Advances in Medical Devices 3

A common sequela of subarachnoid hemorrhage is ischemic injury to the brain due to vasospasm, a narrowing of cerebral arteries supplying blood to the cerebral cortex. Continuous monitoring of subarachnoid hemorrhage patients to detect vasospasm post-injury is currently not feasible. The Lindegaard ratio is used to detect vasospasm in the middle cerebral artery. It is defined as the mean blood flow velocity in the middle cerebral artery divided by the mean blood flow velocity in the internal carotid artery. As part of a solution for continuous monitoring of blood flow velocity in the internal carotid artery for Lindegaard ratio measurements, a proof-of-concept wearable ultrasound device is described and demonstrated.

Benjamin D. Hage

Dr. Hage is a postdoctoral research associate in the Department of Biological Systems Engineering at the University of Nebraska-Lincoln. His research focuses on novel uses of transcranial Doppler ultrasound for monitoring and diagnosing disease and for functional imaging.

Central Venous Catheterization is a frequently performed medical procedure where a catheter is inserted into a central vein within the body to enable access to the heart for administering medication and conducting measurements. However, complications such as arrhythmia and arterial punctures can lead to detrimental impacts and even mortality. Medical training has been shown to greatly reduce such preventable complications from occurring. This presentation will cover a novel CVC medical simulator called the Dynamic Haptic Robotic Trainer (DHRT), as well as the design of a sensorized syringe to improve the fidelity of the DHRT. The syringe provides a lower cost alternative to the robotic-assisted syringes previously utilized in such training. It also supports additional training steps, such as the ability to place the guidewire through the needle and proper aspiration (pulling back on the syringe) follow-through. An experiment compared the forces required by both types of syringes (sensorized and robotic assisted) to insert the needle, as well as aspirate, to determine how the syringe could be improved.

Aayod Kaul

Aayod is an undergraduate in his 3rd year studying Mechanical Engineering at Penn State University in the Schreyer Honors College. He does joint research under Dr. Jason Moore and Dr. Scarlett Miller (Precision Medical Instrument Design Lab and Britelab Engineering Design Group, respectively). His research focus is on designing & analyzing medical devices for simulation training.

Needle angulation is often desired in needle-based procedures for precise targeting inside tissue and/or to avoid obstacles. It has been shown that needle-based procedures such as prostate brachytherapy could benefit from angular needle insertion, e.g., reaching targets that are not accessible via a straight shot or to bypass pubic arch interface. Recent research has also shown that angular needle insertions as well as needle bending could improve catheter implantation in high-dose-rate brachytherapy conformal to the prostate boundaries, and consequently improve the outcome of the procedure via improved dosimetric constraints. This work presents a novel needle guide template to facilitate needle’s initial angulation prior to puncture. The needle guide is designed with two parallel templates featuring similar grid patterns. The distance between the templates is adjustable, and the template proximal to the patient can rotate to achieve a desired needle angulation. The needle guide is primarily tested, and the access region is estimated. 

Rex Imanaka
University of Hawaii at Manoa

Rex Imanaka received his B.S. degree from the Department of  Biological Engineering at the University of Hawaii at Manoa in 2021. He is currently pursuing his M.S. degree in Mechanical Engineering under Dr. Bardia Konh. His research is currently focused on working with medical robotics and simulating needle interventions especially for prostate brachytherapy/biopsy purposes.

This paper presents design advancements for minimally invasive surgical stapler-cutters.  Considering existing constraints including range of articulation, a cable-pulley transmission design is pursued.  Kinematic relationships to optimize toward constant cable path length are presented.  A more ergonomic handle layout is proposed to improve force transmission and comfort for the surgeon.  Prototyping results demonstrate achievement of design goals related to range of motion and instrument size
 

Carl Nelson
University of Nebraska-Lincoln

Carl Nelson is a professor in the Department of Mechanical and Materials Engineering at the University of Nebraska-Lincoln.

Systematic (12-core) ultrasound-guided prostate biopsy is a poor technique traditionally used for detection of prostate cancer, originated in a time predating MRI technology. While ultrasound can reveal the position of the prostate and the needle, it is incapable of locating cancers within the gland— a capability that MRI possesses. Blind systematic biopsies are associated with significant rates of underdiagnosis and overdiagnosis. MRI has introduced the ability to locate the tumor, presenting a unique opportunity to perform targeted prostate biopsies. However, in-bore MRI prostate biopsy is not widely practiced, primarily because the procedure is time-consuming and expensive. Robotic teleoperated instruments that could expedite the operation could be the solution. This work presents design considerations and development of an MRI-compatible robot capable of performing in-bore teleoperative MRI-guided prostate biopsy. The robot can perform tasks that are seen in clinical practice such as needle insertion as well as tendon manipulation for active needles.

Rex Imanaka
University of Hawaii at Manoa

Rex Imanaka received his B.S. degree from the Department of  Biological Engineering at the University of Hawaii at Manoa in 2021. He is currently pursuing his M.S. degree in Mechanical Engineering under Dr. Bardia Konh. His research is currently focused on working with medical robotics and simulating needle interventions especially for prostate brachytherapy/biopsy purposes.