Percutaneous electrodes

The acute recording of evoked potentials and the stimulation at the spinal cord has been a well-established method for more than 20 years. The procedures require electrodes that are similar to pacemaker electrodes. Applications can be found in the field of skoliosis correction [38, 39] and the repair of aorta aneurysms [40]. An intraoperative stimulation of fibers of the sacral spinal cord was performed during dissection of unilateral testicle tumors to preserve ejaculation [41]. The main application of implants for chronic stimulation of the spinal cord is the handling of chronic pain [42]. There are two types of electrodes the percutaneous electrodes resemble the pacemaker electrodes. They consist of a mandrel with up to four ring electrodes of a platinum iridium alloy (Fig. 6). They have a length of 3 mm with an interelectrode distance of 6 mm or a length of 6 mm with an interelectrode distance of 12 mm. 

While the wireless RF BION device eliminates the need for the leads associated with the percutaneous electrodes, it requires the patient to wear an external coil during use, to transmit power and data to the implanted device. Both to improve patient acceptance of this technology, and to increase the rehabihty of the system, it was necessary to eliminate the need to constantly use an external coil to power and control the device. Thus, the idea for a battery-powered BION device (hereinafter BPB) was conceived at the AMF. 

Cullander, C. and Guy, R. H. Visualizing the pathways of iontophoretic current flow in real time with laser-scanning confocal microscopy and the vibrating probe electrode. In R. C. Scott, R. H. Guy and J. Hadgralt, eds. Prediction of Percutaneous Penetration, Vol. 2, IBC Technical Services, London, 1991. 

Phenol can be applied percutaneously by the use of a monopolar needle electrode or by open injection when the nerve is exposed surgically. In addition, main nerve trunks or motor branches can be injected, depending on the clinical indication. 

The multiple coated wire type catheters developed at General Electric have also been evaluated in vivo. For example, the pH-sensing device was implanted in the femoral artery of beagle dogs for up to 6 hours (L3). Over that time span, the pH of the blood as measured by the in vivo coated wire electrode was nearly identical to that measured in vitro with conventional glass electrode instrumentation. In addition, the same catheter also has been used percutaneously to measure the muscle pH of dogs in shock (K14). The... 

In-Vivo Percutaneous Implant Experiment. The principle of percutaneous attachment has extensive application in many biomedical areas, including the attachment of dental and orthopedic prostheses directly to skeletal structures, external attachment for cardiac pacer leads, neuromuscular electrodes, energy transmission to artificial heart and for hemodialysis. Several attempts to solve the problem of fixation and stabilization of percutaneous implants(19) have been made. Failures were also attributed to the inability of the soft tissue interface to form an anatomic seal and a barrier to bacteria. In the current studies, the effect of pore size on soft tissue ingrowth and attachment to porous polyurethane (PU) surface and the effect of the flange to stem ratio and biomechanical compliance on the fixation and stabilization of the percutaneous devices have been investigated.(20)... 

Marsolais, E.B. and Kobetic, R. (1986), Implantation techniques and experience with percutaneous intramuscular electrodes in the lower extremities, /. Rehabil. Res. De., 23. 

Artificial ear implants capable of processing speech have been developed with electrodes to stimulate cochlear nerve cells. Cochlear implants also have a speech processor that transforms sound waves into electrical impulses that can be conducted through coupled external and internal coils. The electrical impulses can be transmitted directly by means of a percutaneous device. 

Caldwell C.W and Reswick J.B. 1975. A percutaneous wire electrode for chronic research use. IEEE Trans. Biomed. Eng. 22 429. 

Knutson J.S., Naples G.G., Peckham P.H., and Keith M.W 2002. Fracture rates and occurrences of infection and granuloma associated with percutaneous intramuscular electrodes in upper extremity functional electrical simulation applications. Rehab. Res. Dev. 39 671-684. 

Memberg, W, Peckham, P.H., Thorpe, G.B., Keith, M.W, and BQcher, T.R 1993. An analysis of the reh-ability of percutaneous intramuscular electrodes in upper extremity FNS applications. IEEE Trans. Biomed. Eng. 1 126. 

Friesen A, Klein GJ, Kostuk WJ, Ahuja SP (1977) Percutaneous insertion of a permanent transvenous pacemaker electrode through the subclavian vein. Can J Surg 20(2) 131-135... 

Initially, almost all pacemaker and ICD procedures were approached exclusively from the epicardial point of view. But with the development of a transvenous approach, either by cutdown or percutaneous techniques, now almost aU pacemaker and ICD procedures are approached on a transvenous or nonthoracotomy basis. Today, the epicardial approach is reserved for certain unique circumstances. Electrodes can be placed on the epicardium by a variety of techniques. This involves a subxiphoid incision, and limited thoracotomy, or direct application of electrodes on an exposed heart. Recently, mediastinoscopy and thoracoscopy have been used to apply permanent pacing and rate-sensing electrodes as well as patch electrodes. The transvenous approach can be performed by venous cutdown, percutaneous venous access, or a combination of the two. 

Table 4.10 Venous access for dual-chambered pacing. Venous cutdown Isolate one or two veins Percutaneous Two separate sticks and sheath applications Percutaneous Two electrodes down one large sheath Percutaneous Retained guidewire (Belott technique)...

Dual-chambered pacing calls for the introduction of an atrial and ventricular electrode. The cutdown technique is less suited for this approach because all too often the cephalic vein can hardly acconunodate one electrode, and even less two. The percutaneous approach appears ideally suited for dual-chambered pacing as there is potential for unlimited access to the venous circulation. Various options for dual-chambered pacing venous access are listed in Table 4.10. There are four percutaneous approaches for dual-chambered pacing. 

There are a number of proposed mechanisms and potential solutions (62-65). Electrodes of a more complex design, such as bipolar coaxial construction, are most susceptible to this phenomenon. A more lateral percutaneous approach... 

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