Dynamic spectrum management has the advantage of well-organised assignment of channels. But analysis shows that still the spectrum is not used efficiently always. For the proficient management of this valuable spectrum cognitive radio has proved to be a helpful tool. The main function of the cognitive radio is to sense the availability of the spectrum for its occupancy. So spectrum sensing becomes the prime task. This sensing process by a cognitive radio is interrupted by malicious user who is also a cognitive radio but selfish in gaining the access of the spectrum. Hence a helper node based authentication scheme has been proposed. Authentication based data transfer is achieved by the inclusion of tag in the data send by the helper node to the cognitive user depicting the absence of primary user. The authentication tag is generated using Bhutasankya algorithm and Katapayadi algorithm and embedded in the error control code block of Orthogonal Frequency Division Multiplexing (OFDM) based helper node. Utilizing the sensed spectrum, patient information is transmitted to the hospital from the remote location. This avoids the travel need to be made by the elderly persons from the remote center to the hospital for further consultation. To gain the advantage of re-programmability, the authentication scheme is implemented on Cyclone II FPGA.