to diagnose non-acid reflux. Passage of a naso-esophageal tube is uncomfortable. Imaging studies are of short duration and may miss reflux entirely. Herein, we present proof of concept of a noninvasive accelerometric device that detects acid and non-acid reflux in premature infants. An accelerometer was taped over the subxiphoid process in patients suspected of having GER who were already scheduled for pH probe or multichannel impedance monitoring. The largest cohort was preterm infants, but term infants and toddlers were also studied. Low-frequency subaudible signals were obtained on a digital recorder (sampling rate 200 Hz) signals. Fast Fourier transforms graphically displayed the frequency and amplitude of signals. Data were then resampled at a rate of 60 Hz to create a spectrogram with a focused range of 0–30 Hz representing reflux-associated events. Proof of concept was attained through successful comparison with results from concurrent pH probes, multichannel impedance recordings, and ultrasound studies. We have thus validated accelerometry as a noninvasive method for assessing both acid and non-acid GER. The noninvasiveness of this diagnostic modality allows for repeated testing to assess the efficacy of anti-reflux medications, even when patients remain on antacids. This technology allows for more rational management of patients with GER and represents a major advance in the diagnosis and treatment of GER.

This study proposes an optically sensorized force-sensing tendon for minimally invasive surgical instruments. The tendon is composed of a high strength, polarization maintaining (PM) optical fiber with Bragg sensors (FBGs) that negate the cross-sensitivity of conventional FBGs. The PM-FBG fiber is locally reinforced with high stiffness Kevlar that enhances its load carrying capacity while enabling higher curvatures in tendon routing. The composite tendon has a mean diameter of ∼268 μ m which preserves the form-factor of instruments within this scope. Importantly, the tendons can improve the functionality of such tools by enabling local force and tissue-resistance estimation. This paper explores the performance of these sensorized tendons in terms of strength, stability, response under dynamic load, friction, and sensitivity as a force measuring tool within an 18 Ga articulate Nitinol (NiTi) cannula (a proxy for potential applications). Results reaffirm the potential of a bi-modal sensing and actuation component within instruments for robotic surgery.

Tactile sensing is an emerging technological advancement in surgical robotics in order to probe interactions between confined tissue environments and instruments based on touch information. The tactile sense can assist in improving the efficiency of the whole practice and hence enhance precision, control, and safety during surgery. This paper demonstrates a distinct proof-of-concept therapeutic device equipped with a soft tactile sensor. The tactile sensor was custom-made using flexible piezoresistive materials and conductive ink, wrapped with a biocompatible hydrogel polymer matrix for safer human–tissue interactions. The proposed tactile sensor was then calibrated and its performance was compared with gold standard sensors. It was further tested with a continuous force (5 N) for an extended period of time (about 6 h) to address robustness and repeatability. The sensor showed a sensitivity of 0.833 N −1 and a drift of ≤1%. Successful cadaver experiment demonstrates the efficiency of tactile sensing assistance to clinicians.

This study proposes a novel integrated wheelchair-compatible support system for wheelchair users with partial or complete paralysis. This system not only provides sit-to-stand and stand-to-sit (STS) learning support for stroke and spinal cord injury patients but also enhances the independence of wheelchair users. It integrates a lower limb movement support unit with a wheelchair and supports STS movement by moving the seat up and down linearly. It also measures the ground reaction force (GRF) on both sides of the body and supports proper STS movement to allow users to improve their movements and postures. Individual experiments were conducted to evaluate the system-provided STS movement support for two patients with partial paralysis and one patient with complete paralysis. Patients with partial paralysis, both hemiplegic and quadriplegic, were able to operate the system and perform the STS movement learning with visual biofeedback. Moreover, using our system, a wheelchair user with complete paraplegia was able to perform tasks at an elevated position independently. Therefore, this system will help wheelchair users achieve the self-motor-learning of STS movement and enhance their quality of life independently.

Descemet membrane endothelial keratoplasty (DMEK) is the most efficacious partial endothelial keratoplasty, offering the highest likelihood of 20/20 vision and the shortest recovery times. However, current devices do not effectively address the difficult step of unrolling the corneal graft within the eye which is the greatest barrier to DMEK adoption. Here, we present the design, development, and testing of a novel device that simplifies and standardizes DMEK graft transplantation. The patent-pending cartridge facilitates the trifold technique, a graft preparation method that allows the graft to naturally unroll in the eye and reduces time-consuming manipulation steps required in alternative techniques. Injection molding was used to manufacture devices which were tested with research-grade corneal grafts. The cartridge's design allows it to fit into a typical corneoscleral incision, maintains trifolded grafts (p = 0.006), and reduces endothelial cell loss (ECL) (p = 0.049). These results demonstrate that the device introduced here is suitable for DMEK and may simplify this procedure for corneal surgeons.

Slotted cutting guides are used by orthopaedic surgeons to improve the accuracy of bone resection during total knee replacement. Accuracy of the saw cuts has an effect on patient mobility and on implant survival time. While computer navigation systems have improved the accuracy of cutting guide placement, the contribution to cutting error from blade toggle within the slots of the cutting guide persists. In this research, equations were derived to quantify angular cutting error based on the parameters affecting blade and cutting guide geometry. Analytically, the relationship between cutting plane error and blade thickness was determined to be linear. A smaller gap, due to thicker blades with minimal tooth offset, results in less cutting error. From an experimental standpoint, six commercially available cutting guides were tested for femoral plane cutting accuracy by resection of synthetic bone under the guidance of computer navigation. The results indicate an average flexion/extension error of 3.8 deg for a 0.89 mm thick blade and 2.0 deg for a 1.27 mm blade. Varus/valgus error due to twisting of the blade within the slot was less than 1.0 deg, regardless of blade thickness. To improve upon cutting accuracy, an adjustable slot cutting guide was designed and tested. From more closely matching slot width to blade thickness, the results indicate that cutting plane error can be reduced to less than 1.0 deg in both the flexion/extension and varus/valgus planes.

Diastolic dysfunction likely contributes to all cases of congestive heart failure and is solely responsible for many. Existing cardiac support devices largely ignore diastolic dysfunction and may exacerbate it. Current diastolic devices in development rely on either extensive extraventricular fixation or intraventricular implantation with complications associated with blood contact. A diastolic recoil device is proposed that pneumatically locks to the outside of the heart wall. The end-diastolic total biventricular pressure-volume relationship (EDTBPVR) was used to evaluate, in vitro, the ability of a recoil device to modulate filling mechanics through pneumatic locking as the method of fixation. The pressure in a model heart was incremented and the corresponding volume changes were measured. The heart model and device were pneumatically locked together using a vacuum sac to model the pericardium. The diastolic recoil component shifted the EDTBPVR towards lower pressures at low volumes, providing up to 0.9 kPa (9 cm H2O) of suction, demonstrating enhanced diastolic recoil at beginning diastole. We conclude that pneumatic locking appears to be a viable method for a recoil device to engage the heart.