#include "heart_suanfa.h"

heart_suanfa::heart_suanfa()
{

}

void maxim_heart_rate_and_oxygen_saturation(unsigned int *pun_ir_buffer,
int n_ir_buffer_length, unsigned int *pun_red_buffer,
int *pn_spo2, int *pch_spo2_valid, int *pn_heart_rate, int *pch_hr_valid)
{
#if 1
unsigned int un_ir_mean ,un_only_once ;
 int k ,n_i_ratio_count;
 int i,s ,m, n_exact_ir_valley_locs_count ,n_middle_idx;
 int n_th1, n_npks,n_c_min;
int an_ir_valley_locs[15] ;
 int an_exact_ir_valley_locs[15] ;
 int an_dx_peak_locs[15] ;
 int n_peak_interval_sum;
int n_y_ac, n_x_ac;
 int n_spo2_calc;
int n_y_dc_max, n_x_dc_max;
int n_y_dc_max_idx, n_x_dc_max_idx;
int an_ratio[5],n_ratio_average;
int n_nume, n_denom ;
 // remove DC of ir signal
un_ir_mean =0;
for (k=0 ; k < n_ir_buffer_length ; k++ )
un_ir_mean += pun_ir_buffer[k] ;
un_ir_mean =un_ir_mean/n_ir_buffer_length ;
for (k=0 ; k<n_ir_buffer_length ; k++ ) {
an_x[k] = pun_ir_buffer[k] - un_ir_mean ;
}
// 4 pt Moving Average
for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
 n_denom= ( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3]);
 an_x[k]= n_denom/(int)4;
}
// get difference of smoothed IR signal
for( k=0; k<BUFFER_SIZE-MA4_SIZE-1; k++) {
 an_dx[k]= (an_x[k+1]- an_x[k]);
 }
// 2-pt Moving Average to an_dx
for(k=0; k< BUFFER_SIZE-MA4_SIZE-2; k++){
 an_dx[k] = ( an_dx[k]+an_dx[k+1])/2 ;
 }
// hamming window
// flip wave form so that we can detect valley with peak detector
for ( i=0 ; i<BUFFER_SIZE-HAMMING_SIZE-MA4_SIZE-2 ;i++){
 s= 0;
 for( k=i; k<i+ HAMMING_SIZE ;k++){
 s -= an_dx[k] *auw_hamm[k-i] ;
}
 an_dx[i]= s/ (int)1146; // divide by sum of auw_hamm
}
n_th1=0; // threshold calculation
for ( k=0 ; k<BUFFER_SIZE-HAMMING_SIZE ;k++){
 n_th1 += ((an_dx[k]>0)? an_dx[k] : ((int)0-an_dx[k])) ;
 }
n_th1= n_th1/ ( BUFFER_SIZE-HAMMING_SIZE);
 // peak location is acutally index for sharpest location of
// raw signal since we flipped the signal
maxim_find_peaks( an_dx_peak_locs, &n_npks, an_dx,
 BUFFER_SIZE-HAMMING_SIZE, n_th1, 8, 5 );
n_peak_interval_sum =0;
 if (n_npks>=2){
 for (k=1; k<n_npks; k++)
 n_peak_interval_sum += (an_dx_peak_locs[k]-an_dx_peak_locs[k -1]);
 n_peak_interval_sum=n_peak_interval_sum/(n_npks-1);
 *pn_heart_rate=(int)(6000/n_peak_interval_sum);// beats per minutes
*pch_hr_valid = 1;
 }
 else {
 *pn_heart_rate = -999;
 *pch_hr_valid = 0;
 }
for ( k=0 ; k<n_npks ;k++)
 an_ir_valley_locs[k]=an_dx_peak_locs[k]+HAMMING_SIZE/2;
// raw value : RED(=y) and IR(=X)
// we need to assess DC and AC value of ir and red PPG.
for (k=0 ; k<n_ir_buffer_length ; k++ ) {
 an_x[k] = pun_ir_buffer[k] ;
an_y[k] = pun_red_buffer[k] ;
}
// find precise min near an_ir_valley_locs
n_exact_ir_valley_locs_count =0;
for(k=0 ; k<n_npks ;k++){
 un_only_once =1;
 m=an_ir_valley_locs[k];
 n_c_min= 16777216;//2^24;
if (m+5 < BUFFER_SIZE-HAMMING_SIZE && m-5 >0){
 for(i= m-5;i<m+5; i++)
 if (an_x[i]<n_c_min){
 if (un_only_once >0){
 un_only_once =0;
 }
n_c_min= an_x[i] ;
 an_exact_ir_valley_locs[k]=i;
 }
 if (un_only_once ==0)
 n_exact_ir_valley_locs_count ++ ;
 }
 }
 if (n_exact_ir_valley_locs_count <2 ){
 *pn_spo2 = -999 ; // do not use SPO2 since signal ratio is out of range
*pch_spo2_valid = 0;
return;
 }
 // 4 pt MA
for(k=0; k< BUFFER_SIZE-MA4_SIZE; k++){
 an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int)4;
 an_y[k]=( an_y[k]+an_y[k+1]+ an_y[k+2]+ an_y[k+3])/(int)4;
}
//using an_exact_ir_valley_locs , find ir-red DC andir-red AC for
//SPO2 calibration ratio
//finding AC/DC maximum of raw ir * red between two valley locations
n_ratio_average =0;
n_i_ratio_count =0;
for(k=0; k< 5; k++) an_ratio[k]=0;
 for (k=0; k< n_exact_ir_valley_locs_count; k++){
 if (an_exact_ir_valley_locs[k] > BUFFER_SIZE ){
*pn_spo2 = -999 ; // do not use SPO2 since valley loc is out of range
*pch_spo2_valid = 0;
return;
 }
 }
 // find max between two valley locations
// and use ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2
for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
 n_y_dc_max= -16777216 ;
n_x_dc_max= - 16777216;
if (an_exact_ir_valley_locs[k+1]-an_exact_ir_valley_locs[k] >10){
 for (i=an_exact_ir_valley_locs[k]; i< an_exact_ir_valley_locs[k+1]; i++){
 if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i];n_x_dc_max_idx =i; }
 if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i];n_y_dc_max_idx=i;}
 }
 n_y_ac= (an_y[an_exact_ir_valley_locs[k+1]] -
an_y[an_exact_ir_valley_locs[k] ] )*(n_y_dc_max_idx
-an_exact_ir_valley_locs[k]); //red
n_y_ac= an_y[an_exact_ir_valley_locs[k]] +
n_y_ac/ (an_exact_ir_valley_locs[k+1] - an_exact_ir_valley_locs[k]) ;
n_y_ac= an_y[n_y_dc_max_idx] - n_y_ac;
n_x_ac= (an_x[an_exact_ir_valley_locs[k+1]] -
an_x[an_exact_ir_valley_locs[k] ] )*(n_x_dc_max_idx -
 an_exact_ir_valley_locs[k]); // ir
n_x_ac= an_x[an_exact_ir_valley_locs[k]] +
n_x_ac/ (an_exact_ir_valley_locs[k+1] -
an_exact_ir_valley_locs[k]);
n_x_ac= an_x[n_y_dc_max_idx] - n_x_ac;
n_nume=( n_y_ac *n_x_dc_max)>>7 ;
n_denom= ( n_x_ac *n_y_dc_max)>>7;
 if (n_denom>0 && n_i_ratio_count <5 && n_nume != 0)
 {
an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ;
 n_i_ratio_count++;
 }
 }
 }
maxim_sort_ascend(an_ratio, n_i_ratio_count);
 n_middle_idx= n_i_ratio_count/2;
if (n_middle_idx >1)
 n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2;
else
n_ratio_average = an_ratio[n_middle_idx ];
if( n_ratio_average>2 && n_ratio_average <184){
 n_spo2_calc= uch_spo2_table[n_ratio_average] ;
 *pn_spo2 = n_spo2_calc ;
 *pch_spo2_valid = 1;
 }
 else{
 *pn_spo2 = -999 ;
*pch_spo2_valid = 0;
}
#else
unsigned int un_ir_mean,un_only_once ;
 int k, n_i_ratio_count;
 int i, s, m, n_exact_ir_valley_locs_count, n_middle_idx;
 int n_th1, n_npks, n_c_min;
int an_ir_valley_locs[15] ;
 int n_peak_interval_sum;

 int n_y_ac, n_x_ac;
 int n_spo2_calc;
int n_y_dc_max, n_x_dc_max;
int n_y_dc_max_idx, n_x_dc_max_idx;
int an_ratio[5], n_ratio_average;
int n_nume, n_denom ;
// calculates DC mean and subtract DC from ir
un_ir_mean =0;
for (k=0 ; k<n_ir_buffer_length ; k++ ) un_ir_mean += pun_ir_buffer[k] ;
 un_ir_mean =un_ir_mean/n_ir_buffer_length ;

 // remove DC and invert signal so that we can use peak detector as valley detector
for (k=0 ; k<n_ir_buffer_length ; k++ )
an_x[k] = -1*(pun_ir_buffer[k] - un_ir_mean) ;
// 4 pt Moving Average
for(k=0; k< n_ir_buffer_length-MA4_SIZE; k++){
 an_x[k]=( an_x[k]+an_x[k+1]+ an_x[k+2]+ an_x[k+3])/(int)4;
}
 // calculate threshold
n_th1=0;
for ( k=0 ; k<n_ir_buffer_length ;k++){
 n_th1 += an_x[k];
 }
n_th1= n_th1/ n_ir_buffer_length;
 if( n_th1<30) n_th1=30; // min allowed
if( n_th1>60) n_th1=60; // max allowed
for ( k=0 ; k<15;k++)
an_ir_valley_locs[k]=0;
 // since we flipped signal, we use peak detector as valley detector
maxim_find_peaks(an_ir_valley_locs, &n_npks, an_x,
n_ir_buffer_length, n_th1, 4, 15 );
n_peak_interval_sum =0;
 if (n_npks>=2){
 for (k=1; k<n_npks; k++) n_peak_interval_sum +=
(an_ir_valley_locs[k] -an_ir_valley_locs[k -1] ) ;
 n_peak_interval_sum =n_peak_interval_sum/(n_npks-1);
 *pn_heart_rate =(int)((FS*60)/ n_peak_interval_sum );
 *pch_hr_valid = 1;
 }
 else {
*pn_heart_rate = -999;
*pch_hr_valid = 0;
 }
// load raw value again for SPO2 calculation : RED(=y) and IR(=X)
for (k=0 ; k<n_ir_buffer_length ; k++ ) {
 an_x[k] = pun_ir_buffer[k] ;
an_y[k] = pun_red_buffer[k] ;
}
// find precise min near an_ir_valley_locs
n_exact_ir_valley_locs_count =n_npks;
//using exact_ir_valley_locs , find ir-red DC andir-red AC for SPO2 calibration an_ratio
//finding AC/DC maximum of raw
n_ratio_average =0;
n_i_ratio_count = 0;
for(k=0; k< 5; k++) an_ratio[k]=0;
 for (k=0; k< n_exact_ir_valley_locs_count; k++){
 if (an_ir_valley_locs[k] > n_ir_buffer_length ){
 *pn_spo2 = -999 ; // do not use SPO2 since valley loc is out of range
*pch_spo2_valid = 0;
return;
 }
 }
 // find max between two valley locations
// and use an_ratio betwen AC compoent of Ir & Red and DC compoent of Ir & Red for SPO2
for (k=0; k< n_exact_ir_valley_locs_count-1; k++){
 n_y_dc_max= -16777216 ;
n_x_dc_max= -16777216;
if (an_ir_valley_locs[k+1]-an_ir_valley_locs[k] >3){
 for (i=an_ir_valley_locs[k]; i< an_ir_valley_locs[k+1]; i++){
if (an_x[i]> n_x_dc_max) {n_x_dc_max =an_x[i]; n_x_dc_max_idx=i;}
 if (an_y[i]> n_y_dc_max) {n_y_dc_max =an_y[i]; n_y_dc_max_idx=i;}
 }
 n_y_ac= (an_y[an_ir_valley_locs[k+1]] -
an_y[an_ir_valley_locs[k] ] )*(n_y_dc_max_idx -
 an_ir_valley_locs[k]); //red
n_y_ac= an_y[an_ir_valley_locs[k]] +
n_y_ac/ (an_ir_valley_locs[k+1] - an_ir_valley_locs[k]) ;
n_y_ac= an_y[n_y_dc_max_idx] - n_y_ac;
n_x_ac= (an_x[an_ir_valley_locs[k+1]] -
an_x[an_ir_valley_locs[k] ] )*(n_x_dc_max_idx -
 an_ir_valley_locs[k]); // ir
n_x_ac= an_x[an_ir_valley_locs[k]] +
n_x_ac/ (an_ir_valley_locs[k+1] - an_ir_valley_locs[k]);
n_x_ac= an_x[n_y_dc_max_idx] - n_x_ac;
n_nume=( n_y_ac *n_x_dc_max)>>7 ;
n_denom= ( n_x_ac *n_y_dc_max)>>7;
 if (n_denom>0 && n_i_ratio_count <5 && n_nume != 0)
 {
an_ratio[n_i_ratio_count]= (n_nume*100)/n_denom ;
n_i_ratio_count++;
 }
 }
 }
 // choose median value since PPG signal may varies from beat to beat
maxim_sort_ascend(an_ratio, n_i_ratio_count);
 n_middle_idx= n_i_ratio_count/2;
if (n_middle_idx >1)
 n_ratio_average =( an_ratio[n_middle_idx-1] +an_ratio[n_middle_idx])/2; // use median
else
n_ratio_average = an_ratio[n_middle_idx ];
if( n_ratio_average>2 && n_ratio_average <184){
 n_spo2_calc= uch_spo2_table[n_ratio_average] ;
*pn_spo2 = n_spo2_calc ;
 *pch_spo2_valid = 1;
 }
 else{
 *pn_spo2 = -999 ;
*pch_spo2_valid = 0;
}
#endif
}
void maxim_find_peaks(int *pn_locs, int *pn_npks,
int *pn_x, int n_size, int n_min_height, int n_min_distance, int n_max_num)
{
 maxim_peaks_above_min_height( pn_locs, pn_npks, pn_x, n_size, n_min_height );
 maxim_remove_close_peaks( pn_locs, pn_npks, pn_x, n_min_distance );
 *pn_npks = MY_MIN( *pn_npks, n_max_num );
}
void maxim_peaks_above_min_height(int *pn_locs, int *pn_npks,
int *pn_x, int n_size, int n_min_height)
{
 int i = 1, n_width;
 *pn_npks = 0;
while (i < n_size-1){
 if (pn_x[i] > n_min_height && pn_x[i] > pn_x[i-1]){
n_width = 1;
while (i+n_width < n_size && pn_x[i] == pn_x[i+n_width])
n_width++;
 if (pn_x[i] > pn_x[i+n_width] && (*pn_npks) < 15 ){
pn_locs[(*pn_npks)++] = i;
// for flat peaks, peak location is left edge
i += n_width+1;
 }
 else
i += n_width;
 }
 else
i++;
 }
}
void maxim_remove_close_peaks(int *pn_locs, int *pn_npks,
int *pn_x,int n_min_distance)
{
int i, j, n_old_npks, n_dist;
/* Order peaks from large to small */
maxim_sort_indices_descend( pn_x, pn_locs, *pn_npks );
for ( i = -1; i < *pn_npks; i++ ){
 n_old_npks = *pn_npks;
 *pn_npks = i+1;
 for ( j = i+1; j < n_old_npks; j++ ){
 n_dist = pn_locs[j] - ( i == -1 ? -1 : pn_locs[i] );
if ( n_dist > n_min_distance || n_dist < -n_min_distance )
 pn_locs[(*pn_npks)++] = pn_locs[j];
 }
 }
// Resort indices longo ascending order
maxim_sort_ascend( pn_locs, *pn_npks );
}
void maxim_sort_ascend(int *pn_x,int n_size)
{
 int i, j, n_temp;
 for (i = 1; i < n_size; i++) {
 n_temp = pn_x[i];
 for (j = i; j > 0 && n_temp < pn_x[j-1]; j--)
 pn_x[j] = pn_x[j-1];
 pn_x[j] = n_temp;
 }
}
void maxim_sort_indices_descend(int *pn_x, int *pn_indx, int n_size)
{
 int i, j, n_temp;
 for (i = 1; i < n_size; i++) {
 n_temp = pn_indx[i];
for (j = i; j > 0 && pn_x[n_temp] > pn_x[pn_indx[j-1]]; j--)
 pn_indx[j] = pn_indx[j-1];
 pn_indx[j] = n_temp;
 }
}