sim1cm.c File Reference

Simulation of 1-tissue compartmental models. More...

#include "tpcclibConfig.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <string.h>
#include "tpccm.h"

Go to the source code of this file.

Functions
int	simMBF (double *t, double *ci, const int nr, const double k1, const double k2, const double Vfit, double *ct)
int	simC1 (double *t, double *ca, const int nr, const double k1, const double k2, double *ct)
int	simC1_i (double *t, double *cai, const int nr, const double k1, const double k2, double *ct)
int	simC1_d (double *t, double *ca, const int nr, const double k1, const double k2, double *ct)

Detailed Description

Simulation of 1-tissue compartmental models.

Definition in file sim1cm.c.

Function Documentation

simC1()

int simC1	(	double *	t,
		double *	ca,
		const int	nr,
		const double	k1,
		const double	k2,
		double *	ct )

Simulate tissue TAC using 1 tissue compartmental model and plasma TAC, at plasma TAC times.

Memory for ct must be allocated in the calling program.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

See also

simC1_d, simC1_i, simDispersion, simMBF, simC2, simOxygen, simC3vs, convolve1D, simC1DI, simSamples, parExampleTTACs, parExamplePerfectBolus

Returns

Function returns 0 when successful, else a value >= 1.

Author

Vesa Oikonen

Parameters

t	Array of time values.
ca	Array of arterial activities.
nr	Number of values in TACs.
k1	Rate constant of the model.
k2	Rate constant of the model.
ct	Pointer for TAC array to be simulated; must be allocated.

Definition at line 93 of file sim1cm.c.

  {
  int i;
  double dt2;
  double cai, ca_last, t_last;
  double ct1, ct1_last;
  double ct1i, ct1i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(t==NULL || ca==NULL || ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(!(k1>=0.0)) return 3;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0]; 
  cai=ca_last=0.0;
  ct1_last=ct1i_last=0.0;
  ct1=ct1i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* arterial integral */
      cai+=(ca[i]+ca_last)*dt2;
      /* tissue compartment and its integral */
      ct1 = (k1*cai - k2*(ct1i_last+dt2*ct1_last)) / (1.0 + dt2*k2);
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
    }
    /* copy values to argument arrays */
    ct[i]=ct1;
    /* prepare to the next loop */
    t_last=t[i]; ca_last=ca[i];
    ct1_last=ct1; ct1i_last=ct1i;
  }
 
  return 0;
}

Referenced by bfm1TCM(), and simDispersion().

simC1_d()

int simC1_d	(	double *	t,
		double *	ca,
		const int	nr,
		const double	k1,
		const double	k2,
		double *	ct )

Simulate tissue TAC using 1 tissue compartmental model and input TAC, at input TAC times.

This version is directly based on ODE, and does not use integral of input TAC.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

See also

simC1, simDelay, simDispersion

Returns

Function returns 0 when successful, else a value >= 1.

Author

Vesa Oikonen

Parameters

t	Array of time values.
ca	Array of arterial activities.
nr	Number of values in TACs.
k1	Rate constant of the model.
k2	Rate constant of the model.
ct	Pointer for TAC array to be simulated; must be allocated.

Definition at line 229 of file sim1cm.c.

  {
  int i;
  double dt2;
  double cap, ctp, tp; // 'p' marks previous
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(t==NULL || ca==NULL || ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(!(k1>=0.0)) return 3;
 
  /* Set 'previous' sample */
  tp=0.0; if(t[0]<tp) tp=t[0]; 
  cap=ctp=0.0;
  /* Calculate curves */
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-tp);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>=0.0) { // must be >= because ct[0] is not set elsewhere
      ct[i]=(k1*dt2*(cap+ca[i]) + (1.0 - k2*dt2)*ctp) / (1.0 + k2*dt2);
    }
    /* prepare to the next sample */
    tp=t[i]; cap=ca[i];
    ctp=ct[i];
  }
 
  return 0;
}

simC1_i()

int simC1_i	(	double *	t,
		double *	cai,
		const int	nr,
		const double	k1,
		const double	k2,
		double *	ct )

Simulate tissue TAC using 1 tissue compartmental model and plasma TAC, at plasma TAC times.

This version uses integral of arterial TAC as input function. Only advantage over simC1() is that the calculation of integral can be fully controlled and possibly more precise in some situations.

The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

See also

simC1, simC2_i, simDelay, simDispersion

Returns

Function returns 0 when successful, else a value >= 1.

Author

Vesa Oikonen

Parameters

t	Array of time values.
cai	Array of AUC 0-t of arterial activities.
nr	Number of values in TACs.
k1	Rate constant of the model.
k2	Rate constant of the model.
ct	Pointer for TAC array to be simulated; must be allocated.

Definition at line 164 of file sim1cm.c.

  {
  int i;
  double dt2;
  double t_last;
  double ct1, ct1_last;
  double ct1i, ct1i_last;
 
 
  /* Check for data */
  if(nr<2) return 1;
  if(t==NULL || cai==NULL || ct==NULL) return 2;
 
  /* Check actual parameter number */
  if(!(k1>=0.0)) return 3;
 
  /* Calculate curves */
  t_last=0.0; if(t[0]<t_last) t_last=t[0]; 
  ct1_last=ct1i_last=0.0;
  ct1=ct1i=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return 5;
    } else if(dt2>0.0) {
      /* tissue compartment and its integral */
      ct1 = (k1*cai[i] - k2*(ct1i_last+dt2*ct1_last)) / (1.0 + dt2*k2);
      ct1i = ct1i_last + dt2*(ct1_last+ct1);
    }
    /* copy values to argument arrays */
    ct[i]=ct1;
    /* prepare to the next loop */
    t_last=t[i]; ct1_last=ct1; ct1i_last=ct1i;
  }
 
  return 0;
}

Referenced by bfm1TCM(), and bfmSRTM().

simMBF()

int simMBF	(	double *	t,
		double *	ci,
		const int	nr,
		const double	k1,
		const double	k2,
		const double	Vfit,
		double *	ct )

Simulate myocardial tissue TAC using Iida's compartment model.

Memory for ct must be allocated in the calling program. The units of rate constants must be related to the time unit; 1/min and min, or 1/sec and sec.

Returns

Function returns 0 when successful, else a value >= 1.

Author

Vesa Oikonen

See also

simC1, simOxygen, simSamples, simDelay

Parameters

t	Array of time values.
ci	Input activities.
nr	Number of values in TACs.
k1	Apparent k1.
k2	Apparent k2.
Vfit	Vfit
ct	Pointer for TAC array to be simulated; must be allocated.

Definition at line 28 of file sim1cm.c.

  {
  int i;
  double dt2;
  double cii, ci_last, t_last;
  double ct_last, cti, cti_last;
 
 
  /* Check for data */
  if(nr<2) return(1);
  if(t==NULL || ci==NULL || ct==NULL) return(2);
 
  /* Calculate curves */
  t_last=0.0; cii=ci_last=0.0;
  cti=ct_last=cti_last=0.0;
  for(i=0; i<nr; i++) {
    /* delta time / 2 */
    dt2=0.5*(t[i]-t_last);
    /* calculate values */
    if(dt2<0.0) {
      return(5);
    } else if(dt2>0.0) {
      /* input integral */
      cii+=(ci[i]+ci_last)*dt2;
      /* Tissue compartment and its integral */
      ct[i] = (Vfit*ci[i] + k1*cii - k2*(cti_last+dt2*ct_last)) / (1.0 + dt2*k2);
      cti = cti_last + dt2*(ct_last+ct[i]);
    }
    /* set very small values to zero
    if(fabs(ct[i])<1.0e-12) ct[i]=0.0; */
    /* prepare to the next loop */
    t_last=t[i]; ci_last=ci[i];
    ct_last=ct[i]; cti_last=cti;
  }
  return(0);
}