Abstract: A device for measuring electrical potentials of a patient's body part, includes substrate nodes made of a flexible material and configured to be disposed on the patient's torso, wherein some pairs of substrate nodes are interconnected by straight portions of flexible material. The substrate nodes and straight portions of flexible material form a flexible substrate. The device includes electrodes, with each electrode disposed on a respective substrate node; and at least one connector. Each electrode is connected to the connector through a respective conductive path. Each conductive path is embedded in the flexible substrate formed by substrate nodes and straight portions. Only some straight portions connecting two substrate nodes have an embedded conductive path. The device removes one or more substrate nodes and corresponding electrodes by cutting portions which connect the substrate nodes with the remaining substrate nodes in the device, without interrupting the conductive paths of the remaining electrodes.