diff --git a/Model.py b/Model.py
index cc5f129..ca82f02 100644
--- a/Model.py
+++ b/Model.py
@@ -318,11 +318,12 @@ class Model:
         ]
 
     def mem_potential(self, t):
+        t = np.asarray(t)
         v1 = 0
         t0 = 100
         t1 = 350
         n = (t // self.period) * self.period
-        return v1 if t0 + n <= t < t1 + n else self.V_mem_rest
+        return np.where((t0 + n <= t) & (t < t1 + n), v1, self.V_mem_rest)
 
     def get_initial_values(self):
         Cai_0 = 0.11712  # Cai
diff --git a/__pycache__/Model.cpython-311.pyc b/__pycache__/Model.cpython-311.pyc
index a9b4952..6b87e5c 100644
Binary files a/__pycache__/Model.cpython-311.pyc and b/__pycache__/Model.cpython-311.pyc differ
diff --git a/fitter.py b/fitter.py
index bdb2852..f1634e6 100644
--- a/fitter.py
+++ b/fitter.py
@@ -69,7 +69,7 @@ class Fitter:
         )
 
         states = self.initial_values
-        t = model.tspan
+        t = [0, 1000]
         V = model.mem_potential(t)
         _calc_curr = model.calculated_current(states, t, V)
         calculated_current = (