Electrical Bioimpedance-Controlled Surgical Instrumentation

Abstract

A bioimpedance-controlled concept for bone cement milling during revision total hip replacement is presented. Normally, the surgeon manually removes bone cement using a hammer and chisel. However, this procedure is relatively rough and unintended harm may occur to tissue at any time. The proposed bioimpedance-controlled surgical instrumentation improves this process because, for example, most risks associated with bone cement removal are avoided. The electrical bioimpedance measurements enable online process-control by using the milling head as both a cutting tool and measurement electrode at the same time. Furthermore, a novel integrated surgical milling tool is introduced, which allows acquisition of electrical bioimpedance data for online control; these data are used as a process variable. Process identification is based on finite element method simulation and on experimental studies with a rapid control prototyping system. The control loop design includes the identified process model, the characterization of noise as being normally distributed and the filtering, which is necessary for sufficient accuracy ( ±0.5 mm). Also, in a comparative study, noise suppression is investigated in silico with a moving average filter and a Kalman filter. Finally, performance analysis shows that the bioimpedance-controlled surgical instrumentation may also performs effectively at a higher feed rate (e.g., 5 mm/s).

Development of a Novel Medical Device for Mucositis and Peri-Implantitis Treatment

“…As mentioned in the previous section, the bioimpedance measurement permits to focus the radio frequency alternating current in the impaired area, since the current densities and pathways from an electrical signal are determined to a considerable extent by the electric properties of biological tissues [39]. Depending on the measured bioimpedance values and, thus, on the severity of the pathology, the therapeutic signal can be properly set to tune the treatment to the pathological conditions of the peri-implant tissues.…”

“…In particular, the composition of the tissue can be characterized if the measurement is performed in a very localized and precise way [ 36 ], allowing valuable applications of body impedance analysis (BIA) [ 37 , 38 ]. Brendle et al [ 39 ] used bioimpedance to detect tissues boundary as a control during the bone cement removal in total hip replacement operation. Indeed, the bioimpedance method can be useful to diagnose an inflamed area of tissue when compared with the corresponding healthy one, employed as a control [ 40 ].…”

Smart bioimpedance-controlled craniotomy: Concept and first experiments

“…An approach for electrical impedance-controlled bone cement removal from a bone cavity in revision total hip replacement has been proposed and evaluated by our group. 12,13,28 Feasibility of breakthrough detection between bone cement and bone and of the estimation of the remaining bone cement thickness has been shown under laboratory conditions. The information can be used for real-time milling path generation and process control.…”

“…Therefore, we propose a novel approach using inprocess bioimpedance measurement for cutting depth control without any further need for preoperative image acquisition, intraoperative registration or navigation. Whereas this approach has been investigated for bone milling and drilling [9][10][11] as well as for bone cement milling, 12,13 the control of a sawing process has not yet been realized and evaluated. Our initial finite element method (FEM) simulations reported by Teichmann and colleagues 14,15 show promising results so far.…”

Fundamentals, Recent Advances, and Future Challenges in Bioimpedance Devices for Healthcare Applications

“…Given their characteristics, bioimpedance measurements allow the characterization of biological media and organic tissues, including the human body, but also inorganic media [38]. In this sense, bioimpedance methods have been employed in skin monitoring (diagnosis of diseases and evaluation of a treatment progress) [38], cancerous tissue characterization and detection [31], sleep apnea detection through bioimpedance measurements [39], as a means of precisely controlling the energy delivered to the heart during defibrillation [40], as a predictor of intradialytic hypotension [41], for precise bone cement milling during revision of total hip replacement [42], for longitudinal knee joint health assessment [43,44], for the evaluation of high-resolution temporal information corresponding to pharyngeal swallowing [45], to monitor the ischemia and viability of transplanted organs [46,47], edema determination [48], brain and pulmonary function monitoring [49,50], and even as a method for the noninvasive measurement of glucose level [51].…”