fhir_search with NOT EQUAL(<> or !=) constraint

[ansuman273]

We have a requirement in fhirbase like searching all the Patient records whose name not equal to 'smith'

So we modified fhir_search(SELECT fhir_search('{"resourceType": "Patient", "queryString": "name=smith"}');) as

SELECT fhir_search('{"resourceType": "Patient", "queryString": "name<>smith"}');
but it is throwing error
ERROR: TypeError: Cannot call method 'split' of undefined
DETAIL: plv8_init() LINE 3912: return x.split(',').map(parse_one_value);
********** Error **********

ERROR: TypeError: Cannot call method 'split' of undefined
SQL state: XX000
Detail: plv8_init() LINE 3912: return x.split(',').map(parse_one_value);
Could you please suggest how to do it or any alternative.