A multifunctional soft robotic shape display with high-speed actuation, sensing, and control.

Shape displays which actively manipulate surface geometry are an expanding robotics domain with applications to haptics, manufacturing, aerodynamics, and more. However, existing displays often lack high-fidelity shape morphing, high-speed deformation, and embedded state sensing, limiting their potential uses. Here, we demonstrate a multifunctional soft shape display driven by a 10 × 10 array of scalable cellular units which combine high-speed electrohydraulic soft actuation, magnetic-based sensing, and control circuitry. We report high-performance reversible shape morphing up to 50 Hz, sensing of surface deformations with 0.1 mm sensitivity and external forces with 50 mN sensitivity in each cell, which we demonstrate across a multitude of applications including user interaction, image display, sensing of object mass, and dynamic manipulation of solids and liquids. This work showcases the rich multifunctionality and high-performance capabilities that arise from tightly-integrating large numbers of electrohydraulic actuators, soft sensors, and controllers at a previously undemonstrated scale in soft robotics.

A Small Deformation Thermoporomechanics Finite Element Model and Its Application to Arterial Tissue Fusion.

Understanding the impact of thermally and mechanically loading biological tissue to supraphysiological levels is becoming of increasing importance as complex multiphysical tissue-device interactions increase. The ability to conduct accurate, patient specific computer simulations would provide surgeons with valuable insight into the physical processes occurring within the tissue as it is heated or cooled. Several studies have modeled tissue as porous media, yet fully coupled thermoporomechanics (TPM) models are limited. Therefore, this study introduces a small deformation theory of modeling the TPM occurring within biological tissue. Next, the model is used to simulate the mass, momentum, and energy balance occurring within an artery wall when heated by a tissue fusion device and compared to experimental values. Though limited by its small strain assumption, the model predicted final tissue temperature and water content within one standard deviation of experimental data for seven of seven simulations. Additionally, the model showed the ability to predict the final displacement of the tissue to within 15% of experimental results. These results promote potential design of novel medical devices and more accurate simulations allowing for scientists and surgeons to quickly, yet accurately, assess the effects of surgical procedures as well as provide a first step toward a fully coupled large deformation TPM finite element (FE) model.

Miniature in vivo robots for remote and harsh environments.

Long-term human space exploration will require contingencies for emergency medical procedures including some capability to perform surgery. The ability to perform minimally invasive surgery (MIS) would be an important capability. The use of small incisions reduces surgical risk, but also eliminates the ability of the surgeon to view and touch the surgical environment directly. Robotic surgery, or telerobotic surgery, may provide emergency surgical care in remote or harsh environments such as space flight, or extremely forward environments such as battlefields. However, because current surgical robots are large and require extensive support personnel, their implementation has remained limited in forward environments, and they would be difficult, or impossible, to use in space flight or on battlefields. This paper presents experimental analysis of miniature fixed-base and mobile in vivo robots to support MIS surgery in remote and harsh environments. The objective is to develop wireless imaging and task-assisting robots that can be placed inside the abdominal cavity during surgery. Such robots will provide surgical task assistance and enable an on-site or remote surgeon to view the surgical environment from multiple angles. This approach is applicable to long-duration space flight, battlefield situations, and for traditional medical centers and other remote surgical locations.

Recent in vivo surgical robot and mechanism developments.

The surgical landscape is quickly changing because of the major driving force of robotics. Well-established technology that provides robotic assistance from outside the patient may soon give way to alternative approaches that place the robotic mechanisms inside the patient, whether through traditional laparoscopic ports or through other, natural orifices. While some of this technology is still being developed, other concepts are being evaluated through clinical trials. This article examines the state of the art in surgical robots and mechanisms by providing an overview of the ex vivo robotic systems that are commercially available to in vivo mechanisms, and robotic assistants that are being tested in animal models.

Mobile in vivo camera robots provide sole visual feedback for abdominal exploration and cholecystectomy.

The use of small incisions in laparoscopy reduces patient trauma, but also limits the surgeon's ability to view and touch the surgical environment directly. These limitations generally restrict the application of laparoscopy to procedures less complex than those performed during open surgery. Although current robot-assisted laparoscopy improves the surgeon's ability to manipulate and visualize the target organs, the instruments and cameras remain fundamentally constrained by the entry incisions. This limits tool tip orientation and optimal camera placement. The current work focuses on developing a new miniature mobile in vivo adjustable-focus camera robot to provide sole visual feedback to surgeons during laparoscopic surgery. A miniature mobile camera robot was inserted through a trocar into the insufflated abdominal cavity of an anesthetized pig. The mobile robot allowed the surgeon to explore the abdominal cavity remotely and view trocar and tool insertion and placement without entry incision constraints. The surgeon then performed a cholecystectomy using the robot camera alone for visual feedback. This successful trial has demonstrated that miniature in vivo mobile robots can provide surgeons with sufficient visual feedback to perform common procedures while reducing patient trauma.

Miniature robots can assist in laparoscopic cholecystectomy.

Laparoscopy reduces patient trauma but eliminates the surgeon's ability to directly view and touch the surgical environment. Although current robot-assisted laparoscopy improves the surgeon's ability to manipulate and visualize the target organs, the instruments and cameras remain constrained by the entry incision. This limits tool tip orientation and optimal camera placement. This article focuses on developing miniature in vivo robots to assist surgeons during laparoscopic surgery by providing an enhanced field of view from multiple angles and dexterous manipulators not constrained by the abdominal wall fulcrum effect. Miniature camera robots were inserted through a small incision into the insufflated abdominal cavity of an anesthetized pig. Trocar insertion and other laparoscopic tool placements were then viewed with these robotic cameras. The miniature robots provided additional camera angles that improved surgical visualization during a cholecystectomy. These successful prototype trials have demonstrated that miniature in vivo robots can provide surgeons with additional visual information that can increase procedural safety.

Radioimmunotherapy for the intensification of conditioning before stem cell transplantation: differences in dosimetry and biokinetics of 188Re- and 99mTc-labeled anti-NCA-95 MAbs.

UNLABELLED: A new concept is the intensification of preparative regimens for patients with advanced leukemia using monoclonal antibodies (MAbs) with an affinity for beta emitter-labeled bone marrow. 188Re is a high-energy beta emitter that has therapeutic promise. Our first aim was to clarify whether the therapeutic application of 188Re-MAb against nonspecific cross-reacting antigen 95 (NCA-95) can be predicted from biokinetic data derived from 99mTc-labeled NCA-95. Our second aim was to show that a radiation absorbed dose of > or =12 Gy in the bone marrow can be achieved using 188Re-MAb. METHODS: Dosimetric data were obtained for both radiotracers from multiple planar whole-body scans (double-head gamma camera), blood samples, and urine measurements from 12 patients with advanced leukemia. Radiation absorbed doses were calculated using MIRDOSE 3 software. RESULTS: Radiation absorbed doses to bone marrow, liver, spleen, lung, and kidney were 2.24, 0.50, 1.93, 0.05, and 0.90 mGy/MBq, respectively, using 99mTc-MAb and 1.45, 0.43, 1.32, 0.07, and 0.71 mGy/MBq, respectively, using 188Re-MAb. These differences were statistically significant for bone marrow, spleen, and kidney. The main differences were less accumulation of 188Re-MAb in bone marrow (31%+/-13% compared with 52%+/-13%) and faster elimination through urine (25%+/-3% compared with 15%+/-5% after 24 h). On the basis of these data, a mean marrow dose of 14+/-7 Gy was achieved in 12 patients suffering from leukemia after application of approximately 10+/-2 GBq 188Re-MAb. CONCLUSION: Myeloablative radiation absorbed doses can easily be achieved using 188Re-MAb. 99mTc- and 188Re-MAb showed similar whole-body distributions. However, direct prediction of radiation absorbed doses from the 99mTc-MAb, assuming identical biokinetic behavior, is not valid for the 188Re-MAb in a single patient. Therefore, individual dosimetry using 188Re-MAb is needed to calculate therapeutic activity.

Sensitivity in detecting osseous lesions depends on anatomic localization: planar bone scintigraphy versus 18F PET.

UNLABELLED: Radionuclide bone scanning (RNB) is considered to be the most practical screening technique for assessing the entire skeleton for skeletal metastases. However, RNB has been shown to be of lower sensitivity than MRI and CT in detecting osteolytic metastases. A prospective study was designed to evaluate the accuracy of planar RNB versus tomographic bone imaging with 18F-labeled NaF and PET (18F PET) in detecting osteolytic and osteoblastic metastases and its dependency on their anatomic localization. METHODS: Forty-four patients with known prostate, lung or thyroid carcinoma were examined with both planar RNB and 18F PET. A panel of reference methods including MRI of the spine, 1311 scintigraphy, conventional radiography and spiral CT was used as the gold standard. RNB and 18F PET were compared by a lesion-by-lesion analysis using a five-point score for receiver operating characteristic (ROC) curve analysis. RESULTS: 18F PET showed 96 metastases (67 of prostate carcinoma and 29 of lung or thyroid cancer), whereas RNB revealed 46 metastases (33 of prostate carcinoma and 13 of lung or thyroid cancer). All lesions found with RNB were also detected with 18F PET. Compared with 18F PET and the reference methods, RNB had a sensitivity of 82.8% in detecting malignant and benign osseous lesions in the skull, thorax and extremities and a sensitivity of 40% in the spine and pelvis. The area under the ROC curve was 0.99 for 18F PET and 0.64 for RNB. CONCLUSION: 18F PET is more sensitive than RNB in detecting osseous lesions. With RNB, sensitivity in detecting osseous metastases is highly dependent on anatomic localization of these lesions, whereas detection rates of osteoblastic and osteolytic metastases are similar. Higher detection rates and more accurate differentiation between benign and malignant lesions with 18F PET suggest the use of 18F PET when possible.

[Positron-emission tomography of the skeletal system using 18FNa: the incidence, pattern of the findings and distribution of benign changes]. / Die Positronenemissionstomographie des Skelettsystems mit 18FNa: Häufigkeit, Befundmuster und Verteilung benigner Veränderungen.

PURPOSE: We evaluated the frequency, distribution and appearance of benign lesions in 18F-PET scans. METHODS: Between March 1996 and May 1997, 18F-PET scans were performed in 59 patients in addition to conventional planar bone scintigraphy. Eleven patients were subjected to additional SPECT imaging. The main indication was searching for bone metastases (58 pat.). The diagnosis was confirmed radiologically. RESULTS: With 18F-PET in 39 patients (66.1%) 152 benign lesions, mostly located in the spine were detected. 99mTc bone scans revealed 45 lesions in 10 patients. Osteoarthritis of the intervertebral articulations (69%) or of the acromioclavicular joint (15%) were the most common reasons for degenerative lesions detected with 18F-PET. Osteophytes appeared as hot lesions located at two adjacent vertebral endplates. Osteoarthritis of the intervertebral articulations showed an enhanced tracer uptake at these localizations, whereas endplate fractures of the vertebral bodies appeared very typical; solitary fractures of the ribs could not be differentiated from metastases. Rare benign lesions were not studied. CONCLUSION: Most of the degenerative lesions (84%) detected with 18F-PET had a very typical appearance and could be detected with the improved spatial resolution and advantages of a tomographic technique. 18F-PET had an increased accuracy in detecting degenerative bone lesions.

Pharmacokinetics of 99Tcm-pertechnetate and 188Re-perrhenate after oral administration of perchlorate: option for subsequent care after the use of liquid 188Re in a balloon catheter.

Radioactive wires and other linear sources are currently being used in clinical trials as endovascular brachytherapy to prevent restenosis after percutaneous transluminal coronary angioplasty. A new concept is the use of a liquid-filled balloon containing a beta-emitting radioisotope. A major advantage is optimal delivery of the radioactivity to the vessel wall. Rhenium-188 (188Re) is a high-energy beta-emitter that is routinely available from a 188W/188Re generator in liquid form. Since 188Re-perrhenate could be released in the unlikely event of balloon rupture, we investigated whether, in analogy to pertechnetate, subsequent use of perchlorate can reduce the uptake of perrhenate in the thyroid. We performed static (n = 9) and dynamic (n = 11) thyroid scintigraphy with 99Tcm-pertechnetate to estimate the overall reduction in activity within 30 min and the washout from the thyroid after oral administration of 600 mg perchlorate (T1/2). In two patients, 188Re was injected to estimate the whole-body distribution and the discharge of thyroid activity after perchlorate use. Based on MIRD Dose Estimate Report No. 8 (valid for 99Tcm-pertechnetate), the radiation burden was calculated for intravenous administration of 188Re and competitive blocking with perchlorate. In 20 patients, 99Tcm uptake by the thyroid was reduced by 85% within 30 min by perchlorate. The mean (+/- S.D.) washout rate (T1/2) was 8 +/- 2 min in 11 patients. Perrhenate showed a whole-body distribution similar to that of pertechnetate and the thyroid activity could be displaced (T1/2 = 6.3 and 9.3 min, respectively) by oral administration of perchlorate, with reductions in uptake of 83% and 75% within 30 min, respectively. Whole-body scanning demonstrated no regional accumulation of 188Re-perrhenate with excretion by urine. Dose estimates gave an effective dose equivalent of 0.42 mSv MBq-1, which decreased to 0.16 mSv MBq-1 after perchlorate blocking. 188Re has favourable properties for endovascular brachytherapy via a balloon catheter and, in the unlikely event of balloon rupture, whole-body radiation can be reduced to 38% by subsequent oral administration of perchlorate.

[Imaging of the normal skeletal system with 18F Na-PET compared with conventional skeletal scintigraphy using Tc99m-MDP]. / Darstellung des normalen Skelett-systems mit 18FNa-PET im Vergleich zur konventionellen Skelettszintigraphie mit 99mTc-MDP.

PURPOSE: We evaluated the feasibility of 18 Fluoride Positron Emission Tomography (18F-PET), investigated the characteristics appearance of bony structures, and compared the quality of 18F-PET images with conventional bone scans (BS). METHOD: 18F-PET scans were performed in 59 patients additional to conventional bone scintigraphy. RESULTS: Even very small details in the spine like the spinous and transverse processes were clearly visible with 18F-PET. Only half of these structures were visualised with BS. When visualising the vertebral bodies of the first rib from the clavicles and the twelfth rib from the kidneys, we arrived at similar results. Hot spots in the skull or at the manubriosternal joint were observed in 29% of the patients without any evidence of trauma, degeneration or metastasis. CONCLUSION: 18F-PET shows more details of the skeleton compared to BS. Some hot spots not occurring with BS must be regarded as physiological.

[Dosimetry fundamentals of endovascular therapy using Re-188 for the prevention of restenosis after angioplasty]. / Dosimetrische Grundlagen für die endovaskuläre Therapie mit Re-188 zur Prävention der Restenose nach Angioplastie.

AIM: Various radionuclides can be used for endovascular brachytherapy. A new concept is to inflate the balloon of a dilatation catheter with a radioactive solution. Re-188 can be eluted from a generator system and is available daily. The aim of this study was to obtain dosimetric data for this radionuclide. METHODS: The dose decrease of Re-188 was calculated and measured with a TLD-system radial to a balloon catheter typically used in cardiology (diameter: 3 mm, length: 20 mm). RESULTS: Using a specific activity of 370 MBq/ml a dose of 0.3 Gy could be achieved within 1 min in a TLD in contact with the balloon. Paired TLDs differed about 3%. A fast dose reduction of 50% and 10% were stated within 0.5 mm and 2.5 mm, respectively. Calculated and measured values were in good agreement. The data are comparable to those known for Y-90. CONCLUSION: Calculations of dose distribution are consistent with TLD measurements of Re-188. Using a specific activity of 1.85 GBq/ml, a dose of 10-15 Gy at the coronary artery wall can be achieved within 2-3 min. Compared to radioactive stents or wires the use of this liquid beta-emitter is a simple alternative for prevention of the restenosis following the angioplasty.

Serologic detection of active infections with human herpes viruses (CMV, EBV, HSV, VZV): diagnostic potential of IgA class and IgG subclass-specific antibodies.

In 175 sera from healthy persons as well as those suffering from primary or secondary herpes virus infections/reactivations, serum antibodies were assessed by an indirect ELISA in the immunoglobulin classes A, G and M and the subclasses G1-4, using carrier-fixed antigens (CMV, VZV, HSV) and monoclonal tracer antibodies. In a similar way EBV-specific antibodies were tested by an indirect IFT. Only IgG1 antibodies were detectable in nearly all persons. Virus-specific IgA and IgG3 may support conventional serological methods (IgM, IgG) indicating recent infection/reactivation with VZV, EBV and possibly CMV. Furthermore, differentiation of primary and secondary CMV and VZV infection was possible in some cases, when IgG3 was detectable before IgG1 in subsequent blood specimens. Recurrent herpes lesions could not be diagnosed serologically.