Monitoring of renal function can be crucial for patients in acute care settings. Commonly during postsurgical surveillance, urinary catheters are employed to assess the urine output accurately. However, as with any external device inserted into the body, the use of these catheters carries a significant risk of infection. In this paper, we present a non-invasive method to measure the fill rate of the bladder, and thus rate of renal clearance, via an external bioimpedance sensor system to avoid the use of urinary catheters, thereby eliminating the risk of infections and improving patient comfort. We design and propose a 4-electrode front-end and the whole wearable and wireless system with low power and accuracy in mind. The results demonstrate the accuracy of the sensors and low power consumption of only 80μW with a duty cycling of 1 acquisition every 5 minutes, which makes this battery-operated wearable device a long-term monitor system.

This paper presents the design, kinematics, fabrication, and magnetic manipulation of a milli-gripper for medical applications. The design employs a permanent magnet for two purposes. It actuates the compliant gripper and allows for maneuverability of the milli-gripper in an externally applied magnetic field generated by an electromagnetic manipulation system. The modular milli-gripper can be manipulated directly or attached to the distal tip of a magnetically steered catheter. Experiments show successful actuation of the gripper and guidance of the device with the integrated gripper in both the tethered and untethered configuration.

This paper presents a hybrid magnetic-mechanical manipulation system for automated capsulorhexis utilizing a flexible catheter with a sharp edge magnetic tip. Vision based closed loop control is implemented to guide the tip on a circular path in the anterior eye segment. A continuous motion with high repeatability is achieved. The system shows the first catheter-based application of the electromagnetic manipulation system, OctoMag, for fast and safe ophthalmic surgery that potentially reduces the risk of complications and improves precision.

In our previous work we introduced the inverted MiniMag, a magnetic manipulation system capable of 5 degree-of-freedom (5-DOF) wireless control of micro- and nano structures. In this work, we implement a depth tracking algorithm to provide feedback on the z-position of manipulated particles in the absence of a side camera. We demonstrate 3D closed-loop servoing of magnetic microbeads along predefined trajectories. We successfully position magnetic microbeads functionalized with antibodies in close proximity to macrophages with sub-cellular resolution and record the phagocytosis of the beads. We also show that the system can be used for 3D targeted microtissue manipulation inside microfabricated devices.

This paper presents a manipulation system capable of five degree of freedom (5-DOF) control of a magnetic nanoagent (3-DOF position, 2-DOF orientation) implemented on an inverted microscope. Magnetic fields up to 50 mT and gradients up to 5 T/m at frequencies up to 6 kHz can be achieved. The independent generation of field and gradient vectors enables holonomic 5-DOF wireless magnetic manipulation at the nanoscale. Multiple types of motion were investigated for nickel nanowires of different lengths and analyzed using resistive force theory.