Angle Control of a Pneumatically Driven Musculoskeletal Model Based on Coordination of Agonist-Antagonist Muscle

In recent years, researchers have been actively pursuing research into developing robots that can be useful in many fields of industry (e.g., service, medical, and aging care). Such robots must be safe and flexible so that they can coexist with people. Pneumatic actuators are useful for achieving this goal because they are lightweight units with natural compliance. Our research focuses on joint angle control for a pneumatically driven musculoskeletal model. In such a model, we use a one-degree-of-freedom joint model and a five-fingered robot hand as test beds. These models are driven by low pressure-driven pneumatic actuators, and mimic the mechanism of the human hand and musculoskeletal structure, which has an antagonistic muscle pair for each joint. We demonstrated a biologically inspired control method using the parameters antagonistic muscle ratio and antagonistic muscle activity. The concept of the method is based on coordination of an antagonistic muscle pair using these parameters. We have investigated the validity of the proposed method both theoretically and experimentally, developed a feedback control system, and conducted joint angle control by implementing the test beds.ArticleJournal of Mechanics Engineering and Automation. 2(12):709-719 (2012)journal articl

Concept of Virtual Incision for Minimally Invasive Surgery

Minimally invasive surgery has been introduced to various surgical fields for its benefits such as smaller scars and less pain as compared to open surgery. Highly skilled surgical techniques are required for surgeons to conduct minimally invasive surgery with fewer ports, whereas minimally invasive surgery has a number of advantages for patients. Single-incision laparoscopic surgery (SILS), in which surgical instruments and a laparoscope are inserted through a single port, has better cosmetic results than conventional multi-incision surgery; moreover, the scar is invisible when the port is opened in navel. However, instrument collisions and visual defects often occur due to the limited space of the single opening. We propose a new surgical approach entitled “virtual incision” that enables surgeons to increase the number of openings virtually. Using our approach, we have developed two types of master-slave surgical robot systems for SILS—remote-operated and local-operated systems—which have operability close to that of multiple-incision surgery. Through evaluation of these systems, we demonstrated that the visual field and operability during virtual incision surgery are similar to those of conventional multi-incision surgery. Our surgical approach can be applied to not only single-incision surgery but also multi-incision surgery, and is very likely to improve operability

Mobile locally operated detachable end-effector manipulator for endoscopic surgery

Purpose\n Local surgery is safer than remote surgery because emergencies can be more easily addressed. Although many locally operated surgical robots and devices have been developed, none can safely grasp organs and provide traction. A new manipulator with a detachable commercial forceps was developed that can act as a third arm for a surgeon situated in a sterile area near the patient. This mechanism can be disassembled into compact parts that enable mobile use.Methods\n A mobile locally operated detachable end-effector manipulator (LODEM) was developed and tested. This device uses crank-slider and cable-rod mechanisms to achieve 5 degrees of freedom and an acting force of more than 5 N. The total mass is less than 15 kg. The positional accuracy and speed of the prototype device were evaluated while performing simulated in vivo surgery.Results\n The accuracy of the mobile LODEM was 0.4 mm, sufficient for handling organs. The manipulator could be assembled and disassembled in 8 min, making it highly mobile. The manipulator could successfully handle the target organs with the required level of dexterity during an in vivo laparoscopic surgical procedure.Conclusions\n A mobile LODEM was designed that allows minimally invasive robotically assisted endoscopic surgery by a surgeon working near the patient. This device is highly promising for robotic surgery applications.ArticleINTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY. 10(2):161-169 (2015)journal articl

Utility of the HYBRID Method Incorporating the Advantages of Both Extracorporeal and Intracorporeal Urinary Diversion in Robotic-Assisted Radical Cystectomy

Background: Robotic-assisted radical cystectomy (RARC) is a well-known standard procedure for muscle-invasive bladder cancer. However, it remains controversial whether extracorporeal urinary diversion (ECUD) or intracorporeal urinary diversion (ICUD) is superior in this technique. We have developed a HYBRID method that combines ECUD and ICUD to retain the advantages of each. The purpose of this study was to compare perioperative outcomes between HYBRID and ECUD in RARC and to evaluate the usefulness of the HYBRID method. Methods: We retrospectively analyzed the perioperative outcomes of 36 consecutive bladder cancer patients who underwent RARC with ileal conduit at our institution between March 2013 and December 2021. Propensity-score matching was used to align patient backgrounds between the HYBRID and ECUD groups. Results: After matching, 12 cases were selected for each group. There was no significant difference in patient demographics between the groups except for the rate of neoadjuvant chemotherapy. Mean console time was significantly longer in the HYBRID group due to intracorporeal manipulation; however, a relatively favorable trend of mean blood loss was observed in this group. There was no significant difference between the groups in terms of positive surgical margin, mean number of lymph node removed, or positive lymph node. The incidences of complications associated and non-associated with the urinary tract and grade ≥III complications at postoperative day (POD) 0–30 and 31–90 were similar between the groups. In the HYBRID group, no complications non-associated with the urinary tract or grade ≥III complications were observed at POD 31–90. Conclusion: The HYBRID method takes advantage of the benefits of both ICUD and ECUD and is a highly applicable technique that can be used in a variety of patient backgrounds

A Study of Spatial Perception in Virtual Space via Display and the Intervention Effects of Haptic Feedback

Okada K., Matsui K., Atsuumi K., et al. A Study of Spatial Perception in Virtual Space via Display and the Intervention Effects of Haptic Feedback. IEEE Access 12, 90124 (2024); https://doi.org/10.1109/ACCESS.2024.3420724.In recent years, technologies for presenting users with virtual spaces have been rapidly developing. Some applications allow users to observe three-dimensional spaces via screens and influence those virtual spaces using certain devices. In such cases, it is necessary not only to rely on the presentation of depth information but also to adapt to depth in the virtual space to completely execute tasks. In this study, we investigated the spatial perception characteristics of commonly used two-dimensional (2D) displays and advanced spatial reality (SR) displays with spatial presentation capabilities. The research participants performed tasks of tracing a trajectory on a wall surface that changes angles in a three-dimensional virtual space. In addition, we examined the effect of haptic feedback intervention on spatial perception during task execution and its persistence. For 2D displays, we realized that haptic feedback improves task accuracy and that the effect persists even after the feedback is removed. However, this applied only to tasks under feedback conditions, and no broad effect on spatial perception was observed. By contrast, for SR displays, we realized that haptic feedback may have a detrimental effect on spatial perception. Moreover, we quantitatively proved that the use of SR displays improves spatial perception accuracy compared with 2D displays and that the relationship between the line of sight and display angle is critical for spatial perception. In conclusion, the following two points are inferred from this study. (1) To improve spatial perception, it is necessary to consider methods that directly intervene in the body schema and the peripersonal space in the future. (2) Feedback by multiple modalities is not necessarily effective in presenting information on virtual space and obtaining spatial perception

Experience of Cadaver Donor Nephrectomy with Cadaver Surgical Training

As cadaver donor nephrectomy in kidney transplantation is performed in only a limited number of cases, few physicians are skilled in the surgical technique. We performed two cadaver donor nephrectomy sessions during cadaver surgical training. The first session was performed by a lecturer who was skilled in the technique, with physicians and nurses participating in order to learn the methodology. The second session was conducted only for physicians. The procedures undertaken were as follows: cannulation of the femoral artery and vein, skin incision and bowel ligation, cross-clamping of the aorta, diaphragmatic incision and inferior vena cava incision, dissection of the aorta and inferior vena cava, and nephrectomy. Although there were some differences from that normally observed in actual patient surgery, such as no bleeding and formalin fixation, some of the procedures were very useful in helping to better understand cadaver donor nephrectomy

Application of Purified Botulinum Type A Neurotoxin to Treat Experimental Trigeminal Neuropathy in Rats and Patients with Urinary Incontinence and Prostatic Hyperplasia

Type A neurotoxin (NTX) of Clostridium botulinum was purified by a simple procedure using a lactose gel column. The toxicity of this purified toxin preparation was retained for at least 1 year at −30°C by supplementation with either 0.1% albumin or 0.05% albumin plus 1% trehalose. When purified NTX was used to treat 49 patients with urinary incontinence caused by either refractory idiopathic or neurogenic detrusor overactivity, 36 patients showed significant improvement in symptoms. These beneficial effects were also observed in cases of prostatic hyperplasia. The results obtained with NTX were similar to that of Botox. The effects of NTX on trigeminal neuralgia induced by infraorbital nerve constriction (IoNC) in rats were also studied. Trigeminal ganglion neurons from ipsilateral to IoNC exhibited significantly faster onset of FM4-64 release than sham-operated contralateral neurons. Intradermal injection of NTX in the area of IoNC alleviated IoNC-induced pain behavior and reduced the exaggerated FM4-64 release in trigeminal ganglion neurons