An official website of the United States government
Medical palpation is a task that traditionally requires a skilled practitioner to assess and diagnose a patient through direct touch and manipulation of their body. In regions with a shortage of such professionals, robotic hands or sensorized gloves could potentially capture the necessary haptic information during palpation exams and relay it to medical doctors for diagnosis. From an engineering perspective, a comprehensive understanding of the relevant motions and forces is essential for designing haptic technologies capable of fully capturing this information. This study focuses on thyroid examination palpation, aiming to analyze the hand motions and forces applied to the patient’s skin during the procedure. We identified key palpation techniques through video recordings and interviews and measured the force characteristics during palpation performed by both non-medical participants and medical professionals. Our findings revealed five primary palpation hand motions and characterized the multi-dimensional interaction forces involved in these motions. These insights provide critical design guidelines for developing haptic sensing and display technologies optimized for remote thyroid nodule palpation and diagnosis.
more »
« less
Feasibility Study and Experimental Evaluation of the Design of Nodule Prototype Developed for Palpation Display Apparatus: A Novel Device for Contactless Primary Tactile Diagnosis
Background: Lack of feasible palpation display for primary diagnosis of a tumor without any need of physician to patient physical contact has been reported as one of the major concerns. To further explore this area, we developed a novel palpation device consisting of a uniquely designed nodule mechanism (based on optimizing nodule top and bottom hemisphere wall thickness and manipulating granular jamming method) that can vary stiffness while maintaining the shape of the same nodule display, for which current devices are not capable of in terms of aping a tumor. Methods: This paper evaluates the manufacturing approach of the nodule, exploring several iterations of the nodule prototype. Experiments were performed on nodule prototypes of varying wall thicknesses in order to evaluate its effect on stiffness and deformation. Results and Conclusions: Experimental results showed that nodule top and bottom wall thickness had a significant effect on the stiffness and deformation of the nodule. The higher the thickness of the top hemisphere and the lower the thickness of the bottom hemisphere, the greater the stiffness the nodule can achieve. Similarly, the display shape of the nodule can be maintained with minimal or no deformation if the nodule top hemisphere thickness is optimally higher than bottom hemisphere thickness.
more »
« less
- Award ID(s):
- 2026516
- PAR ID:
- 10300747
- Date Published:
- Journal Name:
- Micromachines
- Volume:
- 12
- Issue:
- 5
- ISSN:
- 2072-666X
- Page Range / eLocation ID:
- 576
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Medical palpation is a vital diagnostic technique where practitioners assess a patient’s condition through tactile examination. Advancements in remote health technologies should emphasize supporting tactile/haptic modalities to enable some aspects of physical examination to be conducted at a distance. In thyroid examinations, differentiating nodule sizes is critical for identifying malignant lumps. This study investigates how palpation motion affects the sensing performance of single-point normal force sensors in detecting thyroid nodules. Using a phantom skin model with lumps of varied sizes and depths, force data was captured and visualized as a stiffness distribution (tactile imaging). The captured lump shapes were compared to actual shapes using Correlation Coefficient (CC), Mean Squared Error (MSE), and Structural Similarity Index (SSIM) methods. Results showed that single-point normal force sensors effectively detect lumps, particularly during typical palpation motions such as Poke and Push & Pull, with Poke consistently yielding superior performance across various sizes and depths. However, estimating lump shapes becomes increasingly challenging as lump depth increases, regardless of the motion applied. These findings emphasize the importance of motion in optimizing singlepoint sensors for palpation and provide valuable insights for developing sensorized gloves for clinical use, particularly in remote healthcare systems.more » « less
-
During wound healing, tumor growth, and organ formation, epithelial cells migrate and cluster in layered tissue environments. Although cellular mechanosensing of adhered extracellular matrices is now well recognized, it is unclear how deeply cells sense through distant matrix layers. Since single cells can mechanosense stiff basal surfaces through soft hydrogels of <10 μm thickness, here we ask whether cellular collectives can perform such “depth-mechanosensing” through thicker matrix layers. Using a collagen-polyacrylamide double-layer hydrogel, we found that epithelial cell collectives can mechanosense basal substrates at a depth of >100 μm, assessed by cell clustering and collagen deformation. On collagen layers with stiffer basal substrates, cells initially migrate slower while performing higher collagen deformation and stiffening, resulting in reduced dispersal of epithelial clusters. These processes occur in two broad phases: cellular clustering and dynamic collagen deformation, followed by cell migration and dispersal. Using a cell-populated collagen-polyacrylamide computational model, we show that stiffer basal substrates enable higher collagen deformation, which in turn extends the clustering phase of epithelial cells and reduces their dispersal. Disruption of collective collagen deformation, by either α-catenin depletion or myosin-II inhibition, disables the depth-mechanosensitive differences in epithelial responses between soft and stiff basal substrates. These findings suggest that depth-mechanosensing is an emergent property that arises from collective collagen deformation caused by epithelial cell clusters. This work broadens the conventional understanding of epithelial mechanosensing from immediate surfaces to underlying basal matrices, providing insights relevant to tissue contexts with layers of varying stiffness, such as wound healing and tumor invasion.more » « less
-
Abstract This study presents a methodology for a high-throughput digitization and quantification process of plant cell walls characterization, including the automated development of two-dimensional finite element models. Custom algorithms based on machine learning can also analyze the cellular microstructure for phenotypes such as cell size, cell wall curvature, and cell wall orientation. To demonstrate the utility of these models, a series of compound microscope images of both herbaceous and woody representatives were observed and processed. In addition, parametric analyses were performed on the resulting finite element models. Sensitivity analyses of the structural stiffness of the resulting tissue based on the cell wall elastic modulus and the cell wall thickness; demonstrated that the cell wall thickness has a three-fold larger impact of tissue stiffness than cell wall elastic modulus.more » « less
-
Abstract BackgroundThe developing zebrafish ventricle generates higher intraventricular pressure (IVP) with increasing stroke volume and cardiac output at different developmental stages to meet the metabolic demands of the rapidly growing embryo (Salehin et al. Ann Biomed Eng, 2021;49(9): 2080‐2093). To understand the changing role of the developing embryonic heart, we studied its biomechanical characteristics during in vivo cardiac cycles. By combining changes in wall strains and IVP measurements, we assessed ventricular wall stiffness during diastolic filling and the ensuing systolic IVP‐generation capacity during 3‐, 4‐, and 5‐day post fertilization (dpf). We further examined the anisotropy of wall deformation, in different regions within the ventricle, throughout a complete cardiac cycle. ResultsWe found the ventricular walls grow increasingly stiff during diastolic filling with a corresponding increase in IVP‐generation capacity from 3‐ to 4‐ and 5‐dpf groups. In addition, we found the corresponding increasing level of anisotropic wall deformation through cardiac cycles that favor the latitudinal direction, with the most pronounced found in the equatorial region of the ventricle. ConclusionsFrom 3‐ to 4‐ and 5‐dpf groups, the ventricular wall myocardium undergoes increasing level of anisotropic deformation. This, in combination with the increasing wall stiffness and IVP‐generation capacity, allows the developing heart to effectively pump blood to meet the rapidly growing embryo's needs.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3390/mi12050576
